Master Your Sleep & Be More Alert When Awake

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.

00:00:05.920 | I'm Andrew Huberman, and I'm a professor of neurobiology

00:00:12.260 | and ophthalmology at Stanford School of Medicine.

00:00:15.680 | Today's podcast episode is all about sleep.

00:00:19.060 | We're also going to talk about the mirror image of sleep,

00:00:22.020 | which is wakefulness.

00:00:23.820 | Now, these two phases of our life, sleep and wakefulness,

00:00:27.180 | govern everything about our mental and physical health.

00:00:31.600 | And we're not just gonna talk about

00:00:33.160 | what's useful about sleep.

00:00:35.140 | We're also gonna talk about how to get better at sleeping.

00:00:38.120 | And that will include how to get better at falling asleep,

00:00:40.840 | timing your sleep, and accessing better sleep quality.

00:00:44.920 | In doing so, we're also gonna discuss

00:00:46.620 | how to get more focused and alert in wakefulness.

00:00:50.780 | So because sleep and wakefulness are related,

00:00:52.620 | we really can't have a conversation

00:00:53.960 | about one without the other.

00:00:56.080 | Now, in keeping with this theme,

00:00:57.700 | you may catch a few snores in the background.

00:01:01.020 | Unlike me, my bulldog Costello

00:01:02.980 | can fall asleep anywhere, anytime,

00:01:04.900 | and he happens to be sleeping over there in the corner.

00:01:07.180 | So if you hear snoring, that's what that's about.

00:01:10.320 | As always, I wanna just mention that this podcast

00:01:12.700 | is part of my effort to bring zero cost to consumer,

00:01:15.460 | public education about science and science-related tools.

00:01:19.260 | It is unrelated to my teaching and research roles

00:01:21.820 | at Stanford School of Medicine.

00:01:23.180 | Today's podcast is brought to us by Helix Mattresses.

00:01:26.240 | Having the proper sleep environment,

00:01:28.240 | both the environment you're sleeping in

00:01:29.960 | and the object you're sleeping on,

00:01:31.840 | is critically important to getting a good night's sleep.

00:01:34.640 | Helix Mattresses are a little different than most

00:01:37.120 | because they're matched to your specific sleep needs,

00:01:40.020 | as well as whether or not you tend to run hot or cold

00:01:43.320 | as you sleep through the night,

00:01:44.620 | what position you sleep in, and so forth.

00:01:46.860 | So if you go to their website,

00:01:48.480 | they have a quiz that you can take

00:01:49.760 | that matches you to the particular mattress

00:01:51.720 | that's gonna be best for your sleep needs.

00:01:54.080 | I've always had a lot of trouble sleeping.

00:01:55.900 | I'm one of these people that can fall asleep easily,

00:01:57.660 | but then I wake up and I have a hard time

00:01:59.500 | getting back to sleep.

00:02:00.720 | And once I switched to a Helix Mattress

00:02:02.840 | that was precisely matched to my sleep needs,

00:02:05.400 | I found I could sleep through the night,

00:02:06.720 | which has made a tremendous difference for me.

00:02:09.020 | If you wanna try Helix Mattresses,

00:02:10.660 | you can go to helixsleep.com/huberman,

00:02:14.400 | and that will give you up to $200 off on a mattress order,

00:02:17.480 | as well as two pillows free with your mattress order.

00:02:20.760 | And of course, having the proper pillows

00:02:22.640 | is just as important as having the proper mattress.

00:02:25.780 | Today's podcast is also brought to us by Headspace.

00:02:28.880 | Headspace is a meditation app

00:02:30.560 | that teaches you how to meditate.

00:02:32.880 | It's fair to say that now there's a ton of research

00:02:35.280 | out there in peer-reviewed journals

00:02:37.320 | supporting the fact that mindfulness meditation

00:02:39.560 | can support mental and physical health.

00:02:42.600 | But many people find it hard to meditate.

00:02:44.600 | In fact, I'm one of these people.

00:02:46.280 | I started meditating in my teens,

00:02:47.760 | but then I would drop it every few weeks or so,

00:02:49.980 | and then I'd get back to it

00:02:51.220 | maybe the following week or every year.

00:02:53.160 | I just was not very regular about my meditation practice.

00:02:56.920 | And then a few years ago, I was flying a lot for work

00:02:59.540 | and I was on JetBlue flights,

00:03:01.000 | and they have Headspace as part of the choice of things

00:03:04.360 | that you can watch on the TV screen.

00:03:06.120 | And as I started meditating more regularly,

00:03:07.780 | what I found is my sleep was better,

00:03:09.880 | I would arrive feeling more rested.

00:03:12.000 | It just had tremendous effects on my work performance

00:03:14.920 | and other aspects of my life.

00:03:17.020 | If you wanna try Headspace, you can go to headspace.com/specialoffer.

00:03:22.020 | If you do that, you'll get one month

00:03:24.300 | of all of Headspace's meditations for free.

00:03:27.120 | That's the best offer right now.

00:03:28.760 | So if interested, go to headspace.com/specialoffer.

00:03:32.360 | So let's talk about sleep.

00:03:35.180 | Sleep is this incredible period of our lives

00:03:38.000 | where we are not conscious.

00:03:40.320 | We might dream, we might twitch, we might even wake up,

00:03:44.480 | but in sleep, we are only in relation

00:03:47.180 | to things that are happening within our brain and body.

00:03:49.860 | Outside sensory experience, in most cases,

00:03:52.880 | can't really impact us.

00:03:54.820 | And yet sleep is this tremendously important period of life

00:03:58.100 | because it resets our ability to be focused, alert,

00:04:02.620 | and emotionally stable in the wakeful period.

00:04:06.200 | So we can't really talk about wakefulness, focus,

00:04:09.500 | motivation, mood, wellbeing without thinking about sleep.

00:04:14.120 | And that's why we're devoting this entire month

00:04:16.140 | to the discussion about sleep.

00:04:18.220 | But we also can't talk about sleep and think about sleep

00:04:20.700 | without thinking about wakefulness,

00:04:22.340 | because it turns out that the period that we call sleep

00:04:26.100 | and the period we call wakefulness

00:04:27.740 | are tethered to one another.

00:04:29.660 | What we do in the waking state determines

00:04:32.420 | when we fall asleep, how quickly we fall asleep,

00:04:35.880 | whether or not we stay asleep,

00:04:37.820 | and how we feel when we wake up the next day.

00:04:40.500 | And today, we're gonna talk mostly

00:04:43.140 | about how to get better at sleeping.

00:04:45.820 | And the reason for starting the conversation that way,

00:04:48.440 | as opposed to just diving into a lot of biology about sleep,

00:04:52.460 | is because first of all, there's a lot of information

00:04:55.340 | out there already about the biology of sleep.

00:04:58.340 | We're gonna touch on a little bit of this,

00:04:59.760 | things like stages of sleep and sleep spindles,

00:05:02.740 | melatonin, and dreaming.

00:05:05.360 | But I think that by now, most people are aware

00:05:09.440 | that getting a really good night's sleep

00:05:11.360 | on a consistent basis is critically important.

00:05:14.540 | But most people don't know how to do that.

00:05:17.060 | In fact, I'm guessing that very few of you out there

00:05:20.340 | are consistently getting seven to nine hours

00:05:23.320 | of really terrific sleep, waking up feeling rested,

00:05:26.260 | like you're ready to attack the day,

00:05:27.900 | and being able to go through the day feeling focused

00:05:30.100 | and alert without dips in energy or focus.

00:05:33.560 | So if you're like most people, which includes me,

00:05:36.880 | you have some challenges with sleep,

00:05:38.740 | at least every third or fifth night or so,

00:05:41.080 | and maybe even more often.

00:05:42.680 | So we're really gonna go tool heavy today

00:05:44.540 | and talk about tools that can help you fall asleep,

00:05:48.000 | sleep better, and emerge from sleep feeling more rested.

00:05:51.660 | And we're gonna do that by grounding our discussion

00:05:54.300 | of tools in peer-reviewed studies,

00:05:57.400 | mostly from the last 10 years,

00:05:59.300 | although some even more recent than that.

00:06:01.500 | And we're gonna start by discussing what is sleep

00:06:05.080 | and what governs the timing of the onset of sleep.

00:06:08.500 | In other words, what makes you get sleepy

00:06:10.540 | at a particular time of day.

00:06:12.500 | So what determines how well we sleep

00:06:15.060 | and the quality of our wakeful state?

00:06:18.180 | Turns out that's governed by two forces.

00:06:20.680 | The first force is a chemical force.

00:06:23.320 | It's called adenosine.

00:06:25.580 | Adenosine is a molecule in our nervous system and body

00:06:28.860 | that builds up the longer we are awake.

00:06:31.740 | So if you've just slept for eight or nine or 10

00:06:35.020 | really deep restful hours,

00:06:37.420 | adenosine is gonna be very low in your brain and body.

00:06:40.860 | If however you've been awake for 10, 15 or more hours,

00:06:44.940 | adenosine levels are going to be much higher.

00:06:47.700 | Adenosine creates a sort of sleep drive or a sleep hunger.

00:06:52.460 | And actually hunger is the appropriate word here

00:06:54.980 | because for most of what we're gonna discuss today,

00:06:57.860 | we can think of it in an analogous way to nutrition.

00:07:01.380 | Your nutrition and how well you feel

00:07:04.340 | after you eat certain foods,

00:07:06.340 | your overall level of fitness and your cellular health

00:07:09.740 | and your heart health isn't governed by any one food item

00:07:13.100 | that you might eat or not eat.

00:07:14.600 | It's governed by a number of different factors.

00:07:16.400 | How often you eat, how much you eat,

00:07:18.400 | which items you eat, et cetera,

00:07:20.380 | and what works best for you.

00:07:22.420 | In the same way, your sleep and your wakefulness

00:07:26.140 | are the product of kind of the average

00:07:28.860 | of a number of different behaviors.

00:07:30.700 | How long you've been awake is a key one

00:07:32.720 | because of this molecule adenosine.

00:07:35.300 | So the reason you get sleepy

00:07:36.980 | when you've been up for a while

00:07:37.940 | is because adenosine is creeping up steadily

00:07:40.820 | the longer you've been awake.

00:07:42.620 | And a good way to remember this and think about adenosine

00:07:45.900 | is to think about caffeine.

00:07:48.340 | Caffeine for most people,

00:07:50.240 | except a very small percentage of people, wakes them up.

00:07:53.300 | It makes them feel more alert.

00:07:55.040 | In fact, some people are so sensitive to caffeine

00:07:57.740 | that they feel jittery if they drink it

00:08:00.180 | even in small amounts.

00:08:01.620 | Other people can drink large amounts of caffeine

00:08:03.780 | and not feel jittery at all.

00:08:05.740 | Caffeine acts as an adenosine antagonist.

00:08:11.260 | What that means is that when you ingest caffeine,

00:08:14.220 | whether or not it's coffee or soda or tea

00:08:16.400 | or in any other form, it binds to the adenosine receptor.

00:08:20.720 | It sort of parks there,

00:08:21.780 | just like a car would park in a given parking slot,

00:08:24.500 | and therefore adenosine can't park in that slot.

00:08:27.920 | Now, when caffeine parks in the adenosine receptor slot,

00:08:32.140 | nothing really happens downstream of that receptor.

00:08:35.100 | The receptor can't engage the normal cellular functions

00:08:37.940 | of making that cell and you feel sleepy.

00:08:41.540 | So the reason caffeine wakes you up

00:08:44.340 | is because it blocks the sleepiness receptor.

00:08:48.100 | It blocks the sleepy signal.

00:08:49.820 | And this is why when that caffeine wears off,

00:08:52.500 | adenosine will bind to that receptor

00:08:54.580 | sometimes with even greater, what we call affinity,

00:08:57.380 | and you feel the crash, you feel especially tired.

00:09:01.060 | Now, I'm not here to demonize caffeine.

00:09:03.020 | I love caffeine.

00:09:04.740 | I drink it in the morning and I drink it in the afternoon.

00:09:07.500 | But I'm one of these people that either

00:09:09.260 | because of my tolerance or because of some genetic variations

00:09:13.240 | that exist among people

00:09:14.700 | in terms of their adenosine receptors,

00:09:17.340 | I can drink caffeine as late as four or 5 p.m.

00:09:19.820 | in the evening and still fall asleep just fine.

00:09:22.700 | Some people can't have any caffeine at all

00:09:25.360 | or can't have any caffeine past 11 a.m.

00:09:27.720 | or else their sleep is totally disrupted.

00:09:30.000 | All of this has to do with the relationship

00:09:32.780 | between adenosine and these adenosine receptors,

00:09:35.820 | genetic variation, things that are very hard to find out

00:09:38.700 | except experimentally, meaning each of you needs to decide

00:09:42.120 | and figure out for yourselves

00:09:43.820 | whether or not you can tolerate caffeine

00:09:45.640 | and at what times of day you can tolerate caffeine

00:09:48.280 | in order to still fall asleep easily and get good sleep.

00:09:52.280 | So rather than demonize caffeine or say that,

00:09:56.540 | everyone can drink caffeine until late,

00:09:58.760 | you need to figure out what's right for you.

00:10:01.320 | Caffeine has a lot of health benefits.

00:10:04.180 | It also, for some people can be problematic for health.

00:10:07.280 | It can raise blood pressure, et cetera.

00:10:09.380 | Caffeine increases this molecule

00:10:11.660 | that's a neuromodulator that we call dopamine.

00:10:14.220 | We discussed this in episode one,

00:10:16.160 | which tends to make us feel good,

00:10:17.780 | motivated and give us energy

00:10:20.180 | because as you may have learned in episode one,

00:10:23.380 | dopamine is related to another neuromodulator

00:10:26.260 | called epinephrine, which gives us energy.

00:10:28.380 | In fact, epinephrine is made from dopamine.

00:10:30.840 | So let's just take a step back

00:10:32.120 | and think about what we're talking about

00:10:33.860 | when we're talking about sleepiness.

00:10:35.620 | Sleepiness is driven by increases in adenosine

00:10:38.900 | that happen naturally.

00:10:40.460 | Caffeine prevents the adenosine from having its action

00:10:46.320 | of making us sleepy by blocking that receptor.

00:10:48.960 | So it gives us energy and it increases our dopamine levels,

00:10:52.460 | but some people can't tolerate caffeine very well.

00:10:55.500 | Other people can tolerate it just fine.

00:10:57.620 | So you need to determine that experimentally.

00:11:00.260 | All the data say there's tremendous variation

00:11:02.860 | and right now the only way that I'm aware of

00:11:05.020 | for you to decide whether or not caffeine

00:11:06.660 | is a good or a bad thing for you

00:11:08.780 | and whether or not you should ingest it

00:11:10.540 | at a given time of day or at all

00:11:13.020 | is really to figure that out on your own.

00:11:14.700 | In fact, there's a small subset of people

00:11:16.820 | that can drink caffeine until very late

00:11:19.420 | and they have no trouble falling asleep

00:11:21.060 | because they actually have a mutant form

00:11:23.380 | of the adenosine receptor.

00:11:25.020 | So in keeping with the theme of science

00:11:26.920 | and science-related tools,

00:11:28.520 | this is one of those cases where I can't give you

00:11:30.680 | a one-size-fits-all prescription except to say,

00:11:33.920 | you need to experiment with caffeine

00:11:35.660 | in a way that's safe for you and explore that

00:11:38.080 | and figure out what works for you and then stick with that.

00:11:41.160 | Okay, so adenosine is driving the sleep hunger.

00:11:44.540 | When adenosine is low, it's like we're well-fed,

00:11:47.420 | we're not very hungry.

00:11:48.540 | And when adenosine is high,

00:11:50.520 | it's like we're fasted for a long time

00:11:52.160 | and we tend to be very hungry.

00:11:53.820 | So when adenosine is high, we really wanna fall asleep.

00:11:57.500 | If you want, I'm not suggesting you do this experiment,

00:11:59.840 | but you can do it, you can stay up for four more hours

00:12:03.320 | than you're used to staying up

00:12:04.540 | and you'll find that you're very, very sleepy.

00:12:07.200 | That's because adenosine is building up

00:12:08.860 | at levels higher and higher

00:12:10.580 | because you've been awake for those extra four hours.

00:12:13.780 | However, if you've ever pulled an all-nighter,

00:12:16.280 | you'll notice something interesting.

00:12:18.160 | As morning rolls around, you'll suddenly feel an increase

00:12:21.540 | in your energy and alertness again.

00:12:23.460 | Even though adenosine has been building up

00:12:26.260 | for the entire night.

00:12:28.560 | Why is that?

00:12:30.100 | The reason that is is because there's a second force

00:12:32.660 | which is governing when you sleep and when you're awake.

00:12:35.760 | And that force is a so-called circadian force.

00:12:39.700 | Circadian means about a day or about 24 hours.

00:12:44.380 | And inside all of us is a clock

00:12:47.140 | that exists in your brain and my brain

00:12:49.560 | and the brain of every animal that we're aware of

00:12:52.860 | that determines when we want to be sleepy

00:12:55.940 | and when we want to be awake.

00:12:57.980 | Just think about it.

00:12:58.800 | We don't go through the day

00:12:59.780 | wanting to fall asleep every 30 minutes

00:13:01.900 | and then feeling like we're wide awake.

00:13:04.220 | Our sleep and our period of sleepiness

00:13:06.220 | tends to be condensed into one block.

00:13:09.660 | Typically one six to 10 hour block.

00:13:12.140 | Although there's also variation

00:13:13.820 | in terms of how much people want to sleep.

00:13:15.820 | And we're going to discuss

00:13:17.020 | how you can diagnose your absolute sleep need

00:13:20.340 | as well as how to recover sleep that you've lost.

00:13:23.660 | That block of sleep

00:13:25.460 | and when it falls within each 24 hour cycle

00:13:28.660 | is governed by a number of different things.

00:13:31.940 | But the most powerful thing that's governing

00:13:33.700 | when you want to be asleep

00:13:35.060 | and when you want to be awake is light.

00:13:38.780 | And in particular, it's governed by sunlight.

00:13:41.400 | Now I can't emphasize enough how important

00:13:43.820 | and how actionable this relationship is

00:13:46.700 | between light and when you want to sleep.

00:13:50.420 | It's quite simple on the face of it.

00:13:53.500 | And it's quite simple to resolve

00:13:55.060 | but people tend to make a big mess

00:13:56.900 | of this whole circadian literature, frankly.

00:13:59.460 | So let's just break it down from the standpoint

00:14:02.260 | of what's going on in your brain and body

00:14:05.180 | as you go through one 24 hour day.

00:14:08.360 | Let's start with waking.

00:14:09.820 | So regardless of how well you slept at night

00:14:11.940 | or whether or not you were up all night,

00:14:14.120 | most people tend to wake up sometime

00:14:16.940 | around when the sun rises.

00:14:19.200 | Maybe not right at sunrise,

00:14:20.580 | but within an hour or two or maybe three of sunrise.

00:14:24.100 | I realize there are night shift workers

00:14:25.900 | and there are people traveling and experiencing jet lag

00:14:28.740 | where this is not gonna be the case.

00:14:30.400 | We are gonna deal with jet lag and shift work

00:14:33.140 | at the end of this podcast.

00:14:35.040 | But for most people, we tend to wake up

00:14:36.840 | about the time that the sun is rising or so.

00:14:40.380 | And as we do that, adenosine levels tend to be low

00:14:44.320 | if we've been asleep for reasons that you now understand

00:14:48.120 | and our system generates an internal signal

00:14:52.380 | that is in the form of a hormone.

00:14:54.400 | Now I've talked a lot about neuromodulators

00:14:56.540 | and neurotransmitters.

00:14:57.460 | I haven't talked a lot about hormones yet on this podcast.

00:15:01.480 | The definition of a hormone is it's a substance,

00:15:04.220 | a chemical that's released from one organ in your body

00:15:08.060 | that goes and acts on other organs elsewhere in your body,

00:15:11.760 | including your nervous system.

00:15:13.980 | When you wake up in the morning,

00:15:15.700 | you wake up because a particular hormone called cortisol

00:15:19.360 | is released from your adrenal glands.

00:15:21.660 | Your adrenal glands sit right above your kidneys

00:15:23.780 | and there's a little pulse of cortisol.

00:15:26.000 | There's also a pulse of some, and when I say a pulse,

00:15:29.120 | I just mean that the release of a little bit.

00:15:31.400 | There's also a pulse of epinephrine,

00:15:34.360 | which is adrenaline from your adrenals

00:15:37.280 | and also in your brain and you feel awake.

00:15:40.600 | Now that pulse of cortisol and adrenaline

00:15:43.320 | and epinephrine might come from your alarm clock.

00:15:45.520 | It might come from you naturally waking up,

00:15:48.160 | but it tends to alert your whole system in your body

00:15:51.440 | that it's time to increase your heart rate.

00:15:53.040 | It's time to start tensing your muscles.

00:15:54.560 | It's time to start moving about.

00:15:56.960 | It's very important that that cortisol pulse

00:16:00.040 | come early in the day

00:16:02.120 | or at least early in your period of wakefulness.

00:16:04.880 | I say that because some people are waking up at 8 p.m.

00:16:07.720 | and are sleeping all day,

00:16:09.200 | but it's very important that that pulse of cortisol

00:16:11.400 | occur early in the day

00:16:13.040 | and that it happens all at once.

00:16:16.120 | It sort of sets a rising tide of cortisol in your system.

00:16:20.100 | Now, many of you have probably heard about cortisol

00:16:22.460 | in relation to stress.

00:16:23.880 | And indeed, as we go through our day and our life,

00:16:26.840 | different stressors, different events happen in our life

00:16:30.120 | that make us feel more alert.

00:16:32.160 | Some of the more stressful ones

00:16:33.440 | might be looking at your credit card bill

00:16:35.440 | and seeing what seems to be a fraudulent charge

00:16:38.680 | or looking at your phone and suddenly seeing a text

00:16:41.380 | that something you thought was gonna happen

00:16:42.760 | in a particular time is not gonna happen

00:16:44.340 | or you're running late.

00:16:45.580 | Those will tend to increase norepinephrine and epinephrine

00:16:48.960 | and adrenaline in your system.

00:16:50.920 | And if they're severe enough,

00:16:52.480 | you'll start getting some pulses of cortisol

00:16:55.000 | released from your adrenals throughout the day.

00:16:57.400 | But there's this normal, healthy, rising tide of cortisol

00:17:01.240 | that happens early in the day.

00:17:02.560 | And I say healthy because it wakes you up.

00:17:04.880 | It makes you feel alert.

00:17:05.880 | It makes you feel able to move and wanting to move

00:17:08.760 | and to go out about your day for work, for exercise,

00:17:11.400 | for school, for social relations, et cetera.

00:17:14.680 | So when you wake up in the morning

00:17:16.600 | is when that cortisol pulse takes off

00:17:19.720 | and something else important happens.

00:17:21.980 | A timer is set in your body and in your nervous system

00:17:25.840 | that dictates when a different hormone called melatonin,

00:17:29.840 | which makes you sleepy,

00:17:31.920 | will be secreted from a particular brain region.

00:17:34.700 | So let's talk about that.

00:17:36.680 | When you wake up in the morning

00:17:37.800 | and you experience that rise in cortisol,

00:17:41.000 | there's a timer that starts going,

00:17:43.560 | and these are cellular timers,

00:17:45.040 | and they're dictated by the relation

00:17:46.740 | between different organs in your body

00:17:48.620 | that says to your brain and body

00:17:51.200 | that in about 12 to 14 hours, a different hormone,

00:17:55.400 | this hormone we're calling melatonin,

00:17:57.320 | will be released from your pineal gland.

00:18:00.280 | So there's two mechanisms here,

00:18:01.680 | a wakefulness signal and a sleepiness signal.

00:18:04.400 | And the wakefulness signal triggers the onset of the timer

00:18:08.200 | for the sleepiness signal.

00:18:10.280 | Now that sleepiness signal that we call melatonin

00:18:12.560 | that's released from the pineal comes only from the pineal.

00:18:16.920 | Unless you're taking exogenous melatonin,

00:18:19.120 | you're supplementing with melatonin,

00:18:21.120 | the only source of melatonin in your body

00:18:23.880 | is going to be this pineal gland.

00:18:25.900 | So let's talk about the pineal gland for a second.

00:18:28.480 | The pineal gland is a gland that sits

00:18:31.920 | kind of in the little structure

00:18:34.720 | for the aficionados out there.

00:18:36.460 | It's kind of near the fourth ventricle.

00:18:38.560 | It's about the size of a pea.

00:18:40.400 | Descartes, the philosopher,

00:18:42.400 | said that the pineal was the seat of the soul.

00:18:45.280 | He said that because it's one of the few structures

00:18:48.120 | in the human brain that there's only one of them.

00:18:51.680 | Most structures, there's one on either side of the brain,

00:18:54.120 | so-called bihemispheric, but the pineal, there's only one.

00:18:57.400 | I don't know anything about souls really,

00:19:00.080 | certainly not the science of souls,

00:19:01.800 | but I think it's very unlikely

00:19:03.320 | that the pineal is the seat of the soul,

00:19:05.840 | but it is a very interesting organ

00:19:08.200 | because it's the only organ in our body

00:19:10.520 | that releases melatonin,

00:19:13.360 | and that melatonin makes us sleepy and lets us fall asleep.

00:19:18.160 | Now, I'm guessing that many of you are probably asking,

00:19:21.360 | should I take melatonin?

00:19:23.460 | My personal bias on this is, except in rare cases, no,

00:19:28.460 | for the following reason.

00:19:29.960 | Melatonin has a second function,

00:19:32.200 | which is that melatonin also suppresses the onset of puberty.

00:19:36.900 | In kids, and especially in babies,

00:19:38.800 | melatonin isn't just released in the evening,

00:19:41.400 | 12 to 16 hours after we wake.

00:19:44.200 | Melatonin is released chronically or tonically

00:19:47.840 | throughout the day and night,

00:19:49.600 | and that chronic or tonic release of melatonin

00:19:52.340 | is known to suppress some of the other hormones

00:19:54.680 | in other regions of the brain

00:19:56.120 | that trigger the onset of puberty.

00:19:58.240 | Now, if you or your child has been taking melatonin,

00:20:00.520 | don't freak out.

00:20:01.880 | As always, any kind of supplement

00:20:04.720 | or anything that you're going to take

00:20:06.220 | or think about taking,

00:20:07.900 | you really need to consult with your doctor.

00:20:09.920 | I've said this many times on this podcast,

00:20:11.800 | and it's in the show notes, et cetera,

00:20:13.640 | but before you remove anything or add anything

00:20:17.560 | to what you're already doing,

00:20:18.960 | please do consult with a healthcare professional.

00:20:21.460 | However, melatonin is known to suppress the onset of puberty,

00:20:26.460 | so much so that regular cyclic cycled periods

00:20:31.000 | of melatonin release from the pineal

00:20:33.040 | really correlate with the onset of puberty

00:20:35.260 | and early adulthood,

00:20:37.000 | meaning as we start secreting melatonin only at night,

00:20:40.760 | that's also when we tend to transition out of puberty.

00:20:43.760 | Now, there are a lot of things that correlate

00:20:45.160 | in our nervous system,

00:20:46.040 | so it doesn't necessarily mean it controls it,

00:20:48.120 | but in this case, we know based on lots of data,

00:20:51.360 | endocrinology and so forth,

00:20:53.040 | that melatonin suppresses the onset of puberty.

00:20:56.160 | So supplementing melatonin could be problematic

00:20:58.760 | for that reason,

00:21:00.360 | but if you've already gone through puberty,

00:21:03.080 | it could also have some impact

00:21:05.400 | on other hormone systems in your body.

00:21:07.500 | So that's why I personally don't like

00:21:09.460 | to use melatonin to fall asleep.

00:21:12.040 | There's another reason,

00:21:12.880 | which is that melatonin will help you fall asleep,

00:21:14.840 | but it won't help you stay asleep,

00:21:16.680 | and many people who take melatonin find that they wake up

00:21:19.420 | three to five hours later, unable to fall back asleep.

00:21:22.760 | Part of the reason for that might be

00:21:25.140 | that melatonin purchased,

00:21:27.760 | you can buy it over the counter in most areas of the world,

00:21:30.440 | even though it's a hormone, which is a little unusual,

00:21:32.260 | you can't just go into a pharmacy, at least in the US,

00:21:34.540 | and buy testosterone or cortisol or estrogen,

00:21:37.380 | you need a prescription,

00:21:38.360 | but you can go buy melatonin for whatever reason,

00:21:40.540 | I don't know the reasons for that legality,

00:21:44.720 | but it's been shown many times,

00:21:46.900 | and now I'm borrowing from some items

00:21:49.400 | that were in Matt Walker's book, "Why We Sleep,"

00:21:52.080 | where he stated there is evidence

00:21:54.760 | that in commercially available melatonin,

00:21:57.200 | the amount of melatonin has been tested for various brands,

00:22:01.560 | and it can range anywhere from being 15%

00:22:05.540 | of what's listed on the bottle,

00:22:07.840 | so if they list up, this is 100 milligrams,

00:22:09.880 | would be a tremendously high dose,

00:22:11.920 | it turns out it's only 15 milligrams

00:22:14.120 | in that particular pill or capsule,

00:22:16.420 | or up to 400 times more than what's listed on the bottle,

00:22:20.980 | so it's completely unregulated,

00:22:22.800 | and so for those of you taking melatonin,

00:22:25.000 | I will discuss at the end of the podcast

00:22:26.700 | some other potential alternatives that are probably safer

00:22:30.760 | and don't have these issues,

00:22:32.580 | so should you take melatonin?

00:22:34.960 | My personal bias is no, but for many people,

00:22:39.020 | they find that it does help them,

00:22:40.480 | and so if you do find it helps you,

00:22:42.000 | then just consider what I'm saying

00:22:43.760 | in light of the other practices that you're doing

00:22:47.180 | and talk to your healthcare professional.

00:22:49.120 | Okay, so the rhythm of cortisol and melatonin

00:22:53.440 | is what we call endogenous,

00:22:55.080 | it's happening in us all the time

00:22:57.140 | without any external input,

00:22:59.040 | in fact, if we were in complete darkness,

00:23:01.400 | living in a cave with no artificial lights whatsoever,

00:23:04.520 | or we were in complete brightness,

00:23:07.220 | where we never experienced any darkness,

00:23:10.120 | these rhythms of cortisol and melatonin would continue,

00:23:14.240 | you would have a bump in cortisol or a pulse in cortisol

00:23:17.040 | that would drop off with time,

00:23:18.480 | and then melatonin would come up

00:23:20.140 | about 12 to 14 hours later,

00:23:23.240 | but these endogenous systems of our body,

00:23:27.360 | which are both hormonal and neural,

00:23:30.600 | were set so that external things

00:23:34.900 | could govern when they happen.

00:23:36.880 | Now, this takes us back to episode one of the podcast

00:23:40.100 | that if you haven't listened to already,

00:23:41.680 | you might wanna listen to,

00:23:42.720 | where we talked about sensation and perception and all that,

00:23:45.320 | I'm not gonna review it again here,

00:23:47.240 | but there's one particular sensory event,

00:23:51.060 | one particular influence on your nervous system

00:23:53.960 | that determines when that cortisol

00:23:56.040 | is going to start to rise.

00:23:58.320 | So if you were in complete darkness,

00:24:00.520 | it would happen once per 24 hour cycle,

00:24:03.600 | but it would be somewhat later and later each day,

00:24:08.280 | whereas under normal circumstances,

00:24:11.540 | what happens is you wake up,

00:24:13.840 | and what happens when you wake up?

00:24:15.640 | You open your eyes.

00:24:17.000 | When you open your eyes, light comes into your eyes.

00:24:20.400 | Now, the way this system works

00:24:22.140 | is that you have a particular set of neurons in your eye,

00:24:24.820 | they're called retinal ganglion cells.

00:24:26.440 | You don't have to remember that if you don't want to,

00:24:28.780 | but these retinal ganglion cells are brain neurons.

00:24:32.380 | Again, the retina is just the one piece of your brain,

00:24:35.120 | actually two pieces,

00:24:35.960 | 'cause most of you have two retinas,

00:24:37.860 | that resides outside the skull per se.

00:24:41.880 | When light comes into the eye,

00:24:43.560 | there's a particular group of retinal ganglion cells

00:24:46.580 | or type of retinal ganglion cells

00:24:48.920 | that perceives a particular type of light

00:24:52.120 | and communicates that to this clock that resides

00:24:54.720 | right above the roof of your mouth,

00:24:56.020 | called the suprachiasmatic nucleus, okay?

00:24:59.360 | So I know this can get a little complicated,

00:25:00.960 | but these retinal ganglion cells,

00:25:03.420 | when you open your eyes, light comes in,

00:25:05.740 | and an electrical signal is sent to this central clock

00:25:08.800 | we call the suprachiasmatic nucleus,

00:25:11.080 | and the suprachiasmatic nucleus has connections

00:25:15.180 | with essentially every cell and organ of your body.

00:25:18.800 | Now, it's vitally important that we get light

00:25:21.680 | communicated to this central clock

00:25:23.880 | in order to time the cortisol and melatonin properly.

00:25:27.880 | When I say properly, I can say that with confidence,

00:25:30.760 | because we know based on a lot of evidence

00:25:33.280 | that if you don't get your cortisol

00:25:35.680 | and melatonin rhythms right,

00:25:38.000 | there are tremendously broad and bad effects

00:25:43.000 | on cardiovascular health, dementia, metabolic effects,

00:25:46.800 | learning, depression, dementia.

00:25:49.520 | In fact, there's so many negative effects associated

00:25:52.000 | with getting this wrong

00:25:53.600 | that I don't want to go into it in too much detail.

00:25:55.320 | In fact, I feel like we've been bombarded

00:25:58.220 | with all this information about how we're not sleeping well,

00:26:00.500 | we're not sleeping at the right times,

00:26:01.700 | we're not sleeping enough,

00:26:02.880 | to the point where people now have sleep anxiety.

00:26:05.720 | If they can't sleep well for a night,

00:26:07.660 | they're feeling overwhelmed by that,

00:26:09.200 | and it's sort of now they're stressed

00:26:10.520 | about not being able to sleep,

00:26:11.700 | which is making it harder to sleep, et cetera.

00:26:14.120 | I really want to focus on what we can do

00:26:16.520 | to anchor these systems properly.

00:26:18.880 | So let's think about what happens when we do this correctly

00:26:22.160 | and how to do it correctly.

00:26:23.580 | When we wake up, our eyes open.

00:26:25.840 | Now, if we're in a dark room,

00:26:28.240 | there isn't enough light to trigger the correct timing

00:26:32.320 | of this cortisol melatonin thing, these rhythms.

00:26:36.340 | You might say, well, why won't any light do it?

00:26:39.420 | Well, it turns out that these neurons in our eye

00:26:42.660 | that set the circadian clock

00:26:44.320 | and then allow our circadian clock to set all the clocks

00:26:47.300 | of all the cells and organs and tissues of our body

00:26:49.980 | responds best to a particular quality of light

00:26:54.420 | and amount of light.

00:26:55.740 | And those are the qualities of light

00:26:59.320 | and amount of light that come from sunlight.

00:27:02.380 | So these neurons, what they're really looking for,

00:27:07.080 | although they don't have a mind of their own,

00:27:09.040 | is the sun at what we call low solar angle.

00:27:12.460 | The eye and the nervous system don't know anything

00:27:14.100 | about sunrises or sunsets.

00:27:15.900 | It only knows the quality of light that comes in

00:27:19.360 | when the sun is low in the sky.

00:27:20.940 | The system evolved so that when the sun is low in the sky,

00:27:24.880 | there's a particular contrast between yellows and blues

00:27:28.980 | that triggers the activation of these cells.

00:27:31.460 | So if you wake up and you look at your phone

00:27:33.080 | or your computer, or you flip on a bunch

00:27:34.820 | of artificial lights, will these cells be activated?

00:27:38.940 | And the answer is sort of.

00:27:40.620 | They'll be activated, but not in the optimal way.

00:27:43.960 | What you want to do is get sunlight in your eyes

00:27:46.560 | as close to waking as possible.

00:27:48.920 | Now, I wanna be really clear about this

00:27:50.360 | 'cause I've talked about it on other podcasts

00:27:52.880 | when I was a guest, and I've talked about it

00:27:54.400 | on my Instagram feed, and there seemed to be

00:27:56.580 | the same questions coming up again and again.

00:27:59.200 | These neurons don't know sunlight per se.

00:28:02.100 | They don't know sunrise or sunset for that matter.

00:28:05.400 | They don't know artificial light from sunlight.

00:28:08.540 | What they respond best to, however,

00:28:11.340 | is the quality and amount of light that comes in

00:28:14.060 | when the sun is low in the sky.

00:28:16.140 | That means that if you can watch the sunrise, great.

00:28:20.540 | That's perfect for triggering activation of these cells.

00:28:23.980 | However, if you wake up a few hours after the sunrise,

00:28:27.180 | which I tend to most days personally,

00:28:30.100 | you still wanna get outside and view sunlight.

00:28:33.820 | You don't need the sunlight beaming you

00:28:35.660 | directly in the eyes.

00:28:36.780 | There's a lot of photons, light energy,

00:28:39.140 | that's scattered from sunlight at this time.

00:28:41.740 | But the key is to get that light energy

00:28:45.460 | from sunlight ideally into your eyes.

00:28:48.040 | Now, I know many of you are already asking,

00:28:50.140 | well, I live in Scandinavia or I can't get sunlight.

00:28:52.980 | There's buildings around me, et cetera.

00:28:54.640 | We will get to all of that.

00:28:56.700 | But it's critically important that you get outside

00:28:58.940 | to get this light.

00:29:00.460 | I had a discussion with a colleague of mine,

00:29:02.340 | Dr. Jamie Zeitzer, who's in the Department of Psychiatry

00:29:05.700 | and Behavioral Sciences at Stanford, a world expert in this.

00:29:10.500 | And he tells me that it's 50 times less effective

00:29:15.500 | to view the sunlight through a window,

00:29:19.540 | through a car windshield or through a side window of a car,

00:29:23.160 | than it is to just get outside with no sunglasses

00:29:26.180 | and view light early in the day.

00:29:28.740 | Now, if you can't see the sunrise, like I said,

00:29:31.140 | you can see this within an hour or two of sunrise,

00:29:33.500 | but it has to be low solar angle.

00:29:35.120 | Once the sun is overhead, the quality of light shifts

00:29:38.540 | so that you miss this opportunity

00:29:40.620 | to time the cortisol pulse.

00:29:42.500 | And that turns out to be a bad thing to do.

00:29:45.960 | You really wanna time that cortisol pulse properly

00:29:49.140 | because we'll get into this a little bit more later,

00:29:52.320 | but a late shifted cortisol pulse,

00:29:55.460 | in particular in 9 p.m. or 8 p.m. increase in cortisol,

00:29:59.500 | is one of the consequences and maybe one of the causes

00:30:04.540 | of a lot of anxiety disorders and depression.

00:30:07.480 | So it's kind of a chicken egg thing.

00:30:08.620 | We don't know whether or not it's the correlated with,

00:30:10.600 | it's the cause or the effect,

00:30:12.560 | but it's a signature of depression and anxiety disorder.

00:30:15.840 | Bringing that cortisol pulse earlier in your wakeful period,

00:30:19.680 | earlier in your day, has positive benefits

00:30:22.960 | ranging from blood pressure to mental health, et cetera.

00:30:26.480 | I'm not gonna list them all off

00:30:27.520 | 'cause there's just so many of them,

00:30:29.200 | but many, many positive things happen

00:30:31.400 | when you are getting the cortisol early in the day,

00:30:34.580 | far away from your melatonin pulse.

00:30:37.360 | Okay, so how long should you be outside?

00:30:40.060 | Well, this is gonna vary tremendously

00:30:42.260 | because some people live in environments

00:30:43.840 | where it's very bright.

00:30:44.680 | So let's say it's Colorado in the middle of winter,

00:30:48.520 | there's a snow field, there's no cloud cover,

00:30:50.520 | and you walk outside.

00:30:52.000 | There's going to be so much photon light energy

00:30:55.180 | arriving on your retina

00:30:56.680 | that it probably only takes 30 to 60 seconds

00:30:58.820 | to trigger the central clock

00:31:00.440 | and set your cortisol and melatonin rhythms properly

00:31:03.080 | and get everything lined up nicely.

00:31:06.120 | Whereas if you're in Scandinavia in the depths of winter

00:31:09.960 | and you wake up at 5 a.m.

00:31:11.160 | and the sun is just barely creeping across the horizon

00:31:13.720 | then goes back down again a few hours later,

00:31:16.160 | you probably are not getting enough sunlight

00:31:19.880 | in order to set these rhythms.

00:31:22.220 | So many people find that they need to use sunlight simulators

00:31:27.200 | in the form of particular lights

00:31:29.040 | that were designed to simulate sunlight.

00:31:30.800 | However, I'm not out to attack the companies

00:31:33.600 | that produce those.

00:31:34.880 | There's another solution to that.

00:31:36.760 | You can simply go outside for longer.

00:31:40.040 | Even if there's a lot of dense cloud cover,

00:31:42.240 | you're probably getting anywhere

00:31:44.600 | from 10,000 to 50,000 lux, L-U-X,

00:31:48.360 | which is just a measure of light energy.

00:31:50.520 | And that should be sufficient to set the circadian clock.

00:31:54.140 | You could say, well, the lights in my house or my phone

00:31:58.420 | are really, really bright, right?

00:31:59.920 | Everyone's telling us to stay off our phones at night

00:32:01.700 | because they're really bright.

00:32:03.240 | But guess what?

00:32:04.120 | It turns out that early in the day,

00:32:06.320 | your retina is not very sensitive,

00:32:09.240 | which means you need a lot of photons,

00:32:12.120 | ideally coming from sunlight,

00:32:13.520 | to set these clock mechanisms.

00:32:15.280 | So looking at your phone or artificial lights

00:32:17.080 | is fine if you wake up before sunrise,

00:32:19.840 | but it's not going to work to set these clock mechanisms.

00:32:24.160 | And this is supported by dozens, if not hundreds,

00:32:26.660 | of quality peer-reviewed studies.

00:32:29.120 | So you want to use sunlight.

00:32:30.640 | If you can't see sunlight because of your environment,

00:32:33.800 | then you are going to have to opt for artificial light.

00:32:37.120 | And in that case, you're going to want an artificial light

00:32:39.640 | that either simulates sunlight or has a lot of blue light.

00:32:44.040 | Now, without going off course here,

00:32:45.800 | you might be saying,

00:32:46.920 | wait, I've heard blue light is bad for me.

00:32:48.880 | Actually, blue light is great

00:32:50.920 | for this mechanism during the day.

00:32:53.680 | We can talk about blue light and blue blockers,

00:32:57.060 | but you really want a lot of blue and yellow light

00:33:00.120 | arriving on the retina early in the day.

00:33:02.020 | Let me be clear about something.

00:33:03.820 | You never ever want to look at any light,

00:33:06.280 | sunlight or artificial light, that is painful to look at.

00:33:09.980 | If you find that your eyes are watering

00:33:11.740 | or you're having challenges maintaining,

00:33:14.660 | looking at this thing for a while because it's painful,

00:33:17.140 | that light is too bright

00:33:18.140 | and you do not want to damage your retina.

00:33:20.020 | So you don't want to gaze at the sun,

00:33:22.180 | refusing to blink and burn your retina.

00:33:25.840 | That's actually possible to do.

00:33:27.080 | You don't want to do that.

00:33:28.360 | You have a proper blink reflex installed in you since birth.

00:33:33.040 | And if you feel like something's too bright

00:33:34.980 | and you need to blink, it means you need to blink,

00:33:36.660 | that it's too much light.

00:33:38.780 | So please don't beam your eyes with really bright light.

00:33:41.820 | But blue light, in particular,

00:33:43.300 | blue light and yellow light coming from sunlight is ideal.

00:33:45.980 | If you're going to get it from artificial light

00:33:48.040 | because you can't get enough sunlight,

00:33:49.600 | well, then artificial lights that are rich in blue,

00:33:54.380 | blue wavelengths are going to be ideal

00:33:56.600 | for setting this mechanism.

00:33:58.320 | A lot of people will say,

00:33:59.160 | "Oh, I should be wearing blue blockers throughout the day."

00:34:01.240 | No, that's the exact wrong thing.

00:34:03.960 | If you're going to use blue blockers, we can talk about that.

00:34:06.560 | That should be reserved for late in the evening

00:34:09.360 | because light suppresses melatonin.

00:34:12.660 | I've been asked many times before about this pineal gland.

00:34:16.880 | And there are a lot of ancient practices

00:34:19.400 | that map to some of the things that I'm saying.

00:34:21.040 | And people always say,

00:34:21.880 | "Oh, I heard that sunlight is great for the pineal."

00:34:24.680 | Well, perhaps, but we have to be careful about that phrase.

00:34:28.360 | Sunlight inhibits the pineal.

00:34:31.160 | It prevents it from releasing melatonin.

00:34:34.260 | Darkness allows the pineal to release melatonin.

00:34:38.160 | So the pineal is not the gland or the organ of sunlight.

00:34:41.960 | It is the gland of darkness.

00:34:43.860 | In fact, melatonin can be thought of

00:34:46.240 | as a sleepiness signal that's correlated with darkness.

00:34:48.940 | So get up each morning, try and get outside.

00:34:52.040 | I know that can be challenging for people,

00:34:53.680 | but anywhere from two to 10 minutes of sunlight exposure

00:34:58.080 | is going to work well for most people.

00:34:59.840 | And you want to do this on a regular basis

00:35:01.680 | and you don't have to do it exactly at sunrise.

00:35:03.600 | I realize I'm repeating myself,

00:35:05.180 | but somehow, despite barking at people about this

00:35:08.340 | for a couple of years now,

00:35:09.960 | I keep getting the same questions

00:35:11.400 | and somehow it hasn't been sinking in,

00:35:13.660 | which could be related to some circadian disorder.

00:35:16.800 | I'm just kidding.

00:35:17.640 | If it's not sinking in, it's probably

00:35:19.000 | that I'm not being effective

00:35:20.200 | in communicating the information.

00:35:22.680 | But get that bright light early in the day from sunlight.

00:35:25.640 | And if you can't get it from sunlight,

00:35:26.860 | get it from artificial light.

00:35:28.220 | What kinds of artificial lights will work?

00:35:30.000 | Well, there are these sunrise simulators,

00:35:33.140 | but the ring lights that people use for selfies

00:35:37.280 | and this sort of thing for posting on Instagram,

00:35:39.800 | those generate a lot of blue light.

00:35:42.100 | If you want to get experimental about this,

00:35:44.080 | there's a free app.

00:35:45.080 | I have no relationship to the app,

00:35:46.680 | but it's a great app called Light Meter

00:35:48.840 | that you can use your phone

00:35:50.620 | and you can measure the amount of photon energy

00:35:53.080 | in your environment.

00:35:54.120 | And it's kind of a fun experiment to do.

00:35:55.400 | You can go outside in the morning

00:35:56.640 | and you'll see that there's 10,000, 20,000 lux,

00:35:59.180 | even though it might seem like it's kind of dim

00:36:01.120 | or there's tree cover or cloud cover.

00:36:02.740 | You go inside and you shine

00:36:04.080 | that artificial light at your phone,

00:36:07.680 | press the button on Light Meter,

00:36:09.140 | and you'll find that it's only 500 or 1,000 lux.

00:36:12.040 | And you realize that even though it seems really bright,

00:36:15.360 | the artificial light is very condensed,

00:36:17.880 | whereas the outside light is scattered in the atmosphere.

00:36:22.400 | And so you can think that you're not getting much sunlight,

00:36:24.440 | but you're actually getting much more outside.

00:36:26.080 | So get outside, get that sunlight early in the day

00:36:28.280 | and try and do it on a consistent basis.

00:36:30.240 | If you can't do it every day

00:36:31.400 | or you sleep through this period of the early day,

00:36:33.780 | low solar angle, don't worry about it.

00:36:36.220 | The systems in the body,

00:36:37.600 | these hormone systems and neurotransmitter systems

00:36:40.140 | that make you awake at certain periods of the day

00:36:42.640 | and sleepy at other times are operating by averaging

00:36:47.560 | when you view the brightest light.

00:36:50.080 | Now, that can immediately tell us

00:36:52.860 | that what most people are doing is terrible.

00:36:54.680 | They're waking up and they're looking at their phone,

00:36:56.520 | which isn't triggering activation of these cells in the eye

00:36:59.280 | and the central circadian clock.

00:37:01.000 | Then a few hours later,

00:37:02.080 | they might get in their car with sunglasses and drive.

00:37:04.460 | Now, a note about sunglasses and prescription lenses.

00:37:07.280 | Absolutely never, ever, ever compromise safety

00:37:12.320 | for the sorts of things I'm talking about.

00:37:13.960 | So if you need to wear sunglasses for safety reasons,

00:37:16.260 | wear them.

00:37:17.280 | Absolutely, if you wear prescription lenses or contacts,

00:37:20.160 | wear them, they won't filter out the wavelengths of light

00:37:23.720 | that are necessary for setting these central clocks.

00:37:26.100 | So safety first, of course.

00:37:28.160 | If you have a retinal degenerative disorder,

00:37:30.440 | retinitis pigmentosa, macular degeneration or glaucoma,

00:37:33.320 | or those run in your family,

00:37:35.380 | you want to avoid excessively bright light all the time.

00:37:38.660 | You want to be very cautious about that.

00:37:40.300 | You're going to want to get your light exposure

00:37:42.380 | by through seeing dimmer light, including sunlight,

00:37:46.780 | but for longer periods of time, perhaps.

00:37:48.780 | You might immediately ask,

00:37:51.260 | what about low vision or blind people?

00:37:53.800 | How do they set these central clocks?

00:37:55.340 | Well, it turns out that low vision and blind people,

00:37:57.980 | most of them, provided they still have eyes,

00:38:00.260 | that the eyes weren't removed because of a burn or tumor

00:38:02.540 | or something like that,

00:38:03.660 | still maintain these neurons that set the circadian clock,

00:38:07.780 | which brings me to a really important point.

00:38:10.260 | It's not about seeing and perceiving the sun.

00:38:13.720 | This is a subconscious mechanism by which these neurons,

00:38:17.580 | which are called melanopsin ganglion cells,

00:38:20.860 | these neurons set your central clocks

00:38:24.580 | by getting activated by the particular wavelengths of light

00:38:28.060 | that are present in the atmosphere,

00:38:29.540 | even coming through cloud cover,

00:38:32.000 | and you don't need to see or perceive the sun

00:38:35.180 | in order to get this mechanism to start.

00:38:37.580 | Now, it's such a vitally important mechanism

00:38:39.540 | because it dictates how well and what time

00:38:44.100 | you will want to fall asleep later in the day.

00:38:46.260 | So for those of you that are night owls

00:38:47.860 | and you insist that you're a night owl

00:38:49.380 | and you have the genetic polymorphism

00:38:51.100 | that makes you a night owl,

00:38:52.080 | you may very well have that genetic polymorphism,

00:38:54.820 | those genes that make you want to stay up late

00:38:56.900 | and wake up late.

00:38:58.660 | But chances are about half of you

00:39:00.360 | that think that your night owls

00:39:01.940 | are just not getting enough sunlight early in the day.

00:39:04.840 | So viewing light early in the day, ideally sunlight,

00:39:08.380 | is key for establishing healthy sleep-wake rhythms

00:39:12.480 | and for allowing you to fall asleep easily at night.

00:39:16.400 | Now, it's not gonna make sure

00:39:17.740 | that all that happens every single time,

00:39:19.640 | but it is the foundation of proper sleep

00:39:23.200 | and what we call circadian health.

00:39:25.420 | It governs metabolism and so many other things

00:39:28.600 | that are supposed to exist on a regular 24-hour cycle.

00:39:33.480 | Some of you, many of you might be asking,

00:39:36.140 | what else can help set this rhythm?

00:39:37.940 | Well, it turns out that light

00:39:39.480 | is what we call the primary zeitgeber, the time giver,

00:39:43.960 | but other things can help establish this rhythm

00:39:48.140 | of cortisol followed by melatonin

00:39:49.940 | 12 to 16 hours later as well.

00:39:52.480 | The other things besides light are timing of food intake,

00:39:57.020 | timing of exercise, as well as various drugs

00:40:01.380 | or chemicals that one might ingest, not illegal drugs,

00:40:04.440 | although those will impact circadian mechanisms as well.

00:40:07.300 | But the reason we focus so heavily on light

00:40:10.520 | is that light is the main way that the central clock,

00:40:15.520 | the suprachiasmatic nucleus, was supposed to be set.

00:40:18.960 | We know that because it's the only direct input to the clock.

00:40:23.440 | These neurons in the eye that are also part of the brain

00:40:25.560 | that we call melanopsin ganglion cells

00:40:27.720 | that not so incidentally were discovered

00:40:30.240 | by my friend and colleague, David Berson

00:40:32.100 | at Brown University and others,

00:40:34.700 | Samir Hatar, King Wayao, et cetera,

00:40:37.340 | worked out the mechanisms, the molecular mechanisms,

00:40:39.500 | but it was really David Berson

00:40:41.520 | that discovered these incredibly fascinating non...

00:40:46.400 | These are cells that aren't important for sight

00:40:48.520 | like pattern vision, but are for setting our clocks.

00:40:51.940 | David's really credited with making that discovery.

00:40:55.040 | Those cells are the main way

00:40:58.580 | and the only direct way to set the clock.

00:41:01.460 | In fact, it's fair to say that light

00:41:04.620 | viewed by these melanopsin cells, particular sunlight,

00:41:08.600 | is 1,000 to 10,000 times more effective

00:41:12.460 | than say getting up in darkness and just exercising.

00:41:16.040 | That doesn't mean that you shouldn't exercise

00:41:17.600 | early in the day in darkness if that's what you like to do.

00:41:20.040 | It will have somewhat an effect

00:41:22.320 | on raising your wakefulness early in the day

00:41:25.080 | and setting these rhythms.

00:41:27.600 | And this is because of some other pathways.

00:41:29.440 | For the aficionados out there

00:41:31.040 | who want to know more neuroscience, here's how it goes.

00:41:33.860 | You've got this clock above the roof of your mouth

00:41:35.880 | that churns out this 24-hour rhythm

00:41:37.680 | and is communicated to all the other organs

00:41:39.600 | and tissues of your body.

00:41:41.120 | But there's another structure, has a cool name.

00:41:43.560 | It's called the intergeniculate leaflet,

00:41:45.840 | which sits a few millimeters away in the brain.

00:41:48.280 | And it's involved in regulating the clock output

00:41:51.540 | through what's called non-photic, non-light type influences

00:41:55.640 | like exercise and feeding, et cetera.

00:41:58.420 | So if you are not feeling awake during the day

00:42:02.360 | and you're having trouble sleeping,

00:42:04.160 | get the sunlight exposure that we just talked about.

00:42:07.120 | But in addition to that,

00:42:09.140 | if you want to become an early riser, for instance,

00:42:11.500 | and you want to feel more awake

00:42:12.540 | during the early part of the day,

00:42:15.160 | by getting that light exposure

00:42:16.440 | and exercising early in the day,

00:42:18.960 | you will, after two or three days,

00:42:21.220 | you will naturally start to wake up earlier in the day.

00:42:23.640 | And that's because these clock mechanisms

00:42:25.520 | have shifted, it's like setting the clock earlier

00:42:27.820 | as opposed to delaying the clock.

00:42:30.240 | And that takes us to a somewhat complicated

00:42:33.480 | but very important aspect to all this,

00:42:35.780 | which is what sets the clock and keeps it anchored.

00:42:39.360 | The main thing is that bright light early in the day.

00:42:42.520 | The other thing is sunset.

00:42:44.460 | When the sun is also at low solar angle,

00:42:47.640 | low, close to the horizon,

00:42:49.300 | by viewing sunlight at that time of day in the evening

00:42:53.480 | or afternoon, depending on what time of year it is

00:42:55.360 | and where you are in the world,

00:42:57.280 | these melanopsin cells, these neurons in your eye,

00:42:59.760 | signal the central circadian clock

00:43:01.940 | that it's the end of the day.

00:43:04.060 | And there's a really nice study

00:43:05.480 | that was published last year,

00:43:06.900 | and I will put links to these references on a website

00:43:09.720 | not too long from now.

00:43:11.820 | There was a really nice study that showed

00:43:14.760 | that viewing sunlight around the time of sunset,

00:43:18.880 | doesn't have to be just crossing the horizon,

00:43:21.280 | but circa sunset, within an hour or so of sunset,

00:43:25.240 | prevents some of the bad effects of light

00:43:29.880 | in preventing melatonin release later that same night.

00:43:33.800 | So let me repeat this.

00:43:34.760 | Viewing light early in the day is key.

00:43:36.280 | Viewing light later in the day when the sun is setting

00:43:39.460 | or around that time can help protect these mechanisms,

00:43:43.920 | your brain and body,

00:43:45.240 | against the negative effects of light later in the day.

00:43:48.760 | So let me talk about how you would do that.

00:43:51.260 | You'd go view the sunset,

00:43:52.600 | or you would go outside in the late afternoon or evening.

00:43:55.880 | Again, if you safely can do that with sunglasses off,

00:43:58.320 | you will, if you need to wear sunglasses, fine,

00:44:00.600 | but it will take probably 100 to 1,000 times longer

00:44:03.760 | with dark sunglasses than if you take them off.

00:44:06.120 | Again, if you want to do this through a window at work,

00:44:09.640 | that's fine, but it'll take 50 times longer.

00:44:12.040 | So the best thing to do is just to get outside

00:44:14.200 | for a few minutes,

00:44:15.040 | anywhere from two to 10 minutes, also in the afternoon.

00:44:17.720 | Having those two signals arriving to your central clock

00:44:21.100 | that your body, your internal world,

00:44:23.540 | knows when it's morning and knows when it's evening

00:44:25.720 | is tremendously powerful.

00:44:27.980 | Maybe think about it this way.

00:44:30.000 | Every cell in your body needs glucose and energy.

00:44:33.040 | It needs, whether or not it gets that from meat

00:44:35.200 | or it gets it from ketones

00:44:36.280 | or it gets it from carbohydrates or fruit or vegetables,

00:44:38.840 | doesn't matter, it is eventually converted

00:44:40.680 | into a certain form of energy that all your cells use.

00:44:43.960 | But you don't take glucose,

00:44:45.720 | you don't take a bread or a steak or a nice orange

00:44:49.000 | and shove it in your ear, you put it in your mouth,

00:44:51.260 | it goes into your stomach, it's digested,

00:44:53.120 | and then that resource is distributed

00:44:55.640 | to all the cells of your body.

00:44:57.500 | Every cell in your body needs oxygen

00:44:59.860 | and you don't put a hose through your nostril

00:45:03.300 | or through your ear or through some other orifice

00:45:05.160 | in your body.

00:45:06.160 | You inhale air and it's then distributed via the lungs

00:45:10.220 | to the cells in your bloodstream

00:45:12.320 | and that's distributed to all the organs of your body.

00:45:15.360 | Every cell and organ in your body needs light information.

00:45:19.440 | And the way to get that light information to all those cells

00:45:22.160 | because you have a thick skull

00:45:24.480 | and inside of you is dark inside your skin,

00:45:29.200 | there's no sunlight getting in there,

00:45:30.760 | is by viewing sunlight with your eyes

00:45:32.720 | at the two times a day that I'm referring to, okay?

00:45:35.480 | That's the only route.

00:45:37.380 | There was a study published in Science,

00:45:39.000 | an excellent journal, well over 10 years ago,

00:45:43.200 | that showed that light shown on the back of the knee

00:45:46.200 | could set these circadian rhythms.

00:45:49.140 | That study was retracted

00:45:50.640 | and unfortunately most people don't know

00:45:52.080 | that it was retracted.

00:45:53.360 | There were some experimental flaws

00:45:54.960 | that people were actually viewing light through their eyes.

00:45:57.460 | That study was repeated.

00:45:58.720 | Turns out there is no extra ocular photoreception in humans.

00:46:03.400 | Whatever somebody tells you that light to the skin

00:46:05.800 | or light to the wherever is beneficial for your health,

00:46:09.460 | we can talk about that,

00:46:10.660 | but there's no way that light information is setting

00:46:13.100 | your clocks.

00:46:14.700 | You need these cells in your eyes to perceive

00:46:17.940 | or to see light at the particular times of day

00:46:20.660 | that I'm referring to.

00:46:22.020 | Some animals like snakes and other reptiles

00:46:25.060 | actually have a hole in the top of their skull

00:46:27.740 | to get light information directly to their pineal

00:46:31.300 | to suppress melatonin.

00:46:32.900 | We don't have that hole.

00:46:33.960 | I mean, most of you don't have holes in your skull.

00:46:37.100 | These holes in your skull

00:46:38.700 | that we call the sockets for the eyes

00:46:41.300 | are actually there primarily to allow light information

00:46:45.340 | to the central clock.

00:46:46.620 | And then vision and pattern vision and color vision

00:46:48.660 | came much later in evolution.

00:46:50.540 | We know this on the basis of genetic studies

00:46:52.320 | we get to discuss in a future podcast.

00:46:55.100 | So get that light information

00:46:56.900 | to the cells of your brain and body

00:46:59.020 | by viewing sunlight at the two times a day

00:47:01.420 | that I referred to.

00:47:02.380 | There's always a lot of questions about how long,

00:47:06.260 | how much, how do I know if I've had enough?

00:47:07.840 | You'll know because your rhythm will start to fall

00:47:11.020 | into some degree of normalcy.

00:47:13.160 | You'll start to wake up at more or less

00:47:14.580 | the same time each day.

00:47:15.660 | You'll fall asleep more easily at night.

00:47:17.340 | Generally, it takes about two or three days

00:47:19.040 | for these systems to align.

00:47:20.720 | So if you've not been doing these behaviors,

00:47:22.960 | it's gonna take a few days,

00:47:24.180 | but they can have tremendous benefits

00:47:26.300 | and sometimes rather quickly on a number of different mental

00:47:29.340 | and physical aspects of your health.

00:47:31.140 | Now let's talk about the bad effects of light

00:47:35.780 | because light is not supposed to arrive in our system

00:47:40.300 | at any time.

00:47:41.520 | And nowadays, because of screens and artificial light,

00:47:44.440 | we have access to light at times of day and night

00:47:48.540 | that normally we wouldn't.

00:47:50.560 | Now, earlier I said that you need a lot of light

00:47:53.260 | in particular sunlight to set these clock mechanisms.

00:47:56.260 | That's true, but there's a kind of diabolical feature

00:47:59.060 | to the way all this works,

00:48:00.180 | which is the longer you've been awake,

00:48:03.960 | the more sensitive your retina and these cells are to light.

00:48:08.020 | So that if you've been awake for 10, 12, 14 hours,

00:48:11.800 | it becomes very easy for even a small amount of light

00:48:14.720 | coming from a screen or from an overhead light

00:48:19.440 | to trigger the activation of the clock

00:48:21.760 | and make you feel like you wanna stay up late

00:48:23.560 | or make it harder to fall asleep

00:48:24.880 | and disrupt your sleep pattern.

00:48:27.040 | Okay, so the simple way to think about this

00:48:29.440 | is you want as much light as is safely possible

00:48:32.240 | early in the day, morning and throughout the day,

00:48:34.600 | including blue light.

00:48:35.800 | So take those blue blockers off during the day,

00:48:37.840 | unless you have a real issue with screen light sensitivity.

00:48:40.820 | And you want as little light coming into your eyes,

00:48:43.840 | artificial or sunlight, after say 8 p.m.

00:48:47.560 | And certainly you do not want to get bright light exposure

00:48:50.520 | to your eyes between 11 p.m. and 4 a.m., and here's why.

00:48:54.040 | David Berson, who I mentioned before,

00:48:56.120 | and another friend and colleague, Samir Hattar,

00:48:58.280 | who's director of the Chronobiology Unit

00:49:00.020 | at the National Institutes of Mental Health,

00:49:02.200 | published a paper in Cell, which is a journal,

00:49:05.740 | another excellent journal, very high stringency,

00:49:07.920 | showing that light that arrives to the eyes

00:49:12.920 | between 11 p.m. and 4 a.m., approximately,

00:49:16.840 | suppresses the release of dopamine,

00:49:20.320 | this neuromodulator that makes us feel good

00:49:22.220 | as sort of an endogenous antidepressant,

00:49:25.760 | and can inhibit learning

00:49:27.000 | and create all sorts of other detrimental effects.

00:49:30.600 | It does this through a mechanism,

00:49:32.280 | for those of you who want to know the neural pathways,

00:49:34.440 | that involves light to the eyes

00:49:35.880 | that then signal to a structure called the habenula.

00:49:38.800 | The habenula looks like two little bat ears

00:49:40.600 | sitting right in the middle of you,

00:49:41.880 | structuring your brain called the thalamus.

00:49:43.520 | Don't worry about these names

00:49:44.600 | if you're not interested in this stuff.

00:49:45.680 | If you are, these are just avenues to explore.

00:49:48.400 | When that habenula gets activated,

00:49:50.320 | it's actually called the disappointment nucleus,

00:49:53.100 | because it actually makes us feel less happy

00:49:57.040 | and more disappointed

00:49:58.160 | and can lead to certain forms of depression

00:50:00.640 | in the wakeful state.

00:50:02.140 | Now, if you wake up in the middle of the night

00:50:03.400 | and you need to use the bathroom,

00:50:04.420 | or you're on an all-night flight

00:50:05.720 | and you need to read or whatever it is, fine.

00:50:10.280 | Every once in a while,

00:50:12.320 | it's not going to be a problem

00:50:13.280 | to get bright light exposure to your eyes

00:50:15.380 | in the middle of the night.

00:50:16.820 | But if you think about our lifestyle nowadays

00:50:19.480 | and being up late looking at phones,

00:50:21.080 | even if you dim that screen,

00:50:22.800 | you're triggering this activation,

00:50:24.660 | because your retinal sensitivity

00:50:26.120 | and the sensitivity of these neurons has gone up

00:50:28.240 | late in the day.

00:50:29.680 | Now, I'm not here to dictate what you should or shouldn't do,

00:50:32.040 | but for those of you that are experiencing

00:50:34.020 | challenges with mood,

00:50:35.280 | those of you that have anxiety, learning problems,

00:50:37.360 | issues focusing,

00:50:39.160 | the questions I usually get are, how can I focus better?

00:50:41.320 | Well, we will get to that.

00:50:43.040 | But one of the best ways you can support your mechanisms

00:50:46.020 | for good mood, mental health, learning,

00:50:48.520 | focus, metabolism, et cetera,

00:50:50.800 | is to take control of this light exposure behavior at night

00:50:55.640 | and not get much or any bright light exposure

00:50:58.760 | in the middle of the night.

00:50:59.920 | Red light won't trigger this pathway,

00:51:02.580 | but very few people have the kind of infrared lights

00:51:05.200 | that are set up or floor lights.

00:51:07.240 | And that brings me to an important point,

00:51:09.120 | which is about the location of light.

00:51:10.640 | This hasn't been discussed much out there, I don't think.

00:51:13.560 | These cells in our eye,

00:51:15.360 | these neurons that signal the central clock

00:51:18.200 | reside mostly, not exclusively,

00:51:20.460 | but mostly in the bottom half of our retina.

00:51:23.120 | And because we have a lens in front of our retina

00:51:25.720 | and because of the optics of lenses,

00:51:27.840 | that means that these cells

00:51:29.580 | are actually viewing our upper visual field.

00:51:31.960 | There's an inversion of the visual image, et cetera.

00:51:34.480 | You can look that up

00:51:35.300 | if you wanna learn more about retinal optics.

00:51:37.640 | It's fascinating, but not the topic for today.

00:51:40.560 | These cells are in the bottom half of your retina mostly,

00:51:42.920 | and so they're viewing the overhead visual space around you.

00:51:47.920 | This is probably not coincidental

00:51:50.840 | that these cells were essentially designed

00:51:54.260 | to detect sunlight, which is overhead, of course.

00:51:58.080 | So if you want to avoid

00:52:01.600 | improper activation of these neurons,

00:52:05.620 | it's better to place lights that you use in the evening

00:52:08.920 | low in your physical environment,

00:52:10.800 | so on desktops or even the floor,

00:52:13.080 | if you wanna go that way,

00:52:15.600 | as opposed to overhead lights.

00:52:17.940 | So overhead fluorescent lights would be the worst.

00:52:20.900 | That would be the worst case scenario.

00:52:23.300 | Lights that are overhead that are a little bit softer

00:52:25.740 | of the sort of yellow or reddish tints

00:52:28.000 | would be slightly better,

00:52:29.040 | but dim lights that are set low in the room

00:52:31.660 | are going to be best

00:52:32.700 | because they aren't going to activate these neurons

00:52:36.180 | and therefore shift your circadian clock.

00:52:39.140 | So that's a goal.

00:52:40.540 | Some people like Samir Hatar that I mentioned earlier,

00:52:43.580 | he turns his home basically into a cave in the evenings.

00:52:46.660 | Candlelight actually does not

00:52:49.080 | trigger activation of these cells.

00:52:50.660 | So candlelight and fireplaces and campfires are fine.

00:52:55.660 | Dim lights, very dim lights are fine,

00:52:58.260 | and lights low in the physical environment.

00:53:00.000 | Of course, the problem with candlelight and fireplaces

00:53:02.660 | is the fire hazard, but you're smart people.

00:53:05.260 | You know what to do about that.

00:53:07.620 | Don't burn down whatever structure you're in,

00:53:10.820 | including forests, please.

00:53:13.220 | So keep the lights low in your environment.

00:53:16.840 | What if you wake up in the middle of the night

00:53:18.960 | and you find yourself watching TV or on the computer?

00:53:23.020 | And well, in that case, you might want to wear blue blockers

00:53:25.780 | and you certainly would want to dim the screen,

00:53:28.060 | but ideally you're not doing that.

00:53:29.580 | It's remarkable the positive effects

00:53:32.620 | of getting that bit of sunlight early in the day,

00:53:34.600 | maybe even also around sunset and avoiding bright lights

00:53:38.060 | and especially overhead bright lights

00:53:40.520 | between about 11 PM and 4 AM.

00:53:42.680 | Now I'm not talking about shift work.

00:53:44.440 | I'm realizing that we're probably going to have to have

00:53:46.620 | an entire discussion devoted just to shift workers

00:53:49.360 | because there's some good information there

00:53:50.800 | about how they can protect themselves

00:53:52.700 | against some of the very bad health effects of shift work,

00:53:56.300 | getting light in the middle of the night.

00:53:57.800 | But we rely on shift workers and they're super important

00:54:00.640 | to culture and society and the economy.

00:54:03.420 | So I want to acknowledge them and let you know

00:54:05.540 | that we will do a discussion about shift work and jet lag.

00:54:11.020 | But let's talk about what light can do

00:54:14.300 | in terms of shifting us in healthy ways.

00:54:17.540 | So the way to think about this whole system,

00:54:20.200 | again, is you've got adenosine building up

00:54:21.940 | depending on how long you've been awake

00:54:24.040 | and it's making you sleepy.

00:54:25.100 | And then you've got the circadian mechanisms

00:54:26.780 | that are timing your wakefulness

00:54:28.460 | and timing when you want to be asleep,

00:54:30.060 | mainly through cortisol and melatonin.

00:54:32.360 | But there are a bunch of other things

00:54:33.420 | that are downstream of cortisol and melatonin.

00:54:35.500 | Like we tend to be hungrier during our wakeful period

00:54:40.040 | than late at night.

00:54:41.000 | Some people like to eat it late at night,

00:54:42.760 | but if you're finding that you can't become a day person

00:54:45.660 | or a morning person, shifting your light exposure exercise

00:54:49.980 | and food intake to the daytime will help.

00:54:52.900 | Some people like to stop eating around six or 8 p.m.

00:54:56.720 | because of metabolic reasons

00:54:58.880 | or they're trying to maintain their weight or lose weight.

00:55:01.300 | That's actually not supported so well by the literature.

00:55:05.640 | The literature around nutrition essentially says

00:55:07.460 | that it's best to restrict your feeding

00:55:09.840 | to a certain period of each 24 hour cycle

00:55:12.080 | to not be eating around the clock.

00:55:14.140 | And whether or not that's four hours or eight hours

00:55:16.100 | or 16 hours is a much lengthier discussion

00:55:19.560 | than we have time for now.

00:55:20.580 | I would refer you to Sachin Panda's book,

00:55:23.500 | "The Circadian Code," which talks all about that.

00:55:25.580 | He's an expert, a former colleague of mine

00:55:27.340 | from the Salk Institute in San Diego.

00:55:29.700 | You can explore intermittent and circadian fasting,

00:55:33.320 | so to speak, through Sachin's literature.

00:55:35.540 | We'll talk about that.

00:55:36.380 | We might even get Sachin in here

00:55:37.540 | if we're lucky at some point in the future.

00:55:39.820 | But you can actually use light to wake up earlier.

00:55:43.340 | Jamie Zeitzer and colleagues did a beautiful study

00:55:46.400 | showing that if you turn on the lights before waking up,

00:55:51.400 | so around 45 minutes to an hour before waking up,

00:55:54.820 | even if your eyelids are closed,

00:55:56.340 | provided you're not under the covers,

00:55:58.640 | after doing that for a few days,

00:56:01.720 | that increases your total sleep time

00:56:04.420 | and shifts forward the time at which you feel sleepy.

00:56:07.360 | It makes you want to go to bed earlier each night.

00:56:10.700 | Now, in a kind of a diabolical way,

00:56:13.160 | they did this with teenagers who are notorious

00:56:15.720 | for wanting to wake up late and stay up late.

00:56:17.480 | And what they found was bright light flashes,

00:56:19.920 | just turning on the lights in their environment,

00:56:21.400 | overhead lights, 'cause they're trying

00:56:22.800 | to activate the system,

00:56:24.040 | and that's why they're using overhead lights.

00:56:26.480 | Even through the eyelids, before these kids woke up,

00:56:30.080 | then made those kids naturally want to go to bed earlier

00:56:32.640 | and they ended up sleeping longer.

00:56:34.180 | So that's something you could try.

00:56:35.200 | You could put your lights on a timer to go on early

00:56:38.600 | in the day before you wake up.

00:56:40.960 | You could open your blind so that sunlight is coming through.

00:56:44.240 | And again, if you curl up under the covers,

00:56:46.560 | then it's not going to reach these neurons,

00:56:49.280 | but it's remarkable the light can actually penetrate

00:56:51.380 | the eyelids, activate these neurons,

00:56:53.080 | and go to the central clock.

00:56:54.480 | That study illustrates a really important principle

00:56:57.920 | of how you're built, which is you have the capacity

00:57:01.040 | for what are called phase advances and phase delays.

00:57:05.000 | And I don't want to complicate this too much.

00:57:07.160 | So the simplest way to think about phase advances

00:57:10.480 | and phase delays is that if you see light late in the day,

00:57:15.480 | and in particular in the middle of the night,

00:57:17.880 | your brain and body, for reasons that now you understand,

00:57:22.300 | will think that that's morning light,

00:57:24.400 | even though it's not sunlight,

00:57:25.540 | because you have this heightened sensitivity,

00:57:27.120 | and it will phase delay, it will delay your clock.

00:57:29.880 | It will essentially make you want to get up later

00:57:32.000 | and go to sleep later.

00:57:33.740 | So if you get light exposure too late in the evening

00:57:36.520 | or in the middle of the night,

00:57:37.900 | it's going to make it hard to want to wake up

00:57:40.140 | the next morning early and to go to bed early.

00:57:42.800 | The opposite is also true.

00:57:45.940 | If you wake up early, say, 6 a.m. or 7 a.m.

00:57:51.900 | and get light exposure, or even earlier, 4 a.m.,

00:57:55.960 | and get light exposure, it will phase advance your clock.

00:58:00.080 | It's going to make your clock think it's earlier,

00:58:02.580 | and you'll want to wake up earlier.

00:58:04.360 | So the simple way to think about this

00:58:06.680 | is if you're having trouble waking up early

00:58:08.840 | and feeling alert early in the day,

00:58:11.660 | you're going to want to try and get bright light exposure

00:58:14.260 | even before waking up, because it will advance your clock.

00:58:17.520 | It's sort of like turning the clock forward.

00:58:20.180 | Whereas if you are having trouble waking up early,

00:58:22.680 | you definitely don't want to get too much light exposure

00:58:25.880 | or any light exposure to your eyes late in the evening

00:58:29.360 | and in the middle of the night,

00:58:30.220 | because it's just going to delay your clock more and more.

00:58:33.140 | So rather than get into the specifics

00:58:35.420 | of everybody's situation,

00:58:36.680 | because there are many of you out there

00:58:38.040 | with different situations and lifestyle requirements,

00:58:41.040 | et cetera, the way to think about this

00:58:43.960 | is that you have these internal mechanisms

00:58:46.220 | of adenosine and circadian clocks,

00:58:47.960 | and they're always operating.

00:58:49.580 | And what you're trying to do is provide them anchors.

00:58:52.420 | You're trying to provide them consistent, powerful anchors

00:58:55.860 | so that your cortisol, your melatonin,

00:58:59.240 | and then everything that cascades down from that,

00:59:02.420 | like your metabolism and your ability to learn

00:59:05.140 | and your sense of alertness, your dopamine, your serotonin,

00:59:08.220 | all that stuff is timed regularly.

00:59:11.580 | One of the reasons why there's so much challenge out there

00:59:16.580 | with focus and anxiety and depression,

00:59:19.980 | there are a lot of reasons for that,

00:59:21.260 | but one of the reasons is that people's internal mechanisms

00:59:25.380 | aren't anchored to anything regular.

00:59:27.640 | Now, this doesn't require being neurotically attached

00:59:30.620 | to getting up at a very specific time,

00:59:32.380 | going outside, viewing the sunlight, same time every day.

00:59:35.220 | These systems, again, will average,

00:59:36.760 | but if you can provide them consistent light anchors

00:59:39.860 | early in the day and in the evening

00:59:41.760 | and avoiding light at night,

00:59:43.320 | you will be amazed at the tremendous number

00:59:45.700 | of positive effects that can come from that

00:59:47.980 | at the level of metabolic factors, hormones,

00:59:50.980 | and just general feelings of wellbeing.

00:59:53.420 | In fact, most of us are familiar

00:59:56.300 | with what it is to not sleep well

00:59:58.340 | and all the terrible effects that has.

00:59:59.960 | Maybe one night you're fine,

01:00:01.180 | two nights even for the new parents out there,

01:00:04.220 | I sympathize with you,

01:00:06.120 | but most people are not familiar with what it is

01:00:09.540 | to sleep really, really well on a consistent basis.

01:00:13.380 | And when you start doing that

01:00:15.140 | by controlling your sleep environment, right,

01:00:17.000 | get the proper sleep surface, get the proper pillow,

01:00:19.780 | get the temperature in the room right,

01:00:21.800 | get your light exposure right,

01:00:23.760 | start timing your exercise at normal periods or times

01:00:26.720 | throughout the day and week.

01:00:28.760 | It's amazing how many other biological systems

01:00:31.320 | just naturally fall in line.

01:00:33.080 | And this is why whenever people ask me,

01:00:35.800 | "What should I take?"

01:00:36.760 | Which is one of the most common questions I get,

01:00:38.380 | "What supplements should I take?

01:00:39.520 | What drugs should I be taking?

01:00:40.680 | What things should I be taking?"

01:00:42.280 | The first question I always ask them is, "How's your sleep?"

01:00:47.280 | And 90% of the time they tell me

01:00:49.560 | they either have trouble falling asleep or staying asleep

01:00:51.760 | or they don't feel rested throughout the day.

01:00:54.400 | A brief note about naps.

01:00:56.600 | Naps, provided that they're less than one ultradian cycle,

01:00:59.600 | provided they're 20 minutes or 30 minutes or even an hour,

01:01:02.540 | can be very beneficial for a lot of people.

01:01:04.600 | You don't have to take them,

01:01:06.240 | but many people naturally feel a dip in energy

01:01:09.020 | and focus late in the afternoon.

01:01:10.600 | In fact, if we were gonna look at wakefulness,

01:01:12.760 | what we would find is that

01:01:13.760 | you get that morning light exposure, hopefully,

01:01:15.440 | your cortisol goes up, people start feeling awake,

01:01:17.520 | and then around two or three or four in the afternoon,

01:01:19.840 | there's a spike in everything from alertness

01:01:23.420 | to ability to learn, some metabolic factors drop,

01:01:26.420 | and then it just naturally comes back up,

01:01:28.560 | and then it tapers off as the night goes on.

01:01:31.200 | So for some of you, naps are great.

01:01:33.720 | I love taking naps.

01:01:35.320 | Some people, they wake up from naps feeling really groggy.

01:01:38.400 | That's probably because they're not sleeping as well

01:01:41.320 | as they should at night or as long as they should at night,

01:01:43.720 | and so they're dropping into REM sleep

01:01:46.340 | or deeper forms of sleep in the daytime.

01:01:49.120 | And then they wake up and they feel kind of disoriented.

01:01:51.240 | Other people feel great after a nap.

01:01:52.860 | So that's another case where just like with caffeine,

01:01:55.440 | you sort of have to evaluate for yourself.

01:01:57.960 | As we discuss this, you're probably realizing

01:01:59.600 | this is a lot like nutrition,

01:02:01.120 | where nowadays it's just crazy.

01:02:02.680 | I mean, if you go on social media,

01:02:04.200 | it's like you've got people who are pushing carnivore,

01:02:06.320 | you've got other people who are pushing vegan,

01:02:08.260 | other people who are pushing paleo,

01:02:11.040 | every variation of every diet,

01:02:13.000 | and there's a lot of data to support any and all of those,

01:02:15.920 | and the arguments go on and on.

01:02:17.320 | And there's probably a lot of genetic variation

01:02:19.480 | and lifestyle variation that's going to dictate

01:02:21.880 | whether or not something is good for you,

01:02:23.440 | whether or not you like it,

01:02:24.280 | whether or not you'll stick to it.

01:02:26.000 | The same thing is true for circadian

01:02:29.800 | and sleep and wakefulness behaviors,

01:02:32.640 | except the light viewing behavior

01:02:34.360 | that I talked about before.

01:02:35.380 | There's no way around that.

01:02:36.320 | That's hardwired into our system.

01:02:37.840 | The same way we could factually say

01:02:41.200 | that everybody needs some nutrition

01:02:43.720 | at some level from some source,

01:02:45.560 | everybody needs light information arriving in their system

01:02:49.160 | in some way at regular intervals.

01:02:51.640 | So that's really what this is about.

01:02:54.040 | Okay, so naps are going to be good for some people,

01:02:55.960 | not for others.

01:02:56.800 | I have a colleague, a very accomplished neuroscientist

01:02:59.240 | who likes to take naps just after lunch.

01:03:02.800 | I personally like to take a nap around three or 4 p.m.,

01:03:06.080 | but there's a practice that I've adopted

01:03:08.200 | in the last five years

01:03:09.800 | that I've found to be immensely beneficial

01:03:12.340 | that is sort of like napping, but isn't napping.

01:03:15.280 | It's a thing that they call yoga nidra.

01:03:18.720 | Yoga nidra actually means yoga sleep.

01:03:20.960 | And it's a sort of meditation that you listen to.

01:03:23.760 | There are a number of scripts.

01:03:24.760 | I've talked about this on podcasts before,

01:03:26.420 | but I'm going to post a link to the two that I like most

01:03:29.680 | that allows you to consciously bring your entire body

01:03:34.680 | and mind into a state of deep relaxation.

01:03:38.080 | And sometimes you fall asleep and sometimes you don't.

01:03:41.160 | This is done for 10 to 30 or even 60 minutes at a time.

01:03:46.120 | The other thing that works really well is meditation.

01:03:49.240 | So I'm talking about naps,

01:03:51.120 | but I'm also talking about yoga nidra,

01:03:52.680 | which is sort of a form of meditation,

01:03:54.480 | and then more standard forms of meditation.

01:03:57.440 | All three of those do something powerful,

01:04:00.140 | which is that they bring our mind into a state

01:04:02.960 | of less so-called sympathetic nervous system activation.

01:04:06.000 | Go back and listen to episode one

01:04:07.680 | if that doesn't make any sense,

01:04:08.840 | which is what governs your alertness.

01:04:10.440 | And instead it activates cells and circuits in your body

01:04:14.440 | that promote the parasympathetic nervous system

01:04:16.940 | or the calming system.

01:04:18.680 | A lot of people are not good at falling asleep

01:04:20.880 | because they're not good at calming down.

01:04:23.780 | So some people have no trouble falling asleep,

01:04:26.160 | but many people have a hard time falling asleep

01:04:28.600 | or at least every once in a while

01:04:30.040 | experience challenges falling asleep.

01:04:32.280 | I don't have problems falling asleep most nights,

01:04:35.040 | but I've noticed that if I'm working very hard

01:04:37.100 | or if the world is particularly stressful,

01:04:39.000 | my mind gets into a bit of a kind of OCD loop

01:04:41.360 | where I tend to ruminate on things.

01:04:42.820 | And I'm not even thinking about anything in particular.

01:04:44.800 | It's just challenging for me to disengage and fall asleep.

01:04:48.160 | Meditation and yoga nidra scripts

01:04:50.560 | have been immensely helpful for me

01:04:52.560 | in terms of accelerating the transition to sleep.

01:04:55.880 | So they involve taking a few minutes,

01:04:58.720 | 10 to 30 minutes or so, just like you would for a nap,

01:05:01.480 | and just listening to a script almost passively.

01:05:04.520 | And it has you do some particular patterns of breathing

01:05:07.680 | and some other kind of body scan-like things

01:05:10.560 | that can really help people learn to relax,

01:05:13.120 | not just in that moment,

01:05:14.640 | but get better at relaxing and turning off thinking

01:05:17.480 | in order to fall asleep when they want to do that at night.

01:05:20.680 | There's another thing that's similar to this,

01:05:22.320 | which is certain forms of hypnosis for sleep.

01:05:25.000 | For that, I'll just refer you to the website

01:05:26.820 | of a colleague and collaborator of mine, David Spiegel,

01:05:30.600 | who's our Associate Chair of Psychiatry

01:05:33.040 | and Behavioral Sciences at Stanford.

01:05:35.560 | He's developed a website, which is reverie,

01:05:38.200 | R-E-V-E-R-I-E, health.com, so reveriehealth.com,

01:05:43.200 | that has a lot of science-supported,

01:05:46.260 | clinically-supported hypnosis scripts

01:05:49.320 | that essentially take the brain

01:05:50.680 | into states of deep relaxation

01:05:53.100 | for sake of rewiring the brain and neuroplasticity.

01:05:55.820 | But one of those scripts that's there

01:05:57.400 | and is available free is for sleep.

01:05:59.880 | And we'll talk more about hypnosis at a later time

01:06:01.940 | because it has a ton of other effects

01:06:04.280 | that aren't just limited to sleep.

01:06:06.200 | So a period of time each day that you devote

01:06:10.160 | to getting better at falling and staying asleep

01:06:12.400 | is actually a really good practice to adopt.

01:06:15.080 | The other thing about these practices

01:06:16.560 | like meditation, yoga nidra, and hypnosis

01:06:19.760 | is people always say to me, "Well, when should I do them?"

01:06:22.160 | And I always say, "Well, the best time of day to do it

01:06:24.120 | is when you first wake up in the morning,

01:06:26.040 | provided you've gotten your sunlight already,

01:06:28.440 | anytime you wake up in the middle of the night

01:06:30.080 | or any time of day."

01:06:30.920 | In other words, they're always good for you

01:06:32.840 | because it's a training mechanism

01:06:34.480 | by which you self-train your nervous system

01:06:36.720 | to go from a state of heightened alertness

01:06:39.260 | that you don't want to heightened relaxation

01:06:42.040 | that you do want.

01:06:43.400 | And so it's really teaching you to hit the break.

01:06:46.280 | And that brings us to an even more important point perhaps,

01:06:48.960 | which is we've all experienced

01:06:51.520 | that we can stay up if we want to, right?

01:06:54.360 | If we wanna stay up late on New Year's

01:06:56.880 | or we wanna push an all-nighter,

01:06:58.240 | some people can do that more easily than others,

01:07:00.780 | but we're all capable of doing that.

01:07:03.340 | But it's very hard to make ourselves fall asleep.

01:07:05.840 | And so there's a sort of asymmetry

01:07:07.680 | to the way our autonomic nervous system,

01:07:09.600 | which governs this alertness, calmness thing,

01:07:11.820 | the sympathetic and parasympathetic nervous system,

01:07:14.320 | there's an asymmetry there

01:07:15.560 | where we are more easily able to engage wakefulness

01:07:19.440 | and drive wakefulness.

01:07:20.480 | We can force ourselves to stay awake.

01:07:22.660 | Then we are able to force ourselves to fall asleep.

01:07:26.360 | And one of the things that I say over and over again,

01:07:29.320 | and I'm gonna continue to say over and over again,

01:07:31.480 | is it's very hard to control the mind with the mind.

01:07:34.440 | When you have trouble falling asleep,

01:07:36.260 | you need to look to some mechanism that involves the body.

01:07:39.240 | And all the things I described, meditation, hypnosis,

01:07:42.040 | yoga nidra, all involve, exhale emphasized breathing,

01:07:46.720 | certain ways of lying down and controlling the body.

01:07:49.780 | We're gonna get into breathing

01:07:51.080 | in real depth at another time.

01:07:53.080 | But all of those involve using the body to control the mind

01:07:56.580 | rather than trying to wrestle your mind

01:08:00.060 | into a certain pattern of relaxation.

01:08:02.600 | So earlier in episode one, I talked about the Mobius strip,

01:08:07.600 | this continuous loop that is the brain-body relationship

01:08:11.200 | or the mind-body relationship.

01:08:13.020 | And when we're having trouble controlling the mind,

01:08:15.120 | I encourage people to look towards the body,

01:08:17.620 | look toward sunlight, avoid sunlight and bright light

01:08:20.720 | if that happens to be late at night.

01:08:22.580 | So there's a theme that's starting to emerge,

01:08:24.760 | which is in order to control this thing

01:08:26.120 | that we call the nervous system,

01:08:27.520 | we have to look back to some of the things

01:08:29.720 | we discussed earlier like sensation, perception, et cetera.

01:08:32.960 | But we have to ask, what can we control?

01:08:35.120 | Well, I'm talking about controlling light exposure,

01:08:37.760 | controlling your breathing and body.

01:08:40.000 | I'm not going into details right now,

01:08:41.460 | but you can see the yoga nidra script

01:08:43.140 | or the reveriehealth.com or Headspace would be a great place

01:08:46.880 | to adopt the meditation practice.

01:08:49.400 | Any of those are really teaching you to use your body

01:08:52.040 | to control your mind and to allow you to explore

01:08:55.000 | the mind-body relationship in a way

01:08:56.760 | that gives you more control over your mind

01:08:59.760 | and the mind-body relationship, okay?

01:09:02.320 | So we talked about light,

01:09:04.600 | we talked about activity and timing of light,

01:09:07.200 | talked about the usefulness of naps

01:09:09.040 | and these things that I'm calling non-sleep deep rest,

01:09:12.360 | which include meditation, yoga nidra and hypnosis.

01:09:16.840 | Non-sleep deep rest or what I hear after

01:09:20.280 | we will refer to as NSDR, not to be confused with EMDR.

01:09:25.000 | I don't think I've ever heard NSDR.

01:09:26.640 | So I'm planting a flag for NSDR, non-sleep deep rest,

01:09:31.640 | as a way to reset one's ability to be awake

01:09:36.280 | after you emerge from NSDR.

01:09:38.100 | So to get some more wakefulness and ability to attend,

01:09:40.560 | some emotional stability reset,

01:09:43.520 | as well as make it better and easier to fall asleep

01:09:47.640 | when you wanna go to sleep at night.

01:09:49.440 | Now, non-sleep deep rest does have some research

01:09:52.160 | to support it.

01:09:53.140 | There's a beautiful study done out of a university

01:09:56.180 | in Denmark, I will later provide a link to that study,

01:09:59.640 | that showed that this meditation

01:10:02.380 | and yoga nidra type meditation allows dopamine

01:10:06.880 | and other neuromodulators in an area of the brain

01:10:08.840 | called the striatum that's involved in motor planning

01:10:11.080 | and motor execution to reset itself.

01:10:14.360 | In other words, this NSDR can reset our ability

01:10:17.840 | to engage in the world in a way that's very deliberate

01:10:21.280 | in not to throw in another acronym,

01:10:22.940 | but NSDR resets your ability to engage in DPOs,

01:10:26.200 | duration, path and outcome.

01:10:27.800 | So now you're probably rolling your eyes,

01:10:29.240 | like, oh my goodness, the number of acronyms.

01:10:30.880 | But just bear with me because NSDR is so powerful

01:10:35.880 | because first of all, it doesn't require

01:10:39.240 | that you rig yourself to any device.

01:10:41.360 | It doesn't require that you take much time out of your day.

01:10:44.400 | It doesn't require that you ingest anything except air.

01:10:47.800 | And it can have so many positive effects

01:10:51.240 | right down to the neuromodulator level.

01:10:53.400 | So I think in years to come, my lab's exploring this

01:10:56.240 | in collaboration with David Spiegel's lab,

01:10:58.420 | but other labs are looking at this as well.

01:11:00.060 | I think NSDR is going to start to play a more prominent role

01:11:04.040 | in what we call wellness and health,

01:11:06.120 | both mental health and physical health.

01:11:07.520 | So I encourage you to explore those practices.

01:11:09.920 | Okay, so what about things that we can and maybe should

01:11:13.280 | or should not take in order to control

01:11:15.880 | and access better sleep and better wakefulness?

01:11:18.860 | We've talked about things you can do or not do.

01:11:22.840 | We've talked about nutrition and the timing of nutrition.

01:11:26.240 | Now let's talk about compounds.

01:11:27.680 | Those could be prescription drugs.

01:11:29.080 | Those could be supplements.

01:11:30.820 | There are a number of different things

01:11:31.880 | that will affect your circadian timing and behavior.

01:11:36.060 | In fact, almost everything that you could take

01:11:40.440 | will affect your circadian timing and behavior.

01:11:44.020 | That's right.

01:11:44.860 | So years ago, when I was in graduate school,

01:11:47.480 | I had a professor, unfortunately he passed away now,

01:11:49.440 | but his name was Ted Jones, the late Edward Jones,

01:11:52.100 | who was a world-class neuroanatomist.

01:11:53.920 | He wrote the book on the thalamus.

01:11:55.820 | In fact, it's called "The Thalamus"

01:11:57.440 | and an expert on patterns of activation

01:11:59.980 | in the brain during sleep.

01:12:01.480 | And I'll never forget that during one of these lectures,

01:12:03.980 | someone asked Ted the question,

01:12:06.300 | what is the effect of some drug on these waves of activity

01:12:10.100 | in the thalamus or something?

01:12:11.340 | And his answer was incredible.

01:12:13.400 | He was a pretty gruff guy.

01:12:15.400 | And so his answer was delivered in the form

01:12:17.700 | of a kind of aggressive direct statement.

01:12:19.480 | He said, "A drug is a substance that when injected

01:12:23.340 | into a person produces a scientific publication."

01:12:26.920 | And what he was saying is actually quite true,

01:12:29.800 | which is that most every compound will have some effect

01:12:34.200 | on some aspect of biology.

01:12:36.180 | This is why it's hard to sort through everything

01:12:37.880 | that's on PubMed.

01:12:38.720 | If you put any molecule or compound or drug into PubMed

01:12:43.520 | and then you put sleep next to it or alertness next to it,

01:12:47.120 | you're likely to find a paper where there's an effect.

01:12:49.900 | But that's not necessarily telling you

01:12:53.380 | that that drug is useful or helpful for that.

01:12:55.820 | What it's telling you is that anytime you change

01:12:59.440 | what you take or you stop taking something,

01:13:02.700 | say you're taking sleeping pills, Ambien or whatever it is,

01:13:05.200 | and you stop taking them, your sleep behavior will change.

01:13:08.760 | Let's say you take an aspirin,

01:13:10.000 | you don't normally take aspirin,

01:13:11.120 | you will shift your circadian rhythm.

01:13:13.280 | Now you might not shift it perceptibly,

01:13:15.200 | you might not create problems for yourself,

01:13:17.100 | but anytime you ingest a compound at high potency,

01:13:20.820 | you're going to provide some shift to your circadian rhythm.

01:13:24.120 | Now that said, there are a couple of things

01:13:25.960 | that are directly in line with the biology related

01:13:28.600 | to falling and staying asleep

01:13:29.880 | and directly in line with the biology of wakefulness.

01:13:32.920 | There's a whole category of things like stimulants,

01:13:36.440 | cocaine, amphetamine, and prescription stimulants

01:13:39.920 | that are, the prescription ones were designed

01:13:42.040 | for the treatment of narcolepsy,

01:13:43.440 | so things like modafinil or armadafinil

01:13:46.740 | that are designed to create wakefulness.

01:13:48.140 | They are all essentially chemical variants

01:13:52.680 | of things that increase epinephrine and dopamine.

01:13:55.600 | Now, of course, I'm of the standpoint

01:13:58.080 | that things like cocaine and amphetamine

01:13:59.600 | are just across the board bad.

01:14:01.160 | They have so many addictive and terrible effects.

01:14:04.040 | In the proper setting prescribed by the proper professional,

01:14:08.080 | things like modafinil for narcolepsy might be appropriate.

01:14:12.280 | I know that a lot of people out there take Adderall,

01:14:15.560 | even though they haven't been prescribed Adderall,

01:14:18.080 | in order to increase wakefulness.

01:14:20.360 | That is essentially, well, it's illegal for one,

01:14:24.000 | but it's also, it's abusing the system in the sense

01:14:26.540 | that you're pushing back on the adenosine system

01:14:28.720 | slightly differently than you do caffeine.

01:14:31.100 | It will make you feel more alert.

01:14:32.340 | There tends to be a heavy rebound,

01:14:33.560 | and they do have an addictive potential.

01:14:35.340 | There are also some other effects of those

01:14:36.900 | that can be quite bad.

01:14:37.740 | So we're going to explore stimulants

01:14:40.020 | in a whole month related to drugs,

01:14:42.840 | but there are some supplements and some things

01:14:44.900 | that are safer, certainly safer,

01:14:48.280 | and that in cases where you're doing

01:14:51.160 | all the right behaviors,

01:14:52.200 | you're exercising and eating correctly,

01:14:54.720 | and you're still having trouble with sleep,

01:14:56.420 | that can be beneficial for falling and staying asleep.

01:15:00.040 | Now, I want to be very clear, I am not pushing supplements.

01:15:02.540 | I'm just pointing you towards some things

01:15:04.760 | that have been shown in peer-reviewed studies

01:15:07.340 | to have some benefit.

01:15:08.380 | The first one is magnesium.

01:15:11.820 | There are many forms of magnesium,

01:15:13.340 | but certain forms of magnesium can have positive effects

01:15:16.740 | on sleepiness and the ability to stay asleep,

01:15:18.860 | mainly by way of increasing neurotransmitters like GABA,

01:15:23.620 | which help turn off the DPO,

01:15:26.760 | the kind of thinking about the future,

01:15:28.260 | duration path outcome analysis,

01:15:29.880 | and make one's mind kind of drift in space and time

01:15:34.880 | and make it easier to fall asleep.

01:15:36.700 | There are a lot of forms of magnesium out there,

01:15:38.480 | but one in particular is magnesium threonate,

01:15:41.180 | T-H-R-E-O-N-A-T-E,

01:15:43.980 | which you have to check to see if this is right for you,

01:15:47.300 | check with your doctor,

01:15:48.420 | but magnesium threonate is associated with transporters

01:15:51.420 | in the body that bring more of it into cells

01:15:54.480 | that allow people to feel this kind of drowsiness

01:15:57.320 | and help them fall asleep.

01:15:58.380 | So I personally, I can only talk about what I personally do.

01:16:01.100 | I personally take three or 400 milligrams of magnesium

01:16:04.380 | threonate about 30 to 60 minutes before sleep,

01:16:07.380 | and it helps me fall asleep.

01:16:08.820 | The other thing is theanine,

01:16:10.580 | T-H-E-A-N-I-N-E, theanine,

01:16:15.580 | 100 to 200 milligrams of theanine for me

01:16:20.140 | also helps me turn off my mind and fall asleep.

01:16:22.980 | I take it 30 to 60 minutes throughout the day.

01:16:24.940 | Interestingly, theanine is now being introduced

01:16:27.320 | to a lot of energy drinks

01:16:29.320 | in order to take away the jitters

01:16:31.520 | that are associated with drinking too much caffeine

01:16:33.920 | or with some other things that are in the energy drinks.

01:16:36.100 | Energy drinks can be problematic.

01:16:39.120 | They can contain a lot of L-torine.

01:16:41.780 | I'll just tell you an anecdote.

01:16:42.780 | When I was a postdoc,

01:16:43.620 | I was drinking a lot of a particular energy drink,

01:16:45.780 | has a lot of taurine in it,

01:16:47.820 | and actually the whites of my eyes,

01:16:51.080 | the sclera as it's called in my eyes turned beet red,

01:16:54.440 | and I went to a friend who's an ophthalmologist.

01:16:57.680 | I said, "Look, I'm not a marijuana smoker.

01:16:59.780 | I haven't been hit on the head.

01:17:00.880 | I don't know what's going on."

01:17:02.000 | And he looked and he said,

01:17:03.000 | "I think you've got some microvascular damage."

01:17:06.380 | And we walked through what I was taking and doing,

01:17:08.400 | and he said, "Oh, it's probably the taurine,

01:17:10.420 | excessive levels of taurine

01:17:11.560 | can create some microvascular damage.

01:17:13.880 | So if you're having the microvascular damage in your eye,

01:17:15.920 | you'll probably have microvascular damage

01:17:17.400 | deeper in your skull."

01:17:18.900 | So I stopped.

01:17:19.740 | That's the reason why I don't take energy drinks.

01:17:21.720 | So just a consideration.

01:17:23.960 | Again, I'm not here to tell you what to do or not do,

01:17:25.900 | but just want to arm you with information.

01:17:28.120 | The thing about theanine and magnesium is taken together.

01:17:33.800 | They do, for some people,

01:17:35.400 | they can make them so sleepy and sleep so deeply

01:17:38.200 | that they actually have trouble waking up in the morning.

01:17:39.960 | So you have to play with these things and titrate them

01:17:42.140 | if you decide to use them.

01:17:43.240 | Again, if you decide to go this route.

01:17:44.780 | I would not start by taking supplements.

01:17:47.080 | I would start by getting your light viewing behavior correct

01:17:50.420 | and then think about your nutrition

01:17:52.000 | and then think about your activity

01:17:53.280 | and then think about whether or not you want a supplement.

01:17:55.760 | We already talked about melatonin earlier.

01:17:57.860 | There's another supplement that could be quite useful,

01:17:59.820 | which is apigenin, A-P-I-G-E-N-I-N,

01:18:03.700 | which is a derivative chamomile.

01:18:05.680 | 50 milligrams of apigenin also can augment or support

01:18:10.000 | this kind of creation of a sleepiness

01:18:13.160 | to help fall asleep and stay asleep.

01:18:15.400 | A note about sleepwalkers and people with very vivid dreams.

01:18:19.120 | Theanine can often make your dreams very vivid.

01:18:21.720 | Sleepwalkers should be careful about taking theanine.

01:18:24.400 | Everyone should be careful about taking anything

01:18:26.800 | and don't take anything without consulting

01:18:28.560 | your board-certified MD or healthcare professional first.

01:18:31.860 | Your health is your responsibility.

01:18:34.720 | I am not going to take responsibility

01:18:36.120 | for what you decide to do experimentally in any case,

01:18:38.740 | but especially as it relates to supplementation and drugs.

01:18:41.640 | As a important point,

01:18:44.880 | apigenin is a fairly potent estrogen inhibitor.

01:18:48.560 | So women who want to keep their estrogen levels high

01:18:52.280 | or at whatever levels they happen to be at

01:18:54.200 | should probably avoid apigenin altogether.

01:18:56.720 | And men take that into consideration as well.

01:19:00.320 | Men need estrogen also.

01:19:01.580 | You don't want to completely eliminate your estrogen.

01:19:03.960 | That can create all sorts of bad effects

01:19:05.640 | on libido and cognition, et cetera.

01:19:08.220 | So apigenin in some people

01:19:10.240 | is going to be a pretty strong estrogen inhibitor.

01:19:12.080 | So keep that in mind.

01:19:13.640 | There are other things you can take

01:19:15.840 | to help you sleep better.

01:19:17.460 | Those are the legal ones that at least I'm aware of

01:19:20.220 | have pretty broad safety margins.

01:19:21.760 | But again, you need to explore your safety margins

01:19:24.300 | with any compound.

01:19:25.340 | I think a great website that I can refer you to

01:19:29.120 | is examine.com.

01:19:30.780 | Examine the word, just as it sounds, .com is a website.

01:19:33.620 | I have no relation to them.

01:19:35.060 | But there you can find links to peer-reviewed studies

01:19:38.660 | for any compound or supplement,

01:19:40.160 | as well as some important warnings

01:19:41.800 | related to the things I discussed,

01:19:43.360 | as well as any other thing that you might decide

01:19:45.620 | to supplement with or ingest to help improve your sleep.

01:19:49.520 | Okay, that was a lot of information

01:19:53.120 | about how to get better at sleeping,

01:19:55.800 | falling asleep, wakefulness, et cetera.

01:19:58.740 | An important feature of this podcast, as you know,

01:20:01.760 | is that we dive deep into topics

01:20:03.320 | for several episodes at a time,

01:20:05.440 | at least a month at a time.

01:20:07.320 | So by stopping here,

01:20:09.160 | I recognize that there are probably many more questions

01:20:12.520 | that you still have.

01:20:13.800 | And the great thing about that

01:20:15.480 | is that we have another episode coming up soon.

01:20:18.040 | I'm going to hold office hours

01:20:19.980 | where I'm going to answer your specific questions

01:20:22.320 | about episodes one and two.

01:20:24.500 | So if you have questions about this episode,

01:20:26.800 | you have questions about episode one,

01:20:28.280 | write them down, put them in the comments.

01:20:30.940 | I'll also do a post on Instagram

01:20:32.440 | where you can put them in the comments there,

01:20:34.560 | but put them in the comments to this episode.

01:20:37.340 | As well, please recommend the podcast if you like it.

01:20:41.940 | Please subscribe to it here on YouTube.

01:20:44.320 | Please subscribe to it on Apple.

01:20:46.420 | We're now on Spotify as well.

01:20:48.320 | Recommend it to a friend.

01:20:49.860 | The community that we're creating here

01:20:52.040 | around these topics of sleep and wakefulness

01:20:54.100 | and other neuroscience and health-related themes

01:20:56.500 | is best supported by your involvement and your questions.

01:21:00.020 | And so I'm going to be reading all of your questions,

01:21:02.140 | distilling those into the most commonly asked questions

01:21:05.580 | and liked questions.

01:21:06.780 | So if you see something below

01:21:07.840 | that you are particularly interested in,

01:21:09.740 | you don't have to put that question in again,

01:21:11.140 | you can just give it a like, the little thumbs up tab.

01:21:13.780 | And if you're listening to this on Spotify or Apple,

01:21:17.780 | please go to YouTube,

01:21:19.300 | subscribe and put your question there,

01:21:20.940 | or check out the Huberman Lab Instagram

01:21:23.040 | and you can put your questions there

01:21:24.620 | so that next episode I can answer those questions

01:21:27.060 | and then we can move forward even more deeply

01:21:29.460 | into these critical topics around sleep and wakefulness

01:21:32.640 | so that you can be armed with all the information

01:21:34.820 | and resources that you need.

01:21:37.060 | Last but not least,

01:21:38.180 | a number of you have very graciously asked

01:21:40.020 | how you can support the podcast.

01:21:42.080 | The best way to support the podcast

01:21:43.520 | is to subscribe on YouTube or one of the other platforms,

01:21:46.800 | we're now on Spotify and Apple.

01:21:49.820 | And the other way you can really support the podcast

01:21:51.940 | is to check out our sponsors,

01:21:53.520 | which were discussed at the beginning.

01:21:55.220 | So thank you so much for your time and attention

01:21:57.180 | and above all, thank you for your interest in science.

01:21:59.700 | [upbeat music]

01:22:02.280 | (upbeat music)

Master Your Sleep & Be More Alert When Awake

Chapters