Dr. Matthew Walker: The Science & Practice of Perfecting Your Sleep

00:00:00.000 | - Welcome to the Huberman Lab Podcast,

00:00:02.280 | where we discuss science and science-based tools

00:00:04.900 | for everyday life.

00:00:05.900 | I'm Andrew Huberman,

00:00:10.200 | and I'm a professor of neurobiology and ophthalmology

00:00:12.920 | at Stanford School of Medicine.

00:00:15.160 | Today, I have the pleasure of introducing Dr. Matthew Walker

00:00:18.400 | as our guest on the Huberman Lab Podcast.

00:00:21.180 | Dr. Walker is a professor of neuroscience and psychology

00:00:24.120 | at the University of California, Berkeley.

00:00:26.680 | There, his laboratory studies sleep.

00:00:29.480 | They study why we sleep, what occurs during sleep,

00:00:32.800 | such as dreams and why we dream, learning during sleep,

00:00:36.840 | as well as the consequences of getting insufficient

00:00:39.280 | or poor quality sleep on waking states.

00:00:43.140 | Dr. Walker is also the author

00:00:44.760 | of the international bestselling book, "Why We Sleep."

00:00:48.320 | Our discussion today is an absolutely fascinating one

00:00:51.300 | for anyone that's interested in sleep, learning,

00:00:54.240 | or human performance of any kind.

00:00:56.920 | Dr. Walker teaches us how to get better at sleeping.

00:01:00.460 | He also discusses naps,

00:01:01.820 | whether or not we should or should not nap,

00:01:04.220 | whether or not we can compensate for lost sleep,

00:01:06.800 | and if so, how to best do that.

00:01:09.160 | We discuss behavioral protocols and interactions

00:01:12.000 | with light, temperature, supplementation, food,

00:01:15.520 | exercise, sex, all the variables that can impact

00:01:19.220 | this incredible state of mind and body that we call sleep.

00:01:22.840 | During my scientific career,

00:01:24.280 | I've read many papers about sleep

00:01:26.100 | and attended many seminars about sleep.

00:01:28.620 | Yet, my discussion with Dr. Walker today

00:01:31.320 | revealed to me more about sleep, sleep science,

00:01:34.680 | and how to get better at sleeping

00:01:36.580 | than all of those papers and seminars combined.

00:01:39.720 | I'm also delighted to share

00:01:40.960 | that Dr. Walker has started a podcast.

00:01:44.040 | That podcast, entitled "The Matt Walker Podcast,"

00:01:47.560 | releases its first episode this month

00:01:49.860 | and is going to teach all about sleep

00:01:51.980 | and how to get better at sleeping.

00:01:53.760 | So be sure to check out "The Matt Walker Podcast"

00:01:56.260 | on Apple, Spotify, or wherever you listen to podcasts.

00:01:59.740 | Before we begin, I'd like to mention that this podcast

00:02:02.220 | is separate from my teaching and research roles at Stanford.

00:02:05.100 | It is, however, part of my desire and effort

00:02:07.160 | to bring zero cost to consumer information

00:02:09.260 | about science and science-related tools

00:02:11.380 | to the general public.

00:02:13.060 | In keeping with that theme,

00:02:14.280 | I'd like to thank the sponsors of today's podcast.

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00:06:10.760 | And now my discussion with Dr. Matt Walker.

00:06:13.860 | Great to finally meet you in person.

00:06:15.320 | - Wonderful to connect.

00:06:17.360 | I mean, it's been too long,

00:06:18.900 | but I suspect it would have been a shorter time

00:06:21.260 | before we'd met, lest the pandemic.

00:06:23.760 | - Yeah.

00:06:24.720 | - Thank you.

00:06:25.540 | - No, thank you.

00:06:26.380 | Yeah, I'm delighted

00:06:27.400 | that we're finally sitting down face to face.

00:06:28.980 | I've been tracking your work, both in the internet sphere,

00:06:32.540 | and I read your book and loved it.

00:06:34.680 | And also from the perspective of science,

00:06:36.840 | you actually came to Stanford a couple of years ago

00:06:39.360 | and gave a lecture for brain mind.

00:06:43.560 | - Oh yeah, yeah, yeah, yeah.

00:06:45.240 | - And there, of course, you talked about sleep

00:06:48.600 | and its utility and its challenges

00:06:50.600 | and how to conquer it, so to speak.

00:06:54.800 | Let's start off very basic.

00:06:56.820 | What is sleep?

00:06:57.940 | - Sleep is probably the single most effective thing

00:07:03.040 | you can do to reset your brain and body health.

00:07:05.440 | So that's a functional answer in terms of,

00:07:08.440 | you know, what is sleep in terms of its benefits.

00:07:11.920 | Sleep as a process, though,

00:07:13.840 | is an incredibly complex physiological ballet.

00:07:18.680 | And if you were to recognize or see what happens

00:07:21.760 | to your brain and your body at night during sleep,

00:07:24.800 | you would be blown away.

00:07:26.920 | And the paradox is that most of us,

00:07:28.720 | and I would think this too, you know,

00:07:30.720 | if I wasn't a sleep scientist,

00:07:32.400 | we go to bed, we lose consciousness for seven to nine hours,

00:07:37.360 | and then we sort of wake up in the morning

00:07:39.200 | and we generally feel better.

00:07:41.560 | And in some ways that denies the physiological

00:07:44.960 | and biological beauty of sleep.

00:07:48.200 | So upstairs in your brain,

00:07:49.900 | when you're going through these different stages of sleep,

00:07:52.400 | the changes in brainwave activity are far more dramatic

00:07:56.900 | than those that we see when we're awake.

00:07:59.160 | And we can speak about deep sleep and what happens there.

00:08:01.920 | REM sleep is a fascinating time,

00:08:03.920 | which is another stage of sleep often called dream sleep,

00:08:07.260 | which is rapid eye movement sleep.

00:08:09.480 | That stage of sleep, some parts of your brain

00:08:11.600 | are up to 30% more active than when you're awake.

00:08:15.600 | So again, it's kind of violating this idea

00:08:18.240 | that our mind is dormant

00:08:20.540 | and our body is just simply quiescent and resting.

00:08:24.460 | So I would happy to just sort of double click

00:08:26.800 | on either one of those

00:08:27.920 | and also what changes in the body as well.

00:08:30.600 | But it is an intense evolutionary adaptive benefit

00:08:35.560 | and system.

00:08:37.160 | That said though,

00:08:38.200 | I would almost push back against an evolved system

00:08:43.200 | when we think about the question of sleep

00:08:45.880 | and what sleep is.

00:08:47.420 | Our assumption has always been that we evolved to sleep.

00:08:52.320 | And I've actually questioned that

00:08:53.680 | and I have no way to get in a time capsule

00:08:56.600 | and go back and prove this.

00:08:57.820 | But what if we started off sleeping

00:09:02.360 | and it was from sleep that wakefulness emerged?

00:09:05.760 | Why do we assume that it's the other way around?

00:09:09.040 | And I think there's probably some really good evidence

00:09:12.580 | that sleep may have been the proto state,

00:09:15.980 | that it was the basic fundamental living state.

00:09:20.120 | And when we became awake, as it were,

00:09:23.500 | we always had to return to sleep.

00:09:26.800 | In some ways at that point,

00:09:28.320 | sleep was the price that we paid for wakefulness.

00:09:31.900 | And that's another way of describing what sleep is.

00:09:35.060 | But again, I think it sort of denies

00:09:37.320 | that the active state of sleep,

00:09:39.400 | it's not a passive state of sleep either.

00:09:41.780 | And then finally you can say,

00:09:43.820 | what is sleep across different species?

00:09:47.140 | And in us human beings and in all mammalian species

00:09:50.540 | and avian species as well,

00:09:52.220 | sleep is broadly separated into these two main types.

00:09:55.540 | And we've got non-rapid eye movement sleep on the one hand,

00:09:58.380 | and then we've got rapid eye movement sleep on the other.

00:10:01.540 | And we can speak about how they unfold across the night

00:10:04.820 | and their architecture,

00:10:05.980 | because it's not just intellectually interesting

00:10:09.020 | from the perspective of what sleep is.

00:10:11.580 | It's also practically impactful for our daily lives.

00:10:15.220 | And I'd love to sort of go down that route too,

00:10:17.100 | but you navigate, you tell me I can-

00:10:19.120 | - Let's definitely go down that route.

00:10:20.580 | So you mentioned how active the brain is

00:10:23.260 | during certain phases of sleep.

00:10:25.500 | When I was coming up in science,

00:10:28.140 | REM sleep, rapid eye movement sleep,

00:10:29.740 | was referred to as paradoxical sleep.

00:10:32.180 | Is that still a good way to think about it?

00:10:34.260 | Paradoxical because the brain is so active

00:10:36.140 | and yet we are essentially paralyzed, correct?

00:10:38.780 | - Yeah, it really is a paradox.

00:10:40.480 | And where that came from

00:10:42.540 | was simply the brainwave recordings.

00:10:45.100 | That if all I'm measuring about you

00:10:47.460 | is your brainwave activity,

00:10:50.100 | it's very difficult for me

00:10:51.980 | sitting outside of the sleep laboratory room

00:10:54.700 | to figure out, are you awake or are you in REM sleep?

00:10:58.460 | Because those two patterns of brain activity

00:11:00.620 | are so close to one another,

00:11:02.860 | you can't discriminate between them.

00:11:05.500 | Yet the paradox is that when you are awake,

00:11:08.180 | I go in there and you're sort of sitting up,

00:11:10.580 | you're clearly conscious and awake.

00:11:12.740 | But yet when you go into REM sleep,

00:11:15.220 | you are completely paralyzed.

00:11:18.640 | And that's one of the,

00:11:21.100 | I think that's part of the paradox,

00:11:23.200 | but the paradox really just comes down

00:11:25.000 | to two dramatically different conscious states.

00:11:29.000 | Yet brain activity is dramatically

00:11:32.360 | more similar than different.

00:11:34.200 | And the way I can figure out which of the two you are in

00:11:37.900 | is by measuring two other signals,

00:11:40.040 | the activity from your eyes

00:11:41.860 | and the activity from your muscles.

00:11:44.420 | So when we're awake,

00:11:46.040 | we will occasionally have these blinks

00:11:47.660 | and we'll have sort of saccades.

00:11:49.640 | But during REM sleep,

00:11:50.740 | you have these really bizarre horizontal

00:11:53.300 | shuttling eye movements that occur.

00:11:55.760 | And that's where the name comes from, rapid eye movements.

00:11:58.800 | - Are they always horizontal?

00:12:00.400 | - Mostly they are horizontal.

00:12:02.380 | And that's one of the ways that we can differentiate them

00:12:04.940 | from other waking eye movement activity.

00:12:07.900 | 'Cause it's not always, it can be sometimes horizontal,

00:12:10.840 | but can also have diagonal and also vertical in that plane.

00:12:14.940 | But then the muscle activity is the real dead giveaway.

00:12:19.460 | Just before you enter REM sleep,

00:12:22.520 | your brainstem, which is where the dynamics of non-REM

00:12:26.240 | and REM are essentially played out

00:12:28.320 | and then expressed upstairs in the cortex

00:12:30.960 | and downstairs in the body.

00:12:33.160 | When we go into REM sleep

00:12:34.400 | and just a few seconds before that happens,

00:12:37.520 | the brainstem sends a signal

00:12:39.960 | all the way down the spinal cord.

00:12:41.960 | And it communicates with what are called

00:12:43.720 | the alpha motor neurons in the spinal cord,

00:12:45.960 | which control of voluntary skeletal muscles.

00:12:48.960 | And it's a signal of paralysis.

00:12:51.600 | And when you go into dream sleep,

00:12:53.520 | you are locked into a physical incarceration

00:12:57.480 | of your own body.

00:12:59.400 | - Amazing.

00:13:00.240 | - You know, why would mother nature do such a thing?

00:13:04.300 | And it's in some ways very simple.

00:13:07.260 | The brain paralyzes the body

00:13:09.560 | so that the mind can dream safely.

00:13:12.160 | Because think about how quickly

00:13:13.780 | we would have all been popped out of the gene pool.

00:13:15.920 | You know, if I think I'm one of the best skydivers

00:13:19.440 | who can just simply fly,

00:13:21.620 | and I've had sometimes those dreams too,

00:13:24.160 | and I get up on my apartment window and I leap out.

00:13:28.000 | - You're done. - You're done.

00:13:29.960 | So that's one of the sort of,

00:13:31.480 | that's part of the paradox of REM sleep,

00:13:34.080 | both its brain activity similarity,

00:13:36.280 | despite the behavioral state being so different,

00:13:38.780 | and this bizarre lockdown of the sort of brain

00:13:43.720 | of the body itself.

00:13:45.080 | Now, of course, the involuntary muscles,

00:13:47.400 | thankfully, aren't paralyzed.

00:13:49.840 | So you keep breathing, your heart keeps beating.

00:13:52.440 | - Is this why men have erections during REM sleep

00:13:55.620 | and women have vaginal lubrication during sleep?

00:13:58.200 | - That's one of the reasons.

00:13:59.400 | Part of the other reason, though,

00:14:00.680 | that is because of the autonomic activity.

00:14:03.440 | So there is a part of our nervous system

00:14:06.280 | called the autonomic nervous system,

00:14:08.080 | and it controls many of the automatic behaviors.

00:14:11.660 | And some of those are aspects of our reproductive facilities.

00:14:16.660 | During REM sleep, what we later discovered

00:14:20.780 | is that you go through these bizarre,

00:14:23.120 | what we call autonomic storms, which sounds dramatic,

00:14:26.520 | but it actually is when you measure them.

00:14:28.960 | That you'll go through periods

00:14:30.320 | where your heart rate decelerates and drops

00:14:33.240 | and your blood pressure goes down,

00:14:35.120 | and then utterly randomly,

00:14:37.040 | your heart rate accelerates dramatically

00:14:39.700 | and what we call the fight or flight branch

00:14:41.760 | of the autonomic nervous system

00:14:43.020 | or the sympathetic nervous system,

00:14:44.880 | a badly named 'cause it's anything but sympathetic,

00:14:47.140 | it's very aggravating, that all of a sudden fires up

00:14:51.400 | and then it shuts down again.

00:14:53.080 | And it's not in any regular way.

00:14:55.320 | And it's when you get those autonomic storms,

00:14:57.520 | you get very activated from a physiological perspective,

00:15:01.020 | that you can have these erections

00:15:02.640 | and you have vaginal discharge, et cetera.

00:15:04.600 | - But you're totally paralyzed.

00:15:05.920 | - But you are still paralyzed.

00:15:07.740 | There are only two voluntary muscle groups

00:15:12.740 | that are spurred from the paralysis, bizarre.

00:15:18.280 | One, your extra ocular muscles,

00:15:20.620 | because if they were paralyzed,

00:15:22.780 | you wouldn't be able to have rapid eye movements.

00:15:25.720 | And the other that we later discovered

00:15:27.700 | was the inner ear muscle.

00:15:30.120 | And we've got no good understanding

00:15:33.200 | as to why those two muscle groups

00:15:35.400 | are spurred from the paralysis.

00:15:37.160 | It may have something to do with cranial nerve,

00:15:39.760 | but I don't think it's that.

00:15:42.040 | I think it's perhaps something more sensory related.

00:15:45.200 | Some people have argued that the reason the eyeballs

00:15:47.660 | are spurred from the paralysis

00:15:49.480 | is because if your eyeballs are left

00:15:51.200 | for long periods of time inactive,

00:15:53.540 | you may get things such as oxygen sort of issues

00:15:56.840 | in the aqueous or vitreous humor.

00:16:00.000 | And so the eyeballs have to keep moving in some way.

00:16:02.440 | - The drainage systems of the anterior eye

00:16:04.680 | are made to require movement.

00:16:06.520 | - Exactly.

00:16:07.360 | - People with glaucoma have deficits in drainage

00:16:10.040 | through the anterior chamber.

00:16:11.220 | But there I'm speculating.

00:16:12.560 | I'm also speculating when I asked this,

00:16:14.720 | I would imagine that there are states in waking

00:16:20.520 | that also resemble slow wave sleep,

00:16:22.480 | or rather that there are states that slow wave sleep

00:16:25.100 | also resembles waking states.

00:16:27.020 | You've beautifully illustrated how REM sleep

00:16:30.080 | can mimic some of the more active brain states

00:16:32.240 | that we achieve in waking.

00:16:34.200 | What sort of waking state that I might have experienced

00:16:36.960 | or experienced on a daily basis

00:16:38.400 | might look similar to slow wave sleep, non-REM sleep,

00:16:42.520 | if any?

00:16:43.640 | - It's a genius way of thinking about it.

00:16:45.720 | Turns the tables, I love it.

00:16:47.960 | We almost never see anything like the true ultra slow waves

00:16:52.960 | of deep non-REM sleep.

00:16:55.520 | So we spoke about these two stages, non-REM and REM.

00:16:59.200 | Non-REM is further subdivided into four separate stages,

00:17:03.000 | stages one through four,

00:17:04.520 | increasing in their depth of sleep.

00:17:06.580 | So stages three and four,

00:17:07.960 | that's what we typically call deep non-REM sleep,

00:17:10.420 | stages one and two.

00:17:11.520 | - So maybe take me through the arc of a night,

00:17:13.160 | just so that, so I put my head down.

00:17:16.560 | Well, for you, what time do you normally go to sleep?

00:17:18.680 | - So I'm usually sort of around about a 10.30 p.m. guy,

00:17:23.520 | and usually I'll naturally wake up

00:17:26.040 | sort of a little bit before seven,

00:17:27.840 | sometimes before 6.45 or seven.

00:17:30.140 | I have an alarm set for 7.04 a.m.

00:17:34.020 | - You heard it here, folks.

00:17:35.040 | Matt Walker does use an alarm clock.

00:17:37.520 | - I really, really, I'm usually--

00:17:39.260 | - He doesn't recommend it, but he does use it.

00:17:40.940 | - Yeah, I usually-- - You're human after all.

00:17:42.860 | - Oh, I am so human, and I've had my sleep issues,

00:17:46.620 | and I'd love to speak about that too,

00:17:47.940 | but it's only just in the event that,

00:17:52.200 | 'cause I like to keep regularity too,

00:17:54.780 | you've got to keep those two things in balance.

00:17:56.940 | And 7.04, just because, you know, why not be idiosyncratic?

00:18:01.240 | I don't know why we always set things on these hard numbers.

00:18:05.000 | So, yep, so when--

00:18:06.840 | - So you go to sleep around 10.30.

00:18:08.760 | So using you as an example,

00:18:11.120 | because I imagine a number of people go to sleep

00:18:12.620 | at different times, but 10.30 is about when I go sleep,

00:18:14.740 | 11 is for me, but, so you go to sleep at 10.30.

00:18:17.840 | So for that first, let's say three hours of sleep,

00:18:22.000 | what is the architecture of that sleep look like

00:18:24.420 | as compared to the last three hours of your sleep

00:18:27.300 | before morning?

00:18:28.140 | - Yeah, so I should note that that sort of 10.30 to seven,

00:18:32.340 | that's just based on my chronotype and my preferential.

00:18:36.100 | It's different for different people.

00:18:37.500 | I'm not suggesting that that's the perfect sweet spot

00:18:40.020 | for humanity's sleep.

00:18:41.560 | It's just my--

00:18:42.400 | - But I imagine most people probably go to sleep

00:18:45.460 | somewhere between 10 and p.m. and midnight,

00:18:50.020 | and most probably wake up between 5.00 a.m. and 7.00 a.m.,

00:18:53.300 | or 5.30 and 7.30.

00:18:55.180 | - Yeah, yeah.

00:18:56.580 | At least in, if you look at sort of first world nations,

00:18:59.340 | that's a typical sleep profile.

00:19:01.760 | So when I first fall asleep,

00:19:05.100 | I'll go into the light stages of non-REM sleep,

00:19:07.900 | stages one and two of non-REM,

00:19:10.240 | and then I'll start to descend down

00:19:12.100 | into the deeper stages of non-REM sleep.

00:19:14.580 | So after about maybe 20 minutes,

00:19:16.420 | I'm starting to head down into stage three non-REM

00:19:19.620 | and then into stage four non-REM sleep.

00:19:22.820 | And as I'm starting to fall asleep,

00:19:24.820 | as I've cast off from the, usually with me,

00:19:28.060 | murky waters of wakefulness,

00:19:30.020 | and I'm in the shallows of sleep stages one and two,

00:19:33.080 | my heart rate starts to drop a little bit,

00:19:35.780 | and then my brainwave pattern activity starts to slow down.

00:19:39.960 | Normally when I'm awake, it's going up and down

00:19:42.380 | maybe 20, 30, 40, 50 times a second.

00:19:46.180 | As I'm going into light non-REM sleep,

00:19:49.900 | it will slow down to maybe 15, 20,

00:19:53.140 | and then really starts to slow down,

00:19:54.820 | down to about sort of 10 or eight cycles per second,

00:19:58.180 | eight cycle waves per second.

00:20:00.100 | Then as I'm starting to move into

00:20:04.340 | stages three and four non-REM sleep,

00:20:06.660 | several remarkable things happen.

00:20:08.780 | All of a sudden, my heart rate really does start to drop.

00:20:12.400 | Oh, and I'll come back to temperature.

00:20:15.300 | I'm going to write temperature down

00:20:16.560 | 'cause I always forget these things.

00:20:18.780 | Now I'm solidly in the foothills of middle age.

00:20:21.800 | So as I'm starting to go into those

00:20:24.060 | deeper stages of non-REM sleep,

00:20:26.280 | all of a sudden, hundreds of thousands of cells

00:20:29.220 | in my cortex all decide to fire together,

00:20:33.840 | and then they all go silent together.

00:20:36.100 | And it's this remarkable physiological coordination

00:20:40.340 | of the likes that we just don't see

00:20:43.260 | during any other brain state.

00:20:45.180 | - That's really interesting.

00:20:46.020 | Having recorded from the brains of animals

00:20:48.140 | and a little bit from humans,

00:20:49.420 | I don't think I've ever seen the entire cortex

00:20:51.380 | or even entire regions of cortex light up like that.

00:20:54.260 | - Yeah, it's stunning.

00:20:56.140 | It's almost like this beautiful sort of mantra chant

00:21:00.460 | or this sort of, it's a slow inhale

00:21:03.460 | and then a meditative exhale, inhale, exhale.

00:21:07.020 | And these waves are just enormous in their size.

00:21:10.240 | - And the body is capable of movement at this time.

00:21:12.380 | There is no paralysis.

00:21:14.220 | - There is no paralysis, but for the most part,

00:21:16.540 | muscle tone has also dropped significantly

00:21:19.700 | at that point.

00:21:21.180 | And then you will, or I will then stay there

00:21:23.780 | for about another 20 or 30 minutes.

00:21:26.140 | So now I'm maybe 60 or 70 minutes into my first sleep cycle.

00:21:31.140 | And then I'll start to rise back up,

00:21:33.440 | back up into stage two non-REM sleep.

00:21:36.100 | And then after about 80 or so minutes,

00:21:38.500 | I'll pop up and I'll have a short REM sleep period.

00:21:41.620 | And then back down I go again,

00:21:43.540 | down into non-REM, up into REM.

00:21:46.140 | And you do that reliably, repeatedly,

00:21:49.060 | and I will be doing that and I do do that every 90 minutes.

00:21:53.160 | At least that's the average for most adults.

00:21:56.880 | It's different in different species.

00:21:59.180 | What changes to your question is the ratio of non-REM to REM

00:22:03.580 | within that 90 minute cycle as you move across the night.

00:22:07.540 | And what I mean by this is in the first half of the night,

00:22:10.540 | the majority of those 90 minute cycles

00:22:13.180 | are comprised of lots of deep non-REM sleep.

00:22:15.820 | That's when I get my stage three and four

00:22:18.220 | of deep non-REM sleep.

00:22:19.940 | Once I push through to the second half of the night,

00:22:22.860 | now that seesaw balance changes.

00:22:25.500 | And instead, the majority of those 90 minute cycles

00:22:28.700 | are comprised either of this lighter form

00:22:31.160 | of non-REM sleep, stage two non-REM sleep,

00:22:33.740 | and much more and increasingly more

00:22:36.440 | rapid eye movement sleep.

00:22:37.940 | And the implication that I was sort of speaking about

00:22:41.220 | pragmatically is let's say that

00:22:45.260 | I have to, and I usually never do early morning flights

00:22:48.280 | or red eyes just because I'm a mess if that happens.

00:22:51.760 | I'm not suggesting that other people shouldn't.

00:22:53.500 | - I'm suggesting people not do that.

00:22:55.140 | Every time I've taken a red eye or I've done that,

00:22:57.420 | two or three days later,

00:22:58.480 | I get some sort of general feeling of malaise.

00:23:01.200 | My brain doesn't work as well.

00:23:02.800 | I think red eyes should be abolished for the pilots too.

00:23:06.460 | I mean, and for the emergency room,

00:23:10.300 | I mean, long shifts have been shown to lead to

00:23:12.900 | physician-induced errors that lead to a lot of fatalities.

00:23:17.120 | I mean, there are a lot of reasons why staying up too long

00:23:19.700 | or being up at the wrong times,

00:23:20.780 | if you're not adapted to it, is just terrible.

00:23:23.300 | - The data in all of those cases,

00:23:25.300 | and particularly physicians too,

00:23:26.780 | there was some recent data looking at suicidality.

00:23:29.860 | And the rates of suicide in training physicians

00:23:32.620 | are far, far above the norm.

00:23:35.460 | And I don't suspect that their schedules are helping them.

00:23:40.140 | I suspect that sleep is a missing part

00:23:43.500 | of that explanatory equation.

00:23:45.620 | - I teach medical students and they're phenomenal,

00:23:48.620 | but yeah, they're under extremely challenged conditions.

00:23:52.140 | - We shouldn't put them under those conditions.

00:23:53.860 | - No, it's not optimizing performance.

00:23:56.060 | I have one-- - But sorry, I was, sorry.

00:23:57.360 | - No, no, this is important, it's an important digression.

00:24:00.840 | I have one question,

00:24:02.100 | which is you're saying that as across the night,

00:24:04.660 | a greater percentage of these 90-minute cycles

00:24:06.700 | are going to be occupied by REM sleep

00:24:08.580 | as you progress through the night.

00:24:10.620 | I'm aware that based on work that you've done

00:24:15.780 | and from your public education efforts and others,

00:24:19.300 | that we have so-called circadian forces

00:24:25.020 | and we have other forces that are driving

00:24:27.500 | when we sleep and when we want to sleep, et cetera,

00:24:29.440 | without going into the details of those.

00:24:31.200 | I have a simple question.

00:24:32.140 | The experiment is the following.

00:24:33.520 | Let's say, God forbid,

00:24:35.460 | you are prevented from going to sleep at your normal time

00:24:38.900 | and you stay up for the four hours or five hours

00:24:42.920 | that normally you would be

00:24:44.060 | in predominantly slow-wave sleep.

00:24:45.840 | - Yep.

00:24:46.800 | - Let's say you finally get to lie down at 3 a.m.,

00:24:51.200 | a time when normally your sleep would be occupied

00:24:53.800 | mostly by rapid eye movement sleep.

00:24:56.080 | - Yep.

00:24:57.460 | - Will you experience a greater percentage

00:25:00.500 | of rapid eye movement sleep

00:25:01.800 | because of these so-called circadian forces,

00:25:04.580 | meaning that's what's appropriate for that time?

00:25:06.740 | Or will your system need to start

00:25:09.060 | at the beginning of the race that we're,

00:25:11.620 | as I'm referring to it, that we're calling sleep?

00:25:14.400 | - Yep.

00:25:15.240 | - If that's not clear to anybody,

00:25:16.180 | basically what I'm asking is if you are forced

00:25:18.260 | to skip the slow-wave sleep part of the night,

00:25:20.580 | will your system leap into rapid eye movement sleep

00:25:24.700 | or does it have to start at the beginning

00:25:26.400 | and get slow-wave sleep first?

00:25:27.820 | In other words, does one sleep state

00:25:29.820 | drive the entry to the next sleep state?

00:25:32.440 | - Great question.

00:25:33.340 | So there is some degree of reciprocity

00:25:35.580 | between the sleep states, I should note,

00:25:37.740 | that when we drive one of those up,

00:25:40.420 | we often, but not always, see a change in the other.

00:25:44.880 | There are some pharmacologies

00:25:46.580 | that have shown an independence to that

00:25:49.300 | and we've also played around with things like temperature

00:25:51.580 | and sometimes you can nudge one

00:25:55.020 | and not seem to upset or perturb the other.

00:25:58.700 | But to your, I think, lovely point,

00:26:02.460 | the answer is it's a mix, but it's mostly the latter,

00:26:06.580 | meaning you will mostly go into your REM sleep phases

00:26:11.580 | and be significantly deficient in your deep sleep.

00:26:15.940 | So just because I start my sleep cycle at 3 a.m.

00:26:19.640 | rather than at 10.30 p.m.,

00:26:22.780 | it doesn't mean that my brain just says,

00:26:24.380 | well, I've got a program

00:26:25.740 | and I'm just going to run the program

00:26:27.140 | and the way the program runs is that we always start

00:26:29.660 | with a first couple of hours of deep sleep.

00:26:32.820 | So we're just gonna begin act number one, scene one.

00:26:36.660 | It doesn't do that.

00:26:37.900 | Now, I will get some deep sleep to begin with

00:26:41.660 | and part of that is just because of how sleep works

00:26:45.140 | based on how long I've been awake.

00:26:47.460 | Longer I'm awake,

00:26:48.560 | there is a significantly greater pressure for deep sleep.

00:26:51.900 | But we actually use exactly what you just described

00:26:56.000 | as an experimental technique

00:26:57.740 | to selectively deprive people

00:26:59.980 | of one of those stages of sleep or the other.

00:27:02.540 | So we will do first half of the night deprivation

00:27:06.020 | and then let you sleep the second half.

00:27:08.180 | So that means that you will be mostly deep sleep deprived

00:27:12.100 | and you will still get mostly all of your REM sleep.

00:27:14.840 | And then we switch it so you only get your first four hours,

00:27:19.580 | which means you will mostly get deep non-REM sleep,

00:27:22.280 | but you will get almost no REM sleep.

00:27:24.540 | So in both of those groups,

00:27:26.100 | they've both had four hours of sleep.

00:27:28.100 | So the difference between them

00:27:29.420 | in terms of an experimental outcome is not the sleep time

00:27:33.220 | because they've both slept for the same amount.

00:27:35.740 | It's the contribution of those different stages.

00:27:38.340 | Now, we actually have more elegant methods

00:27:40.780 | for sort of selectively going in there

00:27:42.780 | and scooping out different stages of sleep.

00:27:45.440 | But that's the way we used to do it old school

00:27:47.460 | was just using this timing difference.

00:27:49.740 | - And who suffers more, those that lack the early phase

00:27:52.980 | and were those that lack the later phase of the night sleep?

00:27:55.940 | In other words, if I have to sleep only four hours

00:27:59.780 | for whatever reason, am I better off getting

00:28:01.540 | the early part of the night sleep

00:28:03.000 | or the second half of the night sleep?

00:28:05.440 | - Depends on what the outcome measure is.

00:28:08.120 | - So that gets right to the differences

00:28:09.780 | between slow wave sleep and REM.

00:28:12.140 | I was probably misinformed, but my understanding,

00:28:15.840 | a very crude understanding, I should say before--

00:28:18.580 | - I very much doubt it, au contraire with someone like you.

00:28:21.460 | - Which is very nice of you.

00:28:22.740 | But the first part of the night,

00:28:24.580 | this slow wave sleep is restorative to the musculature,

00:28:27.380 | to motor learning, and that the dream content

00:28:29.920 | tends to be less emotional.

00:28:31.420 | The second half of the night being more emotional dreams

00:28:33.960 | and sort of the unpairing of the emotional load

00:28:36.820 | of our previous day and other experiences.

00:28:39.960 | So in other words, if I were to deprive myself of REM,

00:28:43.780 | I would be hyper emotional, maybe not as settled

00:28:46.800 | with the kind of experiences of my life.

00:28:49.020 | Whereas if I had to have myself of slow wave sleep,

00:28:51.760 | I would feel a more physical malaise.

00:28:54.280 | Is that correct or is that far too simple?

00:28:56.340 | And if it is too simple, please tell me where I'm wrong.

00:28:59.680 | - No, I think much of that is correct.

00:29:02.020 | And it's sort of that plus.

00:29:04.660 | So for example, during deep non-REM sleep,

00:29:07.880 | that's where we get this, it's almost a form

00:29:09.780 | of natural blood pressure medication.

00:29:12.140 | And so when I take that away from you, the next day,

00:29:15.080 | we're usually going to see autonomic dysfunction.

00:29:17.680 | We're usually going to see abnormalities in heart rate,

00:29:20.440 | blood pressure.

00:29:21.640 | We also know that during deep non-REM sleep

00:29:24.020 | that there is a certain control of specific hormones.

00:29:26.980 | For example, we know that the insulin regulation

00:29:29.820 | of sort of metabolism, meaning how will you look

00:29:34.140 | from a regulated blood sugar perspective

00:29:37.220 | versus dysregulated pre-diabetic look of profile,

00:29:42.220 | that's where deep sleep seems to matter.

00:29:44.420 | If we selectively deprive you of that,

00:29:46.420 | we can see-- - Growth hormone.

00:29:47.900 | - Growth hormone is different actually.

00:29:49.620 | So that's a beautiful demonstration

00:29:51.480 | where growth hormone seems to be more REM sleep dependent.

00:29:55.100 | And that's why we can come on to the effects of alcohol.

00:29:58.120 | And there was some really impressive frightening data

00:30:00.860 | on alcohol and its disruption of sleep.

00:30:04.780 | But then we also know testosterone.

00:30:07.680 | Peak levels of testosterone happen during REM sleep.

00:30:11.180 | - So the second half of the night.

00:30:12.720 | - Which is the second half of the night.

00:30:14.460 | So it really just means that your profile of mental

00:30:19.780 | and physical dysfunction will be different

00:30:23.200 | under both of those conditions.

00:30:25.480 | Which one would you prefer?

00:30:27.900 | I would prefer neither of them.

00:30:29.440 | And it really depends on what you're trying to optimize for.

00:30:33.200 | So it's just so complete.

00:30:35.080 | Sleep is just so plory potent.

00:30:39.320 | It's so physiologically systemic

00:30:42.980 | that it's almost impossible not to undergo

00:30:46.840 | one of those two things, just deep sleep deprivation

00:30:49.360 | or just REM sleep deprivation and not show a profile

00:30:52.680 | that you would really prefer to avoid.

00:30:55.560 | And that's the reason from an evolutionary standpoint

00:30:59.580 | that we have preserved those stages of sleep.

00:31:02.040 | I mean, sleep is just so idiotic

00:31:05.200 | from an evolutionary perspective.

00:31:06.980 | - Or maybe waking is idiotic.

00:31:08.560 | - Or waking is, well, yeah.

00:31:11.100 | - Based on your previous idea.

00:31:13.000 | - Who have you been talking to?

00:31:13.840 | I think that comment is very specific to me.

00:31:16.340 | Yeah, I am normally always an idiot

00:31:19.180 | when waking, but I think this idea that sleep

00:31:24.180 | is so profoundly detrimental to us.

00:31:28.540 | If you were to take it at face value,

00:31:30.720 | you're not finding a mate, you're not reproducing,

00:31:33.220 | you're not foraging for food,

00:31:34.560 | you're not caring for your young.

00:31:36.160 | And worst of all, you're vulnerable to predation.

00:31:39.280 | On any one of those grounds,

00:31:41.080 | sleep probably should have been selected against.

00:31:44.000 | But it wasn't.

00:31:44.840 | Sleep has fought its way through heroically.

00:31:48.040 | Every step along the evolutionary path.

00:31:51.040 | And therefore, every sleep stage has also survived

00:31:56.040 | as best we can tell.

00:31:58.220 | What that means is that those are non-negotiable.

00:32:01.220 | If mother nature had found a way to even just sort of,

00:32:05.220 | you know, thin slice some of that sleep from us,

00:32:09.240 | there would have been vast, I'm sure, evolutionary benefits.

00:32:12.880 | But it looks as though she hasn't.

00:32:14.920 | And I'm usually in favor of her wisdom

00:32:17.860 | after 3.6 million years, so.

00:32:20.360 | - Yeah, it's incredible.

00:32:22.480 | I want to introduce another Gedanken experiment,

00:32:25.760 | another thought experiment.

00:32:26.940 | So in this arc of the night,

00:32:28.640 | slow-wave sleep predominates early in the night

00:32:31.700 | and then REM sleep.

00:32:33.460 | There's a scenario that many people,

00:32:34.960 | including myself, experience on a regular basis,

00:32:37.680 | which is they go to sleep, sleeping just fine,

00:32:41.400 | three, four hours into it, they wake up.

00:32:43.720 | They wake up for whatever reason.

00:32:45.400 | Maybe there was a noise, maybe the temperature isn't right.

00:32:47.400 | We will certainly talk about sleep hygiene, et cetera.

00:32:50.140 | They get up, they go to the restroom.

00:32:53.460 | They might flip on the lights, they might not.

00:32:56.200 | They'll get back in bed.

00:32:57.640 | Hopefully they're not picking up their phone

00:32:59.500 | and starting to browse and wake up the brain

00:33:01.800 | through various mechanisms,

00:33:02.920 | light and cognitive stimulation, et cetera.

00:33:05.400 | They go back to sleep.

00:33:06.960 | Let's say after about 10, 15 minutes,

00:33:08.680 | they're able to fall back asleep,

00:33:10.480 | and then they sleep till their more typical wake time.

00:33:12.860 | - Yeah.

00:33:14.120 | - How detrimental is that wake up episode or event

00:33:19.120 | in terms of longevity, learning, et cetera?

00:33:25.000 | I would love to sleep the entire night through every night,

00:33:27.800 | but most nights I don't.

00:33:29.760 | And yet I feel pretty good throughout the day.

00:33:32.000 | Some days better than others.

00:33:33.640 | So if you were to kind of evaluate that waking episode

00:33:37.800 | and compare it to sleeping the whole night through,

00:33:42.420 | what are your thoughts on that?

00:33:44.520 | - So I think if you're waking up sort of frequently

00:33:47.540 | as you're describing,

00:33:49.180 | I would probably get your estate in order

00:33:51.320 | because my guess is within the next year,

00:33:53.820 | you're gonna be done for, no, I'm kidding you.

00:33:57.520 | Absolutely kidding you.

00:33:58.820 | It is perfectly natural and normal,

00:34:01.700 | particularly as we progress with age.

00:34:04.560 | Children tend to have typically more continuous sleep.

00:34:08.240 | Now it's not that they aren't waking up

00:34:10.360 | for brief periods of time.

00:34:11.500 | They are, and in fact, we all do.

00:34:13.800 | When we come out the other end of our sleep cycle,

00:34:16.560 | at the end of our REM sleep period of the 90 minute cycle,

00:34:21.120 | almost everybody wakes up and we make a postural movement.

00:34:25.600 | We turn over because we've been paralyzed for so long

00:34:28.760 | and the body will also like to shift.

00:34:30.880 | - Do we ever look around?

00:34:31.920 | Do we ever open our eyes and look around?

00:34:34.520 | - Sometimes people will open their eyes,

00:34:36.560 | but usually it's only for a brief period of time

00:34:39.160 | and they usually never commit those awakenings to memory.

00:34:42.940 | - Right.

00:34:44.180 | - Your situation, and it's my situation as well,

00:34:47.060 | I usually now at this stage of life,

00:34:48.660 | I don't sleep through the night,

00:34:50.000 | I'll usually have a bathroom break,

00:34:52.860 | and then I'll come back.

00:34:54.820 | That's perfectly normal.

00:34:57.660 | We tend to forget that in sleep science,

00:35:00.600 | we think of sleep efficiency.

00:35:02.780 | So of the total amount of time that you're in bed,

00:35:06.540 | how much of that percent time is spent asleep?

00:35:11.320 | And we usually look to numbers that are above 85% or more

00:35:16.180 | as a healthy sleep efficiency.

00:35:19.180 | So if you were to think about me going to bed

00:35:21.780 | and I spend, let's say eight and a quarter,

00:35:25.540 | eight and a half hours of time in bed

00:35:28.080 | with a normal healthy sleep efficiency,

00:35:31.460 | I still may be only sleeping a total of seven and a half

00:35:35.860 | hours or seven and three quarter hours,

00:35:38.620 | meaning that I'm going to be awake in total,

00:35:43.180 | not in one long bout,

00:35:45.700 | but I'm going to be awake for upwards of 30 minutes,

00:35:48.980 | net some time.

00:35:51.460 | Sometimes that can be after a 10 minute,

00:35:54.960 | dalliance after having gone to the bathroom

00:35:56.920 | and I'm just gradually drifting back off again.

00:35:59.980 | Other times it will just be for a couple of minutes

00:36:02.460 | and most of those you don't commit.

00:36:04.680 | So I think we need to stop.

00:36:06.520 | We don't need to get too worried about, you know,

00:36:10.380 | periods of time awake,

00:36:11.960 | just because we're not sleeping throughout the night.

00:36:13.620 | I would love to do that too.

00:36:14.680 | And I remember when I, that used to happen

00:36:16.480 | and it still happens occasionally.

00:36:18.560 | - It feels great when it does happen.

00:36:20.080 | - It's a lovely thing.

00:36:21.080 | - It's a surprise, right?

00:36:22.400 | - It is now a surprise.

00:36:23.240 | - I slept through the whole night.

00:36:24.280 | - Yeah, it is a surprise.

00:36:25.820 | But for the most part,

00:36:27.660 | I think we can be more relaxed about that.

00:36:30.060 | Where we have to be a bit more attentive though,

00:36:33.020 | is if you are spending long periods of time,

00:36:36.220 | not being able to get back to sleep.

00:36:37.940 | And usually we define that by saying,

00:36:40.300 | if it's been 20, 25 minutes,

00:36:42.900 | normally that's a time when we would really say,

00:36:45.760 | okay, let's explore this.

00:36:47.380 | What's going on?

00:36:48.220 | Let's see what's happening.

00:36:49.920 | The other thing is if it's happening very frequently.

00:36:52.700 | So even if you're, you know,

00:36:55.620 | not awake for 25 minute stretches,

00:36:58.620 | but you're finding yourself waking up

00:37:00.620 | and being consciously aware that you've woken up

00:37:03.700 | for maybe six, seven or eight times throughout the night,

00:37:07.140 | and your sleep is very what we call fragmented.

00:37:09.960 | The great science of sleep in the past five or 10 years

00:37:14.160 | has been yes, quantity is important,

00:37:17.780 | but quality is just as important.

00:37:21.100 | And you can't have one without the other

00:37:23.760 | in terms of a good beneficial next day outcome.

00:37:27.660 | You can't just get four hours of sleep,

00:37:30.220 | but brilliant quality of sleep and be unimpaired,

00:37:33.660 | nor can you get eight hours of sleep,

00:37:36.340 | but have very poor quality of sleep

00:37:38.780 | and be unimpaired the next day.

00:37:41.620 | So that's why I just sort of want to asterisk this idea of,

00:37:45.900 | let's not get too worried about waking up

00:37:48.020 | and having some time awake.

00:37:49.320 | That's perfectly normal and natural.

00:37:51.960 | But if it's happening very frequently throughout the night,

00:37:54.860 | all those periods of time,

00:37:56.500 | a long stretches of time, upwards of 25 minutes,

00:37:59.680 | then let's look into it.

00:38:01.100 | - Well, I can assure you just helped a lot of people

00:38:04.380 | feel better about this waking up episode

00:38:07.580 | that I and many other people experience.

00:38:09.800 | - I hope so because I think it's really important that we,

00:38:13.280 | I think I've been desperately guilty of perhaps,

00:38:19.000 | early on being too puritanical about sleep.

00:38:23.040 | I've retrospected and I've tried to explore

00:38:27.200 | why this was the case.

00:38:28.760 | It was almost sleep or else dot, dot, dot.

00:38:32.320 | And at the time when I was starting to write the book,

00:38:36.640 | which was back in 2016,

00:38:39.560 | sleep was still a neglected step sister

00:38:42.140 | in the health conversation of today.

00:38:44.240 | And I could see all of the-- - That has certainly changed.

00:38:46.580 | - And it's changing and not because of my efforts,

00:38:49.140 | but because of all of my colleagues.

00:38:50.420 | - I would say, well, it's great that you give attribution

00:38:54.900 | to your other people involved in it.

00:38:56.780 | Of course, it's a big field,

00:38:58.060 | but I think you've done a great service

00:39:00.460 | by cuing people to the importance of this state,

00:39:03.380 | not just for avoiding troublesome outcomes,

00:39:06.740 | but also for optimizing their waking state.

00:39:09.200 | It's really, I view sleep as this period that feels good,

00:39:13.180 | but we're not aware of how it feels

00:39:14.500 | when we're in it necessarily.

00:39:16.780 | It has tremendous benefits when you're doing it well,

00:39:19.140 | so to speak, and it has tremendous deficits when we're not.

00:39:24.120 | And I think it was an important thing for you to do

00:39:28.440 | to cue people to this issue.

00:39:29.880 | And I would say mission accomplished,

00:39:32.780 | that people are aware of the need for sleep.

00:39:35.760 | I think that knowing that waking up

00:39:37.520 | in the middle of the night is normal,

00:39:39.680 | provided it's not too frequent, is great,

00:39:42.240 | and will also help people

00:39:43.840 | who may have been overly concerned about that.

00:39:46.260 | I do want to use this as an opportunity

00:39:48.040 | to raise something about the so-called Uberman schedule,

00:39:52.400 | not to be confused with the Huberman schedule.

00:39:55.920 | Fortunately, no one has confused those yet.

00:39:59.320 | Some years ago, there was a discussion

00:40:02.720 | about the so-called Uberman schedule,

00:40:04.960 | meaning the Superman schedule.

00:40:06.560 | So that's Huberman without an H,

00:40:08.320 | which I have nothing to do with.

00:40:09.920 | If you read your Nietzsche, this will have a subtext.

00:40:13.640 | But regardless, the Uberman schedule, as I understand,

00:40:17.160 | is one in which the person elects to sleep

00:40:21.280 | in 90-minute bouts spread throughout the day and night

00:40:25.440 | in an attempt to get more productivity

00:40:28.440 | and/or reduce their overall sleep need.

00:40:30.760 | There was a paper published recently

00:40:32.480 | that explored whether or not this is good or bad for us.

00:40:36.020 | Maybe you just give us the take-home message on that.

00:40:38.520 | - Yeah, so these Uberman-like schedules,

00:40:41.680 | and there's lots of different forms of that,

00:40:44.240 | they tried to essentially pie chart the 24-hour period

00:40:49.240 | into short bouts of sleep with some shorter,

00:40:53.700 | well, slightly longer periods of wakefulness,

00:40:55.700 | then short bouts of sleep, then wakefulness.

00:40:57.960 | I sort of made it, I think, a quip.

00:41:01.800 | It's almost like you're sleeping like a baby,

00:41:04.120 | 'cause that's the way that babies will sleep,

00:41:06.840 | that they will have these brief naps, then they're awake,

00:41:09.280 | then they're asleep, then they're awake,

00:41:10.280 | and to the chagrin of parents across the night,

00:41:13.120 | it's basically the same.

00:41:14.640 | They're awake, they're asleep, they're awake, they're asleep.

00:41:16.800 | And that's more the schedule that these types

00:41:19.920 | of protocols have suggested.

00:41:23.640 | And there was a really great comprehensive review

00:41:26.760 | that found not only that they weren't necessarily helpful,

00:41:30.640 | but they were actually really quite detrimental.

00:41:33.280 | And on almost every performance metric,

00:41:35.880 | whether it be task performance,

00:41:37.600 | whether it be physiological outcome measures,

00:41:40.320 | whether it even be the quality of the sleep

00:41:43.040 | that they were having when they were trying to get it,

00:41:45.820 | all of those were in a downward direction.

00:41:48.880 | And it's not surprising.

00:41:50.120 | If you look at the way that your physiology is programmed,

00:41:53.320 | if you look at the way your circadian rhythm is programmed,

00:41:56.440 | none of that screams to us

00:41:58.360 | that we should be sleeping in that way.

00:42:02.160 | - Well, I'm chuckling,

00:42:03.000 | because we always hear sleep like a baby.

00:42:04.920 | This is how babies sleep.

00:42:06.460 | And I would say, don't sleep like a baby,

00:42:08.620 | sleep like an adult, be an adult.

00:42:10.680 | Get your solid eight hours.

00:42:11.960 | - It's Billy Crystal's line,

00:42:12.840 | he was a long standing suffering insomniac.

00:42:16.260 | He says, I sleep like a baby, I'm awake every 20 minutes.

00:42:19.580 | And I think this is another one of those demonstrations

00:42:23.520 | that when you fight biology, you normally lose.

00:42:28.260 | And the way you know you've lost

00:42:29.860 | is disease, sickness and impairment.

00:42:32.580 | And I think if you sleep in accordance

00:42:35.940 | with the natural biological edict

00:42:38.580 | that we've all been given,

00:42:40.260 | life tends to be both of a higher quality

00:42:43.160 | and a longer duration.

00:42:44.760 | - Yeah, I agree.

00:42:45.680 | Along those lines, as a vision scientist,

00:42:48.920 | I've been very excited by the work

00:42:50.380 | on these non-image forming cells in the eye,

00:42:52.480 | the so-called melanopsin cells

00:42:53.800 | that inform the brain about circadian time of day.

00:42:56.420 | And I'm a big proponent of people getting some sunlight,

00:43:01.080 | ideally sunlight, but other forms of bright light

00:43:03.440 | into their eyes early in the day

00:43:04.880 | and when they want to be awake.

00:43:06.760 | Essentially during the phase of their 24 hour

00:43:09.020 | circadian cycle when temperature is rising

00:43:12.400 | and then starting to get less light in their eyes

00:43:15.620 | as our temperature is going down

00:43:17.680 | later in the day and in the evening.

00:43:19.540 | Are there any adjustments to that general theme

00:43:22.360 | that you'd like to add or is in any way?

00:43:25.900 | - No, I think that's exactly what we recommend right now,

00:43:29.340 | which is try to get at least 30 to 40 minutes of exposure

00:43:33.900 | to some kind of natural daylight.

00:43:35.620 | Now, there may be parts of the world where, you know-

00:43:38.700 | - Yeah, you're from a rather cloudy part of the world.

00:43:41.380 | - I am from, yeah, Liverpool, England

00:43:44.700 | and the Northwest of England is not known

00:43:47.820 | for its beach resorts and fine weather.

00:43:51.620 | I remember I sort of, I went back home for a trip

00:43:55.700 | when I'd first been out in California

00:43:58.380 | and I thought, why is the sky so low?

00:44:01.300 | You know, it's just, you know, constantly out.

00:44:03.900 | We joke that in the UK,

00:44:06.940 | we usually have nine months of bad weather

00:44:09.660 | and then three months of winter

00:44:11.460 | and then that's your entire year in terms of a climate.

00:44:15.420 | But to come to your point, you're exactly right.

00:44:17.780 | Try to get that daylight.

00:44:19.000 | Now, it can be, you know, working next to a window

00:44:22.480 | and you're getting that natural sunlight,

00:44:24.520 | but that natural sunlight is,

00:44:26.860 | even on a cloudy day in England,

00:44:28.880 | is usually far more potent than anything that you'll get

00:44:31.880 | from indoor lighting.

00:44:34.300 | Despite you thinking sort of from a perception wise,

00:44:37.240 | maybe they're much closer than I would think.

00:44:40.620 | - Yeah, I've been, sorry to interrupt,

00:44:42.300 | I've been a big proponent of there's an app

00:44:44.700 | called Light Meter, which will, it's a free app.

00:44:47.380 | I have nothing to do with it.

00:44:48.340 | They will allow you to get a pretty decent measurement

00:44:51.080 | of the amount of light energy coming toward you.

00:44:53.240 | And if you hold it up to a cloudy morning

00:44:56.940 | where you don't think it's very bright out,

00:44:58.280 | kind of a dismal day,

00:44:59.340 | you'll notice that there'll be a thousand, two thousand,

00:45:01.860 | even, you know, 5,000 lux, lux just being a measure

00:45:04.460 | of brightness, of course.

00:45:05.420 | And then you can point the same light meter

00:45:07.960 | toward an indoor light that seems very bright

00:45:10.100 | and very intense and it'll say 500 lux.

00:45:13.260 | And you realize that the intensity as we gauge it

00:45:15.980 | perceptually is not really what the system is receiving.

00:45:19.540 | So outdoor light is key.

00:45:20.860 | How do you, how do you get this natural stimulation

00:45:24.120 | or I should just say light stimulation early in the day?

00:45:27.020 | What is your typical, what does Matt Walker do

00:45:29.660 | to get this light stimulation?

00:45:31.120 | - I am no poster child, but usually I will,

00:45:35.520 | if I'm working, I usually work out most days.

00:45:38.520 | And I shopped around and I found a gym

00:45:41.240 | that has huge amounts of window exposure facing to the east.

00:45:45.560 | This is sound, this is going to sound so ridiculous.

00:45:48.720 | You know, Matt Walker chooses a gym on the basis

00:45:51.320 | of the solar input. - I love it.

00:45:52.920 | - So he can, you know, correct a circadian.

00:45:54.760 | - There are a lot of criteria for selecting gyms.

00:45:55.960 | This one is actually grounded in physiology and biology.

00:45:59.720 | - And selfishness about my own sleep.

00:46:02.040 | - Oh, that's great.

00:46:02.880 | So you get your exercise and your light stimulation

00:46:05.140 | simultaneously. - That's right, yep, yep.

00:46:05.980 | - And so you're stacking cues for wakefulness

00:46:08.880 | early in the day.

00:46:09.720 | - Exactly, so both exercise and daylight

00:46:12.440 | are wonderful cues for circadian rhythm alignment

00:46:16.440 | and also circadian rhythm reset each day.

00:46:19.280 | And so I will use both exercise.

00:46:22.040 | I mean, I am, I'm neither a strong morning type

00:46:24.640 | or a strong evening type and my preference to exercise

00:46:28.040 | is probably some time in the middle of the day,

00:46:32.100 | probably somewhere around 1 p.m., sorry, not 1 a.m.

00:46:35.020 | But I'm usually working out probably around

00:46:39.480 | the sort of 7, sort of 45, 8 a.m. time.

00:46:44.480 | That's usually when I'll start my workout.

00:46:46.720 | And there I'll start with cardio, spin bike,

00:46:49.160 | facing a window, and luckily for the most part

00:46:51.940 | here in California, there's usually sunlight coming through.

00:46:55.640 | But it doesn't matter to me because just as you said,

00:46:58.720 | even when it's a cloudy day, that lux coming through

00:47:02.840 | of light, the intensity is splendid.

00:47:07.000 | So I would prefer to favor my exercise

00:47:10.840 | just because for efficiency too,

00:47:12.320 | I wanna get also working on the day.

00:47:14.780 | I'll try to match my exercise more

00:47:19.520 | with my circadian light exposure

00:47:22.080 | than I would probably if I'm going to,

00:47:24.320 | do I really wanna crush a workout

00:47:26.040 | or do I want to just make sure it's a good workout?

00:47:30.120 | I would prefer to work out at a different time,

00:47:32.920 | but I like that because of the daylight.

00:47:34.800 | And we can speak about exercise timing at some point

00:47:37.200 | because there's a lot of discussion around that,

00:47:38.820 | when is the right time to exercise during sleep?

00:47:41.660 | And we can sort of bust some myths there too.

00:47:44.100 | So I think you're spot on with the suggestion,

00:47:49.040 | get some morning daylight, try to get that exposure,

00:47:52.260 | usually at least 30 to 40 minutes.

00:47:54.740 | There was some great work recently coming out

00:47:56.860 | in the occupational health domain,

00:47:59.040 | where they moved workers from offices

00:48:01.580 | that were just facing walls

00:48:03.220 | and didn't have any exposure to natural daylight.

00:48:06.680 | And then they did a time period during that study

00:48:09.620 | where they actually were in front of a window and working.

00:48:12.960 | And they measured their sleep and their sleep time

00:48:16.520 | and their sleep efficiency increased quite dramatically.

00:48:19.480 | I'm forgetting the numbers now,

00:48:20.720 | but I think the increase in total sleep time

00:48:23.140 | was well over 30 minutes.

00:48:24.760 | And the improvement in sleep efficiency was five to 10%.

00:48:28.720 | And if you're batting an 80% sleep efficiency average,

00:48:33.100 | we're a bit concerned about that.

00:48:35.500 | But add 10% to that, now you're in a great echelon

00:48:39.200 | of healthy sleepers.

00:48:40.680 | And all you did was just spend some time

00:48:43.140 | working in front of windows.

00:48:44.400 | - That's great.

00:48:45.240 | And probably folks might want to consider

00:48:47.200 | spending a little less time with sunglasses

00:48:48.820 | provided they can do that safely.

00:48:50.660 | Driving, et cetera.

00:48:51.800 | You're not alone with your exercise behavior

00:48:53.620 | in facing east.

00:48:54.460 | So the one and only Tim Ferriss told me recently

00:48:57.760 | that his morning routine nowadays consists of

00:49:01.100 | jumping rope while facing east

00:49:03.240 | to get the sunlight stimulation of the eyes.

00:49:05.760 | And as Matt and I both know,

00:49:08.640 | it has to be of the eyes, right?

00:49:10.560 | I mean, these portals are the only way

00:49:12.560 | to convey to the rest of the brain and body

00:49:15.680 | about the time of day and wakefulness.

00:49:19.820 | - Along the lines of wakefulness,

00:49:22.040 | I have a number of questions about caffeine.

00:49:24.480 | The dreaded and beloved caffeine.

00:49:26.720 | I love caffeine, but I like it in relatively

00:49:30.560 | restricted periods of time.

00:49:35.540 | So I'm a big fan of waking up

00:49:38.800 | and even though I wake up very groggy,

00:49:40.440 | allowing my natural wakefulness signals to take hold.

00:49:43.920 | Meaning I wake up very slowly,

00:49:45.640 | but I don't drink caffeine right away.

00:49:47.760 | I sort of delay caffeine by a little while,

00:49:51.200 | usually 90 minutes to two hours.

00:49:53.540 | And that idea came to me on the basis of my understanding

00:49:58.040 | of how caffeine and the adenosine receptor interact.

00:50:01.640 | I have a feeling you're going to pronounce

00:50:02.760 | adenosine differently than I do.

00:50:04.000 | - No, no, no. I will go with adenosine.

00:50:06.320 | - I'll try to go with your skeletal instead of skeletal

00:50:09.300 | and synapse and synapse.

00:50:11.460 | - Schedule and schedule.

00:50:12.500 | - There we go.

00:50:13.340 | But to make it really simple for folks,

00:50:17.580 | how does caffeine work to make us feel more alert?

00:50:21.720 | And does the timing in which we ingest caffeine

00:50:25.560 | play an important role in whether or not it works for us

00:50:28.940 | or against us?

00:50:30.080 | So maybe we just start with how does caffeine work?

00:50:32.960 | Why is it that when I drink mate or coffee,

00:50:35.560 | which are my preferred sources of caffeine,

00:50:37.620 | do I feel a mental and physical lift?

00:50:40.380 | - Yeah. So I'm going to suggest counter

00:50:43.160 | to what most people would think, drink coffee.

00:50:47.780 | - Or mate, is mate okay also?

00:50:51.020 | Whatever form you enjoy.

00:50:51.860 | - Well, we'll come on to sort of why I suggest that,

00:50:55.100 | but when it comes to coffee,

00:50:58.060 | I would say the dose and the timing makes the poison.

00:51:02.900 | So let's start with how caffeine works.

00:51:06.700 | Caffeine is in a class of drugs

00:51:08.460 | that we call the psychoactive stimulants.

00:51:11.100 | So it works through a variety of mechanisms.

00:51:15.540 | One is a dopamine mechanism.

00:51:18.380 | Dopamine we often think of as a reward chemical,

00:51:21.900 | or, but dopamine is also very much

00:51:24.880 | an alerting neurochemical as well.

00:51:27.780 | And caffeine has some role it seems to play

00:51:30.460 | in increasing dopamine,

00:51:32.200 | but it's principal mode of action we believe

00:51:34.980 | in terms of making me more alert

00:51:36.960 | and keeping me awake throughout the day

00:51:39.720 | is on the effects of adenosine.

00:51:42.260 | And to explain what adenosine is from the moment

00:51:44.700 | that you and I woke up this morning,

00:51:46.900 | this chemical adenosine has been building up in our brain.

00:51:51.060 | And the longer that we're awake,

00:51:52.820 | the more of that adenosine accumulates.

00:51:55.300 | - Is it, may I ask, is it accumulating in neurons,

00:51:59.380 | in glia or in the blood vessels?

00:52:02.140 | Where, and is it also accumulating in my body?

00:52:05.340 | Where is this adenosine coming from

00:52:07.140 | and where is it accumulating?

00:52:08.260 | - Yeah, so the adenosine here that we're talking about

00:52:10.940 | that is creating the sleep pressure

00:52:12.620 | is a central brain phenomenon,

00:52:14.960 | and it comes from the neurons themselves combusting energy.

00:52:19.260 | And as they're combusting energy,

00:52:20.980 | one of the offshoots of that is this chemical adenosine.

00:52:25.980 | And so as we're awake throughout the day

00:52:28.260 | and our brain is metabolically very active,

00:52:31.340 | it's accumulating and building up this adenosine.

00:52:35.820 | Now, the more adenosine that we have,

00:52:38.980 | the sleepier that we will feel.

00:52:41.180 | So it really is like a sleep pressure is what we call it.

00:52:45.680 | Now, it's not a mechanical pressure.

00:52:47.500 | Don't worry, your head's not going to explode.

00:52:49.000 | It's a chemical pressure.

00:52:51.460 | And it's this weight of sleepiness

00:52:53.780 | that we feel gradually growing as we get into the evening.

00:52:57.860 | - May I just interrupt you again to just ask,

00:53:00.220 | do we know what the circuit mechanism is for that?

00:53:03.020 | I mean, not to go too far down the rabbit hole,

00:53:05.660 | but for the aficionados and for myself,

00:53:08.680 | we have brain mechanisms like locus coeruleus

00:53:11.320 | that release things that our brain areas,

00:53:14.120 | locus coeruleus just being a brain area, of course,

00:53:15.620 | that release things that proactively create wakefulness.

00:53:20.220 | So are those neurons shutting down as a consequence

00:53:22.640 | of having too much adenosine?

00:53:24.980 | Or are there areas of the brain that promote sleepiness

00:53:29.600 | that are becoming activated?

00:53:31.200 | Because these, you can imagine both things

00:53:32.760 | working in parallel.

00:53:33.720 | One or the other would accomplish the same end point.

00:53:36.140 | - Yeah, and it's both.

00:53:38.300 | And so there are two main receptors for adenosine,

00:53:41.300 | the A1 receptor and the A2 receptor,

00:53:44.800 | and they have different modes of activating brain cells

00:53:48.240 | or inactivating or decreasing the likelihood of firing.

00:53:52.780 | And adenosine works in this beautiful, elegant way

00:53:56.660 | where it will inhibit and shut down

00:53:59.660 | the wake promoting areas of the brain

00:54:02.480 | whilst also increasing and dialing up the volume

00:54:06.540 | on sleep activating,

00:54:08.240 | sleep promoting reach. - Biology is so beautiful.

00:54:10.000 | - Oh, it's always a push pull.

00:54:11.640 | - Yeah.

00:54:12.480 | - I mean, and we could have a larger discussion

00:54:13.500 | at some point about that everything,

00:54:16.340 | seeing dark edges, seeing light edges,

00:54:18.640 | our ability to smell or to sense pressure on this,

00:54:21.840 | everything's a push pull in biology.

00:54:22.680 | - Oh, that's great, yeah, yep.

00:54:23.760 | - So this is another example where as I am awake longer,

00:54:28.240 | adenosine is released in the brain

00:54:30.760 | and my wakefulness areas are being actively shut down

00:54:34.280 | by that adenosine and my sleepiness brain areas,

00:54:37.800 | so to speak, are being promoted to be more active.

00:54:41.100 | Is that correct?

00:54:41.940 | - That's right, and it's a very progressive process.

00:54:44.060 | It's not like a step function where,

00:54:46.520 | and sometimes that happens occasionally,

00:54:49.020 | but it's usually because you've been sort of driving through

00:54:51.660 | and as we'll come on to have caffeine in the system.

00:54:54.500 | And then all of a sudden you just hit a wall

00:54:56.400 | and it just engulfs you and you go from a zero

00:55:00.200 | to the one of sleepiness within a short period of time.

00:55:03.160 | - What explains the fatigue after a hard conversation?

00:55:06.600 | The desire to go to sleep

00:55:07.800 | or the desire to go to sleep during a hard conversation.

00:55:11.640 | - That's an interesting one.

00:55:12.560 | I think it's usually just based

00:55:13.960 | on personality type interactions and for the most part-

00:55:16.940 | - Not that I've ever experienced that before.

00:55:18.400 | - No, people with you don't, but with me, they almost-

00:55:20.760 | - Oh, no, no, no, I mean, I've experienced the desire

00:55:22.800 | to some conversations, I'm halfway through them

00:55:26.520 | and I feel like I want to take a nap, right?

00:55:30.120 | - And I would love to look at people's sleep history.

00:55:32.640 | We've sort of seen that time and time again,

00:55:34.800 | but, and then it could be, you know, with folks like me,

00:55:38.040 | people just lose the will to live

00:55:39.580 | within about five minutes of speaking with me, so.

00:55:41.840 | - Not true.

00:55:42.680 | They hear that sleep is important, that's all.

00:55:44.240 | - Unrelated and that's flattery, that's great.

00:55:46.200 | But so the way that then caffeine comes into this equation,

00:55:50.580 | as I was saying, it's usually a kind of a linear process

00:55:53.040 | or maybe it's probably closer to an exponential

00:55:55.600 | in terms of your subjective feeling of sleepiness.

00:55:59.320 | And we haven't really been able to measure that in humans

00:56:02.600 | because normally we, it's hard to actually, you know,

00:56:05.620 | stick something into the brain and be, you know, sucking,

00:56:08.360 | siphoning off stuff every couple of minutes,

00:56:10.400 | as you could do in animal studies

00:56:12.000 | and keep asking people every couple of minutes,

00:56:13.800 | how sleepy do you feel, how sleepy?

00:56:15.440 | And track to see if there's a linear rise in, you know,

00:56:19.560 | adenosine, which then creates an exponential rise

00:56:23.140 | in subjective sleepiness or what the dynamics are.

00:56:26.040 | But I'm kind of nerding out.

00:56:27.580 | Caffeine comes into play here because caffeine,

00:56:32.500 | comes into your system and it latches onto those welcome

00:56:36.320 | sites of adenosine, the adenosine receptors.

00:56:39.740 | But what it doesn't do is latch onto them and activate them

00:56:44.740 | because if it was doing that, then it would, you know,

00:56:47.840 | in lots of ways it would dial up more sort of sleepiness.

00:56:51.640 | It does the opposite.

00:56:53.240 | The way that caffeine works is that it comes in,

00:56:56.520 | competes with quite sharp elbows with adenosine,

00:57:00.660 | competitively forces them out of the way,

00:57:03.600 | hijacks that receptor by latching onto it,

00:57:07.100 | but then just essentially blocks it.

00:57:09.840 | It doesn't inactivate the receptor.

00:57:12.740 | It doesn't activate the receptor.

00:57:15.240 | It functionally inactivates it in the sense that it takes it

00:57:20.000 | out of the game for adenosine.

00:57:21.880 | So it's like someone, you know, coming into a room

00:57:25.400 | and you're just about to sit down on the chair

00:57:27.480 | and caffeine comes in and just pulls out the chair

00:57:29.320 | and you're like, well, now I've got nowhere to sit.

00:57:32.080 | And caffeine just keeps pulling out the chairs

00:57:34.240 | from adenosine and adenosine,

00:57:36.440 | even though it's at the same concentration in your brain,

00:57:40.500 | your brain doesn't know that you've been awake for,

00:57:44.420 | you know, 10 hours, 16 hours at that point

00:57:47.660 | when you've downed a cup of coffee,

00:57:50.040 | because all of that adenosine that's still there

00:57:54.080 | can't communicate to the brain that you've been awake

00:57:58.200 | for 16 hours because-

00:57:59.600 | - But the adenosine is still in brain-

00:58:01.120 | - Correct.

00:58:02.580 | - So the real question is what happens when caffeine

00:58:04.920 | is dislodged from the adenosine receptor?

00:58:07.260 | - Unfortunate things happen.

00:58:08.600 | And that's what we call the caffeine crash,

00:58:10.720 | which is caffeine has a half-life and it's metabolized.

00:58:15.360 | - Do you recall what the half-life is?

00:58:16.720 | - Yeah, the half-life is somewhere between five to six hours

00:58:20.400 | and the quarter-life therefore is somewhere

00:58:22.160 | between 10 to 12 hours.

00:58:24.180 | It's variable.

00:58:25.280 | Different people have different durations of its action,

00:58:29.800 | but for the average adult, five to six hours.

00:58:32.320 | That variation, we understand it's down to a liver enzyme

00:58:35.780 | or a set of liver enzymes of the class

00:58:38.200 | that we call the cytochrome P450 enzymes.

00:58:41.300 | And there are, I think last I delved into the data,

00:58:45.080 | which was pretty recently,

00:58:46.280 | there are two gene variants that will dictate

00:58:50.000 | the enzymatic speed with which the liver breaks down caffeine

00:58:55.000 | and that's why you can have some people

00:58:56.440 | who are very sensitive to caffeine

00:58:58.840 | and other people who say,

00:59:00.440 | I'm just doesn't affect me really that much at all.

00:59:03.000 | - These are the people that have a double espresso

00:59:04.520 | after a 9 p.m. dinner and can sleep just fine.

00:59:07.160 | - Well, and we'll come on to-

00:59:08.000 | - Or at least subjectively they think they're sleeping.

00:59:10.360 | - Yeah, and we should speak about that,

00:59:12.220 | that assumptive danger too.

00:59:14.800 | So then the caffeine is in the system

00:59:18.320 | and after some time period,

00:59:20.120 | it will be inactive in the system.

00:59:23.440 | So let's say that I've been awake for 12 hours now

00:59:27.200 | and it's 8 p.m. and I'm feeling a bit tired,

00:59:31.120 | but I want to push through

00:59:32.340 | and I want to keep working for another couple of hours.

00:59:34.980 | So I have a cup of coffee.

00:59:36.600 | All of a sudden I was feeling tired,

00:59:38.660 | but I don't feel like I've been awake for 12 hours anymore

00:59:41.780 | because with the caffeine in the system,

00:59:43.880 | maybe only half of that adenosine is being communicated

00:59:48.560 | through the receptor to my brain.

00:59:50.480 | 100% of the adenosine is still there,

00:59:53.080 | only half of it is allowed to communicate to my brain.

00:59:55.400 | So now I think, well, I haven't been awake for 12 hours,

00:59:57.680 | I've just been awake for six hours, I feel great.

01:00:00.360 | Then after a few hours

01:00:01.980 | and the caffeine is starting to come out of my system,

01:00:05.080 | not only am I hit with the same levels of adenosine

01:00:09.220 | that I had before I'd had the cup of coffee

01:00:11.960 | several hours ago,

01:00:13.280 | it's that plus all of the adenosine

01:00:16.200 | that's been building up during the time

01:00:18.720 | that the caffeine has been in my system.

01:00:20.640 | - So sort of an avalanche of adenosine.

01:00:23.520 | - It is a tsunami wave, yeah, and that's the caffeine crash.

01:00:25.920 | - And it's interesting because the caffeine crash

01:00:28.320 | at two o'clock in the afternoon

01:00:29.900 | when you have work to do is a terrible thing.

01:00:32.320 | But what about the person,

01:00:34.920 | maybe this person is me in my 20s,

01:00:37.160 | who says I'm going to drink caffeine all day long

01:00:40.880 | and then I want the crash because at nine or 10 PM,

01:00:44.480 | if I stopped drinking caffeine at say 6 PM and I crash,

01:00:48.800 | then I crash into a slumber, a deep night of sleep.

01:00:53.240 | Is that sleep really as deep as I think it is?

01:00:55.640 | Because given the half-life of caffeine

01:00:57.680 | that you mentioned a few moments ago,

01:01:00.440 | I have to imagine that having some of that caffeine

01:01:02.960 | circulating in my system might disrupt the depth of sleep

01:01:06.560 | or somehow the architecture of sleep in a way

01:01:09.220 | that even if I get eight or who knows,

01:01:11.840 | even 10 hours of sleep,

01:01:13.460 | it might not be as restorative as I would like it to be.

01:01:16.940 | - Yeah, and that is the danger.

01:01:19.040 | Just sort of those people that you described who say,

01:01:22.200 | and a lot of them will speak with me too,

01:01:24.800 | say, look, I can have two espressos with dinner

01:01:27.460 | and I fall asleep fine and I stay asleep

01:01:29.860 | because usually those are the two phenotypes

01:01:32.220 | that we typically see with too much caffeine.

01:01:34.460 | I just can't fall asleep as easily as I want to,

01:01:37.080 | or I fall asleep but I just can't stay asleep

01:01:39.540 | and caffeine can do both of those things quite potently.

01:01:42.180 | - How late in the day do you think is,

01:01:44.540 | assuming somebody, translate this folks,

01:01:46.660 | if you go to bed earlier or later,

01:01:48.060 | you have to shift the hours accordingly,

01:01:49.700 | but given somebody who typically gets into bed

01:01:52.960 | around 10, 10, 30 and falls asleep around 11, 11, 30,

01:01:57.480 | when would you recommend they halt caffeine intake?

01:02:02.660 | And these are not strict prescriptives

01:02:04.620 | but I think people do benefit

01:02:05.860 | from having some fairly clear guidelines

01:02:08.440 | of what might work for them.

01:02:10.980 | Would you say cut off caffeine by what time of the day?

01:02:15.020 | - I would usually say take your typical bedtime

01:02:17.820 | and count back sort of somewhere between 10 to eight hours

01:02:21.720 | is probably getting a little bit close,

01:02:23.360 | but take back sort of 10 hours or eight hours of time.

01:02:27.220 | That's the time when you should really stop using caffeine

01:02:31.500 | is the suggestion.

01:02:33.100 | And the reason is because for those people

01:02:34.780 | who even just keep drinking up until into the evening,

01:02:39.440 | you're right that they can fall asleep fine,

01:02:41.520 | maybe they stay asleep, but the depth of the deep sleep

01:02:44.360 | is not as deep anymore.

01:02:46.640 | And so there are two consequences.

01:02:49.000 | The first is that for me, and it can be up to by 30%,

01:02:53.160 | and for me to drop your deep sleep by 30%,

01:02:55.700 | I'd have to age you by between 10 to 12 years,

01:02:59.440 | or you can just do it every night to yourself

01:03:01.380 | with a couple of espressos.

01:03:03.560 | The second is that you then wake up the next morning

01:03:07.480 | and you think, well, I didn't have problems falling asleep

01:03:10.720 | and I didn't have problems staying asleep,

01:03:13.360 | but I don't feel particularly restored by my sleep.

01:03:15.860 | So now I'm reaching for three or four cups of coffee

01:03:18.680 | the next morning rather than just two or three cups

01:03:20.840 | of coffee, and so goes this dependency cycle

01:03:24.280 | that you then need your uppers to wake you up

01:03:26.880 | in the morning, and then sometimes people will use alcohol

01:03:30.380 | in the evening to bring them down

01:03:31.960 | because they're overly caffeinated,

01:03:34.320 | and alcohol, and we can speak about that too,

01:03:36.160 | also has very deleterious impacts on your sleep as well.

01:03:39.760 | So you're right that it's not just the quantity

01:03:44.000 | of your sleep or even difficulties falling

01:03:46.320 | or staying asleep, it can also be deep sleep.

01:03:49.320 | But here again, I think, I don't want

01:03:51.840 | to be frightening people, and I mentioned this before,

01:03:54.140 | I think one of the real problems or mistakes that I made,

01:03:58.000 | 'cause I didn't, I'd never had much public exposure

01:04:00.920 | before the book, and I was so saddened

01:04:05.440 | by the disease and the suffering that I was seeing

01:04:08.980 | as a consequence of a lack of sleep in our society,

01:04:12.640 | and the fact that it wasn't really being discussed

01:04:14.800 | very much, I sort of came out a little bit headstrong,

01:04:18.980 | more than a little bit headstrong,

01:04:20.920 | and I think I was perhaps too much gas pedal

01:04:25.920 | and too little break as it were,

01:04:30.280 | and I don't think that's the right way

01:04:33.240 | to approach health message within the public sphere,

01:04:38.120 | and I've become much softer

01:04:40.760 | in how I think about these things.

01:04:43.380 | I have ideas about what the ideal world looks like for sleep,

01:04:47.560 | but I also realized that none of us live

01:04:49.500 | in this thing called the ideal world.

01:04:51.680 | - We certainly don't.

01:04:52.520 | - So I want to be really mindful of that,

01:04:55.260 | and I think I've done a really bad job

01:04:57.000 | of being sort of too forthright,

01:04:58.840 | particularly for people who struggle with sleep.

01:05:01.560 | Early on when I would offer these messages about sleep,

01:05:06.160 | I want to be veritical when it comes to the science.

01:05:10.860 | I want to be faithful to the science,

01:05:13.080 | but I also don't want to go out

01:05:14.560 | and scare the living daylight out of people,

01:05:16.420 | particularly people who are struggling with their sleep,

01:05:19.040 | 'cause it's probably only gonna make matters worse,

01:05:21.560 | so I've been beautifully schooled

01:05:23.760 | by learning how to be a slightly better public communicator.

01:05:27.960 | I'm nowhere near of the standing that you are.

01:05:30.360 | You're very elegant, and it's very intuitive to you.

01:05:32.960 | I'm still with training wheels,

01:05:34.800 | but I'm getting a little bit better,

01:05:36.360 | but I just want to say that

01:05:37.960 | when I'm speaking about caffeine,

01:05:39.160 | 'cause it sounds as though I'm very sort of overt about it,

01:05:42.940 | but I will come back to why I say drink coffee,

01:05:46.580 | but I just want to make that point.

01:05:48.000 | - Yeah, well, I appreciate you making that point,

01:05:49.520 | and I'm sure our listeners will too.

01:05:52.040 | I still will stand behind my statement,

01:05:56.580 | which is that what you've done for the notion

01:05:59.440 | that sleep is vital for all aspects of health

01:06:02.880 | and for performance, mental, and physical, and wakefulness,

01:06:06.160 | the message and the packaging it was contained in

01:06:09.120 | and has been clearly, clearly net positive.

01:06:13.300 | People needed to be cued to this.

01:06:15.520 | The I'll sleep when I'm dead mentality is one that I had.

01:06:18.320 | It's one that other people have.

01:06:20.140 | People in a huge number of vital communities,

01:06:22.320 | not just your students, but also people.

01:06:26.460 | The messaging that you provided and continue to provide

01:06:29.300 | has positively impacted the first responder community,

01:06:33.540 | the medical community.

01:06:34.520 | There's still steps that need to be taken,

01:06:36.040 | the military community,

01:06:38.060 | and of course the civilian community.

01:06:40.200 | And so I think these adjustments about,

01:06:42.380 | yeah, caffeine's okay,

01:06:43.460 | just restrict it to the early part of the day

01:06:45.440 | if you can most days.

01:06:47.060 | I mean, I think the law of averages,

01:06:48.620 | it's like the light viewing behavior.

01:06:50.380 | I think it is critical to view sunlight or natural,

01:06:53.940 | some other form of bright light early in the day.

01:06:56.060 | But if you miss a day,

01:06:57.240 | it's not that your whole system is going to dissolve

01:06:59.220 | into a puddle of tears.

01:07:00.540 | That'll happen on the second or the third day.

01:07:02.760 | No, I'm kidding.

01:07:03.600 | You got a couple of days.

01:07:04.420 | Biology works in averages except with respect

01:07:08.080 | to accident or injury.

01:07:09.580 | A car accident is a car accident, right?

01:07:11.460 | You don't get to have three of those

01:07:13.200 | before the brain damage occurs

01:07:14.940 | if the accident is severe enough.

01:07:16.900 | But with sleep behavior,

01:07:18.100 | these homeostatic type behaviors,

01:07:20.580 | or with food, one chocolate sundae,

01:07:22.660 | is it going to kill you?

01:07:23.500 | No.

01:07:24.320 | Every night, yeah.

01:07:25.220 | It's going to make you demented and kill you early.

01:07:27.620 | We know this.

01:07:28.460 | And so I think the middle ground

01:07:30.680 | is often a hard place to achieve.

01:07:33.180 | So I think you've done a phenomenal job,

01:07:34.780 | but I appreciate you raising these points.

01:07:36.860 | And I think it's clear that we all need to,

01:07:41.860 | that we all can and should do certain things better,

01:07:45.020 | including being gentle with ourselves from time to time

01:07:48.280 | when we deviate from these ideal circumstances.

01:07:52.620 | Along these lines, I do want to talk about alcohol

01:07:55.500 | because I think caffeine and alcohol represent

01:07:57.580 | the kind of two opposite ends of the spectrum.

01:08:00.060 | Clearly there are other stimulants.

01:08:02.260 | There are your Adderalls and your high energy drinks

01:08:05.500 | that people use.

01:08:06.420 | But alcohol and caffeine are the most commonly consumed.

01:08:10.180 | A stimulant and sedatives, depressants,

01:08:12.320 | as they're sometimes called.

01:08:13.980 | So what happens when somebody has a glass,

01:08:18.980 | we always hear a glass or two of wine in the evening

01:08:22.620 | or a cocktail after dinner or before dinner,

01:08:27.620 | how does that impact their sleep?

01:08:29.820 | And then we'll be sure to circle back

01:08:32.900 | in terms of what is reasonable ranges of behavior

01:08:35.960 | when it comes to avoiding alcohol

01:08:38.940 | or if it's age appropriate, et cetera, enjoying alcohol.

01:08:42.900 | - Yeah.

01:08:43.740 | So alcohol, if we're thinking about classes of drugs,

01:08:46.980 | they're in a class of drugs that we call the sedatives.

01:08:50.180 | And I think one of the first problems that people

01:08:52.760 | often mistake, alcohol is often used as a sleep aid

01:08:57.760 | for people who are struggling with sleep

01:08:59.580 | when things like over the counter remedies, et cetera,

01:09:02.900 | or herbal remedies have just not worked out for them.

01:09:05.900 | And alcohol unfortunately is anything but a sleep aid.

01:09:09.540 | The first reason that most people use it

01:09:11.520 | is to try and help them fall asleep.

01:09:14.260 | - And this process of this event that we call falling asleep,

01:09:18.020 | I have to imagine is a process.

01:09:19.700 | - It is a process.

01:09:20.540 | - Like everything in biology.

01:09:21.500 | And that that process involves in some way,

01:09:24.820 | as we talked about pushable before,

01:09:26.140 | turning off thinking, planning, et cetera,

01:09:29.580 | and turning on some sort of relaxation mechanism.

01:09:32.820 | I have to imagine that these two things

01:09:34.180 | are knobs turning in opposite directions

01:09:35.980 | that gives us this outcome we call falling asleep.

01:09:39.160 | Alcohol, it seems is helpful for some people

01:09:41.940 | to turn off their thoughts or their planning.

01:09:45.260 | Is that right?

01:09:46.580 | - Yes, it is.

01:09:47.520 | And so I think, if we look at the pattern of brain activity,

01:09:50.920 | if I were to place you inside an MRI scanner

01:09:53.280 | where we're looking at the activity of your brain

01:09:55.560 | and watch you drifting off,

01:09:57.160 | some parts of your brain will become less active,

01:10:00.160 | other parts will become more active.

01:10:02.000 | And this is the push-pull model, it's inhibition excitation.

01:10:06.960 | But alcohol is quite different in that regard.

01:10:09.760 | Alcohol is because it's a sedative.

01:10:12.420 | What it's really doing is trying to essentially

01:10:15.100 | knock out your cortex.

01:10:16.760 | It's sedating your cortex.

01:10:20.020 | And sedation is not sleep.

01:10:22.160 | But when we have a couple of drinks in the evening,

01:10:24.100 | when we have a couple of night caps,

01:10:25.740 | we mistake sedation for sleep saying,

01:10:28.240 | well, I always, when I have a couple of whiskeys

01:10:31.100 | or a couple of cocktails,

01:10:32.440 | it always helps me fall asleep faster.

01:10:35.220 | In truth, what's happening is that

01:10:36.640 | you're losing consciousness quicker,

01:10:38.900 | but you're not necessarily falling

01:10:41.360 | naturalistically asleep any quicker.

01:10:44.060 | So that's one of the first sort of things

01:10:46.320 | just to keep in mind.

01:10:47.740 | The second thing with alcohol

01:10:49.240 | is that it fragments your sleep.

01:10:51.160 | And we spoke about the quality of your sleep

01:10:53.160 | being just as important as the quantity.

01:10:56.360 | And alcohol through a variety of mechanisms,

01:10:59.080 | some of which are activation

01:11:01.320 | of that autonomic nervous system,

01:11:03.160 | that fight or flight branch of the nervous system,

01:11:06.520 | alcohol will actually have you waking up

01:11:09.140 | many more times throughout the night.

01:11:11.220 | So your sleep is far less continuous.

01:11:14.360 | Now, some of those awakenings will be

01:11:16.800 | of conscious recollection the next day.

01:11:19.020 | You'll just remember waking up.

01:11:20.680 | Many of them won't be.

01:11:22.640 | And so, but yet your sleep will be littered

01:11:25.780 | with these sort of punctured awakenings

01:11:28.720 | throughout the night.

01:11:29.560 | And again, when you wake up the next morning,

01:11:31.920 | you don't feel restored by your sleep.

01:11:35.200 | Fragmented sleep or non-continuous sleep

01:11:38.080 | in this alcohol induced way

01:11:40.480 | is usually not good quality sleep

01:11:42.500 | that you feel great on the next day.

01:11:45.120 | The third part of alcohol in terms of an equation

01:11:48.960 | is that it's quite potent at blocking your REM sleep,

01:11:52.040 | your rapid eye movement sleep.

01:11:53.980 | And REM sleep is critical

01:11:55.500 | for a variety of cognitive functions,

01:11:57.900 | some aspects of learning and memory,

01:11:59.780 | seems to be critical for aspects

01:12:01.360 | of emotional and mental health.

01:12:03.180 | - You've described it before

01:12:04.240 | as a sort of self-generated therapy

01:12:06.840 | that occurs while we sleep.

01:12:08.240 | - Yeah, it's overnight therapy.

01:12:10.240 | It's emotional first aid.

01:12:12.440 | - Well, certainly people that don't get enough sleep

01:12:14.780 | are very easy to derail emotionally.

01:12:17.480 | Not that one would want to do that to people,

01:12:19.100 | but we all sort of fall apart emotionally.

01:12:23.200 | I always think of it as almost like our skin sensitivity

01:12:26.020 | can be heightened when we are sleep deprived.

01:12:29.080 | Our emotional sensitivity

01:12:31.720 | is such that when we're sleep deprived,

01:12:34.880 | such that it takes a much finer grain of sandpaper

01:12:39.300 | to create that kind of friction.

01:12:41.320 | Things bother us.

01:12:42.760 | - Threshold to trigger? - Even online comments

01:12:45.280 | bother us when we're sleep deprived.

01:12:47.280 | And never when we're well rested.

01:12:49.120 | - I would love to say that I never look at them,

01:12:51.120 | except I look at maybe every one of them.

01:12:54.840 | - Here I will editorialize,

01:12:56.000 | because the notion of not looking at comments

01:12:58.300 | is unreasonable to ask of any academic,

01:13:02.780 | because academics,

01:13:04.520 | we are all trained to look at our teaching evaluations.

01:13:07.760 | And just like with online comments,

01:13:09.520 | to ignore 20% of them.

01:13:11.400 | No, I'm kidding.

01:13:12.360 | We look at them all.

01:13:13.360 | In any event, so in terms of translating this to behavior,

01:13:17.200 | I'm not, I don't particularly enjoy alcohol.

01:13:19.360 | I guess I might be fortunate in that sense,

01:13:21.420 | but I also have never really experienced

01:13:23.260 | the pleasure of drinking alcohol.

01:13:25.920 | I sometimes like the taste of a drink,

01:13:27.920 | but I never liked the sensation.

01:13:29.440 | So that's, I don't have a lot of familiarity with this,

01:13:32.360 | but many people do, and I understand that.

01:13:34.600 | So let's say somebody enjoys a glass of wine or two

01:13:39.600 | with dinner, and they eat dinner at 7 p.m.

01:13:43.280 | Is that likely to disrupt their sleep at all?

01:13:46.800 | Let's just sort of, let's make this a series of gradations.

01:13:49.600 | - Yeah, and the answer is yes.

01:13:52.640 | I think once they just looked at a single glass of wine

01:13:56.320 | in the evening with dinner,

01:13:57.920 | and I would be untruthful if I didn't just simply say

01:14:02.640 | it has an effect, and we can measure that

01:14:06.360 | in terms of the actual-- - Less REM sleep.

01:14:07.740 | - Less REM sleep, and one of the fascinating studies,

01:14:10.680 | I can't remember what dose,

01:14:12.040 | I think they got them close to a standard

01:14:15.280 | illegal blood alcohol level.

01:14:17.600 | So maybe they were a little bit tipsy,

01:14:20.040 | and yes, you see all of the changes that we just described.

01:14:24.060 | They sort of lose consciousness more quickly.

01:14:26.200 | They have fragmented sleep,

01:14:27.560 | and they have a significant reduction in REM sleep.

01:14:30.000 | But what was also interesting,

01:14:31.160 | because REM sleep, as we spoke about before,

01:14:33.360 | is a time when some hormonal systems

01:14:36.280 | are essentially recharged and refreshed,

01:14:38.760 | growth hormone being one of them,

01:14:40.600 | there was well over a 50%, five-zero drop

01:14:44.540 | in their growth hormone release

01:14:46.600 | during alcohol-laced sleep at night.

01:14:49.760 | - Wow, and growth hormone is so vital

01:14:51.580 | for metabolism and repair of tissues,

01:14:54.120 | and keeping body fat low. - It's not just for kids.

01:14:56.800 | This is essentially adults. - It's essential, essential.

01:14:59.940 | Along those lines, I just want to highlight the fact

01:15:02.440 | that this information that you're sharing,

01:15:06.040 | that growth hormone is released as strongly tethered

01:15:09.640 | to the presence of healthy amounts of REM sleep,

01:15:13.360 | is interesting to me because I always thought

01:15:15.680 | that growth hormone was released

01:15:17.000 | in the early part of the night.

01:15:18.440 | - Well, it is released across both of those,

01:15:21.440 | but across the different stages.

01:15:23.720 | But what we also know is that when you disrupt REM sleep,

01:15:26.440 | there are those growth hormone consequences.

01:15:29.320 | So it's not an exclusive system.

01:15:32.080 | Just like with testosterone,

01:15:33.820 | we can see changes throughout non-REM sleep,

01:15:36.480 | but if you ask when are the peak release rates

01:15:39.580 | of testosterone, it's right before we go into REM sleep

01:15:42.720 | and then during REM sleep.

01:15:44.360 | - And of course, testosterone being important

01:15:46.500 | both for males and for females, right?

01:15:48.840 | For libido and tissue repair and wellbeing.

01:15:51.460 | Nobody, regardless of chromosomal, hormonal,

01:15:54.880 | or any other background,

01:15:56.360 | wants to have their normal levels of testosterone

01:15:59.480 | reduced acutely.

01:16:00.880 | That's just a bad,

01:16:01.920 | it equates to a terrible set of psychological

01:16:04.840 | and physical symptoms.

01:16:05.680 | - Yeah, and the mortality risk that's associated

01:16:08.000 | with low testosterone is non-trivial.

01:16:09.920 | - Prostate cancer.

01:16:10.760 | - Right, exactly.

01:16:12.000 | So coming back to just the point on REM sleep

01:16:16.780 | that you mentioned regarding emotional instability,

01:16:19.760 | and we see that that's one of the things,

01:16:21.520 | one of the most reliable signatures

01:16:23.120 | of just insufficient sleep,

01:16:24.580 | it doesn't have to be sleep deprivation.

01:16:26.740 | What we've discovered over the past 20 years

01:16:29.680 | here at the Sleep Center is that

01:16:31.760 | there is no major psychiatric disorder that we can find

01:16:36.240 | in which sleep is normal.

01:16:38.400 | And so I think that firstly told us

01:16:40.240 | there is a very intimate association

01:16:42.140 | between your emotional mental health and your sleep health.

01:16:45.700 | But when it also comes to REM sleep,

01:16:49.940 | I think what's fascinating is that

01:16:52.580 | it's not just about your emotional health.

01:16:54.560 | It's not just about your hormonal health.

01:16:57.560 | We've also been seeing other aspects of cognition,

01:17:01.760 | but then there was a report,

01:17:03.940 | I think it could have been about two years ago,

01:17:06.820 | out of Harvard.

01:17:08.240 | I think it was Beth Clearman's group.

01:17:10.460 | They found that,

01:17:13.400 | and they replicated it in two different large populations.

01:17:16.640 | If you look at the contribution of different sleep stages

01:17:20.240 | to your lifespan,

01:17:22.320 | REM sleep was the strongest predictor of your longevity.

01:17:27.320 | And it was a linear relationship.

01:17:29.520 | It wasn't sort of one of these U-shape or J-shaped curves

01:17:32.800 | that we often see with total sleep and mortality risk.

01:17:36.460 | It really was linear,

01:17:38.000 | that the less and less REM sleep that you were getting,

01:17:40.420 | the higher and higher your probability of death.

01:17:44.120 | And then they did--

01:17:44.960 | - Was that death due to natural causes or accident?

01:17:47.920 | 'Cause I could imagine if you're not getting enough REM sleep

01:17:49.960 | you're more likely to drive off the freeway,

01:17:51.800 | step off a cliff.

01:17:52.640 | - Yeah, I think it was all cause and effect.

01:17:53.480 | - Or just make bad decisions about anything,

01:17:55.380 | and love relationships,

01:17:57.000 | which can also be life threatening.

01:17:58.560 | - Yeah, I've tried to lean into that

01:18:00.160 | and claim that with those bad relationship situations,

01:18:03.080 | oh, I just didn't have enough REM sleep last night,

01:18:05.240 | my darling.

01:18:06.080 | - The REM sleep defense.

01:18:07.220 | - But she's far wiser than I thought.

01:18:10.860 | So they did this great machine learning analysis,

01:18:15.760 | and I may get these numbers backwards,

01:18:18.600 | but I think for every 5% reduction in REM sleep,

01:18:23.600 | there was a 13% associated increased risk of mortality.

01:18:28.720 | And I could have, I'll have to go back and check.

01:18:31.980 | But to me, in the machine learning algorithm,

01:18:36.120 | what they ultimately spat out

01:18:38.040 | was that of all of the sleep stages,

01:18:40.120 | REM sleep is the most predictive of your longevity,

01:18:43.360 | of your lifespan.

01:18:44.820 | So we often, I hear people saying,

01:18:46.840 | how can I get more deep sleep?

01:18:49.160 | Or they sometimes say, how can I get more dream sleep?

01:18:51.840 | And my answer is a question.

01:18:54.880 | Why do you want to get more of that?

01:18:56.680 | And they'll say, well, isn't that the good stuff?

01:18:58.920 | And I'll say, well, actually all stages of sleep.

01:19:00.800 | - It's all the good stuff.

01:19:02.640 | Well, it's like the exercise question.

01:19:04.200 | And it took decades for people to understand

01:19:07.500 | that moving around at, for about 150,

01:19:12.240 | probably 180 minutes a week

01:19:14.320 | at doing endurance type work, zone two cardio type work,

01:19:18.060 | it is correlated with living longer,

01:19:20.560 | feeling better, less diabetes, et cetera.

01:19:22.360 | There's really no way around it.

01:19:24.200 | I mean, you can ingest metformin until the cows come home.

01:19:29.200 | You can take NMN,

01:19:31.140 | all of which I think have their place in certain contexts.

01:19:34.440 | I'm a big fan of the work surrounding all those protocols,

01:19:37.480 | but without getting proper amounts of movement,

01:19:41.480 | meaning sufficient numbers.

01:19:43.120 | So it doesn't matter how many 12 minute exercise regimes

01:19:46.140 | you follow per week, you need that threshold level.

01:19:49.960 | And it sounds like the same is true of REM sleep

01:19:53.000 | and total amount of sleep.

01:19:54.440 | There's just, you pay the piper somehow.

01:19:58.160 | - Yeah, the return on investment, I mean, to flip the coin,

01:20:01.040 | the return on investment is astronomical.

01:20:04.440 | I think of sleep, it is the tide that moves,

01:20:08.440 | that raises all of those health boats.

01:20:10.920 | And the most fundamental layer of mental and physical health.

01:20:14.000 | Whenever people ask me, even though I'm not a physician,

01:20:16.480 | they'll ask me, what should I take or what should I do?

01:20:19.680 | The first question is always, how's your sleep?

01:20:22.000 | Meaning, how well do you sleep every night

01:20:23.720 | and how long you sleep?

01:20:25.240 | I always recommend your book.

01:20:26.820 | I always recommend the podcast

01:20:29.520 | you've been a guest on, et cetera.

01:20:32.220 | Who knows, maybe you'll even release your own podcast

01:20:36.560 | at some point soon and keep,

01:20:37.920 | because I do think people need to hear from you more often.

01:20:40.520 | One thing, I don't want to return to the notion

01:20:43.600 | of public health discourse too much,

01:20:46.040 | but I do want to say one issue with books in general

01:20:49.200 | is that they can be revised,

01:20:51.800 | but it's more or less a one and done kind of thing

01:20:54.200 | until the next book comes out.

01:20:55.700 | One thing that I like about the podcast format

01:20:58.240 | is that updates can be provided regularly,

01:21:00.360 | corrections and updates as new data come out.

01:21:03.400 | And so that's a wonderful aspect to this format

01:21:06.680 | and hopefully the format that you'll be embracing.

01:21:09.800 | I think the world needs to hear more from you more often

01:21:13.360 | about sleep and its various contours, not less.

01:21:17.480 | And so I do have a question about drinking alcohol,

01:21:22.480 | not that we want to promote day drinking,

01:21:24.640 | but let's say that the one or two glasses of wine

01:21:29.040 | or a cocktail is consumed with lunch,

01:21:31.360 | something that isn't traditionally done nowadays,

01:21:33.760 | or in a late afternoon happy hour cocktail,

01:21:37.600 | and then one is going to sleep seven or eight hours later.

01:21:40.480 | Do you think that that will improve

01:21:43.740 | or somehow mitigate the effects of alcohol?

01:21:46.120 | Or if you have a drink,

01:21:48.000 | are you basically screwed for the next 24 hours?

01:21:51.080 | - No, I think there's going to be a time window dependency.

01:21:56.080 | Now, I don't know of anyone who's essentially done

01:21:59.200 | what you and I would like,

01:22:00.400 | which is the time separation dose dependent curve

01:22:04.720 | where, okay, you drink at 10 a.m.,

01:22:07.200 | then, or 11, 12, one, two, three, four, five,

01:22:10.000 | all the way up to 10 p.m.,

01:22:12.460 | and estimate what is the blast radius,

01:22:15.580 | and is it linear or is it non-linear?

01:22:18.280 | Is it such that only when you drink in the last four hours,

01:22:22.200 | do you just hit this exponential and it's bad, bad, bad,

01:22:25.600 | or is there some other curve that we could imagine?

01:22:28.840 | There would be many possibilities.

01:22:31.360 | But certainly what we know is that the less alcohol

01:22:34.600 | and the less, and more specifically the metabolic byproducts,

01:22:37.680 | aldehydes and ketones,

01:22:39.280 | they're the sort of the nefarious players here.

01:22:41.560 | - And not the ketones that people are all excited about.

01:22:44.480 | The other ketones, the chemists know

01:22:47.180 | what we're referring to.

01:22:48.020 | - Yeah, this is not about ketogenesis.

01:22:49.160 | - This is not about ketogenesis.

01:22:50.360 | There are ketone bodies that are released

01:22:53.960 | after ingesting alcohol that are not of the positive sort

01:22:58.040 | that a ketogenic diet might promote.

01:23:00.160 | - Right, so I think in terms of that alcohol,

01:23:04.600 | profile, we certainly know that,

01:23:07.520 | as you're heading into the evening hours,

01:23:10.200 | once again, timing and dose make the poison.

01:23:13.260 | But I think it's also important once again,

01:23:16.960 | from that public message standpoint, and thank you,

01:23:19.280 | I think I am leaning into the sort of the podcast

01:23:23.040 | consideration arena at some point,

01:23:25.040 | but I don't want to be puritanical here.

01:23:28.720 | I'm just a scientist,

01:23:30.560 | and I'm not here to tell anyone how to live.

01:23:33.080 | All I'm trying to do is empower people

01:23:35.840 | with some of the scientific literature regarding sleep,

01:23:39.660 | and then you can make whatever informed choices

01:23:42.500 | that you want.

01:23:43.340 | Now, unlike you, it turns out I'm not a big drinker.

01:23:46.360 | It's just because I've never liked the taste.

01:23:48.720 | And I'm surprised that they haven't taken away

01:23:50.980 | my British passport because I don't like lager or beer.

01:23:54.160 | But I also want to say that life is to be lived

01:23:59.080 | to a certain degree.

01:24:00.480 | It's all about checks and balances.

01:24:02.600 | So if I go out and I have an ice cream sundae,

01:24:06.600 | I'm not big on those either, but sure,

01:24:09.520 | I know that my blood glucose is not gonna be ideal

01:24:13.340 | for another 12 hours maybe.

01:24:16.160 | That's just the price you pay for having

01:24:18.440 | some kind of relaxed, fun life.

01:24:20.820 | I don't want to look back on life and think,

01:24:23.960 | gosh, I lived until I was 111,

01:24:28.240 | and it was utterly miserable.

01:24:32.100 | But it's all about some kind of a balance.

01:24:34.620 | My job is not to tell people a prescription for life.

01:24:39.820 | It's just to offer some scientific information.

01:24:42.260 | - Oh, I think you're doing a terrific job of that.

01:24:44.440 | People are, I always say we have all these neural circuits,

01:24:47.100 | and if it's working properly, we all have a circuit

01:24:50.320 | that allows us to skip over information as we wish, right?

01:24:53.960 | If the circuits between your brain and your thumbs

01:24:56.540 | are working, you can slide right along.

01:24:58.880 | You can drop to the next content however you like.

01:25:01.820 | I would like to ask about marijuana and CBD.

01:25:06.640 | This is a discussion that I think five years ago

01:25:08.580 | would have ventured into the realm of illegal,

01:25:10.520 | but now in many places, not all,

01:25:13.840 | medical marijuana is approved or is legal,

01:25:16.340 | and certainly it's in widespread use.

01:25:20.560 | Certainly not recommending people do it.

01:25:22.160 | I have my own thoughts about marijuana, CBD.

01:25:24.400 | I've been fortunate, I suppose,

01:25:26.480 | that I don't particularly like marijuana or CBD.

01:25:29.400 | I don't even know if I've ever tried CBD.

01:25:32.320 | First of all, does marijuana disrupt the depth of sleep,

01:25:37.320 | the architecture of sleep?

01:25:40.140 | And if so, as with alcohol and caffeine,

01:25:44.060 | does when you ingest it or when it's in your bloodstream,

01:25:48.580 | does relative to when you go to sleep,

01:25:50.740 | does that play an important role?

01:25:52.260 | So does marijuana disrupt sleep?

01:25:55.240 | - Yeah, it does.

01:25:56.860 | And there's a pretty good amount of data on,

01:26:00.360 | so we can break sort of cannabis down

01:26:03.000 | into two of its key ingredients.

01:26:05.640 | We've got THC, tetrahydrocannabinol, and we've got CBD.

01:26:10.480 | And CBD is sort of the less,

01:26:14.600 | what we think of as the non-psychoactive component.

01:26:17.640 | In other words, when you take CBD, you don't get high.

01:26:21.120 | If you take THC, you can get high.

01:26:24.040 | That's the psychoactive part of the equation.

01:26:27.020 | - Are both considered sedatives in the technical sense?

01:26:30.380 | - No, they're not.

01:26:32.660 | Neither of them have that class right now.

01:26:36.900 | THC can, seems to speed up the time

01:26:41.900 | with which you fall asleep.

01:26:44.260 | But again, if you look at the electrical brainwave signature

01:26:48.140 | of your falling asleep with and without that THC,

01:26:51.540 | it's not going to be an ideal fit.

01:26:54.000 | So you could argue it's non-natural,

01:26:56.460 | but many people use THC for that fact

01:26:58.920 | because they find it difficult to fall asleep.

01:27:01.600 | And it can speed the onset of at least non-consciousness,

01:27:05.440 | I guess is the best way of describing it.

01:27:07.520 | But there are problems with THC and there are twofold.

01:27:11.880 | The first is that it too, but through different mechanisms

01:27:15.080 | seems to block REM sleep.

01:27:16.920 | And that's why a lot of people when they're using

01:27:18.900 | will tell me, look, I definitely, I was dreaming,

01:27:22.380 | I don't remember many of my dreams.

01:27:24.660 | And then when they stop using THC,

01:27:28.100 | they'll say I was having just crazy, crazy dreams.

01:27:31.860 | And the reason is because there is a rebound mechanism.

01:27:35.340 | REM sleep is very clever and alcohol is the same way

01:27:38.460 | in this sense, it's the same homeostatic mechanism.

01:27:40.980 | Some people will tell me, look,

01:27:42.620 | if I have a bit of a wild Friday night with some alcohol,

01:27:46.460 | maybe I'll sleep late into the next morning.

01:27:48.780 | And I'll just have these really intense dreams.

01:27:52.100 | So, and I thought I wasn't having any REM sleep.

01:27:54.800 | Well, the way it works is that it's during

01:27:56.740 | in the middle of the night, really,

01:27:59.040 | when alcohol blocks your REM sleep and your brain is smart.

01:28:03.900 | It understands how much REM sleep you should have had,

01:28:06.900 | how much REM sleep you have not

01:28:08.660 | because the alcohol has been in the system.

01:28:10.580 | And finally, in those early morning hours,

01:28:12.760 | when you're getting through to sort of six, seven, 8 AM,

01:28:16.180 | all of a sudden your brain not only goes back

01:28:18.460 | to having the same amount of REM it would have had,

01:28:21.220 | it does that plus it tries to get back

01:28:23.860 | all of the REM sleep that it's lost.

01:28:25.780 | Does it get back all of the REM sleep?

01:28:27.560 | No, it doesn't.

01:28:28.520 | It never gets back all of the REM sleep, but it tries.

01:28:31.740 | And so you have these really intense periods of REM sleep.

01:28:34.740 | Hence, you have really intense, bizarre dreams.

01:28:38.100 | And that's what happens also with THC.

01:28:40.540 | You build up this pressure for REM sleep,

01:28:44.020 | this debt for REM sleep.

01:28:45.900 | Will you ever pay it back?

01:28:48.180 | Doesn't seem as though you get back everything that you lost,

01:28:51.260 | but will you get back some of it?

01:28:52.820 | Yes, the brain will start to devour more

01:28:55.240 | because it's been starved of REM sleep for so long.

01:28:59.500 | But one of the bigger problems with THC that we worry about

01:29:03.500 | is withdrawal dependency.

01:29:05.820 | So as you start to use THC for sleep,

01:29:09.140 | there can be a dependency tolerance.

01:29:12.880 | So you start to need more to get the same sleep benefit.

01:29:16.780 | And when you stop using,

01:29:18.300 | you usually get a very severe rebound insomnia.

01:29:21.740 | And in fact, it's so potent

01:29:23.300 | that it's typically part of the clinical withdrawal profile

01:29:27.740 | from THC, from cannabis.

01:29:30.620 | - And there's anxiety withdrawal.

01:29:32.340 | I don't ask anybody to change their behavior.

01:29:38.380 | We just, as you said,

01:29:39.560 | we try and inform people about what the science says

01:29:41.620 | and let them make choices for themselves.

01:29:43.600 | People who are regular pot smokers,

01:29:46.700 | many will insist they're not addicted.

01:29:48.900 | And maybe indeed they don't actually follow the profile

01:29:52.660 | of classical addiction.

01:29:53.820 | I don't know, I'm guessing some do, some don't.

01:29:56.200 | But if you ask them,

01:29:58.260 | well, what if I took away all marijuana consumption

01:30:01.700 | for, I don't know, two weeks?

01:30:04.480 | That thought scares many of them.

01:30:06.980 | And many of them will experience intense anxiety

01:30:10.260 | without marijuana, which speaks to perhaps not addiction,

01:30:13.140 | but a certain kind of dependency.

01:30:15.380 | And again, I know many pot smokers,

01:30:18.020 | some of whom have jobs that are quite high performing

01:30:21.340 | and they manage.

01:30:22.820 | - Here in Berkeley, I don't know any of those.

01:30:24.420 | - Yeah, none of those, right.

01:30:25.820 | What about CBD?

01:30:28.500 | I mean, we hear so much about CBD.

01:30:30.020 | I've been a little concerned about the fact

01:30:31.560 | that the analysis of a lot of CBD supplements out there

01:30:34.800 | has confirmed that much like with melatonin,

01:30:37.420 | the levels that are reported on the labels

01:30:40.220 | in no way, shape or form match the levels

01:30:43.460 | that are actually contained in the various supplements.

01:30:45.540 | Sometimes the levels are much higher

01:30:47.640 | than they're reported on the labels.

01:30:49.620 | Other times it's much lower.

01:30:51.300 | What is ingesting CBD do to the architecture

01:30:56.220 | and quality of sleep?

01:30:58.280 | - Right now, I don't think we have enough data

01:31:00.980 | to make some kind of meaningful sense out of it.

01:31:05.220 | I think the picture that is emerging, however,

01:31:07.780 | is probably the following.

01:31:09.740 | Firstly, CBD does not seem to be detrimental

01:31:13.840 | in the same ways that THC is.

01:31:16.220 | So we can start by saying,

01:31:18.340 | does it create potential problems?

01:31:22.340 | Not of the nature necessarily that we see with THC,

01:31:26.900 | but the devil is a little bit in the details

01:31:29.840 | from the data that we do have

01:31:31.260 | and it comes onto your valid point of purity.

01:31:33.820 | At low dose, CBD can seem to be wake promoting

01:31:40.140 | so in low doses, let's say sort of five or 10 milligrams,

01:31:43.460 | I'm trying to remember some of the studies

01:31:44.880 | off the top of my head,

01:31:46.640 | there it actually may enhance wakefulness

01:31:49.560 | and cause problems with sleep.

01:31:51.960 | It's only once you get into the higher dose range

01:31:54.600 | that there seem to have been some increases in sleepiness

01:31:59.600 | or sort of sedation like increases.

01:32:03.800 | And that's usually, I think above about 25 milligrams

01:32:08.160 | as best I can recall from the data.

01:32:10.560 | And then when we look in animal models,

01:32:13.840 | you typically see the same type of profile too.

01:32:17.880 | So then the question becomes,

01:32:20.160 | and now again, you just don't know about purity,

01:32:23.860 | it's very difficult.

01:32:25.440 | Although I think, and again, I'm not a user,

01:32:28.520 | not necessarily because I have anything against it,

01:32:31.520 | it's just that's not necessarily my cup of tea.

01:32:35.480 | There are some firms that are now doing third party

01:32:38.900 | independent laboratory tests.

01:32:41.140 | I don't know how gamed that is so I've got no sense of it.

01:32:44.480 | - I think some supplement companies are quite honest

01:32:47.160 | and accurate about the amounts of various substances

01:32:49.740 | that are in other products and some are not.

01:32:53.200 | - Yeah.

01:32:54.040 | - And I think there's just a huge range.

01:32:55.540 | I think the FDA is starting to explore CBD.

01:32:58.360 | There are, certainly I saw some grant announcements

01:33:01.280 | to explore the function of CBD.

01:33:03.260 | Most of the work on CBD is being done by the general public

01:33:05.940 | ingesting it and seeing how they feel.

01:33:07.660 | I gave it to my dog who was,

01:33:09.140 | had some dementia related sleep disturbances

01:33:11.980 | and it actually created a heightened wakefulness.

01:33:14.740 | It completely screwed up his sleep.

01:33:16.220 | - It sounds as though it just wasn't.

01:33:17.060 | - He's a bulldog so if he's going to get access to sleep,

01:33:19.220 | he's going to take it.

01:33:20.220 | - Okay.

01:33:21.140 | - Really messed him up, took it away, he did better.

01:33:24.440 | But that's a canine so.

01:33:27.660 | - Right, and it could have been sort of dose related too.

01:33:30.700 | - Or binders or other things that are in there.

01:33:32.700 | - Correct, yeah, and we, but right now if we were to,

01:33:36.540 | and I'm not making this statement,

01:33:38.300 | I don't think anyone can make the statement now,

01:33:39.980 | but if it ends up being that CBD is potentially beneficial

01:33:44.640 | for sleep, how can we reconcile that mechanistically?

01:33:49.300 | And I think there are, to me at least,

01:33:51.940 | there are at least three candidate mechanisms

01:33:54.020 | that I've been exploring and thinking about.

01:33:57.400 | The first is that it's thermoregulatory.

01:34:00.440 | And what we found in some animal models is that CBD

01:34:04.540 | will create a profile of hypothermia.

01:34:07.440 | In other words, it cools the body,

01:34:09.040 | the core body temperature down.

01:34:10.640 | And that's something that we know is good for sleep.

01:34:12.940 | The second is that it's an anxiolytic,

01:34:15.080 | that it can reduce anxiety.

01:34:16.840 | And that data is actually quite strong,

01:34:19.400 | even with some functional imaging work

01:34:21.260 | that's been coming out recently,

01:34:22.600 | showing that one epicenter of emotion called the amygdala

01:34:25.600 | deep within the brain is quietened down with CBD.

01:34:30.240 | So I think that's at least a second

01:34:31.680 | non-mutually exclusive possibility.

01:34:35.520 | I think the third is some recent data that's come out

01:34:38.920 | that was suggesting that CBD can alter

01:34:41.760 | the signaling of adenosine.

01:34:43.960 | So it doesn't necessarily mean

01:34:45.360 | that you produce more adenosine,

01:34:48.320 | but what it can do is perhaps modulate the sensitivity,

01:34:52.000 | perhaps, of the brain so that the weight

01:34:54.920 | of that same adenosine is weightier in its brain

01:35:00.720 | signal, and therefore it creates

01:35:03.680 | this stronger pressure for sleep.

01:35:06.220 | So I think these are all tentative mechanisms.

01:35:09.040 | I think any one of them is viable.

01:35:10.700 | I think all three are viable together.

01:35:13.320 | But right now, I think, does that sort of help

01:35:15.560 | think through the tapestry of THC and CBD?

01:35:18.560 | - Yeah, very much so.

01:35:19.540 | And actually, it's a perfect segue from,

01:35:22.140 | we've talked about caffeine, alcohol, THC,

01:35:27.280 | and CBD as sort of, we framed them anyway,

01:35:30.920 | as things that done in moderation at the appropriate times

01:35:33.600 | are probably okay for most people,

01:35:36.120 | certainly not for everybody,

01:35:37.140 | there will be differences in sensitivity,

01:35:39.000 | but that done at the incorrect times

01:35:42.120 | and certainly in the incorrect amounts

01:35:44.520 | will greatly disrupt this vital stage of life we call sleep.

01:35:48.120 | CBD, it seems, represents a kind of bridge

01:35:50.520 | to the topic I'd like to talk about next,

01:35:52.560 | which is things that promote more healthy sleep,

01:35:56.940 | or somehow contribute to enhancing the architecture

01:36:00.700 | and quality of sleep.

01:36:02.220 | So I'd love to chat for a moment about the kind of grant,

01:36:06.700 | the original, I should say that, not the granddaddy,

01:36:09.280 | but the OG of sleep supplementation, which is melatonin.

01:36:13.580 | The so-called hormone of darkness

01:36:15.960 | that's inhibited by light, et cetera,

01:36:18.460 | frame for us melatonin in the context

01:36:21.420 | of its naturally occurring form.

01:36:23.520 | And then I'd like to talk about melatonin, the supplement,

01:36:25.840 | because as in my experience,

01:36:27.340 | anytime I say the word melatonin,

01:36:28.760 | people think about the supplement melatonin,

01:36:32.120 | which in itself is an interesting phenomenon

01:36:35.780 | that people are so cued to its role as something you take,

01:36:39.300 | we often forget that this is something

01:36:40.740 | that we make endogenously.

01:36:42.200 | I'd love for you to comment in particular on,

01:36:44.460 | even though without necessarily getting

01:36:47.140 | into precise nanograms per deciliter values,

01:36:50.140 | what are the typical amounts of melatonin

01:36:52.620 | that we release each night?

01:36:53.760 | And then I'd like to compare that to what is contained

01:36:56.640 | in say a three milligram or six milligram tablet

01:36:59.440 | that one might buy at the pharmacy.

01:37:01.560 | So I go to sleep at night,

01:37:04.060 | has melatonin already kicked in before I shut my eyes

01:37:06.820 | and lay down my head?

01:37:07.780 | - Usually, yes.

01:37:08.900 | If your system is working in the correct way,

01:37:12.060 | as dusk is starting to happen,

01:37:14.420 | so let's say that you look at hunter-gatherer tribes

01:37:17.300 | who aren't touched by electricity.

01:37:19.620 | And so that's sort of the puritanical state,

01:37:22.620 | par excellence when it comes to electric light influence.

01:37:26.740 | And usually it's as dusk is approaching,

01:37:30.580 | that's when melatonin will start to rise.

01:37:33.700 | And so when you lose the brake pedal of light

01:37:38.120 | coming through the eyes,

01:37:39.940 | that normally acts like a hard brake pedal

01:37:42.860 | that stamps down and prevents the release

01:37:45.660 | and production of melatonin.

01:37:47.740 | As that light brake pedal starts to fade with dusk,

01:37:52.420 | then we ease off the brake pedal and melatonin,

01:37:55.380 | the spigot of melatonin is opened up

01:37:58.340 | and melatonin starts getting released.

01:38:00.820 | And usually we'll see this rising peak of melatonin

01:38:04.900 | sometime, usually an hour, two hours later or around,

01:38:09.940 | and it varies from different people

01:38:11.780 | around the time of sleep itself,

01:38:14.900 | but it's already been on the march for some hours

01:38:18.420 | before you actually hit sleep itself.

01:38:22.620 | - Interesting.

01:38:23.460 | And I was always taught and I'm assuming it's still true

01:38:26.380 | that the only source of melatonin in the brain and body

01:38:28.940 | is the pineal gland.

01:38:30.140 | Is that still true?

01:38:31.500 | - Yeah, it seems to be from best that we can tell

01:38:34.140 | and the pineal gland sort of meaning pee-like sort of shape.

01:38:39.140 | It's actually, I think usually people say it's pee-like.

01:38:42.680 | I think if you look at the Latin derivative,

01:38:44.660 | it's more, I think it's derived from pine cone,

01:38:48.180 | not pee, because in fact, if you look at the pineal,

01:38:50.860 | it is more pine cone shaped and so it's aptly named.

01:38:54.460 | - Any human brain I've ever dissected,

01:38:56.260 | I confess I've dissected a lot

01:38:57.440 | 'cause I teach neuroanatomy and have for years,

01:39:00.580 | I love looking at the pineal.

01:39:02.220 | It's the one structure in the brain

01:39:04.260 | that's not on both sides.

01:39:05.320 | It's usually pretty easy to find and it's pretty good size.

01:39:08.080 | It looks like a pee and it's sitting right there

01:39:11.340 | and it's remarkable that it releases this hormone,

01:39:15.180 | probably our entire lifespan and is inhibited by light.

01:39:18.560 | So our pineal starts to release this

01:39:22.340 | into the general circulation.

01:39:23.460 | I have to imagine we have melatonin receptors

01:39:25.060 | in the brain and body.

01:39:26.300 | - It's correct, so yep.

01:39:28.060 | Essentially your brain has a central master 24 hour clock

01:39:32.340 | called the suprachiasmatic nucleus that keeps internal time.

01:39:37.340 | Now it's not a precise clock if left to its own devices,

01:39:41.820 | nothing that a Swiss clockmaker would be proud of.

01:39:44.460 | It runs a little bit long and laggy.

01:39:47.140 | - It's like an American clock.

01:39:48.140 | So there are a couple of good American watches by the way.

01:39:51.060 | Hamiltons are very nice, but we're not famous

01:39:53.740 | for our timekeeping or our punctuality for them,

01:39:56.020 | but the Swiss are.

01:39:57.540 | - It's not quite Swiss-like, it's more Berkeley-like,

01:40:01.060 | which is very relaxed, oh, you know, whatever.

01:40:03.600 | So in most adults, the average adult, I should say,

01:40:07.420 | your biological clock normally runs a little bit long.

01:40:10.260 | It's about 24 hours and 13 minutes,

01:40:15.100 | I think was the last calculation.

01:40:17.200 | But the reason that we don't keep drifting forward in time

01:40:20.700 | and kind of running consistently, you know,

01:40:22.980 | more later and later, 30 minutes by 30 minutes

01:40:25.940 | by 30 minutes each day is because your central brain clock

01:40:30.020 | is regulated by external things such as daylight

01:40:33.380 | and temperature, as well as food and activity.

01:40:36.420 | All of these are essentially different fingers

01:40:39.820 | that come along and on the wristwatch of the 24-hour clock

01:40:43.700 | will pull the dial out and reset it each day

01:40:46.660 | to precisely 24 hours.

01:40:48.460 | And I make that point because it knows 24-hour time,

01:40:53.460 | but it needs to tell the rest of the brain and the body

01:40:57.660 | the 24-hour time as well.

01:41:00.500 | And one of the ways that it does this

01:41:02.540 | is by communicating a chemical signal of 24-hour nurse,

01:41:08.660 | of light and day using this hormone melatonin.

01:41:13.020 | And when it is at low levels or it's non-existent,

01:41:16.420 | it's communicating the message, it's daytime.

01:41:19.100 | And for us, diurnal species, it says, it's time to be awake.

01:41:23.340 | Yet at nighttime when dusk approaches

01:41:25.900 | and the brake comes off melatonin and we start to release it

01:41:28.980 | then it signals to the rest of the brain and the body,

01:41:31.900 | look, it's dusk and it's nighttime.

01:41:34.020 | And for us, diurnal species, it's time to think about sleep.

01:41:38.220 | So melatonin essentially tells the brain and the body

01:41:42.820 | when it's day and when it's night.

01:41:44.300 | And with that, when it's time to sleep,

01:41:46.260 | when it's time to wake.

01:41:47.720 | And therefore that's why melatonin helps

01:41:50.120 | with the timing of the onset of sleep,

01:41:53.780 | but it doesn't really help

01:41:55.160 | with the generation of sleep itself.

01:41:56.900 | And this is why we'll come on to what those studies

01:41:58.680 | of supplementation have taught us.

01:42:01.380 | - So it tells the rest of my brain and body,

01:42:03.660 | it's time to go to sleep.

01:42:05.260 | Perhaps even aids with the transition to sleep,

01:42:07.880 | but it's not going to, for instance,

01:42:09.840 | ensure the overall structure of sleep,

01:42:12.180 | or it's not the conductor that's guiding the sleep orchestra,

01:42:16.440 | so to speak, throughout the entire night.

01:42:18.180 | - Yeah, it's-

01:42:19.020 | - It's more like the people that essentially take you

01:42:22.740 | to your seat and sit you down and give you your program.

01:42:25.020 | - Right, exactly, yeah.

01:42:26.060 | Sort of the far less sophisticated analogy I have is,

01:42:31.060 | you know, melatonin is like the starting official

01:42:33.380 | at the 100 meter race in the Olympics.

01:42:35.700 | - That's a better analogy.

01:42:36.540 | - It calls all of the sleep races to the line,

01:42:40.220 | and it begins the great sleep race.

01:42:42.260 | - Yeah, better analogy, by the way,

01:42:43.740 | coming from the sleep researcher of all people.

01:42:46.520 | - But it doesn't participate in the race itself.

01:42:48.920 | That's a whole different set of brain chemicals

01:42:51.440 | and brain regions.

01:42:53.220 | Which then brings us on to perhaps the question

01:42:57.800 | of supplementation, which is,

01:43:02.440 | is it helpful for my sleep?

01:43:04.200 | Will I sleep longer, will I sleep better?

01:43:07.420 | And if I am, what doses should I be taking?

01:43:12.360 | Sadly, the evidence in healthy adults who are not older age

01:43:17.360 | suggests that melatonin is not really particularly helpful

01:43:20.960 | as a sleep aid.

01:43:22.040 | I think there was a recent meta-analysis

01:43:24.420 | that demonstrated when it looked

01:43:28.080 | at all of the different sleep parameters.

01:43:30.040 | Melatonin, and a meta-analysis

01:43:32.560 | for those not knowing what that is,

01:43:34.320 | it's a scientific sort of method that we use

01:43:36.160 | where we gather all the individual studies

01:43:38.960 | and we put them in a big bucket

01:43:40.400 | and we kind of do this kind of statistical fancy

01:43:42.760 | sleight of hand, and we try to come up with a big picture

01:43:45.280 | of what all of those individual studies tell us.

01:43:47.480 | And what that meta-analysis told us is that melatonin

01:43:50.480 | will only increase total amount of sleep

01:43:53.200 | by 3.9 minutes on average.

01:43:56.280 | - Minutes, not even percent.

01:43:58.400 | - And it will only increase your sleep efficiency

01:44:01.180 | by 2.2%.

01:44:04.040 | So it really--

01:44:05.640 | - This is as they say in certain parts of California,

01:44:10.000 | that's weak sauce, that's a weak sauce effect.

01:44:13.500 | - The sauce is not strong,

01:44:14.740 | the force is not strong in this one.

01:44:16.900 | When it comes to a tool that in healthy people

01:44:21.160 | who are not of older age,

01:44:24.200 | it doesn't seem to be especially beneficial.

01:44:26.460 | Now, you know, results can vary.

01:44:28.600 | Everyone is different, of course.

01:44:29.920 | So we're talking about the average,

01:44:31.460 | the so-called average human adult here.

01:44:33.360 | - Well, melatonin in defense of what you're saying,

01:44:36.380 | and also I should mention,

01:44:37.280 | I have a colleague at Stanford, Jamie Zeitzer,

01:44:39.780 | who we know comes from Chuck Zeitzer's lab at Harvard Med,

01:44:42.240 | where he also trained a terrific sleep researcher.

01:44:44.500 | And I asked him about melatonin

01:44:45.840 | and he essentially said the same thing that you just said,

01:44:48.200 | which is very little, if any, evidence

01:44:50.320 | that it can improve sleep.

01:44:51.540 | And yet it's probably the most commonly consumed

01:44:55.000 | so-called sleep aid.

01:44:56.440 | - Hundreds of million dollars industry.

01:44:58.120 | - Yeah, so either massive placebo effect

01:45:00.960 | or it's operating through some other mechanism

01:45:03.200 | related to quelling anxiety, perhaps.

01:45:05.560 | - Yeah, that is actually interesting.

01:45:07.400 | You know, there are some studies

01:45:08.700 | where you do see some, you know, effects.

01:45:10.960 | Now, again, when you do the grand average of all studies,

01:45:13.180 | it just doesn't seem to have an effect.

01:45:14.840 | But let's assume that for some people

01:45:16.620 | it does have an effect.

01:45:17.560 | Let's not, again, be sort of completely dismissive of that.

01:45:20.440 | How could it have that effect?

01:45:22.000 | One of the reasons that I've become

01:45:23.480 | a little bit more bullish on melatonin

01:45:26.040 | from a sleep perspective,

01:45:27.960 | and then melatonin more generally for a,

01:45:31.420 | maybe we can speak about this too,

01:45:32.900 | as a counter measure

01:45:37.440 | when you're undergoing insufficient sleep,

01:45:39.860 | there are two different routes there.

01:45:43.080 | The first reason that I think it could have a sleep benefit

01:45:45.640 | for some people is not because it helps

01:45:47.760 | in the generation of sleep.

01:45:48.800 | We know that it doesn't.

01:45:50.160 | It's because it too seems to drop core body temperature.

01:45:54.400 | - There it is temperature again.

01:45:55.520 | I'm fascinated these days more and more by temperature

01:45:59.000 | as maybe not just a reflection of brain state

01:46:03.620 | and wakefulness and in sleep,

01:46:05.460 | but actually a lever that is quite powerful.

01:46:08.720 | And with all the interest in ice baths and hot showers

01:46:11.560 | and saunas and stuff,

01:46:12.560 | something that we will definitely touch on.

01:46:15.020 | Temperature variation is so key.

01:46:17.320 | So if melatonin is dropping body temperature

01:46:20.180 | by a degree or so,

01:46:21.060 | something that you've said before

01:46:22.580 | can help induce a sleepy state,

01:46:25.400 | maybe that's what's allowing people to get into sleep.

01:46:27.360 | - I think that's one possibility.

01:46:28.400 | I don't think melatonin by itself will drop it

01:46:31.080 | by sort of a degree, certainly not a degree Celsius.

01:46:34.720 | And for ordinary in us to fall asleep

01:46:37.240 | and then stay asleep across the night,

01:46:38.900 | we do need to drop our core body temperature

01:46:41.040 | by about one degree Celsius

01:46:42.800 | or about two to three degrees Fahrenheit.

01:46:45.920 | And that's why it's always easier to fall asleep

01:46:48.120 | in a room that's too cold than too hot.

01:46:50.040 | I think that that's one potential avenue

01:46:54.440 | that we are considering thinking more deeply about

01:46:58.080 | when it comes to melatonin.

01:47:00.160 | And then the other is melatonin as an antioxidant,

01:47:03.540 | but let me table that for now

01:47:05.840 | 'cause I'll just get us sidetracked.

01:47:07.800 | That's what we know so far about melatonin

01:47:11.540 | in terms of its supplementation benefit or lack thereof.

01:47:15.440 | Two final points that I shouldn't forget.

01:47:17.680 | One is the only population where we typically see

01:47:20.980 | some benefit and it often is prescribed is in older adults.

01:47:25.260 | Because as we-- - Older meaning 60 and older?

01:47:27.820 | - Yeah, 60, 65 and older.

01:47:29.680 | Because as we get older, you can typically have

01:47:32.460 | what's called calcification of the pineal gland,

01:47:35.100 | which means that that gland that's releasing melatonin

01:47:37.740 | doesn't work as well anymore.

01:47:40.080 | As a consequence, they tend to have a flatter overall curve

01:47:44.720 | of melatonin released throughout the night.

01:47:47.020 | It's not this beautiful, lovely peak

01:47:49.280 | and this bullhorn message of it's darkness,

01:47:52.000 | please get to sleep.

01:47:53.360 | That's why older adults can have problems falling asleep

01:47:55.900 | or staying asleep.

01:47:56.960 | It's not the only reason by any stretch of the imagination,

01:48:00.360 | but it's one of the reasons

01:48:01.540 | and it's why melatonin supplementation in those cohorts,

01:48:04.640 | older adults, especially older adults with insomnia,

01:48:07.840 | people have thought about that

01:48:09.680 | as maybe an appropriate use case.

01:48:12.520 | - Well, on those lines, if we were to compare dosages,

01:48:17.880 | do we know how much melatonin is typically released

01:48:20.240 | into the bloodstream per night?

01:48:22.160 | And can we use that as a kind of a rule of thumb

01:48:26.440 | by which to compare the typical amount

01:48:28.060 | that someone would supplement?

01:48:29.320 | I mean, typically the supplements for melatonin that I see

01:48:32.920 | in the pharmacy and elsewhere and online

01:48:35.120 | range anywhere from one milligram to 12

01:48:38.200 | or even 20 milligrams.

01:48:40.360 | My guess is that a normal night's release of melatonin,

01:48:45.000 | typical for somebody in their 20s, 30s, 40s

01:48:47.840 | would be far lower than that.

01:48:49.840 | Am I correct or wrong?

01:48:51.480 | - Yeah, it's many magnitudes lower

01:48:54.080 | and this is one of the problems is that I see that too.

01:48:56.480 | I see typical doses are five milligrams or 10 milligrams.

01:49:01.420 | And of course, if you're a supplement company,

01:49:04.600 | putting 10 milligrams versus five milligrams,

01:49:06.720 | if that's what you're actually doing,

01:49:07.960 | which we'll speak about purity as well.

01:49:09.960 | It's kind of like the super gulp size.

01:49:14.800 | Nobody wants to lower price.

01:49:17.000 | They just want you to,

01:49:19.120 | we'll just give you more for the same price

01:49:20.960 | and that's how we'll compete.

01:49:22.000 | So it's been this escalating arms race

01:49:25.080 | of melatonin concentration.

01:49:26.980 | And it really does not look meaningful

01:49:29.800 | for sleep in any way.

01:49:33.000 | What we've actually found is that the optimal doses

01:49:36.600 | for where you do get sleep benefits

01:49:38.720 | in the populations that we've looked at

01:49:41.200 | are somewhere between 0.1 and 0.3 milligrams of melatonin.

01:49:46.200 | In other words, the typical doses are usually 10 times,

01:49:51.320 | 20 times, maybe more than what your body

01:49:55.520 | would naturally expect.

01:49:56.500 | And this is what we call a super physiological dose.

01:50:00.480 | In other words, it's far above

01:50:02.320 | what is physiologically normal.

01:50:04.840 | You know, and to put that in context,

01:50:06.200 | imagine I said to you,

01:50:07.400 | "I want you to eat 20 times as much food today."

01:50:11.200 | - I thought you were going to use testosterone as example.

01:50:13.920 | You're going to take 300 times

01:50:15.520 | the normal amount of testosterone.

01:50:16.720 | We know that would have tons of deleterious effects.

01:50:20.440 | - Right. - It'd be terrible.

01:50:21.280 | - Yeah. - And yet you can do this.

01:50:22.680 | One thing that I'm concerned about

01:50:24.240 | about these super physiological levels of melatonin

01:50:27.240 | is that many years ago, actually here at Berkeley,

01:50:29.500 | when I was a graduate student,

01:50:30.440 | we would inject animals,

01:50:33.360 | which were seasonally breeding animals with melatonin.

01:50:36.760 | And the consequence of that was that their gonads,

01:50:41.280 | either their testes or ovaries,

01:50:42.600 | would shrink many hundred fold or more.

01:50:46.680 | In other words, they would go from having

01:50:48.880 | nice healthy-sized hamster testicles,

01:50:51.400 | what a hamster would consider healthy size for a hamster,

01:50:54.280 | and they would shrink to the size of a grain of rice.

01:50:56.440 | So from like an almonds to a grain size of a grain of rice.

01:50:59.320 | I had to see that only once for me to be very concerned

01:51:01.880 | about super physiological levels of melatonin.

01:51:04.420 | And I realized that melatonin does different things

01:51:06.740 | in different species.

01:51:07.580 | We are not hamsters, we are not seasonal breeders,

01:51:10.900 | seasonally restricted breeders.

01:51:12.420 | There might be more breeding during certain seasons.

01:51:14.140 | I don't know those data.

01:51:15.260 | But nonetheless, hormones are powerful.

01:51:18.540 | And sure, there is an optimal.

01:51:21.980 | And sometimes we see that going slightly

01:51:25.980 | above endogenous levels for certain hormones,

01:51:28.300 | not always, can have beneficial effects.

01:51:30.460 | And sometimes it can have detrimental effects.

01:51:32.980 | I'm just concerned about taking high levels of a hormone

01:51:37.040 | that has effects on the reproductive axis.

01:51:40.060 | And that's one of the reasons why I get very concerned

01:51:42.820 | when I see people really getting aggressive

01:51:46.060 | about melatonin supplementation, taking 110, 500,

01:51:51.060 | sometimes even 10,000 times the amount

01:51:53.620 | that we would normally release.

01:51:54.580 | That's my concern, although it's not nested

01:51:56.740 | in any one specific human study.

01:51:58.780 | I just don't like to see,

01:52:01.220 | I certainly don't want to see other people

01:52:02.900 | and I don't want to personally take a hormone

01:52:06.180 | that's known to be androgen suppressive at high levels.

01:52:10.620 | Why would I take that?

01:52:12.600 | That's the question I ask myself.

01:52:14.340 | - I think it's a very good point.

01:52:16.340 | And if you look at some of the evidence

01:52:19.700 | around melatonin's lethality,

01:52:23.160 | if you want to go to that extreme,

01:52:24.800 | for the most part, it's pretty safe.

01:52:27.520 | - You mean you can take a lot of it before you die.

01:52:29.620 | - Right, exactly, yeah.

01:52:31.140 | But that should not be your yardstick for it

01:52:34.100 | because you really need to think about your health,

01:52:37.580 | not just whether this thing is going to kill you or not

01:52:40.260 | as the decision matrix through which you pop a pill.

01:52:44.580 | And it comes on to this concern around melatonin

01:52:49.060 | because there was a study,

01:52:50.540 | I think it's one that you mentioned too,

01:52:53.280 | where they looked at over,

01:52:54.840 | I think it was at least over 20 different brands

01:52:57.480 | of melatonin supplements.

01:52:59.660 | And what they found is that based on what it said

01:53:01.920 | on the bottle versus what was in the capsules themselves,

01:53:04.960 | it ranged from, I think it was 83% less

01:53:08.460 | than what it said on the bottle

01:53:09.820 | to 478% more than what it said on the bottle.

01:53:14.260 | Now, if that's a 10 milligram pill

01:53:18.820 | and it's 478% more than 10 milligrams

01:53:23.820 | and we're already at 10 milligrams

01:53:26.280 | at many tens of times more than is a physiological

01:53:30.700 | rather than a supra physiological dose,

01:53:34.100 | we do need to be a bit thoughtful.

01:53:35.960 | - Yeah, remember those hamsters.

01:53:37.660 | Well, and I do appreciate the deep dive on melatonin

01:53:43.200 | because I think people need to understand that it's nuanced.

01:53:47.340 | It's a matter of dosages and timing, et cetera.

01:53:50.020 | And then it may have its place

01:53:51.180 | as you mentioned in older individuals.

01:53:53.740 | And I should mention that I'm an avid consumer

01:53:56.720 | of supplements that I believe in for me.

01:53:59.560 | And I have been for a very long time.

01:54:00.900 | So I'm by no means anti supplement.

01:54:04.340 | Some supplements I refuse to take or avoid taking,

01:54:07.200 | others I am quite avidly take.

01:54:09.860 | And along those lines, I personally,

01:54:13.660 | and I don't know what your thoughts on this are,

01:54:17.600 | but there are a few things

01:54:19.120 | that I've personally found beneficial.

01:54:20.500 | I'd love your thoughts on them.

01:54:21.600 | And I would love it if you would tell me

01:54:23.680 | that everything I'm about to refer to as placebo,

01:54:26.560 | that would be fine.

01:54:27.400 | So that's what we do.

01:54:28.680 | We're scientists, we argue,

01:54:29.840 | and then we remain friends as it goes.

01:54:34.500 | So magnesium, there are many forms of magnesium.

01:54:38.320 | Magnesium citrate is, as we know, is a terrific laxative.

01:54:41.840 | Magnesium malate seems, at least from a few studies,

01:54:45.600 | seems to relieve some of delayed onset muscle soreness,

01:54:48.160 | doesn't seem to create a kind of sedation.

01:54:49.960 | Two forms of magnesium that I'm aware of,

01:54:51.700 | magnesium biglycinate and magnesium threonate.

01:54:55.160 | - Yeah.

01:54:56.620 | - We believe, based on the data,

01:54:58.620 | can more actively cross the blood-brain barrier.

01:55:01.540 | So you put it in your gut,

01:55:02.480 | but some of that needs to get in your brain

01:55:03.840 | in order to have the sedative effect.

01:55:05.600 | What are your thoughts on magnesium supplementation?

01:55:08.140 | Do you supplement with magnesium?

01:55:10.560 | And what studies would you like to see done

01:55:14.540 | if they haven't been done already?

01:55:16.180 | - So I don't supplement with magnesium,

01:55:19.240 | but I do think threonate is interesting

01:55:21.800 | because of that higher capacity to cross the blood-brain

01:55:25.740 | barrier and actually have a central nervous system effect.

01:55:28.520 | And the reason that that interests me

01:55:30.160 | is because the sleep is by the brain, of the brain,

01:55:33.880 | and also for the brain, as well as for the body.

01:55:37.840 | We just don't have a particularly good set of studies

01:55:40.840 | that have targeted exclusively threonate.

01:55:43.800 | We do have lots of studies that have just looked

01:55:45.840 | at magnesium in general for sleep.

01:55:48.240 | And overall, the data is uncompelling.

01:55:51.880 | - Interesting.

01:55:52.720 | - And for a while, I was confused as to why.

01:55:57.460 | Where did this come from, this kind of myth of magnesium?

01:56:01.900 | So I started looking back into the literature

01:56:04.340 | and I've best traced it, at least as far as I can tell,

01:56:08.880 | to early studies showing that those who were deficient

01:56:12.440 | in magnesium also had sleep problems.

01:56:15.800 | They had other problems too, of course.

01:56:17.920 | But sleep problems were one of that set of sequelae

01:56:21.200 | that came from having lower magnesium.

01:56:24.260 | And when they supplemented with magnesium

01:56:28.120 | and tried to restore those levels,

01:56:29.760 | some of those sleep problems dissipated.

01:56:32.320 | And then that seems to have gotten lost

01:56:35.000 | in some game of sort of like whispers around the room.

01:56:38.480 | And it's become translated into people

01:56:40.920 | who don't have sleep problems,

01:56:42.720 | who are healthy sleepers and who are healthy in general,

01:56:45.360 | and who have healthy normal levels of magnesium.

01:56:47.920 | If they take more magnesium, they will sleep better.

01:56:51.600 | And the data really there is not good.

01:56:53.740 | Once again, the only study that I've seen

01:56:56.980 | where magnesium did have some efficacy

01:56:59.240 | was in a study with older adults.

01:57:00.880 | I think they were 60 to 80 years old.

01:57:03.000 | It may have been exclusively women, now I think about it.

01:57:06.480 | And they also had insomnia.

01:57:08.400 | And in that population, you did see some benefits.

01:57:11.680 | And my guess is that because it's an older community as well

01:57:15.720 | they were probably deficient in magnesium.

01:57:18.440 | So they fit the former category of simply

01:57:21.660 | when you're deficient and you restore,

01:57:23.840 | you can help sleep sort of return to normal.

01:57:27.460 | But if you are not deficient and you're healthy

01:57:29.640 | and you're not old and you don't have insomnia,

01:57:31.480 | and you're supplementing thinking that it provides sleep,

01:57:34.920 | right now the data isn't supportive of that.

01:57:37.600 | But I just don't think we have enough three and eight data

01:57:39.960 | to actually speak about that

01:57:41.140 | because it could just be a blood brain barrier issue so far

01:57:44.200 | with the other forms.

01:57:45.500 | - So maybe some additional studies looking specifically

01:57:47.960 | at three and eight or by glycinate would be useful.

01:57:51.000 | And magnesium is involved in so many cellular processes.

01:57:54.000 | You can imagine that this effect, if it truly exists is,

01:57:57.640 | as we say in science, in the noise,

01:57:59.160 | meaning it's in the jitter of the data,

01:58:02.360 | but to isolate the real effect

01:58:03.920 | one needs to do some more refined studies.

01:58:07.700 | What are some things that are of interest to you,

01:58:11.160 | if not things that you happen to take?

01:58:13.360 | These are not things that I personally take,

01:58:16.620 | mostly because I just haven't experimented with them.

01:58:19.880 | Valerian root is one.

01:58:22.640 | Tart cherry and kiwi fruit.

01:58:27.080 | Tell me about valerian root, tart cherry and kiwi fruit.

01:58:30.960 | This is new to me.

01:58:32.560 | I mean, I've certainly heard of them

01:58:34.300 | and tart cherry and kiwi sounds delicious,

01:58:38.020 | but what's happening with valerian root,

01:58:41.320 | tart cherry and kiwi and are we talking about

01:58:43.720 | eating tart cherries and kiwis and valerian roots?

01:58:47.480 | What are we talking about taking them in pill form?

01:58:49.120 | - Usually it's supplements,

01:58:50.500 | but it's also both for tart cherries and for kiwis.

01:58:54.880 | It's the actual fruit themselves.

01:58:58.120 | Valerian often touted as a beneficial sleep aid

01:59:02.380 | and lots of people swear by it too.

01:59:04.940 | But the evidence is actually quite against that.

01:59:08.120 | Not that it makes your sleep worse,

01:59:09.920 | but of at least the seven good studies

01:59:13.360 | that I've been able to find.

01:59:14.560 | And typically these are of the nature of what we call

01:59:17.800 | a randomized placebo crossover design.

01:59:21.260 | And I won't bore people with what that means.

01:59:23.640 | It's sort of one of the-- - Good study, solid study.

01:59:25.360 | - Yeah, it's one of the sort of gold standard methods

01:59:27.680 | that we have when we're looking at intervention studies,

01:59:29.540 | such as drug studies.

01:59:30.880 | Five of the seven found no benefit

01:59:33.860 | of valerian root on sleep.

01:59:36.140 | Then two out of the seven,

01:59:37.960 | the data was just insufficient.

01:59:40.700 | I think it was a power issue

01:59:42.100 | where they just couldn't make any strong conclusions.

01:59:45.280 | And then I think there was the most recent study,

01:59:49.020 | I think looked at two different doses of valerian.

01:59:56.300 | I could have this wrong.

01:59:58.420 | And they just failed to find any effects once again.

02:00:01.680 | But the stunning part of that paper, as I recall,

02:00:04.760 | they had this big table

02:00:05.800 | with all of the different sleep metrics that they looked at.

02:00:08.400 | And there were well over 25 different things

02:00:10.800 | that they tried to see if valerian impacted.

02:00:14.240 | And none of them were significant.

02:00:16.300 | Which stuns me because from statistical probabilities,

02:00:19.280 | we know if you just randomly perform 25 statistical tests,

02:00:23.520 | chances are probabilistically,

02:00:25.240 | you'll just get one significant result by random chance.

02:00:28.960 | And even with random chance on their side,

02:00:31.540 | they still couldn't find a benefit of valerian.

02:00:36.160 | - So valerian root might be worse than nothing at all

02:00:38.880 | if there is, so to speak.

02:00:41.080 | - I mean, again, placebo effect,

02:00:43.040 | we can think about that too.

02:00:44.600 | And I would say that if you feel

02:00:45.960 | as though it's having a benefit for you,

02:00:48.180 | and with all of the caveats that we have with supplements,

02:00:51.360 | things like melatonin, purity, concentration, et cetera,

02:00:54.920 | maybe it's no harm, no foul,

02:00:56.620 | but I'm not a medical doctor and I don't tell anyone about.

02:01:01.100 | We have all of these disclaimers about not recommending--

02:01:03.160 | - Sure, and we'll include these.

02:01:04.480 | I mean, I always say, we're not physicians,

02:01:06.400 | we don't prescribe anything.

02:01:07.360 | We're scientists and professors, so we profess things.

02:01:10.000 | And it's up to people to be responsible for their own health,

02:01:13.620 | not just to protect us, but to protect themselves.

02:01:16.180 | I do want to hear about tart cherry and kiwi fruit.

02:01:21.780 | What's the story there?

02:01:24.320 | - Strange, isn't it?

02:01:25.160 | I was, you know, I'm kind of a hard-nosed scientist.

02:01:30.120 | And when people, you know, some years ago started saying,

02:01:32.840 | oh, tart cherries, it's the thing, or kiwi fruits,

02:01:35.560 | I was thinking, oh my goodness, this sounds a bit--

02:01:38.080 | - You've been in California a little too long.

02:01:39.200 | - Yeah, I know, yeah, the sun has softened me.

02:01:42.200 | But I thought, look, one of the things that we have to do

02:01:45.320 | as scientists is be as open-minded as possible,

02:01:49.080 | and I should not be so quick to dismiss.

02:01:51.320 | So I went to the literature, just started reading

02:01:53.960 | as much as I could about it.

02:01:56.120 | And there were three really good randomized

02:01:59.440 | placebo crossover trials with tart cherries.

02:02:03.000 | And what they found was that in one study,

02:02:06.040 | it reduced the amount of time that you spent awake at night

02:02:10.780 | by over an hour, and then the other two studies,

02:02:14.520 | one of them found that it increased the amount of sleep

02:02:17.680 | that you got by 34 minutes.

02:02:19.840 | The other, it increased the amount of sleep

02:02:21.820 | that you got by 84 minutes, which, you know, these are,

02:02:26.580 | and what's striking is that they were independent studies,

02:02:30.140 | I think, meaning that they were from independent groups.

02:02:32.980 | And these were, you know, some of these guys,

02:02:35.440 | you know, I and girls, I know pretty well.

02:02:38.760 | - You know and trust their work.

02:02:40.420 | - Right, I really trust their work too.

02:02:41.980 | - Were they ingesting actual tart cherries,

02:02:43.620 | are they drinking the juice or in capsule?

02:02:45.300 | - It was juice.

02:02:46.240 | So they, in all three studies, it was juice.

02:02:49.340 | Although you can, I think, as a supplement,

02:02:51.260 | you can buy it in a capsule and we've got no idea

02:02:53.440 | whether that changes the benefit or not.

02:02:56.340 | What was also interesting in, I think it was that last study

02:02:58.880 | where they got an increase in sleep by 84 minutes,

02:03:02.340 | it also decreased daytime napping significantly.

02:03:06.380 | - Oh, that's one that I could certainly make use of.

02:03:08.820 | I love my daytime naps, but I'd love to skip them too.

02:03:11.480 | - Right, and we can speak about naps

02:03:13.380 | and sort of the upside and downside of that,

02:03:15.980 | which then made me think, well, if that's the case,

02:03:18.660 | maybe the net net benefit on sleep overall is no different.

02:03:23.380 | It's just that it decreases the amount of time

02:03:25.340 | that some people were taking to sleep during the day

02:03:27.980 | and giving it back to the night.

02:03:29.580 | But that wasn't the case 'cause if you added

02:03:31.580 | the total amount of sleep that they were getting

02:03:33.500 | without tart cherries, both naps and nightly sleep combined,

02:03:37.180 | still when you took tart cherries,

02:03:39.360 | you still got a net sum benefit of total amount of sleep.

02:03:42.900 | So, you know, so far, when it comes to supplements

02:03:48.380 | and those types of studies, they're good studies

02:03:51.860 | and the data looks interesting.

02:03:53.420 | But as a drug itself, you know, if this was clinical drug,

02:03:57.320 | you know, three studies that are somewhat small in nature

02:04:00.460 | and have some positive benefit,

02:04:02.020 | that's what we would call preliminary data

02:04:04.460 | of maybe a chin scratching kind.

02:04:07.580 | So keep this in context. - Yeah, and depending

02:04:08.820 | on the margins for safety, one might think,

02:04:10.820 | well, given that it's a tart cherry

02:04:13.260 | as opposed to some pharmaceutical you need a prescription for

02:04:16.160 | then, you know, some people their threshold

02:04:18.860 | to experiment with supplements is quite low,

02:04:21.060 | some people their threshold is quite high.

02:04:23.100 | I feel like, you know, there are two categories

02:04:25.900 | or at least two categories of folks out there.

02:04:27.960 | People who hear, oh, tart cherry can improve sleep

02:04:31.140 | and will run out and try it.

02:04:32.660 | And people who hear, well, that sounds crazy,

02:04:35.160 | why would I do that?

02:04:36.220 | But of course, we have to remind people

02:04:39.000 | that tart cherry isn't really what we're talking about,

02:04:41.820 | presumably, if this is a real effect

02:04:43.640 | and it sounds like it might be,

02:04:45.300 | that there's a compound in tart cherry

02:04:47.680 | that if we were to call it whatever, whatever,

02:04:50.160 | five alpha six, you know, some molecule,

02:04:53.380 | if we referred to it by its technical name,

02:04:55.580 | then people would say, oh,

02:04:56.980 | that sounds like a very interesting technical way

02:04:59.260 | to approach sleep, but doesn't sound very natural.

02:05:01.220 | So both groups are a little bit misguided

02:05:04.420 | in the sense that people who think

02:05:05.700 | that everything that comes from naturally occurring foods,

02:05:07.980 | plants, et cetera, things that grow out of the ground,

02:05:09.820 | that that's all safe, that's not true.

02:05:12.220 | And people that think that pharmaceuticals

02:05:15.040 | are the, if it's not evidence with the purified molecule,

02:05:18.780 | then something's not of utility.

02:05:20.700 | Well, that's certainly not true.

02:05:21.700 | Somewhere in the middle, I think, lies the answer,

02:05:23.580 | which is, it sounds to me like tart cherry

02:05:25.820 | is at least an intriguing potential sleep aid,

02:05:29.700 | intriguing potential sleep aid,

02:05:31.660 | and I'm underscoring potential.

02:05:34.200 | I'm certainly intrigued by it to the point

02:05:35.880 | where I might experiment a bit,

02:05:37.300 | but I'm an experimenter for myself.

02:05:39.780 | Before I ask you about kiwi,

02:05:43.420 | I've had quite good results from taking something

02:05:45.540 | called apigenin, which is a derivative of chamomile,

02:05:48.540 | but in supplement form, I think I take 50 milligrams

02:05:51.520 | about 30 minutes before sleep,

02:05:53.580 | and I subjectively experience a better night's sleep,

02:05:58.580 | so to speak.

02:05:59.980 | I don't measure, I confess I don't measure my sleep.

02:06:02.020 | I'm not a sleep tracker guy.

02:06:03.600 | But there are a few papers out there.

02:06:08.100 | They're not what we would call published

02:06:10.220 | in blue ribbon journals, but they have control groups,

02:06:13.900 | and it looks somewhat interesting.

02:06:15.400 | And there, when I say apigenin,

02:06:18.080 | people get somewhat intrigued.

02:06:19.300 | Oh, this molecule, chamomile,

02:06:21.140 | has long been thought to be a sedative,

02:06:24.340 | a mild sedative, but a sedative.

02:06:26.260 | Do you drink chamomile tea?

02:06:27.420 | Do you take apigenin?

02:06:28.820 | What are your thoughts on apigenin?

02:06:29.980 | - Yeah, I don't, and I have looked into

02:06:32.820 | some of the data regarding sleep as well.

02:06:35.340 | Right now, from best I can tell,

02:06:37.020 | it's mostly subjective data rather than objective,

02:06:40.240 | hard sort of sleep measures.

02:06:42.300 | And that's why right now I, you know,

02:06:44.400 | it's sort of unclear, not no comment, but just unclear.

02:06:49.400 | Not dismissing it, because I think you and I

02:06:52.340 | both ascribe to the idea of absence of evidence

02:06:55.240 | is not evidence of absence.

02:06:57.020 | So keep your mind open, at least I tell that to myself.

02:07:00.320 | I think if you're finding a benefit,

02:07:04.300 | and you can do what I would think of

02:07:06.700 | if I was personally experimenting,

02:07:08.500 | which is both the positive and negative

02:07:11.260 | parts of the experiment.

02:07:12.220 | What I mean by that is, you know,

02:07:13.660 | let's say that I now want to, you know,

02:07:15.900 | think about some kind of a sleep supplement.

02:07:18.700 | I will take some kind of baseline set of recordings

02:07:21.880 | for a month, and I will just gauge where I'm at,

02:07:26.500 | sort of supplement free.

02:07:28.240 | Then I'll go on for a month

02:07:30.380 | to whatever I'm thinking of taking,

02:07:32.440 | and I don't, you know, supplement,

02:07:34.060 | but let's say that I want to, and I experiment with that.

02:07:37.460 | And I feel as though, based on my metrics,

02:07:39.940 | be them objective from my aura ring,

02:07:41.840 | or be them subjective from whatever I'm, you know,

02:07:44.460 | writing down in the morning,

02:07:45.640 | and both are important and valid, subjective and objective.

02:07:49.160 | We like both in the sleep world.

02:07:50.760 | And I think, okay, look, it's clearly that

02:07:54.280 | it seems to have some kind of an effect.

02:07:56.980 | The key thing, however, is then do the negative experiment,

02:08:00.340 | which is now come off it for another month,

02:08:03.980 | and see, do things get worse?

02:08:06.300 | And if I can see that bidirectionality,

02:08:09.260 | then I'm starting to think,

02:08:11.620 | maybe I'm believing this a little bit more.

02:08:14.100 | So that's the way I would sort of typically approach,

02:08:17.060 | you know, a supplementation regimen if I were to do it,

02:08:20.260 | and that's just me, that's just the way my mind works, but.

02:08:23.020 | - No, that's great.

02:08:23.860 | I think it's very, very scientific and organized

02:08:26.240 | in a way that allows you and would allow other people

02:08:29.600 | to make very informed decisions for themselves.

02:08:32.940 | I like that.

02:08:33.780 | - Right.

02:08:34.840 | - I like to think in terms of manipulating

02:08:37.740 | any aspect of our biology,

02:08:39.700 | that behavioral tools always are the first line of entry.

02:08:43.940 | Then nutrition, everyone has to eat sooner or later,

02:08:46.700 | even if you're fasting.

02:08:48.300 | Then perhaps supplementation, then prescription drugs,

02:08:52.260 | and then perhaps brain-machine interface,

02:08:54.340 | devices that you use to induce something,

02:08:56.560 | and those could be done in combination.

02:08:57.940 | But what concerns me is when I hear people say,

02:09:01.260 | well, what should I take without thinking about

02:09:03.980 | their behavior, their light viewing behavior, et cetera.

02:09:06.140 | But of course these things work in combination.

02:09:08.420 | - I think you're right that there's many,

02:09:11.300 | when it comes to sleep, there are many low-hanging fruits

02:09:14.840 | that don't necessarily require you to, you know,

02:09:18.740 | put sort of exogenous molecules,

02:09:21.180 | in other words, things like supplements into your body,

02:09:23.620 | or, you know, use different types of drugs

02:09:26.500 | to help you get there.

02:09:28.080 | Now, when it comes to prescription sleep aids,

02:09:31.400 | I think I've been, again, a little bit too forthright.

02:09:34.860 | We know in clinical practice that there may be a time

02:09:38.360 | and a place for things like sleeping pills.

02:09:40.600 | They are a short-term solution to certain forms of insomnia,

02:09:45.600 | but they are not recommended for the long-term.

02:09:49.680 | And we also know that there are lots of other ways

02:09:51.440 | that you can get a sleep help,

02:09:55.340 | or you can get a sleep curative profile

02:09:58.020 | from things like cognitive behavioral therapy for insomnia,

02:10:00.780 | which is a non-drug approach, a psychological one.

02:10:02.740 | - And quite effective from what I understand.

02:10:04.260 | - Just as effective as sleeping pills, great data,

02:10:07.140 | more effective in the long-term.

02:10:08.700 | There was a recent study published that

02:10:10.520 | after working with that therapist,

02:10:11.900 | some of the benefits lasted almost a decade.

02:10:14.780 | You know, now, if you stop sleeping pills,

02:10:17.380 | usually you have rebound insomnia,

02:10:19.700 | where your sleep goes back to being just as bad,

02:10:21.620 | if not worse.

02:10:23.200 | And I think the same is true

02:10:24.380 | when we think about supplementation.

02:10:25.800 | There are so many things that are easy to implement

02:10:29.580 | when it comes to sleep

02:10:31.220 | that don't require venturing out into those waters.

02:10:34.340 | And again, we're not here to tell anyone

02:10:36.860 | about whether they should venture or not.

02:10:38.440 | That's completely your choice.

02:10:40.020 | All I'm saying is that

02:10:40.860 | if you want to think about optimizing your sleep,

02:10:43.660 | there are a number of ways that you can do it

02:10:45.820 | that don't necessarily require you to swallow anything,

02:10:49.340 | or inject anything, or smoke anything, or free basis.

02:10:52.720 | - And for which the margins of safety are quite wide.

02:10:55.560 | - Right.

02:10:56.400 | - That's the other one.

02:10:57.220 | - Yeah, sorry, thank you for that.

02:10:58.060 | - So speaking of low-hanging fruit,

02:10:59.040 | I don't know how low it hangs in reality,

02:11:01.100 | but what about kiwi?

02:11:02.620 | They're delicious to me anyway.

02:11:04.260 | - Yeah, the humble kiwi fruit.

02:11:06.080 | Named not, shouldn't be mistaken

02:11:09.400 | for the flightless bird of New Zealand,

02:11:13.400 | which is the native bird there.

02:11:14.800 | We're talking about the kiwi, the fruit here,

02:11:16.700 | which those trees and shrubs are mostly Southeast Asia,

02:11:21.700 | East Asia.

02:11:23.060 | Kiwi fruits have been previously touted

02:11:26.540 | as potentially having a sleep benefit,

02:11:28.860 | which again, got me curious,

02:11:30.100 | and I at first threw it out.

02:11:32.800 | To my knowledge,

02:11:33.820 | there's really only one published human study

02:11:36.460 | that's of any value,

02:11:38.280 | but what they did find was that

02:11:40.580 | it decreased the speed of time

02:11:42.240 | with which it took you to fall asleep.

02:11:43.760 | - These are people ingesting the whole kiwi?

02:11:45.480 | - So it's ingesting the whole kiwi.

02:11:46.820 | - With the skin, I eat the skin.

02:11:48.420 | People cringe when they see me do it,

02:11:49.820 | but don't eat the skin.

02:11:50.820 | - No, no, no.

02:11:51.660 | I think the idea is some of the good stuff,

02:11:53.700 | and I'll come onto this,

02:11:54.680 | may actually be in the skin itself.

02:11:57.080 | - Thank you, you just helped me win a bet.

02:12:00.020 | I'll give you your--

02:12:00.840 | - Okay, okay, yeah, you can pay me later.

02:12:02.420 | By the way, this skin is used,

02:12:03.700 | no, no, no, he just told me to say that,

02:12:05.340 | so he went, no, he did not.

02:12:06.780 | So the skin seems to be part

02:12:09.540 | of this potential sleep equation,

02:12:12.140 | and that's that you fell asleep faster,

02:12:16.460 | and you stayed asleep for longer,

02:12:18.980 | and you spent less time awake throughout the night.

02:12:22.100 | And I just thought, well, you know,

02:12:23.540 | that's one study, what can you really do with that?

02:12:26.340 | There was another study, however,

02:12:28.500 | in an animal model, which is, you know,

02:12:31.160 | a little bit more interesting.

02:12:33.380 | And once again, they found a very similar phenotype

02:12:36.620 | that the rats, oh, sorry, they were mice.

02:12:39.140 | The mice fell asleep faster,

02:12:41.480 | and they also spent longer time in sleep.

02:12:44.860 | The sleep duration also increased.

02:12:47.100 | What was also interesting mechanistically,

02:12:49.300 | and this is not the mechanism

02:12:51.100 | that I think ties together tart cherries,

02:12:55.100 | kiwi fruit, and, you know, things like melatonin,

02:12:58.740 | 'cause I think there could be one common binding mechanism.

02:13:02.260 | What they found in the animal study

02:13:03.800 | is that they could block those kiwi fruit sleep benefits

02:13:08.340 | using a GABA blocking agent.

02:13:11.300 | Now, GABA, GABA, which stands for gamma-aminobutyric acid,

02:13:16.820 | is one of the major inhibitory neurotransmitters of the brain.

02:13:20.220 | It's kind of like the red- - So a naturally occurring

02:13:21.540 | sedative, sort of. - Right, yeah.

02:13:23.220 | It's the kind of the red light on the traffic light signal.

02:13:26.300 | You know, others are green light.

02:13:28.780 | GABA is red light.

02:13:32.020 | So by playing around with some sort of clever drugs

02:13:35.800 | to manipulate the system,

02:13:37.340 | they could prevent the benefit of the kiwi fruit

02:13:40.200 | by sort of buggering around with the GABA receptor,

02:13:43.340 | meaning that perhaps part of the kiwi fruit benefit on sleep

02:13:48.220 | was mediated by the brain's

02:13:50.620 | natural inhibitory neurotransmitter system

02:13:53.820 | called the GABA system. - That's exciting.

02:13:55.420 | - And I thought that that was kind of,

02:13:57.020 | that convinced me a little bit more

02:13:58.500 | that maybe there's something here to read into.

02:14:01.240 | So to be determined, again, here is the banner,

02:14:06.140 | but, you know, tart cherries and kiwi fruits,

02:14:08.500 | the data surprised me because in part I was so preoccupied

02:14:13.500 | with being, you know, I don't know,

02:14:18.540 | a bit pure-ish about it and a bit snobby thinking,

02:14:20.820 | oh, come on, that's definitely not going to work.

02:14:23.220 | Well, the data's so far. - Compounds are compounds.

02:14:25.320 | I look forward to a day when supplements

02:14:26.980 | are no longer called supplements

02:14:28.300 | because at the end of the day,

02:14:29.220 | whether or not something has an effect,

02:14:30.940 | whether or not it's a whole kiwi fruit

02:14:32.280 | or a derivative kiwi fruit

02:14:33.860 | will depend on the molecular compound.

02:14:35.500 | And as you mentioned this potential mechanism

02:14:38.660 | via the GABA system,

02:14:40.180 | that's, we both as scientists get excited about mechanism

02:14:44.400 | 'cause when you can trace a mechanism in a pathway,

02:14:46.500 | it provides a rationale, a grounding for why kiwi

02:14:49.660 | of all things or tart cherry of all things

02:14:51.920 | might help increase total sleep time.

02:14:55.020 | I'd be remiss if I didn't mention

02:14:58.360 | or ask about tryptophan and serotonin.

02:15:01.660 | I can anecdotally say when I've taken tryptophan,

02:15:05.920 | the precursor to serotonin or serotonin itself,

02:15:10.340 | I have a horrendous night's sleep.

02:15:12.620 | I fall asleep very easily

02:15:14.660 | and I experience ridiculously vivid dreams,

02:15:19.540 | neither pleasant nor unpleasant, it's kind of a mishmash.

02:15:22.260 | And then I wake up and I experience several days of insomnia

02:15:26.980 | that, and I've done the positive control

02:15:29.580 | and the negative control and all the variations thereof

02:15:32.340 | to confirm that at least for me,

02:15:34.640 | supplementing with serotonergic agents is a bad idea for me.

02:15:39.640 | And tryptophan is a common sleep supplement

02:15:44.700 | and sleep aid that's discussed.

02:15:46.640 | The normal architecture of sleep

02:15:50.180 | involves the release of serotonin,

02:15:52.100 | but in a very timed and regulated way.

02:15:54.060 | What are your thoughts about serotonin in sleep?

02:15:56.580 | If you had to kind of put that into a nutshell

02:15:59.140 | and then why supplementing with serotonin

02:16:03.520 | and or its precursor, tryptophan,

02:16:05.980 | might be a good or a bad idea for somebody?

02:16:08.640 | - I think one of the potential dangers

02:16:13.620 | is that based on what's going on in your body,

02:16:18.220 | that can change the absorption of natural sort of tryptophan

02:16:22.980 | and serotonin uptake within the brain itself.

02:16:26.180 | So I'm always thoughtful when you're playing around

02:16:29.620 | with that mother nature dynamic, as it were.

02:16:32.820 | The data, as you described,

02:16:34.220 | is a little bit all over the map.

02:16:35.820 | Some people say that it knocks them out.

02:16:37.740 | Other people say, just like you do,

02:16:39.780 | it has a terrible impact on my sleep.

02:16:42.300 | And when I stop, it's pretty bad for a couple of days.

02:16:46.420 | It seems to have this lingering after effect.

02:16:49.580 | I think what could be happening here

02:16:53.860 | is we need serotonin to, just as you described,

02:16:57.260 | be modulated in very specific ways

02:16:59.540 | during the different stages of sleep.

02:17:01.220 | If you look at the firing of the brain epicenters

02:17:05.860 | where serotonin is released,

02:17:07.980 | and there's a bunch of them in the brainstem,

02:17:10.220 | what you find on the release of serotonin too,

02:17:15.220 | when we're awake, it's usually in high concentrations.

02:17:18.180 | As we start to drift off to sleep,

02:17:20.420 | it lowers some, but not necessarily dramatically

02:17:23.820 | as we're going into non-REM sleep.

02:17:26.500 | But then when we go into REM sleep, serotonin is shut off.

02:17:31.500 | The other, one of the other neuromodulators, noradrenaline,

02:17:35.540 | also shut off.

02:17:37.340 | REM sleep is the only time during the 24-hour period

02:17:41.340 | where we see noradrenaline and serotonin,

02:17:43.940 | or norepinephrine, completely shut down.

02:17:46.820 | When I say serotonin, we're also talking 5-HTP,

02:17:49.660 | sorry, 5-HT, that's just its chemical name here.

02:17:52.660 | So whether we're speaking about serotonin or 5-HT,

02:17:56.140 | it's the same thing, norepinephrine, noradrenaline,

02:17:58.340 | both of those need to be shut down

02:18:00.860 | for you to produce REM sleep.

02:18:03.220 | The other, one of the other neuromodulators

02:18:05.500 | that then ramps up to produce REM sleep is acetylcholine.

02:18:09.700 | So these three neuromodulators

02:18:13.380 | have this incredible reciprocal dance that they have

02:18:17.900 | for you to generate what is called a natural architecture

02:18:21.100 | of sleep throughout the night.

02:18:22.340 | - It's the push-pull again.

02:18:23.420 | - It's a push-pull again, it's chest and back,

02:18:28.580 | whatever you want to think of.

02:18:30.900 | That's why I think if you're trying to increase,

02:18:34.180 | dramatically drive up your serotonin levels at night,

02:18:37.820 | and that sustains throughout the night

02:18:39.460 | when you're trying to get into REM sleep,

02:18:41.380 | you could be artificially fragmenting REM sleep.

02:18:43.620 | Now, I don't know the data,

02:18:44.700 | I don't think anyone's really got the data,

02:18:47.140 | but that's why I would be,

02:18:48.780 | if you were to say, Matt, two years time, that's the data,

02:18:53.780 | help me understand the potential mechanism,

02:18:55.860 | or let's design some experiments, where would you go first?

02:18:58.860 | I would say, let's look at the disruption

02:19:00.900 | of REM sleep, non-REM sleep, reciprocal regulation,

02:19:04.500 | because you need serotonin to be up at one time,

02:19:08.700 | down at another, so.

02:19:10.980 | - I agree with everything you said,

02:19:13.460 | and I'm personally never taking tryptophan or serotonin again

02:19:17.860 | unless there's some clinical reason for that,

02:19:20.500 | that I would need to do that.

02:19:21.860 | I want to ask about some other pro-sleep behaviors,

02:19:26.460 | but before I do that, let's talk about naps.

02:19:30.260 | I love naps, I come from a long history of nappers.

02:19:34.740 | My dad always took a nap in the afternoon,

02:19:36.940 | I take a 20 or 30 minute nap, or I do a practice

02:19:40.260 | which I took the liberty of coining NSDR, non-sleep,

02:19:43.740 | deep rest, some sort of just passive laying out there,

02:19:46.980 | feet up, elevated, sometimes people do you,

02:19:49.300 | or I'll do yoga nidra, I'll do hypnosis

02:19:51.580 | or something of that sort, but 20 or 30 minutes of that

02:19:56.060 | has been very beneficial for me to get up from that nap

02:19:59.340 | or period of minimal wakefulness, we'll call it,

02:20:03.100 | and go about my day quite well,

02:20:04.940 | and also fall asleep just fine.

02:20:07.060 | What are the data on naps?

02:20:10.420 | Do you nap, and what are your thoughts

02:20:13.480 | about keeping naps short, meaning 20 to 30 minutes

02:20:17.140 | versus getting out past 90 minutes, two hours?

02:20:20.540 | So for you personally, naps, yay, nay, or meh?

02:20:25.060 | - I don't nap, and I've just never been a habitual napper.

02:20:30.060 | - Is that because you don't feel sleepy in the afternoon

02:20:33.140 | or because-- - I typically

02:20:34.080 | don't feel sleepy. - Okay, so you're just

02:20:35.500 | hardier than I am. - I wouldn't say hardier.

02:20:38.020 | I may be less capable of falling asleep.

02:20:43.020 | My sleep drive-- - But you're not dragging

02:20:45.480 | through the afternoon. - No, no, I don't drag

02:20:47.740 | through a nap. - So you don't nap

02:20:48.580 | because you don't feel a need to nap.

02:20:50.140 | - That's right, yep.

02:20:51.120 | Now, it's not that I am immune to what we call

02:20:54.120 | a postprandial dip in alertness.

02:20:56.520 | I definitely feel as though there can be this

02:20:58.520 | kind of afternoon lull where I'm not quite as on

02:21:03.880 | as I was at 11 o'clock in the morning,

02:21:06.120 | and we know the physiology to that,

02:21:07.900 | which brings us back to whether we were designed to nap.

02:21:10.740 | So for naps, we've done lots of different studies,

02:21:15.140 | and other colleagues have done these studies too.

02:21:17.200 | Naps can have some really great benefits.

02:21:19.580 | We found benefits for cardiovascular health,

02:21:22.180 | blood pressure, for example.

02:21:23.720 | We found benefits for levels of cortisol.

02:21:26.020 | We found benefits for learning and memory,

02:21:28.360 | and also emotional regulation.

02:21:30.900 | - How long are the naps typically in those studies?

02:21:33.460 | - Anywhere between 20 minutes to 90 minutes.

02:21:36.240 | Sometimes we like to use a 90-minute window

02:21:38.680 | so that the participant can have a full cycle of sleep,

02:21:42.000 | and therefore they get both non-REM and REM sleep

02:21:44.560 | within that time period.

02:21:45.680 | Then when we wake them up,

02:21:47.160 | we usually wait a period of time to get them past

02:21:49.540 | what we call sleep inertia,

02:21:51.200 | which is that kind of window of grogginess

02:21:53.060 | where you say to your better half,

02:21:54.800 | look, you know, darling, please don't speak to me

02:21:57.860 | for the first hour after I've--

02:21:59.080 | - Don't anything right now.

02:22:00.240 | - After the first hour of waking up,

02:22:01.800 | you know, I'm just not the best version of myself.

02:22:05.320 | So we wait for that time period,

02:22:06.740 | and then we do some testing,

02:22:08.480 | and we've done some testing before and after,

02:22:10.180 | and we look at the change,

02:22:11.340 | and that's how we measure what was the benefit of naps,

02:22:13.720 | and the reason why we sometimes do 90 minutes

02:22:15.800 | so that they get all of those stages of sleep,

02:22:17.820 | and then we correlate how much benefit

02:22:20.580 | did you get from the nap,

02:22:22.220 | and how much of that benefit was explained

02:22:24.440 | by what REM sleep you got, what deep sleep you got,

02:22:27.660 | what light sleep you got.

02:22:29.100 | So that's the only reason that we use that

02:22:30.880 | as an experimental tool.

02:22:33.200 | What we've also found is that naps of as little as 17 minutes

02:22:37.760 | can have some quite potent effects on, for example, learning.

02:22:41.780 | None of this is novel.

02:22:43.500 | NASA pioneered this back in the 1990s,

02:22:47.020 | and during the missions,

02:22:48.380 | they were experimenting with naps for their astronauts,

02:22:51.340 | and what they found was that naps of little as 26 minutes

02:22:55.480 | improved mission performance by 34%

02:23:00.620 | and improved daytime alertness by 50%,

02:23:04.420 | and it birthed what was then called the NASA nap culture

02:23:08.780 | throughout all terrestrial NASA staff

02:23:12.500 | during that time period.

02:23:13.680 | So it's long been known that naps can have a benefit.

02:23:16.980 | Naps, however, can have a double-edged sword.

02:23:19.240 | There is a dark side to naps,

02:23:22.180 | and it comes back to our story

02:23:23.860 | of adenosine and sleep pressure.

02:23:26.060 | The longer we're awake,

02:23:27.200 | the more of that sleep pressure adenosine that we build up,

02:23:29.980 | but what I didn't tell you is that when we sleep,

02:23:32.740 | the brain gets the chance to essentially clear out

02:23:36.880 | that adenosine, and after about 16 hours of wakefulness,

02:23:41.520 | and then after about eight hours of sleep,

02:23:43.820 | eight hours of sleep seems to be able to allow the brain

02:23:47.220 | to decrease its adenosine levels back to normal,

02:23:50.900 | and so naturally we should start to wake up,

02:23:53.420 | which also aligns with your circadian rhythm,

02:23:55.480 | and those are two separate processes,

02:23:57.600 | but with about eight hours of good quality sleep,

02:24:00.880 | seven to nine hours for the average adult,

02:24:03.160 | we are free of all of that adenosine.

02:24:06.160 | We've evacuated it essentially out of the brain,

02:24:08.960 | and we wake up naturally feeling refreshed.

02:24:11.960 | The reason that naps can be potentially dangerous

02:24:14.740 | is that when you nap,

02:24:16.680 | you are essentially opening the valve

02:24:19.600 | on the pressure cooker of sleep pressure,

02:24:22.560 | and some of that sleepiness is lost by way of the nap,

02:24:27.500 | so for some people, and not all people,

02:24:29.640 | and you're a great example of this,

02:24:32.280 | some people, however,

02:24:33.560 | if they are struggling with sleep at night,

02:24:36.460 | and they nap during the day,

02:24:37.840 | it makes their sleep problems even worse,

02:24:40.360 | so for people with insomnia,

02:24:41.760 | we typically advise against napping,

02:24:44.800 | and the advice is if you can nap regularly,

02:24:47.640 | and you don't struggle with sleep at night,

02:24:50.080 | then naps are just fine,

02:24:51.760 | but if you do struggle with sleep, stay away from naps.

02:24:54.980 | If you are going to nap,

02:24:56.640 | try to limit your naps,

02:24:58.820 | try to cut them off a bit like sort of caffeine,

02:25:01.460 | maybe eight to sort of 12 hours,

02:25:04.300 | maybe not that far off,

02:25:06.120 | maybe sort of seven to six hours is a good rule of thumb.

02:25:09.760 | Try not to nap essentially late in the afternoon,

02:25:12.720 | and if you do take a nap,

02:25:14.940 | and you want to maintain your,

02:25:17.300 | you don't want to have that grogginess hangover

02:25:19.640 | that can happen after a full night of sleep

02:25:21.360 | for the first hour,

02:25:22.560 | try to limit it to about 20, 25 minutes,

02:25:26.060 | and that way you don't go down

02:25:27.600 | into the very deepest stages of sleep,

02:25:30.000 | which if I wrench you out of with an alarm,

02:25:33.160 | then you just kind of feel,

02:25:34.640 | you almost feel worse for the first hour after the nap.

02:25:37.920 | - I've definitely experienced that if I oversleep.

02:25:40.100 | Certainly if the sun goes down during my nap,

02:25:43.080 | and I wake up and overall lighting conditions have changed,

02:25:47.040 | I find it very hard to jolt myself back into the evening,

02:25:50.800 | and it can screw me up,

02:25:52.360 | so I try and keep those naps pretty brief,

02:25:54.600 | and I should say, I'm very happy to hear you mention

02:25:58.620 | individual differences and why some people might want to nap

02:26:01.180 | and other people might not want to nap.

02:26:03.700 | I have a colleague, Leach and Lowe,

02:26:06.220 | he'll be familiar to many neurobiologists,

02:26:08.540 | who's an absolutely spectacular scientist,

02:26:11.020 | member of the National Academy, Howard Hughes Investigator,

02:26:13.120 | just a phenom, and has a ton of energy,

02:26:16.060 | but years ago, I learned that he always takes a nap

02:26:20.280 | in the afternoon, so much so that when he travels

02:26:22.540 | to give seminars at other universities,

02:26:24.380 | he will tell his post lunch, post, whoever it is

02:26:29.380 | that he's supposed to meet with,

02:26:31.480 | may I have your office for 30 minutes

02:26:33.620 | of our sometimes 30 minute discussion

02:26:36.540 | or 60 minute discussion, because I like to take a nap,

02:26:38.860 | and he does that, and then gives his talks

02:26:41.300 | are typically in the afternoon in academic culture,

02:26:43.820 | and he describes the effect of the nap for him,

02:26:48.820 | the short naps in the afternoon being so profound

02:26:51.220 | for his productivity, that's actually what inspired me

02:26:53.220 | to start feeling okay about my desire to nap,

02:26:56.220 | and so I think for me, that was great vindication

02:26:58.720 | for those that might feel guilty about wanting a nap,

02:27:02.120 | but I take to heart your note about avoiding naps

02:27:06.580 | if you have trouble falling and staying asleep,

02:27:08.300 | 'cause I think that I have family members who also,

02:27:10.960 | if they nap, they're a wreck, they can't sleep.

02:27:13.340 | - Yeah, I think it's just,

02:27:14.940 | we've often been very pro sleep,

02:27:17.800 | we as the sort of the sleep community,

02:27:19.300 | so I think it's good to always point out

02:27:22.140 | these potential dark sides of any aspect,

02:27:25.700 | but you're absolutely right, no one should feel guilty

02:27:28.080 | about getting the sleep that they need,

02:27:30.700 | and I think that's been one of the big problems in society,

02:27:33.700 | society has stigmatized sleep with these labels

02:27:36.900 | of being slothful or lazy, and we're almost embarrassed

02:27:40.900 | to tell colleagues that we take a nap.

02:27:43.940 | I think sleep is a right of human beings,

02:27:48.340 | and I therefore think that sleep is a civil right

02:27:51.940 | of all human beings, and no one should make you feel

02:27:55.540 | un-proud of getting the sleep that you need.

02:27:58.540 | - I love that, and it's an important point.

02:28:01.960 | I also feel that one of the best ways to beat

02:28:04.860 | your competition in any endeavor is to outlive them.

02:28:07.440 | So now that we know that sleep can enhance longevity

02:28:12.360 | and lack of sleep can shorten one's life,

02:28:14.720 | that's all the justification I need anyway,

02:28:18.900 | can somebody sleep too much?

02:28:22.120 | Is it possible to get too much sleep?

02:28:23.980 | - It's a very good question, and there are probably

02:28:28.500 | two things to say about it.

02:28:30.660 | There is a condition that we call hypersomnia,

02:28:33.760 | but that's a mixture of things.

02:28:36.220 | It's where people have either a very high sleep need,

02:28:40.120 | or they are very sleepy during the day,

02:28:43.140 | and they're typically falling asleep,

02:28:44.780 | and these can happen in a variety

02:28:46.520 | of different clinical contexts.

02:28:48.380 | One of the places where we've often seen hypersomnia

02:28:52.220 | believed to manifest is in depression,

02:28:56.200 | but if you look at some of those studies,

02:28:58.580 | it turns out it looks more as though those people

02:29:01.380 | are simply reporting being in bed longer,

02:29:04.580 | but not necessarily sleeping longer,

02:29:08.000 | and that fits very well with one of the profiles

02:29:10.180 | that we know of depression, which is anhedonia.

02:29:13.340 | You don't get pleasure from normally pleasurable things,

02:29:15.720 | so you just don't want to go out into the world.

02:29:17.760 | You don't want to interact because you're depressed,

02:29:19.760 | so what do you do?

02:29:20.720 | You just stay in bed.

02:29:21.840 | - Blinds, clothes, watching TV, on the phone.

02:29:23.560 | - Right, and that just looks as though,

02:29:25.800 | when people say, "What time did you go to bed,

02:29:28.160 | "and what time did you get out of bed?"

02:29:30.680 | The mistake made in that question is,

02:29:32.860 | "Okay, that's how much time they're sleeping,"

02:29:34.640 | when you should have said, "What time did you fall asleep,

02:29:37.240 | "and what time did you wake up?"

02:29:39.000 | And the answer could be very different.

02:29:41.220 | So that's hypersomnia from a clinical context.

02:29:46.840 | Can you sleep too much, though?

02:29:49.280 | One of the data points that argue is yes, that's possible,

02:29:52.360 | is when we look at all-cause mortality.

02:29:54.740 | Certainly what you find is that,

02:29:56.440 | using the sweet spot of seven to nine hours,

02:29:59.040 | when you start to drop below seven hours,

02:30:01.600 | there is a relationship which suggests

02:30:03.540 | that the shorter your sleep, the shorter your life.

02:30:05.680 | Short sleep in that regard predicts all-cause mortality.

02:30:08.760 | But it's again not a linear relationship

02:30:10.760 | like the one that we've seen with REM sleep.

02:30:13.060 | Once you get past nine hours,

02:30:15.320 | the mortality curve stops going down,

02:30:18.160 | and then once you get further, 10 or 11 hours,

02:30:20.640 | it hooks back up again.

02:30:21.860 | It's almost like a J shape,

02:30:23.640 | tilted over a little bit and reversed.

02:30:26.240 | So there's this strange hook.

02:30:27.760 | What's going on here?

02:30:29.520 | Right now, sleep science has at least

02:30:32.060 | two non-mutually exclusive explanations for this.

02:30:35.320 | The first is that if you look at some of those populations,

02:30:38.560 | the idea is that whatever was causing them illness

02:30:43.680 | and took their lives was just too much

02:30:46.600 | for sleep to deal with.

02:30:47.940 | However, we know that when we get sick,

02:30:50.320 | one of the things that we do immediately

02:30:51.840 | in this whole mechanism, an inflammatory mechanism,

02:30:54.640 | cytokine mediated, when we get sick, we want to sleep more.

02:30:58.400 | We just want to curl up in bed and sleep it off.

02:31:02.560 | So the argument there is that it's not that sleep

02:31:05.560 | was killing people prematurely,

02:31:07.920 | it was that these people were calling on the help of sleep.

02:31:11.960 | They were calling on this thing called

02:31:13.680 | the Swiss army knife of health that is sleep.

02:31:17.080 | But whatever it is that they were facing

02:31:19.280 | was just too powerful for sleep to overcome.

02:31:23.620 | So it artificially looks as though more sleep

02:31:26.760 | leads to a higher risk of death

02:31:29.400 | when sleep was actually responding to the mortality risk

02:31:32.620 | and it lost the battle.

02:31:33.760 | That's one argument.

02:31:35.400 | The second is that we know that sleep quality

02:31:39.200 | and poor sleep efficiency is a very strong predictor

02:31:43.280 | of all cause mortality.

02:31:45.520 | And when you look at people who often report

02:31:47.960 | sleeping long amounts, 10 or 11 hours,

02:31:51.280 | they typically report having very poor quality sleep.

02:31:54.740 | So because their quality of sleep is poor,

02:31:57.240 | they just try to sleep longer

02:31:59.400 | to try and get some of that back.

02:32:01.740 | So again, here now it's poor quality sleep

02:32:05.280 | masking as too much sleep leading to this artificial hook,

02:32:10.280 | which looks like mortality.

02:32:12.840 | That's a second explanation.

02:32:14.340 | A third, which is more of a good Duncan,

02:32:17.080 | which is just the kind of like a thought experiment.

02:32:19.440 | And I'm of this mentality.

02:32:21.560 | I don't know how many other people share this.

02:32:24.520 | I actually think that could be a thing as too much sleep.

02:32:28.880 | Physiologically, I think it's possible.

02:32:31.360 | But the reason I think that is because it's no different

02:32:34.260 | than food, water, or oxygen.

02:32:37.100 | Can you overeat?

02:32:38.640 | Yes, you can.

02:32:39.480 | Can you under eat?

02:32:40.300 | Of course.

02:32:41.140 | - Or light, light in the early part of the day,

02:32:42.640 | throughout the day, wonderful.

02:32:43.640 | Light late in the day and at night, detrimental.

02:32:45.840 | - Bi-directional.

02:32:47.360 | For water, can you over hydrate hyponutremia?

02:32:51.440 | It can lead, it happened in the 1990s and 2000

02:32:54.800 | with the ecstasy craze,

02:32:56.320 | where governments were saying you're dehydrating,

02:32:58.260 | you're dancing all night, please drink water.

02:33:00.680 | And they drank too much water.

02:33:02.580 | The blood electrolytes went all over the place

02:33:06.080 | and they were having cardiac arrests or stroke.

02:33:08.280 | - Yeah, people were dying.

02:33:09.120 | - And they were dying because of excessive hydration.

02:33:12.000 | Can you get too much oxygen, hyperoxemia,

02:33:14.960 | and it can cause free radical damage,

02:33:17.040 | which can be profoundly harmful and kill brain cells.

02:33:21.080 | Can you sleep too much?

02:33:23.400 | Which is the fifth element of the life equation,

02:33:27.120 | alongside food, water, oxygen.

02:33:31.840 | So fourth, I should say, can't even count.

02:33:34.780 | Clearly I'm sleeping well.

02:33:36.180 | Yes, I think there could be that possibility.

02:33:40.680 | Are most people in danger of getting too much sleep?

02:33:44.720 | Au contraire if you look at the data.

02:33:47.600 | So, but I don't dismiss that idea.

02:33:50.000 | I think it's possible.

02:33:52.040 | - All right, that's a very thorough and very nuanced

02:33:54.960 | and yeah, very clear answer.

02:33:56.340 | So it's so interesting to think that a lot of the data

02:34:01.220 | that out there that talking about being in bed too long,

02:34:04.220 | that it's just trying to compensate

02:34:05.760 | for the actual fragmentation of sleep.

02:34:08.600 | So what I'm coming away with is that there are many paths

02:34:11.780 | to this and both positive and things to avoid.

02:34:14.900 | But the idea is to get most nights a similar amount,

02:34:19.660 | probably seven to nine hours, somewhere in there,

02:34:22.040 | of high quality sleep.

02:34:24.040 | That this notion of sleep quality is going to become,

02:34:27.120 | I would hope, a phrase that more people think about

02:34:30.640 | and learn about and cultivate as a practice.

02:34:33.060 | Want to ask about a set of behaviors that I'm at least,

02:34:38.600 | I'm aware of at least one company is starting to track

02:34:41.440 | in their sleep monitoring device, and that's orgasm.

02:34:46.120 | And sex, orgasm, and masturbation,

02:34:48.640 | topics that are, you know, are somewhat sensitive,

02:34:53.100 | but from the perspective of biology, right?

02:34:57.720 | None of us would be here were it not

02:34:59.320 | for a sperm meets egg in some fashion,

02:35:01.360 | either in a dish or in vivo.

02:35:03.440 | But what are the data, as you know them to be,

02:35:09.340 | or maybe your lab is even doing this kind of work

02:35:12.480 | and exploration, about the role that sex, orgasm,

02:35:17.480 | masturbation play in getting to sleep

02:35:19.960 | and staying asleep and sleep quality?

02:35:22.500 | Certainly those behaviors and those physiological events

02:35:25.680 | have been part of our evolutionary history.

02:35:29.240 | What's the story there?

02:35:30.400 | What can we say about this in terms of science

02:35:33.660 | and dare I say, practice?

02:35:36.940 | - Yeah, I mean, it's almost that caricature of,

02:35:39.740 | you know, in the movies where, you know,

02:35:41.800 | a couple makes love and then all of a sudden

02:35:44.300 | you just sort of hear snoring or, you know,

02:35:47.440 | with the idea that it's somewhat somnogenic,

02:35:51.060 | that it's sleep promoting.

02:35:52.720 | - Well, the post-orgasmic increase in prolactin

02:35:55.400 | is thought to be a naturally occurring sedative

02:36:00.400 | that presumably has a function in-

02:36:03.120 | - And oxytocin has that also that benefit

02:36:05.800 | where you see, you know, a dissipation

02:36:07.920 | of the fight or flight branch of the nervous system,

02:36:09.720 | which has to happen for you to fall asleep.

02:36:12.120 | That's why we often see, you know,

02:36:14.000 | here at the sleep center,

02:36:15.320 | we'll see a phenomenon called wired and tired,

02:36:18.620 | where people say, look, I am so desperately tired.

02:36:22.260 | I just, I'm so, so tired, but I can't fall asleep

02:36:26.220 | because I'm too wired.

02:36:27.740 | So your sleep drive, you're desperately tired.

02:36:31.260 | It's there, but because you're wired,

02:36:33.860 | because you've got too much sympathetic activation,

02:36:36.020 | too much cortisol as well, you can't fall asleep.

02:36:39.060 | It's an impressive roadblock to anything like good sleep.

02:36:44.060 | And it's one of the principle mechanisms

02:36:46.640 | that we now believe, stress and physiological activation,

02:36:49.980 | that is the underlying cause of many forms of insomnia.

02:36:54.180 | But coming back to sex,

02:36:57.320 | the data is actually quite compelling

02:37:00.200 | that both either subjectively assessed sleep quality

02:37:04.000 | or objective amount of sleep.

02:37:06.540 | Sex that has resulted in orgasm,

02:37:10.340 | and I think it's that latter part

02:37:12.440 | that typically needs to happen.

02:37:14.460 | - I would imagine so.

02:37:15.760 | That, you know, so between two mutually exclusive individuals

02:37:20.760 | where both are, you know,

02:37:23.760 | beneficial in terms of receiving an orgasm.

02:37:26.360 | - Yeah, I would say any discussion about sex,

02:37:28.160 | we were referring to consensual, age appropriate,

02:37:32.020 | species appropriate, context appropriate.

02:37:35.880 | - Wow, I would never have even gone

02:37:37.600 | to the species appropriate. - I put species in there

02:37:38.760 | because it's the internet

02:37:39.960 | and people will come up with all sorts of ideas.

02:37:41.680 | So I think that age appropriate,

02:37:43.640 | I think age appropriate, consensual, context appropriate,

02:37:46.600 | and species appropriate covers all the bases.

02:37:48.360 | But if I missed any, put them in the comment section

02:37:50.640 | and we'll be sure to take notes.

02:37:51.840 | - Yeah, no, I think that's really well said

02:37:55.060 | and important to say.

02:37:56.700 | So the data is the,

02:37:58.700 | when you look at couples who have orgasm,

02:38:02.880 | we've also however found benefits of masturbation.

02:38:06.760 | And it's not frequently spoken about,

02:38:09.580 | but if you do some surveys,

02:38:12.960 | it turns out that people will often use masturbation

02:38:16.600 | as a sleep tool if they're struggling with sleep.

02:38:18.840 | And I know this sort of sounds almost

02:38:20.640 | like a strange conversation or it's a taboo conversation,

02:38:23.280 | but I think we just need to be very open about all this.

02:38:25.720 | - I started off in science,

02:38:27.640 | one of the things I worked on early in my career,

02:38:30.360 | not the very first topic,

02:38:31.620 | was the topic of early influences of hormones,

02:38:35.840 | estrogen and testosterone on sexual development

02:38:38.700 | of the brain and body.

02:38:40.040 | And when you are weaned in a laboratory like that,

02:38:43.600 | regardless of what era,

02:38:45.160 | you look at sex and its behaviors and its hormones

02:38:49.440 | and its physiologies as a scientist.

02:38:51.440 | And so I think that's to be clear what we're doing here,

02:38:53.700 | we're exploring these behaviors from that perspective.

02:38:58.700 | I mean, one thing is for certain,

02:39:00.800 | everyone is here because a sperm met an egg,

02:39:03.520 | either in a dish or in vivo, as we said before.

02:39:06.080 | And at least in 2021, there's no way around that fact.

02:39:10.000 | - Yeah.

02:39:10.840 | - And what preceded that is typically this act we call sex.

02:39:14.560 | And sometimes, hopefully, I like to think,

02:39:18.440 | orgasm is associated with that sexual activity.

02:39:21.240 | Masturbation as one dimension of that

02:39:23.860 | is something that I think can and should be discussed

02:39:26.660 | if in fact there are data that relate it to sleep.

02:39:29.260 | - Yeah, and both of those routes

02:39:31.160 | seem to lead to a sleep benefit.

02:39:34.600 | Now, I'm not saying that it's all about the orgasm.

02:39:37.740 | I think as we spoke about with oxytocin,

02:39:40.720 | there is some degree of per bonding

02:39:43.420 | that if you have a partner and you experience

02:39:47.020 | an intimate loving relationship that involves that,

02:39:51.440 | then you can have hormonal benefits that are sleep promoting

02:39:56.120 | that may not necessarily be seen if you're just engaging

02:40:00.400 | in the solo singular act of masturbation.

02:40:03.820 | So what we certainly know,

02:40:06.100 | and I am not someone to take any advice on

02:40:08.800 | when it comes to anything relationship-wise or sex-wise.

02:40:12.480 | - That's a different episode of the podcast.

02:40:13.920 | - Yeah, yeah, yeah, certainly.

02:40:14.960 | And that's not a podcast series

02:40:16.520 | that I'm going to be releasing anytime soon.

02:40:18.440 | It's going to be mostly about sleep,

02:40:20.160 | although I will touch on,

02:40:21.500 | I'll release a podcast on sleep and sex.

02:40:23.880 | But that's the data that we have so far.

02:40:27.040 | We also know that it works both ways though,

02:40:29.360 | and it's commonly the same way with sleep,

02:40:33.040 | you know, sleep and exercise, sleep and diet.

02:40:35.960 | How you eat can affect how you sleep.

02:40:39.680 | How you sleep can affect how you eat.

02:40:41.700 | Same with exercise.

02:40:43.040 | And it turns out it's the same way with sexual behavior too.

02:40:47.160 | So here we're talking about whether sex can help with sleep.

02:40:51.380 | Can sleep help with your relationship and sex?

02:40:54.480 | And the answer is yes, it can.

02:40:56.660 | Firstly, we know, and we've spoken a little bit about this,

02:40:59.220 | that the reproductive hormones

02:41:00.840 | are under profound sleep regulation.

02:41:02.700 | - Both estrogen and testosterone.

02:41:04.180 | - Estrogen, testosterone.

02:41:05.560 | - We hear so often about testosterone,

02:41:07.760 | but women who, or I should say anyone who's interested

02:41:10.600 | in having higher levels of estrogen

02:41:12.520 | or normal healthy levels of estrogen,

02:41:15.340 | I presume the data show for estrogen

02:41:18.120 | what the data also show similarly for testosterone,

02:41:21.360 | which is if you get too little or poor quality of sleep,

02:41:24.920 | both sex steroid hormones as they're referred to,

02:41:26.880 | testosterone, crammed estrogen,

02:41:28.640 | which are present in both males and females

02:41:30.240 | and every variation thereof,

02:41:31.880 | are going to be diminished below normal healthy levels.

02:41:34.480 | - Estrogen, testosterone, FSH in women,

02:41:38.280 | a key hormone in the regulation for,

02:41:41.580 | key for conception, of course.

02:41:44.940 | All of these sex hormones

02:41:46.840 | seem to become significantly disrupted

02:41:50.020 | when sleep becomes of short quantity or poor quality.

02:41:54.680 | We also know that in women,

02:41:56.400 | sleep disruption can usually lead

02:41:58.880 | to menstrual cycle disruption.

02:42:01.760 | We know this particularly from evidence in shift working

02:42:04.560 | women where they are nighttime shift workers,

02:42:07.480 | they struggle with sleep during the day.

02:42:09.520 | Often menstruation is disrupted or even becomes impaired.

02:42:14.520 | But we also know it works this way,

02:42:17.240 | not just for sex hormones, but for sex itself.

02:42:22.240 | For example, we found that for every one hour of sleep,

02:42:26.960 | extra sleep that a woman gets,

02:42:28.840 | her interest in becoming sexually intimate with her partner

02:42:32.320 | increases by 14%, which is a non trivial amount.

02:42:37.320 | And then the final part of,

02:42:39.800 | I think this equation when it comes to sleep and sex

02:42:43.640 | is your relationship itself.

02:42:47.520 | And there's some great work here from UC Berkeley

02:42:49.880 | by Professor Serena Chen.

02:42:52.560 | And what she found was that restless nights

02:42:55.760 | mean for far more brutal fights in your relationship.

02:42:59.880 | And they did this in a number of different elegant ways

02:43:02.740 | and vice versa as well.

02:43:04.240 | - I mean, not that I've ever had conflict in relationships.

02:43:06.880 | - Me like, I just, this is just data I've read,

02:43:09.360 | I've never experienced that at all.

02:43:11.120 | So they found reliably that sleep would predict

02:43:16.080 | higher likelihood of relationship conflict.

02:43:19.640 | Secondly, if you got into that conflict,

02:43:22.240 | the chances of you resolving it were significantly lower

02:43:25.800 | when the parties had not been sleeping well.

02:43:28.880 | Part of the reason is because when you're not well slept,

02:43:32.280 | your empathy goes down.

02:43:35.440 | So you're not, you're taking more of an abrasive stance

02:43:39.640 | with your partner rather than a more agreeable stance

02:43:43.220 | with your partner.

02:43:44.520 | So at almost every dimension

02:43:46.840 | of a human loving relationship,

02:43:50.220 | sleep can have a dramatic impact.

02:43:53.120 | - I think these are really important things to underscore.

02:43:55.720 | One of the most common questions I get,

02:43:58.420 | because there seems to be a community of people

02:44:01.020 | on the internet that are obsessed with this.

02:44:03.440 | I don't know who they are because it's all,

02:44:05.500 | all this internet stuff is shouting into a tunnel

02:44:07.420 | and getting comments back in written form.

02:44:08.960 | It's a very bizarre conversation, so to speak,

02:44:13.480 | is whether or not sexual behavior itself

02:44:17.940 | lowers or increases testosterone.

02:44:19.720 | And I went into the data, which spans many decades actually,

02:44:24.720 | both animal studies and human studies.

02:44:26.580 | And it seems just to underscore this,

02:44:28.640 | as long as we're talking about the subject,

02:44:30.200 | that it does seem that sexual activity,

02:44:34.640 | sex between two people

02:44:36.920 | does seem to increase testosterone in both.

02:44:41.060 | There is this question about orgasm or no orgasm,

02:44:45.700 | ejaculation, no ejaculation.

02:44:47.440 | And indeed, there do seem to be some effects

02:44:50.040 | of restricting ejaculation in males

02:44:54.360 | as a form of further increasing testosterone.

02:44:57.080 | So sex without ejaculation, further increasing testosterone.

02:45:00.260 | But the data are not clean,

02:45:02.780 | presumably because organizing these sorts of studies

02:45:05.160 | and getting truth in self-reporting

02:45:06.880 | is probably hard to get from subjects.

02:45:09.680 | But everything sort of points in the direction

02:45:14.480 | that provided that the relationship is a healthy one,

02:45:19.240 | it's consensual, it's age-appropriate,

02:45:20.800 | context-appropriate, species-appropriate,

02:45:22.800 | that sex between two individuals

02:45:24.100 | does seem to increase the sex steroid hormones,

02:45:26.580 | testosterone and estrogen, toward healthy ranges.

02:45:29.140 | And what I'm hearing now,

02:45:30.680 | the sort of gestalt of the discussion we just had,

02:45:33.000 | is that that too can promote sleepiness,

02:45:37.080 | restful states, and quality sleep.

02:45:40.040 | And I think this is an important conversation

02:45:42.960 | that just hasn't been held enough.

02:45:44.500 | I mean, sooner or later, both in the US and elsewhere,

02:45:47.280 | we're going to have to acknowledge

02:45:48.720 | that we are biological organisms of some sort,

02:45:51.280 | and that we have choice in life about all these things,

02:45:54.940 | from supplementation to sex or no sex, et cetera,

02:45:57.640 | but that they have profound effects on our core biology.

02:46:02.060 | I mean, it's fascinating to me

02:46:04.400 | that the areas of the hypothalamus,

02:46:06.140 | the preoptic area, the superoptic areas,

02:46:08.480 | those areas which the names might not mean anything

02:46:11.400 | to anybody besides Matt and I sitting here,

02:46:13.840 | but those areas sit cheek to jowl with each other

02:46:16.900 | in the hypothalamus and control sleep and sex.

02:46:20.620 | The trigger of orgasm, the appetite for food,

02:46:24.840 | the appetite for water, for electrolytes.

02:46:26.840 | I mean, the hypothalamus is kind of a festival of neurons

02:46:31.840 | with different booths for different primitive behaviors.

02:46:35.160 | - It's such a small, small structure in the brain,

02:46:36.780 | but it's the orchestrator

02:46:38.280 | of a vast number of our behaviors disproportionate

02:46:41.700 | in terms of its size versus effect.

02:46:43.600 | - Yeah, I don't think you can go

02:46:44.720 | to this hypothalamic festival

02:46:46.140 | without at least seeing all the booths,

02:46:48.920 | whether or not you decide to visit them or not.

02:46:50.280 | - Oh, I love that.

02:46:51.560 | Master analogy there.

02:46:53.420 | - So I'm glad that we've broached that conversation,

02:46:58.420 | and I hope people will think that we've approached it

02:47:01.720 | with the appropriate level of sensitivity.

02:47:03.360 | It's an important one that we're going to hear more about

02:47:05.920 | one way or the other.

02:47:06.760 | People are certainly thinking about this,

02:47:08.000 | if not engaging in these sorts of behaviors

02:47:10.440 | or avoiding them.

02:47:11.800 | So the more we can understand about the biology, the better.

02:47:14.560 | - I'll say.

02:47:15.960 | - And so thank you for bringing that topic up

02:47:17.880 | because for the record, Matt tabled it for discussion.

02:47:20.920 | [laughing]

02:47:22.040 | - I said, we were just like chatting outside,

02:47:24.180 | and I think we'd said something about sex,

02:47:26.680 | and I said, yeah, we can go there.

02:47:27.960 | That's actually interesting data.

02:47:29.400 | - Absolutely.

02:47:30.320 | I want to touch on just two remaining topics.

02:47:35.240 | One is, are there any unconventional sleep tips

02:47:40.240 | or things about sleep that we've overlooked?

02:47:42.880 | If we've covered everything, great.

02:47:44.840 | But we're here to keep the room cool.

02:47:47.700 | We're here because of this temperature phenomenon,

02:47:50.680 | the light aspects, the considerations about alcohol,

02:47:53.720 | CBD, marijuana, cognitive behavioral,

02:47:57.800 | tart cherry fruit, kiwis, perhaps.

02:48:01.440 | - Please don't put me on the hook for tart cherries and kiwi.

02:48:03.680 | I was just offering what I know about them.

02:48:05.080 | - No, and these are considerations

02:48:06.800 | and whether or not people batch these things.

02:48:09.480 | I won't even list them off now

02:48:10.860 | because there are too many jokes that one could make.

02:48:13.560 | - And I have no affiliation with any of these products

02:48:17.320 | or companies or whatever. - Well, I'm going to take out

02:48:18.600 | stock in a kiwi company.

02:48:19.800 | No, I'm just kidding.

02:48:21.480 | But the question I have is about any unconventional

02:48:26.440 | or lesser known things, or maybe you do things

02:48:28.700 | or you think about things just in a purely exploratory way

02:48:32.840 | as a scientist, the what-if kind of things,

02:48:37.220 | that what if it turns out that,

02:48:40.760 | and I hear I've got a blank there for you to fill in.

02:48:44.540 | - I think beyond the standard fare

02:48:49.120 | that I've dished out plenty of times of sleep hygiene,

02:48:52.320 | of regularity, temperature, darkness, alcohol, caffeine,

02:48:57.180 | and we've spoken about all of those,

02:48:59.520 | what are some more unconventional tips, I guess?

02:49:03.600 | The first one, which is unconventional

02:49:05.880 | along the lines of naps,

02:49:07.860 | if you've had a bad night of sleep,

02:49:09.880 | let's say that you're starting to emerge with insomnia

02:49:12.840 | and you've had a bad night of sleep,

02:49:14.800 | the advice, and I learned this

02:49:16.540 | from my wonderful colleague, Michael Perlis, do nothing.

02:49:20.440 | What I mean by that is don't wake up any later,

02:49:24.640 | don't sleep in the following day to try and make up for it.

02:49:27.680 | Don't nap during the day,

02:49:30.520 | don't consume extra caffeine to wake you up

02:49:33.880 | to try to get you through the day,

02:49:35.600 | and don't go to bed any earlier

02:49:37.900 | to think that you're going to compensate.

02:49:40.780 | And I can explain all of those things,

02:49:42.960 | but if you wake up later,

02:49:44.740 | you're not going to be sleepy until later the evening,

02:49:47.560 | so you're gonna go to bed at your normal time

02:49:49.640 | and you won't be sleeping, you'll think,

02:49:50.940 | "Well, I just came off a bad night of sleep

02:49:53.600 | "and now I can't even get to sleep

02:49:56.980 | "and it's my normal time."

02:49:58.520 | It's because you slept in later than you would otherwise

02:50:01.400 | and you reduce the window of adenosine accumulation

02:50:04.680 | before your normal bedtime.

02:50:06.600 | So don't go, don't wake up any later,

02:50:09.920 | don't use more caffeine for the reasons that are obvious

02:50:12.640 | because that's only gonna crank you

02:50:13.880 | and keep you awake the following night

02:50:15.380 | or decrease the probability

02:50:17.240 | of a good following night of recovery sleep.

02:50:19.480 | Third, I mentioned don't take naps

02:50:23.360 | because once again, that will just take,

02:50:25.920 | naps particularly later in the afternoon,

02:50:28.340 | I almost liken them to snacking before a main meal,

02:50:31.460 | it just takes your appetite off the edge

02:50:33.680 | of that main meal of sleep, so don't do it.

02:50:36.380 | And then finally, don't go to bed any earlier,

02:50:39.200 | resist and resist and go to bed at your normal time.

02:50:42.960 | What I want to try and do is prevent you from thinking,

02:50:45.680 | "Well, I had such a bad night last night

02:50:47.440 | "and I normally go to bed at 10.30,

02:50:49.140 | "I'm just gonna get into bed at nine o'clock

02:50:51.360 | "because last night was just so bad."

02:50:53.580 | But that's not your natural bedtime

02:50:55.740 | and it's not aligned with your natural chronotype

02:50:58.640 | because presumably you kind of know something about that

02:51:01.560 | or morning type, evening type,

02:51:02.920 | you're trying to sleep in harmony

02:51:04.120 | which is usually how you get best quality sleep.

02:51:07.080 | But you go to bed at nine

02:51:08.360 | and my body is not ready to sleep at nine o'clock,

02:51:12.060 | but I'm worried

02:51:12.960 | because I had a bad night of sleep last night,

02:51:14.920 | so I get into bed and now I'm tossing and turning

02:51:17.680 | for the first hour and a half

02:51:19.040 | because it's not my natural sleep window

02:51:21.120 | but I just thought it was a good idea.

02:51:23.200 | And if I didn't know anything about sleep,

02:51:25.460 | I would think all of these same things too.

02:51:27.720 | So I'm not finger wagging,

02:51:29.720 | but if I have a bad night of sleep and I am not immune,

02:51:33.360 | just because I know a little bit about sleep

02:51:36.000 | doesn't mean I don't have my bad nights, I do.

02:51:38.840 | Doesn't mean I haven't had bouts of insomnia in my life,

02:51:41.360 | I have.

02:51:42.600 | But after a bad night of sleep, I do nothing.

02:51:46.120 | I don't do any of those four things.

02:51:49.480 | I think the second tip I would offer

02:51:52.280 | in terms of unconventional

02:51:53.680 | is have a wind down routine.

02:51:56.680 | Many of us think of sleep as if it's like a light switch,

02:52:01.680 | that we just jump into bed and when we turn the light out,

02:52:04.460 | sleep should arrive in that same way.

02:52:07.060 | Just the binary, it's on or it's off.

02:52:09.440 | Sleep is a physiological process.

02:52:11.200 | It's much more like landing a plane.

02:52:13.940 | It takes time to gradually descend down

02:52:16.660 | onto the terra firma of what we call

02:52:18.760 | good solid sleep at night.

02:52:21.060 | Find out whatever works for you

02:52:23.240 | and it could be light stretching.

02:52:25.320 | I usually meditate for about 10 or 15 minutes before bed.

02:52:30.200 | Some people like reading.

02:52:32.580 | Try not to watch television in bed.

02:52:34.240 | That's usually advised against.

02:52:35.080 | - Something that doesn't emit too much light to your eyes.

02:52:36.400 | - Too much light, too activating.

02:52:38.560 | You know, you can listen to a relaxing podcast,

02:52:40.560 | although we can speak about technology in the bedroom too,

02:52:43.480 | but have some kind of a wind down routine.

02:52:47.280 | It's, you know, it's almost like, you know,

02:52:50.560 | you wouldn't race into your garage

02:52:53.200 | and come to a screeching halt from 60 miles an hour.

02:52:57.740 | You typically downshift your gears

02:53:00.260 | and you slow down as you come into the garage.

02:53:01.800 | There's the same thing with sleep too.

02:53:04.080 | So that's the second thing.

02:53:05.120 | Have some kind of a wind down routine.

02:53:07.040 | Find what works for you.

02:53:08.120 | Maybe it's taking a hot bath or a warm shower

02:53:11.160 | and then stick to it.

02:53:12.480 | Just, we do this with kids all the time.

02:53:14.240 | We find out what their bedroom,

02:53:16.200 | sorry, their bedtime regiment is

02:53:18.660 | and then we just stick to it faithfully

02:53:21.060 | 'cause we humans are the same way too.

02:53:24.460 | The third thing is a myth.

02:53:26.380 | Don't count sheep.

02:53:27.900 | There was a study done here at UC Berkeley.

02:53:29.420 | I didn't do this today, I wish I did.

02:53:30.580 | It was by my colleague, Professor Alison Harvey.

02:53:33.000 | And they found that counting sheep

02:53:35.220 | actually made it harder to fall asleep.

02:53:37.460 | It made matters worse.

02:53:39.240 | As a counter, sorry, counter measure to that,

02:53:42.340 | what they did find was that taking yourself

02:53:45.140 | on some kind of a mental walk.

02:53:47.580 | So think about a nice walk that you take in nature

02:53:50.420 | or a walk on the beach

02:53:51.700 | or even a walk around an urban environment

02:53:54.580 | and visualizing that, that seemed to be beneficial.

02:53:59.000 | The other thing about sort of that idea

02:54:02.260 | of shifting focus away from your mind itself,

02:54:06.260 | get your mind off itself is a good piece of advice.

02:54:10.520 | Catharsis, you can try to write down

02:54:14.240 | all of the concerns that you have

02:54:16.900 | and do this not right before bed,

02:54:19.240 | but usually an hour or two before bed.

02:54:21.980 | Some people call it a worry journal.

02:54:24.680 | And to me, it's a little bit like closing down

02:54:28.020 | all of the emotional tabs on my browser.

02:54:30.600 | Because if I shut the computer down

02:54:33.420 | and all of those tabs are still open,

02:54:35.600 | I'm gonna come back in the morning

02:54:36.440 | and the computer's red hot, the fan's going

02:54:38.780 | because it didn't go to sleep.

02:54:40.580 | Because it couldn't because there were too many tabs

02:54:42.540 | active and open.

02:54:43.700 | I think it's the same way with sleep as well.

02:54:45.580 | So try to think about doing that.

02:54:47.320 | So just vomit out all of your concerns on the page.

02:54:50.660 | - I like that 'cause my 3 a.m. waking

02:54:52.540 | is often associated with me writing down

02:54:54.360 | the list of things that I forgot to do, that I need to do.

02:54:56.980 | And once I eventually wake up from the later night,

02:55:01.260 | second half of the night's sleep,

02:55:03.220 | that stuff seems much more tractable and reasonable,

02:55:05.500 | but it sure would be great to get that stuff

02:55:08.020 | out of the way before sleep.

02:55:09.500 | - Well, there's also something

02:55:10.620 | that I don't think people have spoken about a lot

02:55:12.940 | and I'd like to research it,

02:55:14.980 | which is difficulty and anxiety at night in the dark

02:55:19.980 | is not the same difficulty and anxiety in the light of day.

02:55:27.380 | And when we have those thoughts at night,

02:55:31.380 | it comes with a magnitude of rumination

02:55:33.980 | and catastrophization that is disproportionate

02:55:38.540 | to that which you would describe when you are awake.

02:55:42.460 | And I don't know what's going on about the brain

02:55:47.000 | and thought and emotion at the time.

02:55:49.540 | I've got a bunch of theories as to why.

02:55:52.340 | And that's why I like the idea of closing up,

02:55:55.960 | zipping up all of those different components,

02:55:58.940 | just get them out on the page and it feel,

02:56:03.780 | and I at first thought, this just sounds like Huey,

02:56:06.340 | it sounds very Berkeley, it's kind of come by R,

02:56:08.780 | we all hold hands and walk home at the end of the day.

02:56:12.140 | But then the data started coming out,

02:56:14.520 | really good studies from good people.

02:56:16.220 | And they found that keeping one of those journals

02:56:18.740 | decreased the time it takes you to fall asleep by 50%, five,

02:56:22.060 | zero, it's well on par with any pharmaceutical agent.

02:56:26.300 | - Oh, absolutely.

02:56:27.300 | I'm convinced that, well, I've long thought

02:56:29.900 | that the worries and concerns and ideas I have at three,

02:56:34.100 | four a.m., I've learned to not place any stock in them

02:56:37.420 | because something, I'm glad that you might decide

02:56:41.140 | to eventually look at this in your laboratory

02:56:43.020 | because I feel like something is melted away or altered.

02:56:46.420 | I suspect it's in the regulation

02:56:49.920 | of the autonomic nervous system,

02:56:51.860 | that it makes sense why a concern at three, four a.m.

02:56:55.180 | ought to evoke more of a panic sense than a concern sense.

02:56:59.620 | And certainly that's my experience,

02:57:01.180 | although I'm fortunate to not suffer

02:57:03.040 | from full-blown panic attacks,

02:57:04.480 | but everything seems worse at three, four a.m.,

02:57:06.940 | provided you're awake.

02:57:07.880 | - And we need to sort of look into that

02:57:09.820 | because if you look at suicide rates

02:57:13.060 | around the 24-hour clock face,

02:57:15.460 | disproportionately higher rates

02:57:17.480 | in those middle sort of night hours.

02:57:21.100 | So now I don't know if that's causative or not,

02:57:23.900 | but something, it could just be that that's the time

02:57:26.220 | when we're mostly lonely and we're by ourselves,

02:57:28.440 | and that's the reason.

02:57:29.280 | So it's got nothing to do with sleep or the nighttime.

02:57:31.300 | I don't know.

02:57:32.140 | So that's the third thing.

02:57:34.480 | I think the fourth sort of little tip I would give

02:57:37.660 | that's unconventional is remove all clock faces

02:57:41.340 | from your bedroom.

02:57:42.420 | - Including your phone.

02:57:43.400 | - Including your phone and resist checking it.

02:57:46.780 | Now I know, and I can speak about the phone too,

02:57:49.860 | that genie of technology is out the bottle

02:57:52.640 | and it's not going back in anytime soon.

02:57:54.260 | So we've got to think as scientists and sleep scientists,

02:57:57.540 | as to what we do with phones in the bedroom.

02:58:01.100 | - Years ago, I was a counselor at a summer camp.

02:58:03.180 | I worked with at-risk kids

02:58:04.820 | and there was a phrase that comes to mind here.

02:58:07.100 | It's be a channel, not a dam,

02:58:09.180 | because when you try and dam certain kinds of behavior,

02:58:12.060 | physically dam certain kinds of behavior,

02:58:14.780 | not morally dam, that too,

02:58:17.740 | it just creeps over the edge and you get a waterfall.

02:58:23.740 | So it has to be channeled.

02:58:25.300 | The phone and devices have to be worked with

02:58:27.700 | and negotiated, not eliminated.

02:58:28.740 | - That's right, and think about those mindfully too,

02:58:31.560 | but clock faces, remove all of those,

02:58:34.680 | because if you are having a tough night,

02:58:38.280 | knowing that it's 3.22 in the morning,

02:58:40.600 | or it's 4.48 in the morning,

02:58:43.140 | does not help you in the slightest.

02:58:46.000 | And it's only going to make matters worse than better.

02:58:48.960 | So try to remove all clock faces.

02:58:51.560 | And I think that's one of those other tips

02:58:53.360 | that some people have found helpful,

02:58:55.260 | but those would be sort of some slightly unconventional,

02:58:58.720 | I guess, more than your stock fare of,

02:59:00.920 | here are the five tips for sleep hygiene tonight.

02:59:04.040 | - Those are terrific sleep tips,

02:59:06.520 | and several of which, if not all of which,

02:59:08.380 | I'm going to incorporate.

02:59:09.800 | Matt, this has been an amazing deep dive on sleep

02:59:14.640 | and it's positive and negative regulators.

02:59:16.980 | - I hope it hasn't been too long.

02:59:18.480 | - No, this has been great.

02:59:20.160 | - Please cut it down, shorten it to, you know,

02:59:22.520 | the five minutes of meaningful stuff that I offer.

02:59:24.840 | - Absolutely not, absolutely not.

02:59:26.000 | It is chock-a-block full of valuable takeaways.

02:59:28.960 | It's been tremendously fun for me

02:59:32.080 | to dissect out this incredible aspect of our lives

02:59:35.840 | that we call sleep with a fellow scientist

02:59:37.800 | and a fellow public educator.

02:59:39.760 | I want to say several things.

02:59:42.320 | First of all, we should say where people can find you,

02:59:46.440 | although it shouldn't be that difficult these days.

02:59:48.480 | You're a very present on the internet.

02:59:51.360 | For better or for worse.

02:59:53.440 | I think it's wonderful that you're out there.

02:59:54.960 | Look, it's a public health service that you're doing.

02:59:58.600 | No one requires you or any other scientist to get out.

03:00:01.680 | And share this information.

03:00:04.560 | My sense of you knowing you a bit

03:00:07.080 | and from following your work very closely,

03:00:08.640 | both your scientific work in detail

03:00:10.300 | and your public facing educational work

03:00:13.400 | is that you very much want the best for people.

03:00:16.680 | And it's an interesting thing as a scientist or a clinician

03:00:20.560 | to know that certain answers exist,

03:00:24.680 | that we don't have all the answers,

03:00:25.800 | but that there is a better path.

03:00:27.260 | There are better ways and people can benefit

03:00:29.000 | in a myriad of ways.

03:00:30.440 | So for that, because I know that to be very genuine in you,

03:00:34.320 | you want the best for people

03:00:36.680 | and you're offering tremendous advice and considerations

03:00:41.160 | and people can take it or leave it.

03:00:42.520 | That's the way I view it.

03:00:43.580 | I also want to thank you for taking the time out of your day

03:00:45.700 | to sit with me here and have this discussion.

03:00:49.560 | - It's a privilege.

03:00:50.640 | It's a delight.

03:00:51.800 | You and I, I think we're like kind in lots of ways.

03:00:55.520 | And I take you as a shining example

03:00:59.600 | of how you can effectively connect with the public.

03:01:03.640 | And I know that we've had our conversations

03:01:05.680 | before we ever sat down sort of together

03:01:07.560 | about how to think about communicating with the public

03:01:12.200 | and the pros and cons of that.

03:01:14.240 | And I've just loved your opinions.

03:01:16.460 | I've been drinking it all in.

03:01:18.520 | And then I think the third thing I'd like to say is,

03:01:21.560 | thank you for being such an incredible sleep ambassador.

03:01:25.280 | The series that you've released on sleep,

03:01:27.720 | the way that you speak about sleep,

03:01:29.220 | the way that you moderate and have championed sleep,

03:01:33.040 | it is remarkable.

03:01:34.720 | So thank you for just being a brother in arms in that way.

03:01:39.720 | - Well, we are, and thanks for those words.

03:01:43.240 | 99% of what I discussed there was the work of you

03:01:45.960 | and your colleagues in the sleep field.

03:01:47.560 | So proper acknowledgement, but thank you.

03:01:49.640 | Where can people learn more

03:01:52.000 | about what you're doing currently and what's coming next?

03:01:54.800 | You're on Twitter.

03:01:56.000 | - I am on Twitter.

03:01:58.360 | I typically tweet.

03:02:00.440 | - As the sleep diplomat.

03:02:01.640 | - So it's, no, it's just sleep diplomat.

03:02:03.940 | - Sleep diplomat.

03:02:04.940 | - Sleep diplomat on Twitter, sleepdiplomat.com website.

03:02:09.940 | If you want to learn more about the science that we do here,

03:02:13.360 | it's humansleepscience.com.

03:02:16.280 | It's the Center for Human Sleep Science.

03:02:18.900 | You can pick up a copy of the book if you want.

03:02:23.980 | It's called "Why We Sleep."

03:02:25.600 | If you're curious about sleep,

03:02:27.520 | that's one path to take and it's my view.

03:02:29.400 | - Is there another book someday in the future?

03:02:32.000 | - I think there may be.

03:02:33.480 | Yeah, I think there are.

03:02:35.000 | - Many, many millions of people

03:02:36.560 | will be very happy to hear that.

03:02:38.040 | - I think it's starting to take hold.

03:02:40.440 | And then as we discussed,

03:02:43.040 | I am more than kicking around the idea

03:02:46.680 | of a short form podcast rather than a long form.

03:02:49.700 | Not long form because I don't have the mental capacity

03:02:53.600 | or the interviewing just capability

03:02:57.520 | that someone like you has.

03:02:59.080 | So it will probably just be monologue short form.

03:03:01.380 | So if there is some interest, I'll probably do that as well.

03:03:05.120 | So those are the ways that people can find me.

03:03:07.280 | But overall, if you're interested in sleep,

03:03:10.520 | just listen to Andrew.

03:03:12.160 | That's the best thing I can tell people.

03:03:14.000 | - All right, well, now we're batting back and forth

03:03:16.480 | the vector of action, so to speak.

03:03:19.660 | But I do hope you'll start a podcast,

03:03:22.260 | however brief or lengthy these episodes turn out to be,

03:03:25.800 | because I do believe that's a great venue

03:03:27.560 | to get information out into the world.

03:03:29.480 | And we don't just want to hear more from Matt Walker.

03:03:33.360 | I speak for many people.

03:03:35.260 | We need to.

03:03:36.100 | The work you're doing is both influential,

03:03:38.660 | but more importantly, it is important work.

03:03:41.700 | It has the impact that's needed,

03:03:44.880 | especially in this day and age where science and medicine,

03:03:47.860 | public health, and the issues of the world, et cetera,

03:03:51.460 | are really converging.

03:03:52.360 | So I know I speak on behalf of a tremendous number of people

03:03:56.120 | and I just say thank you for doing the work you do

03:03:58.400 | and for being you.

03:03:59.720 | And thanks for being a good friend.

03:04:01.320 | - Likewise, too.

03:04:02.800 | And by the way, I just going to note that it was nice

03:04:05.680 | that the two of us both got the Johnny Cash memo

03:04:10.380 | about how to dress today.

03:04:12.320 | It seems as though we're both kind of,

03:04:14.280 | we got that same memo,

03:04:15.600 | which will mean nothing to people who are listening.

03:04:18.080 | But if you're watching the video,

03:04:19.920 | you'll probably see what I mean.

03:04:21.180 | Andrew, thank you for taking this time.

03:04:23.020 | Thank you so much. - Thanks so much, Matt.

03:04:25.060 | - Thank you for joining me for my discussion

03:04:27.100 | with Dr. Matt Walker.

03:04:29.020 | Please also check out his podcast, The Matt Walker Podcast.

03:04:32.720 | A link to that podcast can be found in the show notes.

03:04:35.880 | If you're enjoying this podcast,

03:04:37.680 | please subscribe to us on YouTube.

03:04:39.560 | On YouTube, you can also leave us comments and suggestions

03:04:42.480 | for future episodes and guests in the comment section.

03:04:45.560 | As well, please subscribe to us on Apple and on Spotify.

03:04:49.360 | And at Apple, you can leave us up to a five-star review.

03:04:52.240 | You can also support us by checking out our Patreon account.

03:04:55.560 | That's patreon.com/andrewhuberman.

03:04:58.380 | And there you can support us at any level that you like.

03:05:01.800 | Please also check out our sponsors

03:05:03.420 | mentioned at the beginning of this episode.

03:05:05.540 | Links to those sponsors can be found in the show notes.

03:05:08.620 | During this episode and in many previous episodes,

03:05:11.100 | we discussed supplements.

03:05:12.640 | One issue in the supplement industry

03:05:14.260 | is that many supplements don't contain

03:05:16.640 | what's listed on the bottle.

03:05:18.360 | We therefore have partnered with Thorne,

03:05:20.160 | that's T-H-O-R-N-E, Thorne supplements,

03:05:23.160 | because Thorne supplements have the highest levels

03:05:25.160 | of stringency in terms of the purity of the ingredients

03:05:28.080 | and precision with respect to what's listed on the bottle

03:05:31.500 | is actually what's contained in those supplement bottles.

03:05:34.400 | If you'd like to see the supplements that I take

03:05:36.240 | for sleep and for other things,

03:05:38.080 | you can go to thorne.com/u/huberman.

03:05:42.680 | And there you'll see all the supplements that I take

03:05:45.400 | and can get 20% off any of those supplements

03:05:47.640 | as well as any other supplements

03:05:49.480 | that Thorne happens to make.

03:05:50.660 | That's thorne, T-H-O-R-N-E, .com/u/huberman.

03:05:55.660 | And last, but certainly not least,

03:05:59.080 | thank you for your interest in science.

03:06:00.800 | [upbeat music]

03:06:03.380 | (upbeat music)

Dr. Matthew Walker: The Science & Practice of Perfecting Your Sleep | Huberman Lab Podcast #31

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