Nutrients For Brain Health & Performance | Huberman Lab Podcast #42

00:00:00.320 | - Welcome to the Huberman Lab Podcast,

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

00:00:04.880 | for everyday life.

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

00:00:10.340 | and I'm a professor of neurobiology and ophthalmology

00:00:12.840 | at Stanford School of Medicine.

00:00:14.960 | Today, we are talking all about food and the brain.

00:00:18.120 | We are going to talk about foods that are good

00:00:20.080 | for your brain in terms of focus,

00:00:22.720 | in terms of brain health generally,

00:00:24.560 | and the longevity of your brain,

00:00:26.500 | your ability to maintain cognition

00:00:28.600 | and clear thinking over time.

00:00:31.000 | We are also going to talk about why

00:00:33.280 | and how you prefer certain foods to others.

00:00:36.400 | And I'm going to talk about the three major signals

00:00:38.820 | that combine to drive your food choices.

00:00:42.800 | I'll give you a little hint of what those are.

00:00:45.160 | One of those signals comes from your gut

00:00:47.580 | and is completely subconscious.

00:00:49.880 | This is not the gut microbiome per se.

00:00:52.500 | These are neurons in your gut

00:00:53.920 | that are sending signals to your brain

00:00:55.440 | that you are unaware of about the nutrient contents

00:00:58.660 | of the foods that you're eating.

00:01:00.480 | The second signal is how metabolically accessible

00:01:04.920 | a given food is,

00:01:05.780 | meaning how readily that food can be converted

00:01:08.740 | into energy that your brain, not your body,

00:01:11.320 | but that your brain can use.

00:01:13.880 | And the third signal is perhaps the most interesting one.

00:01:17.200 | It's the signal of belief.

00:01:18.900 | It's the signal of what you perceive

00:01:21.120 | and believe the food that you're eating to contain

00:01:24.800 | and what you think it can do for you

00:01:26.780 | health-wise and energy-wise.

00:01:28.920 | And that might sound a little wishy-washy or vague,

00:01:31.180 | but we're going to provide mechanistic data

00:01:34.060 | to support the fact that you can change what you eat,

00:01:37.840 | so much so that you can drive your brain and your body

00:01:42.460 | to crave foods that are good for you,

00:01:44.860 | or at least better for you

00:01:46.720 | than the foods you might currently be eating.

00:01:48.880 | This is an incredibly powerful mechanism that we all have.

00:01:52.560 | It's one that I think is very underappreciated.

00:01:55.180 | And today I'm going to review the data

00:01:56.880 | from both animal models and fortunately more recently,

00:01:59.440 | human studies that really do underscore the fact

00:02:02.960 | that you can control your desire for particular foods.

00:02:07.360 | Before we dive into today's topic,

00:02:09.560 | I just want to briefly touch on some key takeaways

00:02:12.680 | from a previous episode,

00:02:14.580 | which is the episode on time-restricted feeding,

00:02:17.520 | also called intermittent fasting.

00:02:20.160 | The key elements of time-restricted feeding

00:02:23.440 | that will benefit your health the most

00:02:25.940 | in terms of weight loss or maintenance, fat loss,

00:02:29.560 | organ health, quality sleep, and cognition

00:02:33.160 | are that the feeding window begin

00:02:35.240 | at least one hour after waking.

00:02:38.180 | You could push that feeding window out to begin later,

00:02:40.760 | but at least one hour after waking,

00:02:43.440 | and that it end at least two and ideally three hours

00:02:48.400 | before going to sleep.

00:02:50.520 | Some people can end that feeding window

00:02:52.960 | much further away from the beginning of sleep,

00:02:56.280 | meaning they're finishing their last bite of food,

00:02:58.860 | for instance, at 6 p.m.

00:03:00.080 | and they're not going to sleep until midnight.

00:03:01.820 | But many people struggle to get quality sleep

00:03:04.640 | if that feeding window is set too early

00:03:07.660 | relative to when they go to sleep.

00:03:09.160 | So begin the feeding window at least one hour after waking,

00:03:13.540 | end the feeding window at least two hours

00:03:16.060 | before going to sleep.

00:03:17.140 | And a key feature based on the scientific research

00:03:21.200 | is that the feeding window itself fall more or less

00:03:24.760 | at the same period of each 24-hour day from day to day,

00:03:29.100 | meaning if you are going to eat over an eight-hour period,

00:03:32.540 | that's your feeding window,

00:03:34.240 | you wouldn't want to start that feeding window

00:03:36.840 | at 10 a.m. one day and end it at 6 p.m.,

00:03:39.160 | and then the next day start at noon and end it at 8 p.m.,

00:03:42.040 | and the next day start it at 2 p.m.

00:03:44.420 | and end it at 10 p.m. and so forth.

00:03:46.920 | As much as is reasonably possible,

00:03:49.740 | if you want to extract the maximum benefit

00:03:51.740 | from time-restricted feeding,

00:03:53.360 | the idea is to keep that feeding window

00:03:56.440 | at more or less the same phase, as it's called,

00:03:59.340 | of each 24-hour day.

00:04:01.220 | If it slides around a little bit for social reasons

00:04:03.580 | or whatever reasons, it doesn't seem to be a big deal,

00:04:06.540 | but you don't want it sliding around

00:04:08.600 | by many hours from day to day

00:04:10.800 | because of the way that that feeding window

00:04:12.800 | impacts other genes called clock genes

00:04:15.040 | that regulate a bunch of other processes in the body.

00:04:18.360 | Before we begin, I'd like to emphasize

00:04:20.240 | that this podcast is separate

00:04:21.760 | from my teaching and research roles at Stanford.

00:04:24.240 | It is, however, part of my desire and effort

00:04:26.360 | to bring zero cost to consumer information

00:04:28.640 | about science and science-related tools

00:04:30.840 | to the general public.

00:04:32.320 | In keeping with that theme,

00:04:33.760 | I'd like to thank the sponsors of today's podcast.

00:04:36.780 | Our first sponsor is Roca.

00:04:38.960 | Roca makes eyeglasses and sunglasses

00:04:41.140 | that are of the absolute highest quality.

00:04:43.920 | I've spent a career working on the visual system,

00:04:46.480 | and one of the key problems that Roca sunglasses has solved

00:04:50.280 | is if you've ever worn sunglasses

00:04:52.420 | and you've gone from a very bright region

00:04:54.200 | to, say, a region with shadows,

00:04:56.000 | oftentimes you have to take the sunglasses off.

00:04:58.340 | They've designed their sunglasses in a way

00:05:00.080 | that no matter whether you're standing in the shade

00:05:02.860 | or in bright sunlight, you will always see things

00:05:05.060 | with absolute crystal clarity, which is wonderful.

00:05:08.160 | Their eyeglasses as well are designed

00:05:10.320 | so that you can move from one region of brightness

00:05:12.100 | to another without noticing it at all.

00:05:14.520 | The other thing that's really terrific

00:05:15.880 | about Roca eyeglasses and sunglasses

00:05:17.760 | is that they are very lightweight.

00:05:19.220 | Most of the time, you don't even remember

00:05:20.360 | that they're on your face.

00:05:21.700 | And you can wear them whether or not

00:05:23.320 | you're exercising or working

00:05:25.500 | because they won't slip off even if you get sweaty.

00:05:28.240 | The other thing that's really wonderful

00:05:30.840 | is that the aesthetic is terrific.

00:05:32.640 | Unlike a lot of so-called performance glasses out there

00:05:35.560 | that make people look like cyborgs,

00:05:37.300 | or frankly, just look rather strange,

00:05:39.480 | Roca eyeglasses and sunglasses have a terrific aesthetic.

00:05:42.400 | You can wear them to dinner, to work, running, exercising,

00:05:45.900 | and they'll work for all those situations.

00:05:48.140 | If you'd like to try Roca, you can go to roca.com,

00:05:51.240 | that's R-O-K-A.com, and enter the code Huberman

00:05:54.780 | to save 20% on your first order.

00:05:57.540 | Today's episode is also brought to us by Athletic Greens.

00:06:00.560 | Athletic Greens is a vitamin mineral probiotic drink

00:06:03.700 | that's designed to cover your foundational supplementation

00:06:07.140 | and health needs.

00:06:08.500 | I've been using Athletic Greens since 2012,

00:06:10.920 | so I'm delighted that they're sponsoring the podcast.

00:06:13.560 | The reason I started using Athletic Greens

00:06:15.320 | and the reason I still drink Athletic Greens

00:06:17.080 | once or twice per day

00:06:18.600 | is because it covers all of my vitamin mineral basic needs

00:06:22.200 | and because of the probiotics.

00:06:24.320 | There's now ample data supporting the fact

00:06:26.280 | that probiotics support a healthy gut microbiome

00:06:30.080 | and that the gut microbiome is important

00:06:32.280 | for keeping inflammation low, which is good,

00:06:35.600 | as well as for supporting the immune system

00:06:37.560 | and for supporting brain health

00:06:39.320 | through the so-called gut-brain axis.

00:06:41.720 | If you'd like to try Athletic Greens,

00:06:43.240 | you can go to athleticgreens.com/huberman,

00:06:46.200 | and if you do that, you can claim a special offer.

00:06:48.620 | They'll give you five free travel packs,

00:06:50.280 | so these packs make it really easy to mix up Athletic Greens

00:06:52.740 | when you're on the road, in the car, et cetera,

00:06:55.020 | and they'll give you a year's supply of vitamin D3K2.

00:06:58.760 | There's now a lot of data pointing to the fact

00:07:01.320 | that vitamin D3 and K2 are important for hormonal health,

00:07:05.180 | for cardiovascular function,

00:07:06.880 | and so if you go to athleticgreens.com/huberman,

00:07:09.840 | you'll get the Athletic Greens,

00:07:10.960 | the five free travel packs,

00:07:12.020 | and a year's supply of vitamin D3K2.

00:07:15.180 | Today's episode is also brought to us by Headspace.

00:07:18.480 | Headspace is a meditation app

00:07:20.080 | backed by 25 peer-reviewed published studies.

00:07:23.740 | I think by now, most people have heard

00:07:26.040 | of the benefits of meditation,

00:07:28.000 | reduce stress, improve sleep, better cognition, et cetera.

00:07:32.000 | I've been meditating for a long time,

00:07:34.000 | but I have to admit it's been sort of an on and off thing.

00:07:37.800 | There are periods of time over the last 10

00:07:39.880 | or gosh, even 20 or 30 years

00:07:41.920 | that I've meditated consistently,

00:07:43.540 | and then I'll stop meditating.

00:07:45.200 | One of the terrific things about Headspace

00:07:46.940 | is that it has meditations

00:07:48.160 | of different duration and different type.

00:07:50.280 | So I found that as soon as I started using Headspace,

00:07:53.020 | that I was meditating far more consistently.

00:07:55.960 | One of the great things about meditation

00:07:57.760 | is that it works the first time and it works every time,

00:08:01.100 | and the more consistently I do it,

00:08:03.520 | the more positive benefits I seem to derive.

00:08:06.340 | If you'd like to try Headspace,

00:08:07.560 | you can go to headspace.com/specialoffer.

00:08:10.760 | And if you do that, you'll get a free one month trial

00:08:13.600 | with all of Headspace's full library of meditations.

00:08:16.880 | This is the best deal offer by Headspace right now.

00:08:19.280 | So if you're interested,

00:08:20.520 | go to headspace.com/specialoffer.

00:08:23.520 | I'd like to point you toward what I think

00:08:24.920 | is a very valuable zero cost resource online.

00:08:28.520 | Recently, I took part in an event called Rethink Education

00:08:32.560 | that was put on by Logitech.

00:08:34.440 | And there, I gave a 20 minute lecture

00:08:36.800 | where I describe the classic

00:08:39.200 | and modern neuroplasticity literature

00:08:42.080 | in both animal models and humans.

00:08:44.120 | The neuroplasticity literature is, of course,

00:08:45.960 | the literature that describes how to rewire the brain

00:08:48.680 | in order to learn.

00:08:50.600 | During that 20 minute talk, I described that literature,

00:08:52.880 | but I also spell out what I call

00:08:55.000 | the neuroplasticity super protocol,

00:08:57.160 | which is nine plus steps of things that teachers can apply

00:09:01.280 | in the classroom to teach any sort of information,

00:09:03.880 | music, math, sports, anything,

00:09:06.860 | and that students of any kind in any age

00:09:09.240 | can use to enhance the speed and depth of learning.

00:09:12.240 | You can find that talk on YouTube

00:09:14.640 | by following the link in the caption to this episode,

00:09:17.620 | or by simply going to YouTube

00:09:19.120 | and entering the search terms Logitech Huberman.

00:09:22.160 | Some of the most frequent questions I get

00:09:23.800 | are about food and the brain.

00:09:26.320 | Everybody seems to want to know what they should eat

00:09:28.640 | and what they shouldn't eat

00:09:30.160 | in order to have peak brain function,

00:09:32.080 | to be able to focus and memorize things and so forth,

00:09:35.580 | and in order to maintain brain health over time,

00:09:38.380 | because nobody wants to lose their memory

00:09:40.600 | or have troubles with cognition.

00:09:43.160 | Fortunately, there are a lot of data now

00:09:45.320 | from really good quality peer-reviewed studies

00:09:48.500 | that indicate certain things that we can do,

00:09:50.800 | including certain foods that we should eat

00:09:53.240 | and perhaps even some foods that we should avoid

00:09:55.660 | in order to enhance our brain function.

00:09:58.360 | And of course, when I say brain,

00:09:59.720 | what I really mean is nervous system function,

00:10:01.700 | because how we are able to move and remember things,

00:10:05.160 | et cetera, doesn't just depend on the neurons,

00:10:07.480 | the nerve cells that are in our head,

00:10:08.780 | it also depends on our spinal cord

00:10:11.000 | and the neurons that connect to all the organs of our body.

00:10:13.860 | So in general, there are two categories of things

00:10:17.360 | that are going to improve brain health

00:10:19.680 | from the perspective of nutrition.

00:10:22.000 | The first category is the general category

00:10:25.260 | of things that we eat and avoid

00:10:27.080 | and things that we do and avoid doing

00:10:29.360 | that will modulate brain health and function.

00:10:32.180 | What do I mean by modulate?

00:10:33.600 | Well, getting quality sleep on a regular basis,

00:10:37.320 | making sure that you're socially connected,

00:10:40.560 | making sure that you're not depressed.

00:10:42.680 | All these things are vitally important to our overall health

00:10:45.560 | and of course they will impact brain function,

00:10:47.720 | but they do it more or less indirectly, okay?

00:10:50.440 | There are a few things that happen in sleep

00:10:52.000 | which directly benefit brain function and repair, et cetera.

00:10:56.100 | But today I really want to concentrate

00:10:57.840 | not on the things that modulate our overall health,

00:11:00.840 | but rather the things that mediate brain health directly

00:11:04.640 | and in particular, how certain foods enhance brain function.

00:11:08.680 | And we are going to talk about

00:11:10.320 | how we can change our relationship to food,

00:11:12.720 | literally how we can start to prefer certain foods

00:11:15.780 | that are better for us than others.

00:11:18.340 | So just briefly, I want to touch on the modulatory components

00:11:22.080 | because they are vital.

00:11:24.040 | First of all, getting quality sleep on a regular basis

00:11:28.000 | and ample sleep on a regular basis

00:11:30.440 | is the foundation of all mental health and physical health.

00:11:34.720 | There's no question about that.

00:11:36.320 | We have done several episodes,

00:11:38.040 | including the Master Your Sleep episode,

00:11:40.320 | which is episode two of the Huberman Lab Podcast.

00:11:42.720 | And we've done a lot of other episodes

00:11:44.620 | that are all about sleep and how to get better at sleeping.

00:11:47.780 | So I just want to make crystal clear

00:11:50.440 | that unless you're sleeping well on a regular basis,

00:11:53.480 | your brain will suffer.

00:11:54.560 | You won't be able to focus very well, learn very well.

00:11:56.740 | And indeed there are data linking poor quality sleep

00:12:00.520 | to dementia or at least exacerbating preexisting dementias

00:12:04.820 | and things of that sort.

00:12:05.660 | So get your sleep in order.

00:12:07.280 | The other of course is cardiovascular health and exercise.

00:12:10.880 | The general prescription that's out there in the literature

00:12:13.840 | and I think is well-supported

00:12:15.400 | is to get somewhere between 150 and 180 minutes

00:12:19.080 | of cardiovascular exercise per week.

00:12:21.200 | If you choose to also use resistance exercise, that's great,

00:12:24.540 | but the 150 to 180 minutes minimum per week

00:12:28.720 | of cardiovascular exercise is crucial for heart health

00:12:32.800 | and heart health directly relates to brain health

00:12:35.440 | because the brain consumes a lot of oxygen, glucose,

00:12:38.640 | and other factors that are delivered via the blood.

00:12:41.520 | So if your arteries are clogged up

00:12:43.560 | and you've got poor vascular supply to the brain

00:12:46.380 | in any region of the brain, your brain will suffer.

00:12:49.260 | So get cardiovascular health in order.

00:12:51.400 | Now with those two modulatory elements set forth

00:12:56.620 | so that we're all aware that they're there

00:12:58.060 | and they are vitally important.

00:12:59.480 | Now I'd like to turn to the elements that have been shown

00:13:02.160 | to be vitally important for directly controlling,

00:13:04.960 | for mediating neuron function.

00:13:07.260 | Neurons of course are nerve cells in the brain

00:13:09.600 | and there are other cell types too of course

00:13:11.960 | that will impact brain function.

00:13:13.980 | The most prominent of which are the so-called glia.

00:13:17.340 | Glia means glue, but even though for a long time

00:13:20.760 | people thought that these cells

00:13:21.680 | were just kind of holding things together passively,

00:13:23.560 | the glia play a very active role in the metabolism neurons,

00:13:27.920 | in brain function, and probably also in cognition,

00:13:31.100 | in thinking and so forth.

00:13:33.360 | So what are the things that directly impact brain health

00:13:37.000 | and what are the foods that we can eat

00:13:38.840 | that will support brain health?

00:13:40.680 | Generally, when we think about neuron function

00:13:42.680 | and brain function, we default to a discussion about fuel.

00:13:46.940 | The fact that neurons use glucose, which is blood sugar

00:13:50.520 | and that they require a lot of it.

00:13:52.720 | In some cases, they'll use ketones,

00:13:54.560 | which we will talk about a little bit later,

00:13:56.200 | especially in people that are following a low carbohydrate

00:13:58.440 | or ketogenic diet.

00:14:00.440 | But before we can even consider the fuels that neurons use

00:14:03.880 | in order to function, we have to talk about the elements

00:14:07.400 | that actually allow those neurons to be there

00:14:09.640 | and to stay healthy, what actually makes up those neurons.

00:14:12.760 | And that brings us to what I would argue

00:14:14.680 | is the most important food element for brain function.

00:14:19.380 | And that is fat.

00:14:21.180 | And that might come as a surprise,

00:14:22.840 | but unless one considers the water content of the brain,

00:14:26.100 | which is very high, a lot of our brain

00:14:29.540 | and a lot of the integrity of the nerve cells,

00:14:31.780 | the so-called neurons in our brain

00:14:33.840 | and the other types of cells comes from fat.

00:14:36.920 | And that's because nerve cells and other cells in the brain

00:14:39.820 | have a external layer.

00:14:42.800 | It's what's sometimes called a double layered membrane.

00:14:46.560 | It's essentially two thin layers

00:14:48.280 | that serve as a boundary between those cells.

00:14:50.160 | And that boundary is very important

00:14:51.680 | because how things pass across that boundary

00:14:54.220 | actually regulates the electrical activity of neurons,

00:14:57.560 | which is the way that neurons fire and communicate

00:14:59.880 | and keep you thinking and acting

00:15:01.120 | and doing all the good things

00:15:02.040 | that those neurons allow us to do.

00:15:04.240 | And those membranes are made up of fats,

00:15:06.800 | but they're not made up of the fats

00:15:08.040 | that are around our belly,

00:15:10.240 | around the other organs of our body.

00:15:11.960 | They're not made up of storage fat.

00:15:13.600 | They are made up of structural fat

00:15:16.360 | and maintaining the so-called integrity

00:15:18.360 | of that structural fat,

00:15:19.840 | meaning the health of those neurons

00:15:21.960 | is going to come in large part from the foods that we eat.

00:15:25.800 | Now, this needs to be underscored.

00:15:27.960 | What I'm saying is that the foods that we eat

00:15:30.040 | actually provide the structural basis,

00:15:32.040 | the building blocks of the very neurons

00:15:34.120 | that allow us to think over time.

00:15:36.640 | And as I mentioned earlier,

00:15:38.440 | the fat that makes up those neurons and other nerve cells

00:15:40.880 | is different than the other types of fat in the body.

00:15:44.160 | So what type of fat is it and what should we eat

00:15:46.720 | in order to support that fat and those neurons?

00:15:50.520 | And the answer is the so-called essential fatty acids

00:15:53.280 | and phospholipids.

00:15:54.780 | Now, those are more or less the same thing,

00:15:56.400 | but I just want to make a very large literature

00:15:58.840 | very crystal clear.

00:16:01.000 | Essential fatty acids can include the so-called EPA variety

00:16:04.800 | or DHA variety.

00:16:06.400 | You hear about omega-3s and omega-6s.

00:16:09.060 | Most people are getting enough omega-6s from their diet,

00:16:12.460 | not everybody,

00:16:13.300 | but most people are getting enough omega-6s.

00:16:15.240 | However, most people are not getting enough omega-3s

00:16:19.220 | in their diet to support healthy brain function

00:16:21.340 | in the short and long term.

00:16:23.000 | I've talked before about the benefits

00:16:24.740 | of elevating the levels of omega-3s in one's diet

00:16:28.220 | for sake of offsetting depression and for enhancing mood.

00:16:31.840 | And indeed there's a wealth of literature now

00:16:34.360 | pointing to the fact that ingesting at least one or two

00:16:37.960 | or even three grams per day of EPA form

00:16:42.120 | of essential fatty acid can have effects,

00:16:45.220 | positive effects on mood and wellbeing

00:16:47.180 | that are at least on par

00:16:48.280 | with some of the major antidepressant treatments out there,

00:16:50.560 | but without similar side effects

00:16:52.620 | to those antidepressant treatments.

00:16:54.160 | And that for people that are already taking antidepressants,

00:16:57.880 | that supplementing with one to two to three grams of EPA,

00:17:02.400 | essential fatty acids can actually allow a lower dose

00:17:05.880 | of antidepressant treatment to be used

00:17:08.000 | and still be effective.

00:17:09.340 | So that's depression,

00:17:10.940 | but just in terms of maintaining normal cognitive function

00:17:13.820 | in people that aren't depressed,

00:17:15.040 | the EPAs and omega-3s seem to play a very important role.

00:17:19.240 | Of course, you can supplement EPAs through various fish oils

00:17:23.200 | and it could be liquid fish oil or capsule fish oil.

00:17:26.260 | Some people, if they're not interested in eating fish

00:17:29.060 | for whatever reason, they're allergic or for ethical reasons,

00:17:31.920 | they can take krill oil.

00:17:33.200 | And if they don't want to use krill oil,

00:17:34.760 | they can use algae and other forms of EPA.

00:17:37.680 | However, I think it's clear that one can get a lot of EPA

00:17:42.440 | from the proper foods.

00:17:43.840 | And it turns out that those foods, not surprisingly,

00:17:46.780 | don't just contain high levels of EPA,

00:17:49.320 | but they also contain other things

00:17:51.120 | that are beneficial for brain health.

00:17:52.980 | So what are foods that are high in omega-3s

00:17:55.880 | that we should all probably be consuming,

00:17:58.000 | at least on a daily basis?

00:17:59.760 | The number one is fish.

00:18:03.360 | So things like mackerel and salmon and herring and oysters

00:18:07.100 | and sardines and anchovies.

00:18:09.320 | And perhaps the heavyweight champion

00:18:11.320 | of EPAs per unit volume is caviar.

00:18:14.240 | Now, I don't know about you,

00:18:15.640 | but I'm not eating a lot of fish.

00:18:17.420 | I'm not eating a lot of caviar.

00:18:20.040 | I can't remember the last time I had a caviar,

00:18:22.100 | unless it was sprinkled on a little bit of sushi.

00:18:24.560 | I'm not a big fish eater, personally.

00:18:27.520 | I will from time to time,

00:18:28.900 | but that's one reason why one might want to supplement

00:18:32.200 | with EPAs from another source.

00:18:34.640 | But also, EPAs are found in chia seeds, in walnuts,

00:18:39.600 | in soybeans and other plant-based foods.

00:18:41.980 | You can look these up online and you'll immediately see

00:18:44.920 | that there are a lot of sources of EPAs.

00:18:47.540 | And many of the foods that I listed off

00:18:49.760 | might be appetizing to you.

00:18:51.040 | Some of them might be unappetizing to you,

00:18:52.760 | or some of them you might be sort of neutral about.

00:18:55.200 | But it's very clear that eating foods

00:18:57.360 | that are rich in omega-3s and/or supplementing

00:18:59.520 | with omega-3s to get above that 1.5 grams

00:19:02.880 | and ideally up to two or even three grams per day of EPA

00:19:07.100 | can be very beneficial for cognitive function

00:19:10.240 | in the short and long term.

00:19:12.520 | Later in the episode, I'm going to talk about

00:19:14.520 | how to actually change your relationship

00:19:17.000 | to particular foods so that foods

00:19:18.560 | that you don't particularly like,

00:19:19.720 | you can actually start to like more.

00:19:21.840 | And that might be important for those of you

00:19:23.560 | that are thinking mackerel, sardines.

00:19:25.600 | I mean, I'm making this face because frankly,

00:19:27.740 | those are not foods that I naturally like.

00:19:30.300 | But again, I want to emphasize

00:19:31.740 | that you don't have to consume fish and animal products

00:19:34.500 | in order to get sufficient EPAs.

00:19:35.880 | You can get them from plants,

00:19:37.140 | but I do believe based on the quality peer-reviewed research

00:19:41.240 | that everybody should be striving

00:19:43.000 | to get a minimum threshold of at least a gram and a half

00:19:45.800 | of EPAs per day, one way or the other.

00:19:48.360 | The great thing about omega-3s

00:19:49.880 | is that they are also thought to be beneficial

00:19:51.920 | for things like cardiovascular health.

00:19:53.680 | And although there's some controversy there

00:19:56.000 | as to whether or not two grams or three grams or six grams

00:19:59.540 | is ideal for cardiovascular health,

00:20:00.960 | I think the bulk of evidence points to the fact

00:20:03.280 | that getting sufficient omega-3s in the diet

00:20:05.220 | is going to support cardiovascular health.

00:20:07.780 | Certainly not the only thing people should be doing

00:20:09.540 | to support their cardiovascular health,

00:20:11.500 | aerobic exercise and so forth being important also,

00:20:14.640 | but it does seem to support cardiovascular health

00:20:17.640 | and in doing so, supporting brain health.

00:20:20.120 | However, what I'm emphasizing is ingestion of omega-3s

00:20:25.180 | to support the very cells within the brain

00:20:27.760 | that make up our cognition,

00:20:29.000 | that allow for cognition and for movement and memory

00:20:31.660 | and all the other marvelous things that the brain does.

00:20:35.000 | The other compound that has been shown

00:20:36.680 | to be directly supportive of neuronal function

00:20:39.500 | is phosphatidylserine,

00:20:41.460 | which is abundant in meats and in fish.

00:20:44.900 | So here we are again, back to fish being an important source

00:20:47.800 | of brain supporting food.

00:20:50.200 | Phosphatidylserine is something that nowadays

00:20:53.200 | people are supplementing, it's a lipid-like compound

00:20:56.320 | that at least in three studies have been shown

00:20:59.880 | to improve cognition, these weren't huge effects,

00:21:02.280 | but they were statistically significant effects

00:21:04.700 | and as well in more than three, at least five studies

00:21:09.380 | to reduce cognitive decline.

00:21:11.880 | And this is interesting, in every case,

00:21:13.620 | it was 300 milligrams supplemented phosphatidylserine,

00:21:17.500 | but one again, doesn't need to supplement phosphatidylserine.

00:21:21.120 | Phosphatidylserine can be derived as I mentioned

00:21:23.700 | from meats and fish and to some extent

00:21:25.740 | from cabbage of all things.

00:21:27.280 | I don't know how much cabbage people are ingesting,

00:21:29.440 | but later when we talk about gut health

00:21:31.060 | and the relationship between gut health and brain health,

00:21:34.400 | I'll mention fermented foods and of course,

00:21:36.600 | one of the most readily available fermented foods out there

00:21:40.120 | that at least many people find appetizing is sauerkraut,

00:21:43.720 | which is of course made from cabbage, it's fermented cabbage.

00:21:46.440 | So for those of you that do consume meat and fish,

00:21:49.680 | provided you're getting enough fish,

00:21:50.880 | you're probably getting enough phosphatidylserine.

00:21:52.860 | For those of you that are interested

00:21:54.000 | in supplementing phosphatidylserine

00:21:56.000 | to get these effects that were reported

00:21:57.900 | in these various manuscripts,

00:22:00.560 | which by the way, I've read and looked solid.

00:22:03.040 | I mean, I don't think we've seen the landmark studies

00:22:05.800 | showing that supplementing with phosphatidylserine

00:22:08.000 | at 300 milligrams per day is going to create

00:22:11.240 | a huge offsetting of a massive cognitive decline

00:22:14.220 | or a massive increase in brain function.

00:22:16.480 | These seem to be modest effects,

00:22:18.600 | but the effects do appear to be real.

00:22:20.640 | And for those of you that are interested

00:22:22.040 | in supplementing with phosphatidylserine,

00:22:23.880 | it's a relatively inexpensive supplement

00:22:25.920 | that again is lipid-like.

00:22:27.660 | So it's mimicking some of the same things

00:22:29.360 | that you would get from food, but in higher concentration.

00:22:32.560 | Now, after EPA, fatty acids and phosphatidylserine,

00:22:37.560 | I would say third on the list of things that come from food

00:22:41.680 | that can readily support brain function would be choline.

00:22:45.360 | And that's because of the relationship to choline

00:22:47.640 | in the biosynthesis pathway for acetylcholine.

00:22:51.120 | Acetylcholine is a neuromodulator, not a neurotransmitter,

00:22:54.400 | but a neuromodulator in the brain.

00:22:56.680 | A neuromodulator is a chemical that modulates

00:23:00.200 | the function of many brain circuits

00:23:02.480 | and also circuits within the body.

00:23:04.680 | I'll mention what those are in a moment,

00:23:06.400 | but acetylcholine as a neuromodulator

00:23:09.640 | tends to enhance the activity, the electrical activity

00:23:13.000 | and chemical activity of certain sets of neurons

00:23:15.700 | and downplay the activity of other neurons.

00:23:18.720 | So it's sort of a conductor of sorts

00:23:20.680 | leading to enhanced function and activity

00:23:23.540 | in certain brain areas and circuits and others.

00:23:26.340 | For instance, the brain areas that are involved

00:23:29.960 | in focus and alertness.

00:23:31.540 | We have multiple clusters of neurons in our brain

00:23:33.940 | that make acetylcholine.

00:23:35.840 | Two of the most prominent and well-known

00:23:37.620 | are the so-called nucleus basalis,

00:23:39.020 | which is a cluster of neurons deep in the basal forebrain

00:23:42.100 | that highlight particular areas of our brain,

00:23:44.860 | highlight meaning when acetylcholine is released

00:23:47.660 | from those neurons at their nerve endings

00:23:49.840 | in particular areas of the brain,

00:23:50.960 | those particular areas of the brain

00:23:52.680 | can undergo enhanced levels of activity

00:23:54.720 | relative to surrounding area.

00:23:56.260 | So it's kind of a electrical highlighter pen, if you will,

00:23:59.120 | by analogy.

00:24:00.040 | That is the basis of much of what we call focus

00:24:05.360 | or our ability to concentrate on a particular batch

00:24:08.640 | of information that's coming in through our eyes,

00:24:10.440 | our ears, our nose,

00:24:11.280 | or even things that we're just thinking in our head.

00:24:13.520 | So having ample choline for production of acetylcholine

00:24:17.600 | allows for focus through, of course,

00:24:19.680 | many intervening steps.

00:24:21.200 | There are also regions of the brain

00:24:22.960 | in the so-called back of the brain,

00:24:24.080 | the hindbrain that release acetylcholine

00:24:27.040 | that are involved in general states of alertness.

00:24:30.200 | And not surprisingly then,

00:24:32.460 | many of the treatments for Alzheimer's disease,

00:24:34.940 | which is an inability or challenges

00:24:37.480 | with remembering things and focusing

00:24:40.180 | are drugs that impact the acetylcholine pathway

00:24:44.160 | and are aimed at enhancing the amount of acetylcholine

00:24:47.540 | that's available to neurons.

00:24:49.500 | And it can do that through a number of different mechanisms.

00:24:51.740 | You can do that by enhancing the amount of acetylcholine

00:24:53.820 | that's created,

00:24:54.820 | or you can do that by taking a drug

00:24:57.580 | that can reduce the amount of enzyme

00:24:59.860 | that gobbles up the acetylcholine

00:25:01.220 | and in doing so leading to more net acetylcholine.

00:25:04.280 | But outside of the scenario

00:25:06.340 | where somebody has cognitive decline due to Alzheimer's,

00:25:09.360 | all of us are able to focus to some degree or not,

00:25:13.000 | or are able to be alert to some degree or not

00:25:15.780 | based on the amount of acetylcholine that we have.

00:25:18.960 | Now, other processes of course are involved,

00:25:21.040 | but what this means is that making sure

00:25:23.640 | that we have enough of the substrates

00:25:25.920 | to create acetylcholine is vital

00:25:27.920 | if we want to be able to focus.

00:25:29.460 | And that's why dietary choline is so vital.

00:25:31.720 | And the primary source for dietary choline

00:25:34.160 | would be eggs and in particular egg yolks.

00:25:36.960 | And this again has a very interesting relationship

00:25:39.700 | to our evolution as well.

00:25:41.080 | We're always referred to as hunter gatherers,

00:25:44.560 | but when one hears hunters,

00:25:45.920 | we often think about meat and animal sources.

00:25:48.520 | And indeed as a species,

00:25:50.080 | we hunted many, many other species of animals

00:25:53.260 | to consume them and still do.

00:25:55.220 | But we also fished, we talked about that earlier

00:25:57.760 | and consumed a lot of fish and we consumed a lot of eggs.

00:26:01.040 | Eggs are an incredibly rich source

00:26:03.800 | of nutrients for the brain.

00:26:06.820 | And that's because the egg actually, if you think about it,

00:26:10.480 | contains all the nutrients that are required

00:26:12.680 | in order for an organism to grow.

00:26:15.620 | A bird that's in a egg shell, it's got the yolk there

00:26:18.960 | and it's using that yolk for a reason.

00:26:20.940 | It's using that yolk as a source of fuel.

00:26:23.720 | It's using that yolk as a source of literally building blocks

00:26:26.800 | in order to create its nervous system.

00:26:28.400 | Many years ago, I worked on chick embryos

00:26:31.500 | and as these amazing experiments,

00:26:32.920 | you could actually take an egg

00:26:34.880 | and you could create a little window in the top

00:26:37.380 | and these were fertilized eggs.

00:26:38.700 | And you'd see over time, you could peer in there,

00:26:40.900 | literally look in with a microscope

00:26:42.380 | or even with the naked eye.

00:26:43.560 | And you would see this little chick embryo

00:26:45.840 | sitting on top of that yolk growing and growing

00:26:47.660 | and growing and growing

00:26:48.500 | and the yolk getting smaller and smaller.

00:26:50.260 | It's really incredible.

00:26:52.040 | They're using that as a source

00:26:53.420 | for all the building blocks of the body,

00:26:55.260 | but in particular, the nervous system.

00:26:57.480 | So eggs are a rich source of choline.

00:26:59.420 | Some people will supplement with choline.

00:27:02.760 | However, food sources seem to be the best source of choline.

00:27:06.800 | And as with the EPAs and the omega-3s,

00:27:09.420 | there are plenty of foods that are non-animal based

00:27:12.400 | that contain choline.

00:27:14.340 | So if you're somebody who doesn't eat eggs

00:27:16.520 | or doesn't want to eat eggs,

00:27:17.780 | things like potatoes, nuts and seeds and grains and fruit,

00:27:20.940 | they don't have as much choline as eggs,

00:27:22.900 | but they do contain choline.

00:27:24.460 | So you can look up the values of choline

00:27:26.260 | that are present in those various foods

00:27:29.260 | and make sure that you're reaching

00:27:30.340 | the threshold amount of choline for you.

00:27:32.420 | In general, most people should probably strive

00:27:34.580 | to get somewhere between 500 milligrams

00:27:36.680 | and a gram of choline per day, so 1,000 milligrams.

00:27:39.920 | And some people rely on supplementation

00:27:42.240 | in order to hit those levels

00:27:43.840 | because they're not eating a lot of egg yolks

00:27:45.540 | or they're not eating a lot of other foods.

00:27:47.820 | Certain fish contain choline, for instance,

00:27:50.480 | and the other foods I listed off a few minutes ago

00:27:52.900 | from plant-based sources.

00:27:54.960 | So some people will supplement with 50 to 100 milligrams

00:27:59.700 | or whatever amount is necessary

00:28:01.200 | to get them up to that one gram

00:28:02.800 | or even a two gram dose per day.

00:28:04.680 | So we have three things

00:28:06.020 | that we know can support nerve cells.

00:28:08.700 | EPA, in particular, omega-3 fatty acids,

00:28:13.240 | phosphatidylserine and choline.

00:28:16.240 | Those three things I would list off

00:28:17.880 | as the top three things for enhancing neuron function

00:28:22.680 | and the integrity of neurons in the short and long term.

00:28:25.280 | And this is, again, is setting aside

00:28:27.560 | the vitally important factors

00:28:29.040 | of hydration and electrolytes.

00:28:31.040 | I've said it before on other podcasts,

00:28:32.480 | but if you're not ingesting enough water

00:28:34.800 | and you're not getting enough sodium

00:28:36.200 | and magnesium and potassium,

00:28:38.160 | then obviously your neurons can't run

00:28:40.080 | because a lot of the brain is water.

00:28:42.600 | You need to maintain proper hydration

00:28:44.200 | and sodium, potassium, and magnesium are important

00:28:47.000 | in order for nerve cells to function.

00:28:48.320 | In fact, they are actually the components,

00:28:51.520 | the ions that pass across those lipid membranes,

00:28:54.800 | those little fatty membranes

00:28:55.920 | that we were talking about earlier

00:28:57.040 | that allow the neurons to generate electrical activity

00:28:59.960 | and communicate with one another.

00:29:01.520 | So definitely you want to hydrate enough.

00:29:03.840 | We will do an entire other episode

00:29:05.360 | all about hydration and electrolytes,

00:29:07.060 | but omega-3s, the EPAs, phosphatidylserine and choline,

00:29:12.060 | it's obvious, are going to improve brain function.

00:29:17.080 | How much they will improve brain function

00:29:18.600 | probably depends on how well

00:29:19.520 | your brain was working previously.

00:29:20.860 | In fact, many of the studies that have looked

00:29:22.880 | at the effectiveness of these compounds

00:29:24.460 | have looked in people that are suffering from mild

00:29:26.440 | or even severe cognitive decline.

00:29:28.680 | And while the outcomes of those studies vary,

00:29:31.920 | given the interest in maintaining brain function,

00:29:34.080 | given the fact that we don't make new neurons

00:29:36.200 | throughout our entire life,

00:29:37.760 | and given that everybody has to eat,

00:29:40.280 | these are quality, healthy foods

00:29:42.080 | that we should all be ingesting anyways,

00:29:44.800 | and it's clear that they can support brain function

00:29:47.460 | to some degree or another.

00:29:48.880 | Many people ask what I do in light of this information.

00:29:53.080 | And while I can only talk about what works for me,

00:29:56.160 | I choose to ingest fish oil in mainly in liquid form,

00:30:00.080 | because that turns out to be the easiest way

00:30:02.580 | and the most economically affordable way to do it

00:30:05.760 | for most people.

00:30:07.280 | So there are various forms of liquid fish oil out there.

00:30:09.760 | Some of them include some lemon flavoring,

00:30:11.360 | so it doesn't taste like fish oil,

00:30:12.680 | because frankly, fish oil to me is sort of noxious tasting.

00:30:16.000 | And I'll take a tablespoon of that or two per day.

00:30:19.920 | If I'm traveling, I'll use the capsule form

00:30:22.780 | in order to hit that threshold of, for me,

00:30:25.160 | about two, sometimes even three grams per day of EPA.

00:30:29.520 | So not just two or three grams per day of fish oil,

00:30:32.400 | but two or three grams per day of EPA.

00:30:34.640 | Now, if I'm eating fish,

00:30:37.080 | which as I mentioned earlier is not often,

00:30:39.000 | then I might reduce the amount of fish oil that I take,

00:30:41.040 | but that's my major source of fish oil.

00:30:43.280 | Currently, I do not supplement with phosphatidylserine.

00:30:47.460 | A number of people that I know and trust,

00:30:49.240 | and indeed several colleagues of mine

00:30:51.440 | do take phosphatidylserine.

00:30:53.120 | I don't have any good explanation

00:30:54.400 | for why I don't take it yet,

00:30:56.220 | but I have not tried supplementing with it yet.

00:30:58.480 | Maybe if some of you have,

00:30:59.600 | you can place your experience in the comment section.

00:31:03.460 | That would be of interest.

00:31:04.600 | And then in terms of choline,

00:31:06.600 | in order to get choline in my diet,

00:31:08.600 | I do pay attention to the various foods that contain choline

00:31:12.060 | and I try and get those foods on a semi-regular basis.

00:31:14.820 | I do supplement with something called alpha-GPC,

00:31:18.480 | which is essentially in the acetylcholine pathway

00:31:21.960 | or biosynthesis pathway.

00:31:23.800 | I don't take it very often,

00:31:25.240 | but I will take 300 milligrams of alpha-GPC

00:31:28.520 | from time to time.

00:31:29.360 | From time to time,

00:31:30.200 | I mean anywhere from two to three times per week.

00:31:33.280 | I'll generally do it early in the day

00:31:34.680 | 'cause it, for me, can have a little bit

00:31:36.160 | of a stimulant effect,

00:31:37.560 | although it's not nearly as stimulating, say,

00:31:40.040 | as a double espresso or triple espresso.

00:31:42.600 | But that's one way in which I enhance my choline function.

00:31:46.040 | And some people choose to get it from supplementation

00:31:48.440 | because it's straightforward.

00:31:50.120 | There are a lot of supplements out there

00:31:51.280 | that contain alpha-GPC.

00:31:52.820 | Some people are taking dosages

00:31:54.240 | as high as 900 milligrams per day.

00:31:55.920 | That sounds very high to me.

00:31:57.240 | The studies of offsetting cognitive decline

00:32:00.160 | using alpha-GPC did use quite high dosages

00:32:04.100 | of 600 to 900 or even 1200 milligrams per day.

00:32:07.820 | So it has been used at those much higher concentrations,

00:32:10.880 | but because fortunately, at least not yet

00:32:14.300 | or not to my awareness,

00:32:15.200 | I'm not suffering from any cognitive decline,

00:32:17.440 | I will supplement with 300 milligrams every now and again.

00:32:20.760 | Next on my list of compounds that have been shown

00:32:23.160 | in peer-reviewed research to improve neuronal

00:32:25.900 | and brain function is creatine.

00:32:28.480 | Creatine can be derived from meat sources.

00:32:30.840 | It can also be supplemented.

00:32:32.500 | Some of you are probably familiar with creatine

00:32:36.000 | or have heard about creatine from the context

00:32:38.540 | of the health and fitness world,

00:32:39.840 | where creatine is used to bring more water into muscles,

00:32:44.200 | which can enhance the strength of those muscles,

00:32:46.540 | as well as bring water into other tissues.

00:32:49.540 | So it doesn't just draw more water into muscle,

00:32:51.400 | it can draw more water into the body generally.

00:32:54.080 | Creatine has also been shown to have an important role

00:32:58.080 | in brain function.

00:32:59.280 | And once again, this is something that came up

00:33:01.040 | during the discussion about depression a few episodes back.

00:33:04.220 | Creatine can actually be used as a fuel source in the brain.

00:33:08.720 | And there's some evidence that it can enhance the function

00:33:12.100 | of certain frontal cortical circuits that feed down onto

00:33:16.540 | or rather connect to areas of the brain

00:33:18.900 | that are involved in mood regulation and motivation.

00:33:21.160 | And that's where creatine plays a role in depression,

00:33:25.320 | or rather where creatine supplementation seems to be able

00:33:29.060 | to assist in some forms of mild depression.

00:33:32.160 | That's an emerging literature.

00:33:33.360 | It's still not well-established.

00:33:35.280 | However, there is now ample evidence

00:33:38.320 | that creatine supplementation can enhance brain function

00:33:41.320 | in certain contexts.

00:33:42.720 | And if you're interested in learning more

00:33:45.000 | about what those contexts are,

00:33:46.540 | there's an excellent review that just came out.

00:33:48.560 | The first author is Rochelle, R-O-S-C-H-E-L.

00:33:52.440 | We will provide a link to this study,

00:33:54.620 | rather this review, excuse me, in the caption.

00:33:58.200 | This was published just very recently in 2021.

00:34:01.860 | And one thing to make clear is that creatine supplementation

00:34:05.400 | has been shown to be especially useful

00:34:07.940 | for people that are not consuming any meat

00:34:10.440 | or other sources of foods that are rich in creatine.

00:34:13.400 | What is the threshold level of creatine to supplement

00:34:15.940 | in order to get the cognitive benefit?

00:34:18.000 | Appears to be at least five grams per day.

00:34:21.120 | Now, the most typical form of creatine

00:34:22.560 | is so-called creatine monohydrate.

00:34:24.240 | There are other forms of creatine as well,

00:34:26.320 | some of which are thought to not draw as much water

00:34:28.460 | into non-muscle tissues.

00:34:30.480 | And for some people that that's attractive to them,

00:34:32.880 | they don't want water sitting below their skin, et cetera.

00:34:35.560 | I should emphasize that the responses to creatine

00:34:37.760 | in that sense can differ.

00:34:39.660 | Some people get a little bit of water retention.

00:34:41.680 | Some people experience more.

00:34:43.520 | There's some evidence that creatine can impact

00:34:45.880 | some of the hormonal pathways

00:34:47.060 | that it might enhance levels

00:34:48.240 | of so-called dihydrotestosterone, DHT.

00:34:50.880 | And therefore, because DHT is involved in hair loss,

00:34:53.500 | there are these theories that creatine can cause hair loss.

00:34:56.540 | And indeed, for people that are very DHT sensitive,

00:34:59.000 | it might.

00:34:59.960 | There's going to be a lot of variation person to person

00:35:04.680 | in terms of how much creatine impacts DHT

00:35:07.220 | and how many DHT receptors they have on their scalp

00:35:09.600 | and therefore whether or not they experience hair loss.

00:35:11.580 | I'm just giving you all this information

00:35:13.060 | so that you're aware of the various things

00:35:15.040 | that creatine can do.

00:35:16.500 | But nonetheless, I think it's interesting

00:35:18.440 | that creatine supplementation of five grams per day,

00:35:21.120 | that's creatine monohydrate,

00:35:22.640 | has been shown to improve cognition

00:35:24.220 | in people that aren't getting creatine from animal sources.

00:35:27.200 | And there's some evidence detailed within the review

00:35:29.840 | that I just described

00:35:32.520 | that creatine supplementation can also enhance cognition

00:35:35.960 | in people that are also eating animal products.

00:35:40.000 | So I personally take creatine five grams per day

00:35:42.880 | and have for a very long time.

00:35:44.560 | I can't say that I've noticed a tremendous benefit

00:35:47.480 | because I've actually never really come off it.

00:35:49.880 | And so I've never done the control experiment.

00:35:51.640 | I take it more as kind of a baseline insurance policy.

00:35:54.480 | For me, I'm probably losing,

00:35:57.140 | I'm certainly losing some of my hair,

00:35:58.520 | whether or not that's due to creatine or not.

00:36:01.180 | I've never done the analysis.

00:36:03.160 | But what I can say is that I generally consume these things

00:36:06.820 | like EPAs, creatine, alpha GPC,

00:36:11.260 | to set a general context of support for my neurons,

00:36:16.260 | for my brain.

00:36:17.300 | And of course, I also pay attention to the foods

00:36:19.500 | that contain these various compounds.

00:36:21.240 | So I don't actively eat additional meat

00:36:23.660 | just to obtain creatine.

00:36:25.960 | I eat a fairly limited amount of meat.

00:36:27.540 | I don't restrict it, and I do eat meat,

00:36:29.960 | but I don't actively seek out creatine in my diet.

00:36:33.380 | Rather, I use supplementation

00:36:34.640 | in order to hit that five grams per day threshold.

00:36:37.360 | Next on the list of foods

00:36:39.340 | that are beneficial for brain health

00:36:40.820 | is one that you've probably seen pictures of online

00:36:43.420 | because there seems to be a practice

00:36:45.080 | of putting pictures of blueberries and other dark berries

00:36:48.760 | next to any title that says foods that benefit your brain.

00:36:52.260 | There are a lot of foods out there

00:36:55.040 | that have been purported to improve brain function.

00:36:58.940 | The interesting thing about blueberries and other berries,

00:37:02.240 | blackberries, dark currants,

00:37:04.620 | any of these thin-skinned berries

00:37:07.060 | that are purplish in color

00:37:09.580 | is that they contain what are called anthocyanins.

00:37:12.820 | Anthocyanins actually have some really nice data

00:37:15.580 | to support the fact that they improve brain function.

00:37:19.020 | Now, whether or not it is direct effects on neurons

00:37:22.980 | or whether or not it is by lowering inflammation

00:37:25.720 | or some other modulatory effect isn't quite clear,

00:37:29.960 | but I think by now there's enough data

00:37:33.060 | to support the fact that eating a cup or two of blueberries

00:37:36.140 | pretty often every day,

00:37:37.420 | or maybe you have blackberries or maybe it's blackcurrants,

00:37:40.920 | that these anthocyanins are good for us,

00:37:43.720 | that they are enhancing our overall wellbeing

00:37:46.860 | at a number of different levels.

00:37:47.940 | And just to give you a couple of examples

00:37:49.500 | of where there are actually peer-reviewed studies

00:37:51.840 | to support those statements,

00:37:53.900 | the anthocyanins of which blueberries

00:37:57.180 | and other dark berries are rich in

00:38:00.300 | have been shown to reduce the amount of DNA damage,

00:38:04.420 | has been shown to reduce significantly,

00:38:08.140 | albeit slightly, excuse me, cognitive decline.

00:38:11.660 | And that particular study was supplementation

00:38:13.980 | of a blueberry extract.

00:38:16.380 | I'll talk about the difference between extract

00:38:17.980 | and actual blueberries in a moment,

00:38:19.340 | but supplementation of blueberry extract

00:38:22.320 | in offsetting cognitive decline in elderly people.

00:38:26.180 | So, you know, what constitutes elderly

00:38:29.100 | is always a little bit of a debate and a discussion,

00:38:32.500 | but in this case, what they did is they supplemented

00:38:35.600 | with somewhere between 428,

00:38:39.500 | I don't know why they selected 428,

00:38:41.080 | and 598 milligrams of anthocyanins daily for 12 weeks

00:38:45.540 | was associated with improvements

00:38:46.820 | on verbal learning and memory.

00:38:48.320 | And they had some other beneficial changes

00:38:51.800 | that were within the bodily organs

00:38:53.540 | and blood glucose regulation and so forth, positive changes.

00:38:57.180 | But that's one study.

00:38:58.920 | In this case, elderly meant 65 or older.

00:39:02.080 | That study and a number of studies like it,

00:39:04.840 | looking at things like mildly enhanced memory,

00:39:08.540 | reduced insulin levels, reduced oxidation of LDL,

00:39:13.360 | these sorts of things, have basically created a situation

00:39:16.920 | where anytime you Google or look up foods

00:39:20.920 | that enhance brain function,

00:39:23.260 | you're going to see a picture of a blueberry

00:39:25.000 | or some other berry because of these anthocyanins.

00:39:28.020 | I personally don't supplement anthocyanins.

00:39:31.160 | I do like blueberries.

00:39:32.200 | I eat blueberries when they're in season.

00:39:34.700 | I love them.

00:39:35.540 | I'm what you would call a drive-by blueberry eater.

00:39:37.480 | Like if there are blueberries in a bowl on a table

00:39:40.460 | and I'm walking by, I just have to scoop them up

00:39:42.700 | like some sort of bear or other animal

00:39:44.760 | and pop them in my mouth.

00:39:45.720 | So blueberries don't last long around me.

00:39:48.160 | One of the issues with berries,

00:39:49.540 | like blueberries and blackberries and so forth,

00:39:51.240 | is that quality sources of them can be pretty expensive.

00:39:53.880 | And then of course, when they're not in season,

00:39:55.780 | they're hard to get.

00:39:56.620 | And so that's why some people will supplement with them.

00:39:59.060 | So that range of about 400 to about 600 milligrams per day

00:40:04.060 | seems to be the minimum threshold

00:40:07.260 | for getting a cognitive effect in these elderly patients.

00:40:12.260 | In that case, they were patients.

00:40:14.000 | A good review about the anthocyanins

00:40:15.940 | potentially contributing to offsetting cognitive decline

00:40:19.900 | in things like Alzheimer's

00:40:21.460 | and also enhancing brain function

00:40:23.940 | in people that don't have Alzheimer's

00:40:26.260 | is a review by Afzal, A-F-Z-A-L,

00:40:29.340 | that was published in 2019.

00:40:31.180 | We will also provide a link to that study in the caption.

00:40:34.160 | When one looks across the total batch of studies

00:40:38.260 | that are out there on this,

00:40:39.980 | it appears that if one is going to supplement

00:40:43.160 | with blueberry extract

00:40:44.700 | to get the anthocyanin effect on cognition,

00:40:47.460 | dosages of somewhere between five and a half

00:40:51.580 | or about 11 grams seem optimal

00:40:54.380 | with the higher end closer to 10 or 11 grams

00:40:57.520 | being more beneficial.

00:40:59.380 | The blueberry eaters out there like me

00:41:02.360 | who prefer to get their anthocyanins from the actual berries,

00:41:05.300 | it appears that somewhere between 60 to 120 grams

00:41:08.420 | of fresh blueberries each day

00:41:10.500 | is the way that you can get a sufficient anthocyanins

00:41:13.180 | to at least shift your system or bias your brain

00:41:16.920 | towards these enhanced cognitive effects.

00:41:18.900 | So we've got EPA fatty acids,

00:41:20.820 | we've got phosphatidylserine, we've got choline,

00:41:23.780 | we've got creatine, and we have the anthocyanins.

00:41:28.100 | And the last item that I'd like to place

00:41:30.900 | in this list of food-derived things

00:41:33.600 | that can enhance brain function is glutamine.

00:41:37.500 | Glutamine is a very interesting amino acid.

00:41:39.680 | I've talked about glutamine on here before.

00:41:41.940 | There's some evidence, although somewhat scant,

00:41:45.080 | there's some evidence that glutamine

00:41:48.020 | can enhance immune system function.

00:41:49.820 | So people will supplement with glutamine

00:41:51.520 | or people can get glutamine from foods.

00:41:53.840 | Foods that contain a lot of glutamine

00:41:55.200 | are things like cottage cheese.

00:41:56.640 | There are also other sources of glutamine.

00:41:59.040 | Glutamine is rich in protein-rich foods,

00:42:01.680 | things like beef, chicken, fish, dairy products, eggs,

00:42:04.240 | but also for you non-animal food-consuming people out there,

00:42:09.240 | vegetables, including beans, cabbage once again,

00:42:13.680 | spinach, parsley, things of that sort.

00:42:17.040 | So those foods contain glutamine.

00:42:19.480 | For people that supplement with glutamine,

00:42:21.380 | generally they will take anywhere from a gram

00:42:23.600 | as much as 10 grams per day.

00:42:26.120 | Why would they want to do that?

00:42:27.100 | Well, there's also some evidence starting to emerge

00:42:30.360 | that glutamine can help offset sugar cravings.

00:42:33.400 | And I've talked about this on the podcast before.

00:42:35.540 | We're going to talk more about the basis for this

00:42:38.160 | a little bit later, but in brief,

00:42:41.500 | we all have neurons in our gut

00:42:43.620 | that sense the amino acid content, the fat content,

00:42:46.760 | and the sugar content of the foods that we eat

00:42:48.620 | and signal in a subconscious way to our brain

00:42:51.360 | whether or not the foods that we are eating

00:42:53.760 | contain certain levels of certain amino acids.

00:42:57.640 | And so we actually have glutamine-sensing neurons

00:43:01.260 | in our gut that actually have their little processes,

00:43:04.260 | their little axons and dendrites, as we call them,

00:43:06.800 | in the mucosal lining of the gut.

00:43:08.220 | They're not just sensing glutamine,

00:43:09.560 | but when they do sense glutamine, they respond,

00:43:12.060 | and they send signals to the brain

00:43:13.660 | that are signals of satiation, of satisfaction.

00:43:17.400 | And in doing so can offset some of the sugar cravings

00:43:20.120 | that many people suffer from.

00:43:22.080 | Now, here, we're talking about glutamine

00:43:23.460 | for sake of enhancing cognitive function.

00:43:25.980 | And this is interesting because it's been shown

00:43:28.920 | that glutamine supplementation can offset

00:43:31.340 | some of the negative effects on cognition

00:43:34.480 | caused by altitude and oxygen deprivation of other sorts.

00:43:39.480 | Okay, well, that's kind of a strange and unique situation.

00:43:43.840 | If you're going up to altitude,

00:43:45.720 | should you supplement with glutamine

00:43:47.280 | in order to be able to think more clearly?

00:43:48.960 | Well, it appears that there's good rationale for doing that.

00:43:52.240 | But the reason I bring this up,

00:43:54.360 | assuming that most people, including me,

00:43:56.020 | are not going up to high altitudes very often,

00:43:59.760 | is that it's been well-established

00:44:02.520 | that apnea, failure to breathe properly during sleep,

00:44:06.200 | can contribute to age-related

00:44:08.320 | and even non-age-related cognitive decline.

00:44:10.860 | There are a lot of reasons for apneas,

00:44:12.720 | ranging from obesity to obstruction of the airways

00:44:18.560 | for other reasons.

00:44:19.580 | There are a tremendous number of underlying causes of apnea,

00:44:23.960 | and it's something to be taken seriously.

00:44:25.440 | I mean, heart attacks,

00:44:27.080 | all sorts of metabolic issues are caused by apnea.

00:44:30.340 | Apnea is a serious issue that disrupts the depth of sleep,

00:44:33.660 | and it's a serious health issue in general.

00:44:36.280 | In any event, apnea is associated with cognitive decline

00:44:40.000 | and cognitive dysfunction, even in young people.

00:44:42.880 | And it does appear that glutamine supplementation

00:44:46.080 | can offset some of the cognitive deficits

00:44:49.200 | that are associated with reduced oxygenation of the brain.

00:44:52.520 | If you'd like to learn more about how apnea

00:44:55.240 | can negatively impact cognition,

00:44:57.760 | there's an excellent paper

00:44:58.920 | that was published on this in 2018.

00:45:00.760 | The first author is Sharma, S-H-A-R-M-A.

00:45:04.280 | It should be easy to find.

00:45:05.360 | The title of the paper is

00:45:06.200 | Obstructive Sleep Apnea Severity Effects Amyloid Burden

00:45:10.080 | in Cognitively Normal Elderly.

00:45:12.120 | This was a longitudinal study.

00:45:13.780 | Amyloid burden is a correlate of Alzheimer's

00:45:17.520 | and other forms of neurodegeneration and cognitive decline

00:45:20.560 | associated with memory deficits.

00:45:22.420 | So obstructive sleep apnea is a very serious issue

00:45:27.420 | for which glutamine appears to be able to offset

00:45:31.600 | some of the negative symptomology.

00:45:33.860 | So how is it that glutamine,

00:45:35.680 | either from food or through supplementation,

00:45:38.440 | can offset some of these so-called hypoxic effects

00:45:41.760 | caused by sleep apnea,

00:45:42.860 | hypoxia being a lack of oxygen for the brain

00:45:45.640 | that relate to cognitive decline.

00:45:47.500 | It appears to have this positive impact

00:45:51.060 | by way of reducing inflammation.

00:45:53.540 | So if you want to look more deeply

00:45:56.160 | into the various biological pathways

00:45:58.900 | and the supplementation regimes for this,

00:46:01.400 | the paper that I think is really spectacular is a paper,

00:46:04.660 | last author is Quaresma, Q-U-A-R-E-S-M-A.

00:46:09.660 | That's Q-U-A-R-E-S-M-A.

00:46:12.600 | It's a review the possible importance

00:46:14.500 | of glutamine supplementation to mood and cognition

00:46:17.540 | in hypoxia from high altitude.

00:46:19.500 | And even though the paper is about

00:46:21.060 | high altitude induced hypoxia,

00:46:23.220 | it does seem to have direct relevance

00:46:25.240 | to the sorts of apnea that are related to Alzheimer's

00:46:29.140 | and other forms of cognitive decline.

00:46:30.900 | Now I've been taking glutamine as a supplement, gosh,

00:46:33.660 | since I was in college,

00:46:34.640 | mostly because I felt either by superstition or by reality

00:46:38.620 | that it protected me from various flus and colds

00:46:43.320 | and things of that sort

00:46:44.340 | because of the purported immune enhancing effects.

00:46:47.700 | Again, those immune enhancing effects

00:46:50.160 | have some data to support them, not a ton.

00:46:53.160 | However, I got into the habit of taking glutamine

00:46:55.300 | and now that I've learned that glutamine

00:46:57.600 | seems to also have some cognitive enhancing effects,

00:47:00.320 | possibly, it's a supplement that I continue to take.

00:47:03.400 | I take very small amounts of it,

00:47:04.960 | but I do take it on a regular basis.

00:47:07.640 | So that more or less completes the list of things

00:47:10.640 | that at least by my read of the literature

00:47:13.920 | are things that are supported by at least three

00:47:16.700 | and in some cases, as many as hundreds of studies

00:47:19.780 | in various populations that have been explored

00:47:22.980 | in mouse studies often,

00:47:24.460 | but also in a number of human studies.

00:47:27.200 | I want to emphasize again that all of the things

00:47:29.340 | I listed out, whether or not it's EPAs,

00:47:31.580 | whether or not it's phosphatidylserine,

00:47:33.280 | whether or not it's choline,

00:47:34.260 | whether or not it's the various compounds

00:47:37.560 | that are in berries, et cetera,

00:47:38.880 | all of those can be extracted from food.

00:47:41.080 | There is not any law that says that you have to get them

00:47:44.100 | from supplementation.

00:47:45.000 | Supplementation can help you get to the very high levels

00:47:47.920 | of those things if you want to work on the higher end,

00:47:50.320 | if that's right for you,

00:47:51.320 | obviously check with your doctor before taking anything

00:47:53.520 | or removing anything from your diet or supplement regime.

00:47:56.320 | But in general, you can get these things from foods.

00:48:01.000 | It's just so happens that for some of these compounds,

00:48:04.660 | the foods that they're contained in like fish

00:48:06.280 | are not foods that I particularly enjoy.

00:48:09.000 | And so I rely on, excuse me,

00:48:11.180 | I rely on supplements in order to get

00:48:13.680 | sufficient levels for me.

00:48:15.160 | But again, you can get these levels from food.

00:48:17.580 | And the reason I made this list,

00:48:20.520 | the reason that I emphasize these things

00:48:23.240 | in this particular order is that they support

00:48:27.960 | the structure of neurons.

00:48:29.960 | They support the structure of the other cells of the brain

00:48:32.780 | that make up our cognition and that are important

00:48:35.220 | for our focus and our ability to remember things

00:48:37.880 | and so forth.

00:48:38.880 | And they are less so in the category

00:48:40.980 | of so-called modulatory effects.

00:48:44.280 | They will also have modulatory effects on sleep,

00:48:47.300 | on inflammation or reducing inflammation

00:48:49.220 | throughout the body, on cardiovascular function,

00:48:51.640 | all of which I believe are positive effects,

00:48:55.300 | at least what the literature tells us

00:48:57.080 | is that none of these compounds are harming other systems

00:49:00.000 | of the body provided they are taken at reasonable levels.

00:49:04.080 | But everything in this list is directed

00:49:07.260 | towards answering the question, what can I eat?

00:49:10.240 | What can I ingest by way of food and or food supplement

00:49:14.000 | that can support brain function in the short-term

00:49:16.760 | and in the long-term?

00:49:17.720 | So I hope you find that list beneficial for you,

00:49:19.580 | if not for use, at least for consideration.

00:49:22.920 | So now having talked about some of the foods

00:49:25.420 | and micronutrients that are beneficial

00:49:27.380 | to our immediate and long-term brain health,

00:49:30.480 | I'd like to shift gears somewhat and talk about

00:49:32.940 | why it is that we like the foods that we like.

00:49:36.400 | We've all heard before that we are hardwired

00:49:39.560 | to pursue sugar and to like fatty foods

00:49:42.920 | and that calorie-rich foods are attractive to us

00:49:45.080 | for all sorts of reasons,

00:49:46.260 | surviving famines and things of that sort.

00:49:48.640 | And while that is true,

00:49:51.080 | the actual mechanisms that underlie food seeking

00:49:53.820 | and food preference are far more interesting than that.

00:49:57.640 | There are basically three channels in our body

00:50:00.080 | and nervous system by which we decide what foods to pursue,

00:50:04.480 | how much to eat, and whether or not we will find

00:50:06.980 | a particular food attractive,

00:50:09.700 | whether or not we will want to consume more of it,

00:50:12.140 | whether or not we want to avoid it,

00:50:14.340 | or whether or not it's just sort of so-so,

00:50:16.460 | what I refer to as the yum, yuck, or meh analysis.

00:50:21.460 | And indeed, that's what our nervous system is doing

00:50:24.480 | with respect to food.

00:50:25.500 | It's trying to figure out whether or not yum,

00:50:28.420 | I want more of this, yuck, I want to avoid this,

00:50:31.860 | or meh, it's so-so.

00:50:33.840 | Now, while that may seem like a overly simplified version

00:50:37.380 | of food seeking and food preference,

00:50:39.640 | it's actually not that far from the truth.

00:50:42.040 | It actually correctly captures much of the biology

00:50:46.560 | of food preference.

00:50:48.240 | So let's talk about what these three channels

00:50:50.160 | for food preference are.

00:50:52.040 | The first one is an obvious one.

00:50:54.080 | It's taste on the mouth.

00:50:56.160 | It is the sensation that we have of the foods

00:50:58.640 | that we eat while we're chewing them.

00:51:00.880 | And those sensations,

00:51:02.320 | which are literally just somatosensory touch sensations,

00:51:05.300 | you know, the palatability of food

00:51:08.720 | as it relates to the consistency of food.

00:51:11.920 | That's important.

00:51:13.280 | And as you've all heard before,

00:51:15.040 | we have sensors on our tongue and elsewhere in our mouth

00:51:18.300 | that detect the various chemicals contained within food

00:51:21.400 | and lead to the senses of taste,

00:51:24.560 | which we call bitter, sweet, umami, salty, and sour.

00:51:28.200 | Now, most of us are familiar with the sense of bitterness

00:51:30.900 | that comes from something like a raw radish,

00:51:33.760 | sweet, which comes obviously from sugars of different kinds,

00:51:36.700 | fructose, glucose, et cetera, salty, salty, and sour.

00:51:41.700 | Think lemon or lemon juice, for instance.

00:51:46.040 | And then I mentioned umami.

00:51:48.040 | The umami receptor is a receptor

00:51:50.660 | that responds to the savory taste of things.

00:51:53.720 | So that's what you might find

00:51:55.460 | in a really wonderfully rich tomato sauce

00:51:58.460 | for those of you that eat meat and like meat.

00:52:01.480 | A really well-cooked, not necessarily well done,

00:52:04.920 | but properly cooked, I should say, steak,

00:52:08.540 | if that's your thing.

00:52:09.800 | And umami is present in both plant and animal foods

00:52:13.480 | and gives us that sensation of savoriness.

00:52:16.320 | It almost has a kind of little bit of a briny taste to it

00:52:19.780 | or braised taste to it.

00:52:21.400 | And indeed, braising of meats and braising of vegetables

00:52:25.120 | is done specifically to activate that umami receptor.

00:52:29.580 | So we have those five basic tastes.

00:52:31.660 | Those are chemical sensors on the tongue

00:52:34.660 | that what we call transduce those chemicals,

00:52:37.440 | those chemicals literally in food bind to those receptors,

00:52:40.800 | and it is transduced,

00:52:42.880 | meaning the binding of those chemicals to the receptors

00:52:46.860 | is converted into an electrical signal

00:52:48.960 | that travels in from the tongue

00:52:50.760 | along what's called the gustatory nerve.

00:52:52.940 | The gustatory nerve then synapses,

00:52:55.600 | meaning it makes connections in our brainstem,

00:52:58.320 | in the so-called nucleus of the solitary tract.

00:53:00.960 | There are other nuclei back there.

00:53:02.560 | Nuclei are just aggregates of neurons.

00:53:04.560 | And then it sends information up

00:53:06.120 | to the so-called insular cortex, to the insula.

00:53:08.560 | I want to highlight the insula this episode

00:53:11.640 | because we are going to return to the insula

00:53:14.680 | again and again in this episode and later.

00:53:17.460 | The insular cortex is a incredible structure

00:53:21.480 | that we all have that mainly is concerned

00:53:24.540 | with so-called interoception or our perception

00:53:27.660 | of what's going on inside our body.

00:53:29.820 | So it could be the amount of pressure in our gut

00:53:31.460 | because of how much food we've eaten.

00:53:33.200 | It could be the acidity of our gut

00:53:36.420 | if we're having a little bit of indigestion, for instance.

00:53:38.820 | It can also be the case that neurons within the insula

00:53:42.820 | are paying attention to how stressed you are

00:53:44.760 | or how alert you are or how tired you are.

00:53:46.820 | So it's really an inward focusing structure.

00:53:49.920 | It focuses on how we feel internally.

00:53:52.000 | And not surprisingly, the taste system sends information

00:53:56.920 | up to the insular cortex to give us a sense, literally,

00:54:00.600 | of what we've ingested,

00:54:02.680 | whether or not what we're tasting tastes good or not.

00:54:06.040 | We will return to insular cortex in a few moments.

00:54:09.080 | A very important thing to understand is that the neurons

00:54:12.480 | in the areas of the cortex, your cortex and mine,

00:54:15.080 | that respond to particular tastes

00:54:16.980 | are providing an internal representation

00:54:21.940 | of an external sense.

00:54:24.840 | What do I mean by that?

00:54:25.820 | I don't want to be at all abstract.

00:54:27.760 | We take these foods, we break them down in our mouth

00:54:30.360 | by chewing them or sucking on them,

00:54:33.440 | whatever it is that food happens to be.

00:54:35.920 | Those chemicals bind to those receptors

00:54:37.620 | and electrical signals are sent into the brain,

00:54:39.960 | but they are just electrical signals,

00:54:41.640 | just like notes being played on the keys of a piano

00:54:45.000 | there's no unique signature for salty or sweet.

00:54:48.080 | It is the relative activation of one set of neurons

00:54:53.080 | that was activated by sweet or another set of neurons

00:54:55.880 | that was activated by umami.

00:54:57.520 | It's that relative activation traveling into the brain

00:55:00.540 | in essentially the same form, the same electrical signals.

00:55:05.500 | This is really incredible, right?

00:55:06.560 | Electrical signals are sent into the brain and you say,

00:55:08.320 | "Aha, that's sweet and I want more of it."

00:55:10.960 | Or, "That's bitter, I want less of it."

00:55:12.520 | Or, "That's umami flavored and I really, really like that,

00:55:15.380 | really like savory foods as I happen to."

00:55:17.920 | That should immediately strike you as incredible

00:55:21.960 | because it means that your representation

00:55:24.000 | of what you want more of or less of is electrical in nature.

00:55:27.240 | And to really tamp this issue down,

00:55:31.040 | studies that were done by Charles Zucker, Z-U-K-E-R,

00:55:36.000 | he's a absolutely phenomenal neuroscientist

00:55:40.160 | at Columbia University in New York.

00:55:43.100 | Studies done by the Zucker lab have shown that,

00:55:47.000 | first of all, they could identify the neurons in the cortex

00:55:51.400 | deep in the brain that respond to a sweet taste

00:55:54.400 | or to a bitter taste.

00:55:55.360 | It turns out they are non-overlapping populations of neurons.

00:55:58.400 | And then using some molecular tricks,

00:56:01.040 | they were able to either silence or activate the neurons

00:56:05.600 | that, for instance, respond to sweet.

00:56:09.400 | When they do this,

00:56:10.240 | they see incredible consequences on perception

00:56:14.320 | that indeed occur in your brain and my brain as well

00:56:17.880 | all the time without these kinds of manipulations.

00:56:20.180 | Here's the experiment.

00:56:21.280 | They have a subject drink water that contains sugar

00:56:27.240 | or drink water that contains a salty substance

00:56:29.620 | or drink water that contains a bitter substance,

00:56:31.720 | for instance, okay?

00:56:32.780 | I'm sort of paraphrasing a large amount of work.

00:56:36.040 | They identify the neurons that respond to sweet tastes.

00:56:39.940 | They see, as many researchers have seen,

00:56:44.760 | that subjects prefer sweet taste to other tastes

00:56:47.920 | and certainly sweet taste to bitter

00:56:49.480 | or sweet taste to nothing, so to plain water.

00:56:52.060 | And then they go in and they are able

00:56:55.400 | to selectively silence the neurons that represent sweet.

00:57:00.140 | And when they do that,

00:57:02.240 | they eliminate the preference for that sweet taste.

00:57:06.120 | Now, that might seem obvious.

00:57:08.580 | The neurons respond to sweet.

00:57:09.680 | You silence those neurons.

00:57:11.640 | They no longer seek out sweet.

00:57:14.620 | But that should strike you also as incredible

00:57:17.760 | because they're not actually changing

00:57:19.240 | what's happening on the tongue

00:57:20.480 | or in the deeper layers of the brain.

00:57:22.320 | Conversely, they can have subjects drink bitter water

00:57:27.600 | or plain water while activating,

00:57:30.740 | selectively activating the neurons that respond to sweet.

00:57:34.080 | And what they find is that then subjects

00:57:36.680 | will actively prefer bitter or plain water

00:57:41.680 | to actual preferences such as sweet.

00:57:46.360 | So what this means is that your perception

00:57:49.000 | of what you like is a central,

00:57:51.400 | meaning deep within the brain, phenomenon.

00:57:54.480 | It's not about how things taste on your mouth.

00:57:57.480 | Now, of course, under normal conditions

00:57:59.200 | where there aren't these experimental manipulations

00:58:01.280 | being done, those things are positively correlated.

00:58:04.440 | Sweet tastes trigger the activation of sweet neurons,

00:58:07.180 | for instance, neurons in the mouth that respond to umami

00:58:10.760 | trigger the activation of neurons in the brain

00:58:12.820 | that respond to umami and so forth.

00:58:14.640 | So they're correlated in a way that makes you

00:58:18.560 | seek out the things that you like

00:58:19.980 | and avoid the things that you don't like.

00:58:22.220 | But as we'll see in a few minutes,

00:58:24.720 | turns out that that is not a direct relationship

00:58:28.060 | that is hardwired.

00:58:29.480 | You can actually uncouple the preference

00:58:32.480 | for particular tastes with the reward systems in the brain

00:58:36.400 | in a way that, for instance, would allow you to eat,

00:58:40.900 | or I should use myself as an example

00:58:42.360 | 'cause I don't particularly like fish.

00:58:43.800 | I've had a few meals that included fish

00:58:46.200 | that were pretty good, but none of them were memorable

00:58:49.200 | in the kind of positive way,

00:58:50.320 | like some other events in my life are memorable.

00:58:53.000 | But by way of these circuitries

00:58:55.760 | and the way they link up with one another,

00:58:57.280 | it's actually possible to rewire one's sense of taste

00:59:01.380 | and preference for particular foods.

00:59:03.200 | If this is seeming at all vague to you,

00:59:04.800 | just hang in with me a little bit longer

00:59:07.220 | because I will provide you with the information,

00:59:08.920 | tools, and resources with which to navigate this process.

00:59:13.100 | But the most important thing to understand

00:59:15.640 | is that like with our hearing, like with vision,

00:59:20.300 | like with smell, taste is an internal representation

00:59:26.820 | that has particular goals for you.

00:59:31.800 | Your sense of what tastes good is related

00:59:33.760 | to particular things that are occurring

00:59:35.560 | in your brain and body and that are likely

00:59:37.760 | to give your brain and body the things that it needs.

00:59:41.500 | It is not simply a matter of what you quote unquote like

00:59:44.520 | or what tastes good or what doesn't taste good.

00:59:47.160 | Let me give you a relatively simple example

00:59:50.100 | of how your body and your brain are acting

00:59:53.220 | in a coordinated way to make you prefer certain foods

00:59:56.960 | and indeed to pursue certain foods more.

00:59:59.340 | So I just mentioned you have neurons on your tongue

01:00:02.500 | that respond to different tastes,

01:00:04.240 | but of course your digestive tract isn't just your tongue,

01:00:06.880 | it's also your throat, it goes all the way down

01:00:09.220 | to your stomach and of course your intestines.

01:00:11.880 | Here's a long tube of digestion.

01:00:13.700 | All along that tube, there are neurons.

01:00:17.640 | Some of the neurons are responding to the mechanical size

01:00:22.240 | of whatever portion of the digestive tract

01:00:25.040 | it happens to be.

01:00:25.880 | So for instance, how distended or empty or full rather,

01:00:28.720 | and it doesn't have to be distended,

01:00:30.720 | depends on how much you ate,

01:00:31.580 | but how full or empty your gut happens to be,

01:00:34.800 | whether or not something you just ate is temperature hot,

01:00:38.380 | you know, is hot in the sense of hot to the touch

01:00:41.080 | or whether or not it's spicy hot,

01:00:42.940 | whether or not it's soothing,

01:00:44.240 | whether or not it's kind of hard to swallow,

01:00:46.640 | this kind of thing.

01:00:47.560 | So you have neurons all along your gut

01:00:49.560 | that are responding to the mechanics related to food

01:00:52.240 | and digestion, and that are related to the chemistry

01:00:54.620 | of food and digestion.

01:00:55.800 | There's a population of neurons, nerve cells in your gut

01:01:01.400 | that are exquisitely tuned to the chemistry

01:01:04.160 | of whatever it is in your gut.

01:01:06.160 | And these are neurons called neuropod cells.

01:01:09.560 | They were discovered many, many years ago,

01:01:12.480 | but really defined with and classified with modern tools

01:01:17.680 | by Diego Borges, I hope I'm pronouncing your name correctly,

01:01:20.840 | Diego, we've spoken many times,

01:01:22.460 | but I can't ever seem to quite capture

01:01:24.120 | the proper pronunciation just right.

01:01:26.240 | But Diego Borges at Duke University,

01:01:30.440 | who discovered that these cells reside within the gut

01:01:35.440 | and place little processes,

01:01:37.020 | they're little axons and dendrites

01:01:39.600 | within the mucosal lining of the gut.

01:01:43.060 | And there they are paying attention to,

01:01:45.800 | meaning they respond to amino acids,

01:01:49.720 | sugars, and fatty acids.

01:01:52.760 | So as your food is digested,

01:01:55.000 | as food lands within your gut,

01:01:57.180 | neurons there are sensing what types of foods are available

01:02:00.960 | and what types of things are making their way

01:02:03.320 | through the gut environment.

01:02:06.000 | Now those neurons aren't actually taking those foods

01:02:08.440 | and doing much with them.

01:02:09.400 | What they're doing is they're essentially surveying

01:02:13.980 | what qualities of food are there.

01:02:16.640 | And these particular neurons that Diego

01:02:18.720 | and his group discovered send electrical signals

01:02:22.500 | up into the brain through a little passage

01:02:25.720 | that we call the nodos ganglion,

01:02:27.640 | that nodos ganglia is a cluster of neurons

01:02:30.240 | that then go first, send their own process into the brain

01:02:33.680 | and trigger the release of dopamine,

01:02:35.320 | which is a molecule that inspires motivation, reward,

01:02:40.160 | and more seeking for whatever it is led to their activation.

01:02:44.280 | These are super interesting neurons

01:02:46.820 | because what they're essentially doing

01:02:48.940 | is they are providing a subconscious signal

01:02:53.300 | about the quality of the food that you're eating,

01:02:55.660 | what it contains, and then triggering the release

01:02:58.500 | of a molecule within your brain, dopamine,

01:03:01.380 | that leads you to go seek more of those foods.

01:03:04.160 | Now this has profound impact on a number of things.

01:03:09.900 | First of all, there's the consideration

01:03:12.420 | of so-called hidden sugars.

01:03:14.340 | Dr. Robert Lustig, who's a pediatric endocrinologist

01:03:17.420 | at University of California, San Francisco,

01:03:19.740 | has been among the most prominent researchers

01:03:23.180 | to talk about the fact that there are

01:03:24.640 | the so-called hidden sugars in foods.

01:03:26.420 | Now, these are not just sugars that they sneak in

01:03:29.160 | just to be sneaky.

01:03:30.380 | These are sugars that are literally snuck in

01:03:32.860 | in a way that you can't taste them.

01:03:35.480 | That's why they're called hidden sugars.

01:03:37.140 | It's not that they just put them in there for fun.

01:03:39.160 | These are sugars that are placed into processed foods

01:03:42.740 | that are designed to trigger activation of these mechanisms

01:03:46.840 | to lead you to want to eat more of these foods,

01:03:50.060 | but not because they necessarily taste sweet or delicious,

01:03:54.240 | but because they are activating

01:03:56.240 | these subconscious mechanisms that are driving you

01:03:58.580 | to pursue more of these foods.

01:04:00.040 | Sounds like a very diabolical strategy,

01:04:01.960 | and indeed it is somewhat of a diabolical strategy.

01:04:04.580 | However, these neurons are also involved

01:04:08.440 | in signaling to your brain when, for instance,

01:04:10.600 | you are eating a food that is rich in omega-3 fatty acids,

01:04:15.460 | the fatty acids that we were talking about earlier.

01:04:17.820 | So why is it that you don't crave salmon?

01:04:19.840 | Why is it that I don't sit around

01:04:21.260 | daydreaming about mackerel?

01:04:22.980 | Well, because there's also the influence

01:04:24.820 | of the actual taste on the mouth.

01:04:26.580 | Under normal conditions, it's a combination

01:04:28.940 | of the taste of the thing on the mouth

01:04:30.380 | plus the subconscious signaling from the gut.

01:04:33.060 | And while this isn't a discussion about gut microbiome,

01:04:37.280 | I should just mention that it's very clear

01:04:40.140 | that having a healthy gut microbiome

01:04:42.620 | allows these neurons to function

01:04:45.780 | in a way that serves our seeking of healthy foods

01:04:49.260 | in positive ways.

01:04:50.860 | And without getting into a lot of detail about this,

01:04:53.500 | the best way to ensure a healthy gut microbiome

01:04:56.060 | that I am aware of is not necessarily

01:04:59.560 | to take supplemental prebiotics or probiotics.

01:05:03.240 | There are actually some reasons

01:05:04.180 | why you might not want to do that,

01:05:06.220 | but rather to ingest two to four servings

01:05:08.460 | of fermented foods that are low in sugar each day.

01:05:11.300 | There is a recent study published in Cell

01:05:14.060 | showing that the ingestion of fermented foods,

01:05:16.680 | two to four servings each day,

01:05:19.140 | can enhance the quality of the mucosal lining of the gut

01:05:24.880 | that allows certain gut microbiota to flourish

01:05:28.380 | and the gut microbiota that are not good for us

01:05:31.120 | to not flourish 'cause that's the environment

01:05:32.720 | that they settle down into.

01:05:33.880 | This is work that was carried out by my colleagues,

01:05:36.880 | Justin Sonnenberg, which is in the laboratory upstairs

01:05:40.140 | for me, as well as Chris Gardner and others at Stanford.

01:05:43.640 | They're certainly not the only researchers exploring this,

01:05:46.900 | but it does appear that two to four servings

01:05:49.360 | of fermented foods each day,

01:05:52.240 | so these would be things like natto, sauerkraut,

01:05:55.240 | low sugar fermented foods is great for the gut microbiome,

01:05:59.380 | and separate studies, not their study,

01:06:01.440 | but separate studies have shown that the correct gut

01:06:04.280 | microbiome conditions allow these neurons

01:06:06.680 | that signal to the brain to signal at the right times

01:06:10.320 | and in the right ways to promote healthy food seeking.

01:06:13.660 | Many people opt to supplement with capsule form probiotics.

01:06:18.440 | There are some data that suggest that maybe

01:06:21.780 | those don't contain the correct prebiotics and probiotics

01:06:25.360 | for setting the correct gut microbiota conditions.

01:06:28.900 | That's a little bit of a controversial issue.

01:06:31.660 | Nonetheless, getting probiotics from fermented foods

01:06:36.280 | is probably the simplest and most straightforward way.

01:06:38.440 | It's also the way that we evolved to do that over many,

01:06:41.660 | at least hundreds and probably thousands

01:06:43.260 | or even tens or hundreds of thousands of years

01:06:45.140 | people have been ingesting fermented foods,

01:06:47.320 | not just for their taste,

01:06:48.220 | but for their health benefits as well.

01:06:50.500 | So now I've mentioned two of the three mechanisms

01:06:53.420 | by which we prefer certain foods.

01:06:55.900 | One is from the actual taste that we're familiar with,

01:06:58.900 | the taste on our tongue and in our mouth

01:07:00.780 | and the sensations that make us go mm or uh or eh,

01:07:05.260 | the yum yuck meh responses, as I referred to them earlier.

01:07:08.340 | And then there's this subconscious signaling

01:07:10.340 | coming from the gut that's really based

01:07:11.740 | on the nutrient content of the foods.

01:07:13.720 | There's a third pathway,

01:07:17.500 | which is the learned association of a particular taste

01:07:21.520 | with the particular quality or value that a food has.

01:07:25.920 | And this is where things get really interesting

01:07:29.000 | and where there's actually a leverage point

01:07:31.120 | for you to rewire what it is that you find tasty

01:07:35.820 | and that you want to seek more of.

01:07:37.640 | The work I'd like to talk about next

01:07:39.020 | has been carried out in mouse models

01:07:41.440 | and has been carried out in parallel experiments in humans.

01:07:46.280 | This is largely, not exclusively,

01:07:48.360 | but largely the work of Ivan de Araujo and Dana Small.

01:07:53.360 | Ivan de Araujo is at Mount Sinai School of Medicine

01:07:58.700 | and Dana Small is at Yale.

01:08:00.900 | And they and others in their field

01:08:02.780 | have done incredible experiments

01:08:04.860 | exploring how taste and food value,

01:08:08.280 | the nutritional value of food

01:08:10.340 | and the impact of that food on metabolism in the brain

01:08:15.120 | drives our food choices and allows us to change

01:08:18.380 | our food choices for the better.

01:08:20.240 | Their groups have done some really amazing studies

01:08:23.160 | involving ingestion of a particular substance

01:08:26.800 | that either contains sugar

01:08:28.980 | and thereby can elevate glucose, blood sugar or not.

01:08:33.900 | And varying, meaning changing the taste

01:08:37.240 | associated with that ingestion of sugar.

01:08:41.120 | So let me just give you a simple example

01:08:43.280 | where they have subjects,

01:08:45.800 | these could be mice or these could be humans

01:08:47.420 | 'cause they've done both sets of studies,

01:08:50.280 | drink sweet water as an alternative or a choice

01:08:55.280 | to non-sweetened water or bitter water or some other flavor.

01:08:59.600 | What they find is that mice and humans

01:09:01.620 | will prefer to consume the sweet beverage.

01:09:05.080 | Now it's not always sweet water.

01:09:06.500 | Mice like sweet water, but humans will prefer,

01:09:09.920 | for instance, a milkshake, a fatty sweet drink.

01:09:13.720 | They'll consume more of that and not surprisingly,

01:09:18.120 | dopamine levels in the brain increase in response to that.

01:09:21.740 | So the taste and the nutrient content

01:09:26.640 | of what it is that they're ingesting are aligned,

01:09:29.640 | they are matched.

01:09:30.600 | They've also done experiments where they have no taste,

01:09:36.300 | but subjects are being infused with sugar

01:09:39.220 | directly into the gut and not surprisingly,

01:09:43.040 | based on everything I've told you up until now,

01:09:46.120 | subjects will pursue more of that thing

01:09:48.940 | relative to some other taste,

01:09:51.600 | either neutral or negative taste,

01:09:54.200 | because that sugar in the gut

01:09:56.440 | is triggering the activation of the neurons

01:09:58.160 | I mentioned earlier, which is signaling to the brain

01:10:00.060 | to pursue more of that thing.

01:10:01.920 | So this tells us something important.

01:10:03.480 | It tells us that we are driven,

01:10:06.060 | meaning we have mechanisms in our brain

01:10:08.180 | that make us motivated to pursue

01:10:10.120 | more of what brings both a taste of sweetness,

01:10:13.360 | but also that brings actual changes

01:10:15.680 | in blood glucose levels up.

01:10:18.720 | So we are motivated to eat sweet things,

01:10:20.560 | not just because they taste good,

01:10:22.040 | but because they change our blood sugar level,

01:10:24.840 | they increase our blood sugar level.

01:10:26.960 | This is important because it needn't be the case.

01:10:29.440 | It could have been that we were just wired

01:10:31.400 | to pursue things that taste good.

01:10:34.300 | But what this tells us is that we are actually wired

01:10:37.200 | to pursue things that increase our blood glucose.

01:10:40.280 | So much so that when the small lab,

01:10:46.440 | it's not a small lab, it's actually a big lab,

01:10:48.200 | but when Dana Small's lab and/or Ivan de Araujo's lab

01:10:52.440 | have done experiments where they use a compound

01:10:56.560 | called 2-deoxyglucose.

01:10:58.280 | This is a compound that can prevent glucose

01:11:01.660 | from being metabolized by neurons.

01:11:03.940 | So blood glucose is going up, but neurons can't use it.

01:11:06.960 | What they find is that the reinforcing

01:11:09.040 | or the rewarding properties of a food or taste

01:11:12.920 | are eliminated.

01:11:14.320 | Put simply, it is not sufficient

01:11:17.080 | for a food to taste good consciously.

01:11:20.320 | It is not sufficient for a food to increase blood sugar.

01:11:24.700 | You need blood sugar to go up and that blood sugar,

01:11:29.200 | glucose has to be utilized by the neurons,

01:11:32.840 | even if it's not associated with a good taste

01:11:36.360 | and to make it even simpler, if this isn't sinking in,

01:11:39.880 | this should make it very clear.

01:11:41.580 | What your brain, meaning what you are seeking when you eat

01:11:45.920 | is not taste, is not dopamine,

01:11:49.160 | is not even a rise in blood glucose.

01:11:51.620 | What you're seeking, even though you don't realize it

01:11:54.200 | because it's subconscious, is you are seeking things

01:11:57.300 | that allow your neurons to be metabolically active.

01:12:00.880 | And this is fundamentally important for understanding

01:12:04.520 | why you eat particular foods

01:12:08.960 | and how you can change your relationship to those foods.

01:12:11.840 | Now, earlier, I referred to circuits that are wired

01:12:15.000 | for a particular outcome.

01:12:16.840 | And in biology and in particular neuroscience,

01:12:19.100 | we refer to things that are either hardwired,

01:12:22.000 | meaning immutable and unchangeable, or softwired.

01:12:25.140 | A good example of soft wiring would be the areas

01:12:28.820 | of your brain that are responsible for speech and language

01:12:33.240 | are always more or less in the same place in your brain

01:12:37.520 | and everyone else's brain.

01:12:39.440 | However, they are not hardwired to speak French

01:12:43.400 | or to speak English or to speak Chinese or to speak German,

01:12:46.760 | because depending on where you were born

01:12:48.600 | and the parents that you're born to,

01:12:50.600 | you need to be able to speak one

01:12:52.280 | or maybe even more languages.

01:12:54.780 | The taste system and this general system

01:12:57.580 | of seeking particular foods similarly is hardwired

01:13:01.600 | to obtain certain types of nutrients.

01:13:04.160 | It tends to like sweet things.

01:13:05.680 | Most children naturally like sweet things,

01:13:07.520 | some more than others,

01:13:08.840 | but naturally most people from childhood onward

01:13:12.440 | don't particularly crave very bitter substances,

01:13:15.100 | maybe mildly bitter, but not very bitter.

01:13:17.320 | So there's some hard wiring of preference,

01:13:19.640 | but there's also some soft wiring in the system

01:13:22.260 | that allows it to change.

01:13:23.620 | The groups I mentioned earlier

01:13:26.200 | have done some really beautiful experiments

01:13:28.160 | looking at how artificial sweeteners interact

01:13:31.760 | with the actual sweet sensing system.

01:13:34.440 | And this gets right down to a number of issues.

01:13:37.080 | First of all, it gets to the issue

01:13:38.960 | of how we can rewire our taste system

01:13:42.180 | in ways that serve us for better or for worse.

01:13:44.880 | Second of all, it gets right down to the issue

01:13:47.480 | of whether or not artificial sweeteners are good for us

01:13:50.240 | or bad for us.

01:13:51.480 | And indeed, as of just this last year,

01:13:54.680 | we now have an answer to that question.

01:13:57.980 | And turns out it depends.

01:14:00.020 | And I will tell you in a few minutes

01:14:02.460 | when it is okay to ingest artificial sweeteners

01:14:06.120 | and when it is very detrimental

01:14:07.960 | to ingest artificial sweeteners of any kind.

01:14:10.340 | Regardless, I'm not going to name off brand names,

01:14:13.080 | but there are different forms

01:14:14.180 | of these artificial sweeteners nowadays.

01:14:16.940 | And there are various forms

01:14:18.560 | of non-caloric plant-based sweeteners

01:14:21.200 | for which the same information

01:14:22.640 | that I'm about to tell you applies.

01:14:24.920 | Okay, so the experiments that were done

01:14:27.860 | beautifully illustrate that you seek out particular foods

01:14:31.340 | because of the way they taste,

01:14:33.260 | because of their impact on blood glucose levels,

01:14:36.340 | but also on their impact on the dopamine system,

01:14:40.560 | even if your blood glucose levels don't change.

01:14:43.200 | So here's the experiment.

01:14:45.460 | One group of subjects is given a sweet taste

01:14:47.840 | of a substance that also raises blood glucose levels,

01:14:50.280 | blood sugar, and dopamine goes up, not surprisingly.

01:14:53.640 | Second condition, separate subjects,

01:14:57.120 | consume an artificial sweetener or a non-caloric sweetener.

01:15:01.180 | It is not preferred much over other substances,

01:15:04.580 | but it is sweet, so it's preferred somewhat,

01:15:07.560 | and it does not cause an increase in blood glucose levels.

01:15:10.720 | And not surprisingly, dopamine levels don't go up.

01:15:15.360 | So initially, we don't tend to like

01:15:17.360 | artificial sweeteners that much.

01:15:18.660 | That's the simple way of putting it.

01:15:20.060 | However, if subjects continue

01:15:22.780 | to ingest artificial sweeteners,

01:15:25.540 | even though there's no increase in blood glucose level

01:15:27.660 | and therefore no increase in brain metabolism,

01:15:29.960 | dopamine levels eventually start to rise.

01:15:34.340 | And when those dopamine levels eventually start to rise,

01:15:37.520 | you've essentially conditioned or reinforced

01:15:40.020 | that artificial or non-caloric sweetener,

01:15:43.900 | and then subjects start to consume more of it,

01:15:45.840 | and they actually get a dopamine increase from it.

01:15:48.660 | So that's interesting.

01:15:50.380 | It says that consuming more of these artificial sweeteners

01:15:52.780 | or consuming them for a longer period of time

01:15:55.100 | can start to tap into the dopamine system

01:15:56.980 | and lead us to seek out

01:15:58.100 | or consume more of these artificial sweeteners.

01:15:59.860 | Many people are probably familiar with this

01:16:02.000 | because we tend to, or I should say people report

01:16:06.060 | that when they ingest these artificial sweeteners,

01:16:08.100 | at first, they don't taste very good,

01:16:09.280 | but then over time, they seem kind of tolerable,

01:16:11.400 | and then maybe even pleasurable,

01:16:12.540 | and then some people feel quote unquote addicted

01:16:14.980 | to various diet sodas and things of that sort.

01:16:17.980 | Now, there's another condition that's been explored,

01:16:21.900 | and that's the really interesting condition.

01:16:23.780 | And it's the condition where an artificial sweetener

01:16:26.700 | is paired with a substance that can increase blood sugar,

01:16:31.240 | but not because it tastes sugary

01:16:33.700 | like a normal sweet substance.

01:16:34.940 | So now there's an artificial sweetener

01:16:37.780 | that's coupled with an actual increase in blood glucose.

01:16:42.060 | The natural world scenario where this would happen

01:16:45.140 | would be drinking a diet soda, which contains no calories

01:16:48.520 | and therefore would not increase blood glucose,

01:16:50.220 | but is sweet with a food that increases blood glucose.

01:16:54.620 | And when that happens, what you're essentially doing

01:16:58.300 | is tapping into the dopamine system.

01:17:00.020 | This non-chloric sweet taste is paired with it,

01:17:03.980 | and there's an increase in neuron metabolism.

01:17:07.540 | So you have all of the components for reinforcement.

01:17:10.420 | And as a consequence, you get in a sort of Pavlovian

01:17:14.020 | conditioning way, a situation where later

01:17:17.780 | when you ingest that artificial sweetener,

01:17:20.620 | you actually get not only the increase in dopamine,

01:17:23.740 | but you get alterations in blood sugar management.

01:17:27.260 | Now, blood sugar cannot go up if you don't ingest something

01:17:31.440 | that makes blood sugar go up.

01:17:32.600 | So it's not as if you ingest artificial sweetener

01:17:35.140 | with some food that contains calories or sugar,

01:17:38.380 | and then later you remove the food

01:17:40.380 | and you just drink the soda and your blood glucose goes up.

01:17:44.300 | Rather, it's a much worse situation.

01:17:47.640 | If you, I'll make this in the natural world context,

01:17:51.780 | if you ingest an artificial sweetener,

01:17:53.420 | say drink diet soda while consuming foods

01:17:56.940 | that increase blood glucose, then later,

01:18:01.300 | even if you just drink the diet soda,

01:18:04.140 | it's been shown that you secrete much more insulin,

01:18:08.100 | the hormone that regulates blood glucose

01:18:10.980 | in response to that diet soda.

01:18:13.140 | Studies have been done in both adult humans

01:18:16.100 | and in human children.

01:18:17.660 | In general, when we say children, we mean human children,

01:18:19.700 | but just to be very clear what we're talking about,

01:18:22.460 | exploring consuming diet soda with or without food,

01:18:25.700 | then later consuming just the diet soda.

01:18:28.780 | And what they found was having previously consumed

01:18:31.960 | diet soda with food and then later only consuming

01:18:34.700 | the diet soda, of course, there isn't an increase

01:18:38.020 | in blood glucose because they're not bringing in

01:18:40.000 | any calories when they just drink the diet soda,

01:18:42.480 | but there is a significant increase in insulin release.

01:18:46.940 | And that is serious in a terrible way

01:18:50.340 | because increased release of insulin

01:18:52.300 | and so-called insulin sensitivity

01:18:54.220 | is the basis for type 2 diabetes.

01:18:56.780 | So much so that in the study with the children,

01:19:00.280 | consuming non-caloric beverages in this way,

01:19:04.020 | first with food and then on their own,

01:19:07.040 | led to increases in insulin that made them pre-diabetic

01:19:10.140 | and they actually had to halt the study.

01:19:12.260 | So I want to zoom out from this

01:19:14.620 | and just really illustrate the major findings

01:19:16.780 | and then talk about how this can be applied

01:19:18.900 | in the positive sense.

01:19:19.740 | I also want to mention what this means

01:19:21.340 | in terms of your consumption of artificial sweeteners

01:19:24.140 | of any kind.

01:19:25.460 | So first of all, the direct takeaway

01:19:27.480 | about artificial sweeteners.

01:19:29.880 | Artificial sweeteners are not bad for you.

01:19:32.580 | I'm not going to say that.

01:19:34.260 | What I am going to say is that whether or not

01:19:36.000 | you ingest them alone or you ingest them

01:19:39.080 | in combination with foods or as part of foods,

01:19:42.180 | that raise blood glucose is vitally important

01:19:45.340 | for your insulin management.

01:19:46.980 | And the simple extract or tool from this

01:19:50.300 | is if you are going to consume artificial sweeteners,

01:19:53.620 | it's very likely best to consume those

01:19:56.480 | away from any food that raises blood glucose levels.

01:20:00.620 | So if you're going to enjoy diet soda, be my guest,

01:20:04.180 | but do it not while consuming food,

01:20:07.140 | in particular foods that raise blood glucose,

01:20:09.420 | because what these studies show,

01:20:11.160 | and I will provide references for these,

01:20:13.080 | is that they can vastly disrupt blood sugar management

01:20:18.060 | by way of the insulin glucose system, okay?

01:20:20.820 | And actually I'll just give you the reference now.

01:20:22.780 | This is a paper from Dana Small's lab.

01:20:25.420 | The first author is Dalenberg, D-A-L-E-N-B-E-R-G.

01:20:30.100 | And the title of the paper is short-term consumption

01:20:32.660 | of sucralose with, but not without carbohydrate,

01:20:34.900 | impairs neural and metabolic sensitivity to sugar in humans.

01:20:39.720 | This is a paper published in Cell Metabolism

01:20:41.540 | in March of 2020.

01:20:42.780 | I think it's a very important paper

01:20:44.940 | and similar findings have been addressed in mice

01:20:48.420 | and in other studies.

01:20:49.260 | And now because of this paper,

01:20:50.540 | there's now a bunch of other groups working on this issue.

01:20:54.920 | There's some evidence previously published in Nature,

01:20:58.820 | excellent top tier journal among the Super Bowl

01:21:02.620 | of top three journals being Nature Science and Cell.

01:21:05.740 | Paper published in Nature a few years back

01:21:07.820 | showing that particular artificial sweeteners

01:21:10.960 | can disrupt the gut microbiome

01:21:12.720 | and have deleterious health effects.

01:21:14.520 | That result I think stands,

01:21:17.160 | although there are some results that may not agree

01:21:20.660 | with that depending on whether or not

01:21:21.900 | the artificial sweetener is saccharin or sucralose

01:21:24.040 | or aspartame or stevia, that's the gut microbiome.

01:21:27.620 | But what we are talking about here is independent

01:21:30.720 | of the form of artificial or non-chloric sweetener

01:21:33.280 | because it has everything to do with whether or not

01:21:35.000 | there is a match or a mismatch between the perceived taste

01:21:39.120 | and the effect of the thing that you are consuming

01:21:42.640 | on blood sugar and metabolism.

01:21:45.240 | So the first takeaway from this is

01:21:48.920 | if you're going to consume artificial sweeteners,

01:21:51.760 | it's really important that you do that

01:21:53.500 | not in conjunction with foods that increase blood glucose.

01:21:57.660 | Second of all, it points to the fact

01:22:00.140 | that the foods that we prefer

01:22:02.940 | and the activation of the dopamine system

01:22:05.700 | both through the gut and at the level of conscious taste,

01:22:11.300 | in other words, what we like is very plastic,

01:22:15.000 | it's mutable and we can change it.

01:22:17.440 | How can we change it?

01:22:18.620 | Well, earlier I mentioned a structure in the brain

01:22:22.300 | called the insula, this incredible structure

01:22:24.480 | that's involved in interoception

01:22:26.760 | and interoception of all kinds.

01:22:28.120 | In fact, just as an aside, a year or so ago,

01:22:31.900 | my lab published a paper showing that

01:22:34.300 | activity within certain compartments of the insula of humans

01:22:39.300 | is responding to a heightened state of anxiety in the body.

01:22:44.160 | It can respond to changes in our respiration,

01:22:46.600 | changes in our heart rate.

01:22:47.720 | So this is, again, it's a readout of our internal state,

01:22:51.160 | not just of taste, but of many, many different aspects

01:22:54.460 | of the mechanics and chemistry of our internal milieu

01:22:58.600 | within our body.

01:23:00.280 | All of the work that I was describing previously

01:23:02.620 | has also been addressed at the neural level

01:23:06.460 | and using a broad brush to explain these results,

01:23:09.660 | what we can say is when there is dopamine increase,

01:23:14.420 | one sees activation of the so-called nucleus accumbens,

01:23:19.020 | which is part of the so-called mesolimbic reward pathway.

01:23:22.360 | If you'd like to learn more about

01:23:23.560 | the mesolimbic reward pathway and dopamine in general

01:23:27.380 | and humans and in animal studies and all the various

01:23:30.840 | incredible and challenging things

01:23:34.080 | that dopamine can do for us,

01:23:35.940 | there's a episode all about dopamine that you can look up.

01:23:39.000 | It's easy to find at hubermanlab.com.

01:23:41.700 | The increases in dopamine associated with sweet taste

01:23:45.700 | and or blood glucose elevating foods and drinks

01:23:49.560 | cause activation of the nucleus accumbens.

01:23:52.720 | That's not surprising.

01:23:54.520 | Also in the circuit is activation

01:23:56.740 | of the so-called arcuate nuclei within the hypothalamus.

01:23:59.880 | These are areas of the hypothalamus

01:24:01.520 | that respond to hormones from the body

01:24:03.440 | and respond to hormones and neuropeptides in the brain,

01:24:06.920 | as well as neural signals in the brain

01:24:09.180 | to drive us to eat more or to stop eating.

01:24:12.340 | So it's hypothalamus, nucleus accumbens.

01:24:14.840 | These are sort of the hypothalamus

01:24:17.160 | and the arcuate being the motivating to eat

01:24:20.440 | or motivating to stop eating.

01:24:22.740 | Both sets of neurons are contained there.

01:24:25.320 | There are other areas like the lateral hypothalamus as well,

01:24:27.480 | but hypothalamus is sort of the accelerator

01:24:29.160 | and the brake on eating.

01:24:30.300 | And then the nucleus accumbens and dopamine release

01:24:33.100 | can be thought of as kind of a nitro boost, if you will,

01:24:37.820 | like the kids say, do the kids say that anymore?

01:24:39.440 | Anyway, a nitro boost to increase what we call the gain

01:24:43.900 | or the volume of how much you want more of something, okay?

01:24:47.800 | When dopamine is present, it's this kind of generic signal

01:24:50.840 | to go seek out more of whatever caused that release.

01:24:54.280 | And then there's the insula,

01:24:55.920 | this very thoughtful, rational, not really,

01:24:58.800 | it's not thinking, it's a brain area you're thinking,

01:25:00.800 | but it's part of the areas of your brain

01:25:02.420 | that are interpreting what's going on in your body,

01:25:05.360 | whether or not you feel good or not good,

01:25:06.900 | whether or not you feel anxious, excited, or fearful.

01:25:11.680 | It's integrating all that information

01:25:14.320 | and fed into this entire circuit as well

01:25:18.340 | are the inputs from your prefrontal cortex,

01:25:20.520 | which is your thinking, rational, neuronal structure,

01:25:24.400 | if you will, informing you, for instance,

01:25:27.680 | ah, well, I don't really like salmon very much,

01:25:31.580 | or I'm not so crazy about kale, but it has omega-3s,

01:25:36.580 | or it's rich in these polyphenols that are good for me.

01:25:41.520 | And if one decides that they are going to eat these things,

01:25:46.180 | not just because they are good for them,

01:25:48.320 | but believe it or not, if one takes the perception

01:25:52.840 | or adopts the perception that they are both good for you

01:25:56.060 | and that in being good for you,

01:25:59.540 | they are good for your brain metabolism

01:26:01.380 | and that you desire to be healthy, as crazy as it sounds,

01:26:06.380 | those subjective signals of what you tell yourself

01:26:09.880 | about the foods that you're eating

01:26:11.700 | can actually impact how those foods will taste,

01:26:16.120 | maybe not immediately, but eventually,

01:26:18.120 | and can impact the way in which

01:26:20.020 | your body utilizes those foods.

01:26:22.320 | Now, that might seem like a absolute pipe dream.

01:26:25.520 | If I just imagine that I like mackerel,

01:26:27.640 | mackerel will start to taste good.

01:26:29.080 | I'm not saying that.

01:26:30.000 | I didn't say that you could override yuck signals

01:26:34.160 | with this mechanism.

01:26:36.280 | I didn't say that you could take a food

01:26:38.560 | that would be absolutely noxious to you

01:26:41.420 | or make you want to vomit and override that.

01:26:43.320 | However, foods that are somewhat neutral to you

01:26:47.720 | can take on a different value

01:26:51.440 | based on the activation of the dopamine system.

01:26:54.360 | And now knowing what you know,

01:26:56.360 | there are a couple of ways that you could imagine doing that.

01:26:58.880 | First of all, you could,

01:27:01.360 | in this so-called gedanken or thought experiment,

01:27:03.920 | you could, for instance, swap out sucralose,

01:27:07.520 | because sucralose is just a taste, right?

01:27:09.600 | It's an artificial sweet taste.

01:27:11.460 | You could swap that out and insert kale,

01:27:15.380 | but eat the kale with something that raises blood glucose

01:27:19.780 | to some degree or another.

01:27:20.980 | Now, I'm not encouraging anyone to run out there

01:27:23.140 | and spike their blood glucose like crazy.

01:27:25.660 | And in fact, blood glucose isn't really the goal.

01:27:29.060 | If you recall, the goal is to get neurons

01:27:31.900 | to be metabolically active with that blood glucose, okay?

01:27:35.180 | That's what's actually rewarded at a subconscious level,

01:27:38.300 | meaning at a deep subconscious level.

01:27:40.980 | But consuming these foods with other foods

01:27:44.140 | that increase blood glucose and thereby brain metabolism,

01:27:47.380 | or I suppose if you're ketogenic, you're in a ketosis,

01:27:51.800 | I don't know what the range of foods

01:27:53.900 | that are allowed on ketosis are,

01:27:55.180 | so I don't want to misspeak here and, you know,

01:27:57.340 | say cracker, which would probably be a sin

01:27:59.560 | in the context of ketosis, and no knock against ketosis.

01:28:02.420 | I'm offering this in part because I think

01:28:04.980 | that there are a number of people that have

01:28:07.020 | and can positively benefit from a ketogenic diet.

01:28:10.260 | But for instance,

01:28:11.100 | if there's a food that you want to consume more of,

01:28:14.220 | but that you find somewhat meh or mildly yuck even,

01:28:18.880 | pairing it with ketones, if indeed you are using ketones

01:28:24.060 | for your brain metabolism,

01:28:25.860 | 'cause that's what happens on the ketogenic diet,

01:28:27.960 | over time, that food will be reinforced

01:28:31.280 | by the dopamine pathway.

01:28:32.260 | We know this from these studies where sucralose

01:28:34.780 | was the substance paired with the glucose elevating,

01:28:38.940 | in other words, metabolically elevating food substance

01:28:42.960 | or liquid substance.

01:28:44.780 | So how does one go about doing this?

01:28:46.980 | Well, first of all, I want to emphasize

01:28:50.220 | that this experiment actually has been done

01:28:52.820 | in a slightly different context.

01:28:54.580 | Studies by my colleague, Alia Crum,

01:28:58.780 | in the psychology department at Stanford,

01:29:01.220 | have explored the bodily response

01:29:04.620 | in terms of insulin release and the release of other food

01:29:08.020 | and eating related hormones,

01:29:09.880 | as well as overall feelings of satisfaction, et cetera,

01:29:14.980 | in groups of people that drink a milkshake

01:29:19.640 | and are either told that it's a low calorie shake

01:29:22.280 | that contains various nutrients that are good for them,

01:29:25.540 | or a higher calorie shake that has a lot of nutrients,

01:29:29.400 | et cetera.

01:29:30.980 | And what they found was that the different groups,

01:29:33.800 | and here, again, I'm being very general

01:29:35.620 | with my description of these studies,

01:29:37.340 | but what they found is that the physiological response,

01:29:40.980 | the insulin response, the blood glucose response,

01:29:43.420 | and the subjective measures

01:29:45.560 | of whether or not people enjoyed something or not

01:29:48.100 | were heavily influenced by what they were told

01:29:50.580 | were in these milkshakes.

01:29:52.020 | So blood glucose would go up, insulin would go up

01:29:54.240 | when people were told it was a high calorie shake

01:29:56.200 | with lots of nutrients,

01:29:57.240 | less so when people ingested a shake

01:29:59.260 | that they were told had less nutrients and so forth,

01:30:05.300 | when in reality, it was the identical shake.

01:30:09.660 | This is incredible.

01:30:10.500 | This is a belief effect.

01:30:11.800 | This is not placebo, right?

01:30:13.520 | A placebo effect is different.

01:30:15.100 | Placebo effect is in comparison.

01:30:16.860 | It's where the control condition

01:30:18.140 | actually influences outcomes to a same or to some degree,

01:30:23.140 | just like the experimental condition.

01:30:26.500 | This is not a placebo effect.

01:30:27.700 | This is a belief effect where the belief

01:30:30.700 | and the subjective thoughts about what a given food will do

01:30:35.220 | has a direct impact on a physiological measure

01:30:38.300 | like blood sugar and blood glucose, okay?

01:30:40.980 | So let's zoom out from this for a second

01:30:43.060 | and think about how we can incorporate this

01:30:45.740 | into adopting consumption of healthy foods

01:30:50.100 | that serve our brain health in the immediate and long-term.

01:30:53.660 | And if you're wondering what those are,

01:30:54.860 | I listed them out at the beginning of the episode

01:30:56.780 | and their justification for being on that list.

01:30:59.140 | What this means is obviously you want to consume foods

01:31:03.980 | that you like, but because brain health is very important

01:31:07.700 | and many of the foods that promote brain health

01:31:10.580 | perhaps are not the most palatable to you

01:31:13.980 | or desirable to you,

01:31:16.060 | the key would be to ingest the foods

01:31:19.340 | that you want to ingest more of

01:31:21.380 | simply because they're good for you

01:31:23.320 | and not because they taste good to you

01:31:25.180 | alongside foods that increase whatever fuel system

01:31:29.980 | you happen to be relying on.

01:31:31.380 | I think that's the most nutritionally politically correct

01:31:34.300 | way to say it.

01:31:35.140 | So if you're keto, that would mean ketones, okay?

01:31:37.640 | If you're not ketogenic,

01:31:39.220 | and I think most people probably are not in ketosis

01:31:41.560 | or trying to maintain ketosis,

01:31:43.340 | but for instance, people that are on a purely

01:31:45.220 | plant-based diet, that would be one set of foods.

01:31:47.100 | For people that are omnivores, a different set of foods.

01:31:49.420 | And for people that are carnivores,

01:31:50.800 | yet another set of foods.

01:31:52.080 | If you want to eat more of a particular food

01:31:55.060 | because it's good for you,

01:31:55.980 | pair it with something in the same meal.

01:31:58.500 | You don't have to hide it physically or in the flavor sense.

01:32:02.360 | You don't have to hide it within that other food,

01:32:04.220 | but pair it with that other food

01:32:06.300 | that provides you a shift in brain metabolism,

01:32:09.860 | because that's really what your brain and you are seeking

01:32:13.040 | even though you don't realize it.

01:32:14.800 | How long will this take?

01:32:16.180 | Well, according to the data in humans on sucralose

01:32:19.940 | and the conditioning for sucralose to have these effects,

01:32:23.920 | which in many cases were detrimental, right?

01:32:26.740 | Because they were increasing insulin.

01:32:28.380 | But in this case,

01:32:29.460 | you're trying to hijack this conditioning of food preference

01:32:33.620 | for healthy purposes, not with sucralose,

01:32:36.820 | but by ingesting things that are good for you.

01:32:39.160 | Then the data really points to the fact

01:32:41.940 | that even within a short period of time of about seven days,

01:32:44.900 | but certainly within 14 days,

01:32:47.080 | that food will take on a subjective experience

01:32:50.620 | of tasting at least better to you, if not good to you.

01:32:54.900 | Now, I believe this has important implications

01:32:57.440 | for much of the controversy and food wars

01:33:00.600 | that we see out there.

01:33:02.040 | Food wars being, of course,

01:33:04.180 | these groups that ardently subscribe to the idea

01:33:08.960 | that their diet and the things that they are eating

01:33:12.280 | are the foods that are good for us

01:33:13.900 | and that are the most pleasureful

01:33:15.580 | and the things that everyone should be eating.

01:33:18.500 | We see this with every community within the nutrition realm.

01:33:23.120 | Now, of course, there are studies that point to the fact

01:33:25.960 | that certain foods and food components are healthier

01:33:28.940 | probably for us and for the planet,

01:33:31.080 | but you really see it on both ends of the spectrum.

01:33:32.940 | You've got people who are on a pure carnivore diet

01:33:34.900 | who are arguing with a lot of biomedical evidence

01:33:37.700 | that that's what's best for us and beneficial.

01:33:40.380 | And then you've got people

01:33:41.220 | that are arguing the same general sets of arguments,

01:33:44.060 | but for a purely plant-based diet.

01:33:45.600 | And then I think most people fall

01:33:46.780 | into the omnivore category.

01:33:48.340 | What's very clear, however,

01:33:51.880 | is that what we consume on a regular basis

01:33:55.460 | and what leads to increases in brain metabolism

01:33:59.600 | leads to increases in dopamine

01:34:01.640 | and thereby our motivation to eat them.

01:34:04.400 | So what this really says is that what we tend to do regularly

01:34:08.560 | becomes reinforcing in and of itself.

01:34:11.240 | And I think in large part can explain the fact that,

01:34:14.140 | yes, indeed, for certain people,

01:34:15.960 | a given diet not only feels good,

01:34:18.660 | but they heavily subscribe to the nutrient

01:34:21.380 | and kind of health beneficial effects of that diet.

01:34:24.700 | And they often will provide evidence for that,

01:34:27.240 | whether or not you ask them for it or not.

01:34:29.660 | But that's true of every subcategory

01:34:32.020 | within the nutrition realm.

01:34:34.420 | Again, this is not to take away

01:34:36.740 | from some of the beautiful data emphasizing

01:34:39.260 | that certain foods and micronutrients, et cetera,

01:34:42.500 | are better for us or worse for us and for the planet.

01:34:45.540 | That's not a debate I want to get into right now.

01:34:47.380 | What this emphasizes is that foods impact our brain

01:34:52.820 | and its health, but they also impact

01:34:56.140 | how our brain functions and responds to food.

01:34:59.700 | And that is largely a learned response.

01:35:02.580 | We can't completely override, for instance,

01:35:05.460 | that certain foods evoke a strong yuck component.

01:35:09.460 | Certain foods are truly putrid to us.

01:35:11.660 | I should just say certain things are putrid to us

01:35:13.540 | and we should not consume them, right?

01:35:15.280 | And that's at the far end of the spectrum,

01:35:17.860 | it's hardwired for us to avoid those

01:35:19.860 | because they can be dangerous for us.

01:35:21.940 | They can make us very, very sick.

01:35:24.120 | But it's also true that if we continue to eat foods

01:35:27.700 | that are progressively sweeter and sweeter

01:35:29.500 | and highly palatable, it shifts our dopamine system

01:35:32.740 | because it activates our dopamine system

01:35:34.940 | to make us believe that those foods are the only foods

01:35:37.620 | that can trigger this reward system

01:35:39.920 | and make us feel good and that they taste good.

01:35:42.140 | But after consuming foods that perhaps are less sweet

01:35:46.020 | or even less savory that are not what we would call highly,

01:35:49.860 | or I would say nowadays it's super palatable foods,

01:35:52.280 | we can adjust our sense literally of what we perceive

01:35:57.280 | as an attractive and rewarding food.

01:35:59.780 | And indeed the dopamine system

01:36:01.600 | will reward those foods accordingly.

01:36:04.260 | I can't emphasize enough how much this learning

01:36:07.420 | of associated food reward is important

01:36:10.960 | for not just understanding why we like the foods that we eat

01:36:14.540 | and how to eat more of foods that are healthy for us

01:36:17.380 | and enjoy them, but it also speaks to the fact

01:36:21.660 | that our brain as a whole is a perceptual device

01:36:25.500 | trying to make guesses or estimations

01:36:27.720 | about what certain foods are going to do for us.

01:36:30.420 | So put simply, we don't just like sweet foods

01:36:33.180 | because they taste good.

01:36:34.020 | We like them because they predict

01:36:35.280 | a certain kind of metabolic response.

01:36:37.180 | This is important also because Dana Small

01:36:41.960 | and Ivan de Araujo and others have been exploring

01:36:45.520 | whether or not people, for instance,

01:36:47.440 | that have type 2 diabetes or that suffer

01:36:50.380 | from any number of different metabolic disorders,

01:36:52.320 | whether or not somehow these food reward systems

01:36:54.800 | are permanently disrupted.

01:36:56.600 | And through a beautiful set of experiments

01:36:58.480 | that have been done mainly by Dana Small's group at Yale,

01:37:01.580 | but also by the de Araujo group and others,

01:37:05.760 | exploring how the reward pathways are altered

01:37:10.260 | in various metabolic disorders, et cetera,

01:37:12.760 | people suffering from type 2 diabetes.

01:37:16.060 | We don't have time to go into all those data now,

01:37:18.020 | but the takeaway is that food preference

01:37:21.260 | and the ability to reshape these circuits

01:37:23.740 | is not disrupted in these people

01:37:26.100 | to the point where it can't be rewired.

01:37:28.200 | And that's very encouraging because what it means is that

01:37:30.660 | for people that are suffering from these syndromes

01:37:33.300 | through some simple alterations in dietary choice,

01:37:36.780 | provided those are carried out over time

01:37:39.860 | and in the correct way by pairing with the foods

01:37:43.060 | that will appropriately shift metabolism of the brain,

01:37:46.440 | one can actually rewire what they consider

01:37:48.740 | not just palatable, but attractive as foods.

01:37:51.460 | If you want to learn more about food reward

01:37:55.560 | and food reinforcement,

01:37:56.780 | 'cause it turns out those are slightly different things,

01:37:59.100 | there's a wonderful review written by Ivan de Araujo.

01:38:02.940 | They have a middle author, Mark Shachter and Dana Small.

01:38:06.020 | It's called "Rethinking Food Reward,"

01:38:07.840 | and it was published in the Annual Reviews of Psychology.

01:38:10.780 | You can find it very easily online.

01:38:12.220 | It was published in 2019.

01:38:14.020 | And it's a beautiful deep dive,

01:38:16.240 | although quite accessible to most people,

01:38:18.460 | about how different foods and the way that we perceive them

01:38:22.540 | impacts our brain and body

01:38:24.000 | and why we like the things we like

01:38:25.760 | and how to reshape what we like.

01:38:28.020 | So once again, we've done a fairly extensive deep dive

01:38:31.100 | into food and your brain,

01:38:33.660 | focusing first on how particular foods

01:38:36.780 | and compounds within foods that are available

01:38:39.580 | also through supplementation

01:38:41.240 | can impact immediate and long-term brain health.

01:38:44.120 | Came up with a relatively short list

01:38:46.760 | of what I would call super foods,

01:38:48.760 | only because there are ample data to support their role

01:38:52.880 | in enhancing short and long-term cognition

01:38:55.260 | and neuronal health and so on.

01:38:57.280 | And we also talked about food preference

01:39:00.280 | and why particular tastes

01:39:02.300 | and particular events within the gut

01:39:04.260 | and particular events within the brain

01:39:06.420 | combine to lead us to pursue particular foods

01:39:10.900 | and to avoid other foods

01:39:12.660 | and how you can leverage those pathways

01:39:15.340 | in order to pursue more of the foods

01:39:17.140 | that are going to be good for you

01:39:18.660 | and good not just for your brain,

01:39:20.380 | but for your overall body health

01:39:22.140 | and to enjoy them along the way.

01:39:23.980 | If you're learning from and/or enjoying this podcast,

01:39:26.700 | please subscribe to our YouTube channel.

01:39:28.420 | That's a terrific zero-cost way to support us.

01:39:30.700 | In addition, please leave us suggestions for future topics

01:39:34.180 | and guests you would like us to host in the comment section

01:39:36.860 | on YouTube.

01:39:38.020 | As well, please subscribe to the Huberman Lab podcast

01:39:40.860 | on Apple and/or Spotify.

01:39:42.420 | And on Apple, you can leave us up to a five-star review.

01:39:45.980 | If you're not already following us on Instagram,

01:39:48.380 | we are Huberman Lab at Instagram.

01:39:50.580 | And there I do neuroscience tutorials

01:39:53.140 | that sometimes have overlap with the podcast,

01:39:55.200 | but often are original content altogether.

01:39:58.060 | We are also Huberman Lab on Twitter.

01:40:00.920 | Another terrific way to support us

01:40:02.480 | is by checking out our sponsors

01:40:04.000 | that we mentioned at the beginning of the episode.

01:40:05.940 | We also have a Patreon.

01:40:07.200 | It's patreon.com/andrewhuberman.

01:40:09.900 | And there you can support the podcast

01:40:11.680 | at any level that you like.

01:40:13.100 | During today's podcast and on many other previous episodes,

01:40:16.940 | we talked about various supplements.

01:40:18.800 | One of the major issues with supplements

01:40:20.980 | is that supplement companies

01:40:22.500 | don't always have the highest quality standards

01:40:24.760 | and/or the amounts of the supplements

01:40:27.260 | that they list on the bottle

01:40:28.380 | aren't what actually are contained

01:40:30.140 | in the capsules and pills and powders of those supplements.

01:40:33.060 | For that reason, we partner with Thorne, T-H-O-R-N-E,

01:40:35.860 | because Thorne has the highest levels of stringency

01:40:38.880 | with respect to the quality of the supplements they use

01:40:42.000 | and the quantity of the supplements they use.

01:40:44.360 | They've partnered with all the major sports teams

01:40:46.160 | and with the Mayo Clinic,

01:40:47.200 | and we have tremendous confidence

01:40:48.620 | in the quality of their supplements.

01:40:49.940 | If you'd like to see the supplements that I take,

01:40:52.140 | you can go to thorne, thorne.com/u/huberman.

01:40:57.140 | There, you can get 20% off any of those supplements.

01:41:00.820 | And if you navigate into the main site

01:41:03.300 | through that portal of thorne.com/u/huberman,

01:41:06.420 | you can also get 20% off

01:41:07.820 | any of the supplements that Thorne makes.

01:41:10.100 | And last but not least,

01:41:12.420 | thank you for your interest in science.

01:41:14.180 | [upbeat music]

01:41:16.760 | (upbeat music)

Nutrients For Brain Health & Performance | Huberman Lab Podcast #42

Chapters