How Foods and Nutrients Control Our Moods

0:00 - Welcome to the Huberman Lab Podcast

0:02 where we discuss science

0:03 and science-based tools for everyday life.

0:05 [upbeat music]

0:09 My name is Andrew Huberman,

0:10 and I'm a Professor of Neurobiology

0:12 and Ophthalmology at Stanford School of Medicine.

0:15 This podcast is separate

0:17 from my teaching and research roles at Stanford.

0:19 It is however, part of my desire and effort

0:21 to bring zero cost to consumer information about science

0:24 and science related tools to the general public.

0:27 In keeping with that theme

0:28 I'd like to thank the sponsors of today's podcast.

0:31 Our first sponsor today is Theragun.

0:33 Theragun is a handheld percussive therapy device

0:36 that releases deep muscle tension.

0:39 I was first introduced to Theragun in 2017

0:42 while on a laboratory expedition.

0:43 We were in the middle of the Pacific Ocean

0:45 filming great white sharks

0:46 for my laboratory studies on fear using virtual reality

0:50 we were working very hard around the clock

0:52 and I and other people on the trip were picking up a lot

0:55 of aches and pains and just kind of chronic soreness.

0:57 Couple of people had injuries that were flaring up

0:59 because of all the hard work and lack of sleep.

1:02 Someone had a Theragun

1:03 and pretty soon it was getting passed around.

1:05 It became the most coveted device on board.

1:07 Everyone was using it to work

1:08 on these different sites of soreness.

1:10 And I really fell in love with the thing so much

1:12 so that when I got back, I immediately purchased one

1:14 and I've used it almost daily ever since,

1:16 I use it on muscles that are sore,

1:20 I use it on areas that I'm really working on to

1:22 release tension and improve tissue quality and so forth.

1:26 The great thing about Theragun is it's really quiet

1:28 so you can use it while you're

1:29 in a conversation or while you're watching a movie

1:31 and it doesn't disrupt those activities at all.

1:34 If you want to try Theragun

1:35 you can try Theragun by going to theragun.com/huberman

1:41 to get your gen four Theragun, they start at $199.

1:45 But if you think about it, a massage, which is an hour long

1:48 or 90 minutes long is typically in that range of costs.

1:51 And this is something you can use every day

1:53 whenever you want, and even while enjoying other activities.

1:56 So that's theragun.com/huberman.

1:59 The second sponsor of today's podcast is InsideTracker.

2:02 InsideTracker is a personalized nutrition

2:04 platform that analyzes data from your blood

2:06 and DNA to help you better understand your body

2:09 and help you reach your health goals.

2:11 The great thing about InsideTracker

2:13 is that it gives you data that you can make sense of.

2:15 I've long been a believer in getting blood samples taken

2:19 and more recently I've become a believer

2:20 in getting DNA samples taken

2:22 in order to understand what's going

2:24 on at the level of hormones, metabolic factors

2:26 and other things that profoundly influence our immediate

2:29 and long-term health.

2:31 The problem always has been getting those samples taken

2:33 and making sense of those samples.

2:35 InsideTracker makes all of that really easy.

2:38 They'll even come to your home to take the samples.

2:40 Then you get the information back.

2:42 And while typically after getting information back

2:44 there's these long lists of numbers

2:46 and nobody knows what to do with them,

2:47 InsideTracker makes it really easy to

2:49 interpret what those numbers mean.

2:51 And it points to things

2:53 in terms of lifestyle, exercise, nutrition, and so forth

2:57 that can help you adjust some

2:58 of the numbers that you might need to bring

3:00 down or up to put into the appropriate normal range.

3:04 So I find this whole process to be immensely valuable

3:06 for guiding my health choices and also just

3:09 for giving me peace of mind about how my body

3:11 and the rest of my health are doing internally.

3:14 Something you just can't know without a blood and DNA test.

3:17 If you want to try InsideTracker, you can go

3:19 to insidetracker.com/huberman, and you'll get 25% off any

3:24 of their programs, you want to put Huberman at checkout.

3:27 So that's insidetracker.com/huberman to get 25% off any

3:32 of InsideTracker's plans and put Huberman at checkout.

3:35 The third sponsor of today's podcast is Athletic Greens.

3:38 Athletic Greens is an all-in-one vitamin mineral

3:41 probiotic drink.

3:42 I started using Athletic Greens in 2012.

3:45 So I'm delighted that they're a sponsor of the podcast.

3:48 The reason I started using Athletic Greens

3:50 and the reason I still take it once or twice per day,

3:52 is that I find it very hard to know what vitamins

3:56 and minerals I need to take.

3:58 And by drinking Athletic Greens, I get it all in one

4:01 easy to consume great tasting formula.

4:03 I really do like the way it tastes.

4:04 I mix mine with water

4:06 and a little bit of lemon or lime juice.

4:08 And to me it's delicious.

4:09 The other thing about Athletic Greens

4:11 that I really like are the probiotics

4:13 there are so much data out there now telling us,

4:17 and I certainly believe based on the data that I've seen

4:21 that probiotics are really important for support

4:23 of the gut microbiome, the gut brain axis, the immune system

4:27 and many other aspects of our biology.

4:29 So with Athletic Greens, I get the vitamins

4:32 the minerals and the probiotics that I need.

4:34 If you want to try Athletic Greens

4:36 you can go to athletigreens.com/huberman.

4:39 And if you do that, they'll also give you a year supply

4:43 of vitamin D3K2.

4:45 Vitamin D3 we also know is really important

4:48 for things like immune system and metabolic support.

4:51 So that's athleticgreens.com/huberman to get

4:54 Athletic Greens and a year's supply

4:57 of vitamin D3K2.

4:58 And they'll give you five free travel packs.

5:00 Today we're talking all about emotions,

5:03 and emotions are central to our entire experience of life.

5:07 Whether or not we're happy or sad

5:08 or depressed or angry is our life experience.

5:13 And yet I think with all the importance

5:15 we've placed on emotions.

5:17 Very few people actually understand how emotions arise

5:19 in our brain and body.

5:21 And I mentioned brain and body because as you'll see today

5:24 emotions really capture the brain body relationship.

5:28 We cannot say that emotions arise just from what

5:30 happens in our head.

5:31 It also involves events, biological events

5:34 chemical events within our body.

5:38 The other thing about emotions

5:39 is that there's no real agreement

5:41 as to what's a good emotion or a bad emotion.

5:44 Today we're gonna talk about the biology

5:46 of the chemicals and pathways that give rise to emotions.

5:49 And I'm going to equip you with several,

5:51 if not many tools that will allow you to regulate

5:55 and change and steer your emotions should you want,

5:57 but not using the typical advice.

6:00 You know, everyone's probably heard of this thing.

6:01 Oh if you're feeling depressed, just smile,

6:03 you know, it's impossible to be depressed while smiling.

6:07 Look, if that were true

6:08 we wouldn't have any depressed people

6:09 because depressed people don't want to be depressed.

6:12 And it is not the case that simply smiling will

6:15 reverse depression or sadness.

6:17 And it's simply not the case

6:19 that smiling can inhibit sadness.

6:22 It just doesn't work that way.

6:24 However, it is the case

6:25 that certain things that are happening

6:27 in our body influence how our brain functions

6:30 and the chemicals that are released.

6:31 And today we're gonna talk a lot about how the brain

6:35 and body interact to create these things called emotions

6:38 in the context of food and nutrition.

6:41 And the reason we're doing that is not

6:43 because I am beating the drum

6:45 about particular diet regimens or anything.

6:47 In fact, I'm not gonna do any of that.

6:48 What I'm gonna do is I'm gonna review some

6:51 of the most important scientific data that point

6:53 to how ingesting certain nutrients, both macro nutrients

6:57 like proteins, fats, and carbohydrates,

6:59 as well as micronutrients can impact the chemicals

7:02 in our brain that give rise to the feelings of being happy

7:06 or sad or sleepy or alert when you want to be sleepy

7:10 or sleepy when you want to be alert.

7:12 So this is sure to be a broad discussion

7:15 and yet we're gonna get very specific

7:17 about what emotions are, how they arise in the body,

7:21 tools that one can use in order

7:23 to better control their emotions,

7:24 tools that people can use to believe it or not

7:27 feel happier or feel calmer.

7:30 And that's because in the last 20 years or so

7:32 there's been an explosion of scientific studies

7:35 exploring how the brain and body interact

7:38 to support certain neurochemicals

7:40 that give us these feelings

7:41 of being alert and happy or depressed or certain

7:46 that our life is gonna be terrible

7:47 or certain that our life is going to be great.

7:49 So as mysterious as all that might sound

7:51 and confusing as all that might sound

7:53 we're gonna make it very clear today.

7:54 And you're gonna come away from this conversation

7:56 with a lot of tools that you can act on immediately.

8:01 And those tools are grounded in scientific data.

8:03 We are gonna provide links

8:05 to several of the studies, and I'm gonna mention

8:07 several of those studies as we go along.

8:10 But overall, the goal today is

8:11 for you to understand how moods and emotions arise

8:14 and the different pathways in your brain

8:16 and body that allow them to happen

8:18 and how you can use those pathways to change those emotions

8:21 and the tools that you can rely

8:24 on in very specific ways to shift

8:27 from being, say, slightly depressed, to feeling happier.

8:30 There actually are ways to do that,

8:31 or from feeling too alert and anxious to feeling calmer.

8:35 And these are tools that are distinct

8:37 from the tools I've talked about in previous episodes.

8:39 The discussion around emotions has a long

8:41 and rich history going back to Darwin.

8:44 And even long before Darwin,

8:46 this is a conversation that philosophers

8:48 and scientists have been having for hundreds

8:51 if not thousands of years.

8:53 The idea that Darwin put forth

8:56 and that was really attractive

8:57 for about the last hundred years was

9:00 that emotions are universal and that some

9:02 of the facial expressions around emotion are universal

9:04 and other people have capitalized on that idea.

9:08 And to some extent it's true.

9:10 I mean, I think that the two most robust examples

9:14 of that would be when we see something

9:17 or we smell something or we taste something that we like,

9:20 there does tend to be a postural leaning in.

9:24 We tend to inhale air at that time, we tend to bring

9:28 in more of whatever chemical substances there is.

9:30 We tend to these mm's and kind

9:32 of lean in closer to things that are attractive to us.

9:35 And when we see and experience things that we don't like

9:40 sometimes it's a mild aversion.

9:41 We just kind of lean back or look away.

9:43 Other times it's an intensive version

9:46 of disgust and we tend to cringe our face.

9:48 We tend to avoid inhaling any of the chemicals.

9:50 This probably has roots

9:51 in ancient biological mechanisms that are to prevent us

9:56 from ingesting things that are bad for us,

9:58 chemical compounds and tastes that might be poisonous.

10:01 So much of the foundation of any discussion

10:04 about emotion has to center around this kind of push pull

10:07 of attraction to things or aversion from things.

10:11 Now that's a very basic way of thinking about emotions

10:14 but if you think about it, it works for a lot

10:16 of different circumstances and in the brain everywhere

10:19 from the deep circuits of the brain to the more kind

10:21 of what we call higher order evolved centers of the brain.

10:25 We have this push pull thing where

10:27 either a previous episode, I talked about go,

10:29 the circuits that allow you to emphasize action

10:33 and then no go circuits, the circuits and the basal ganglia

10:36 that allow you to de-emphasize action and prevent action.

10:40 We talked about how that's a push pull.

10:42 So aversion and attraction is a push pull too.

10:44 Delight or happiness or excitement are attractions

10:48 to certain things and ideas, songs, people, places, foods

10:52 aversion is a leaning out.

10:55 It's a disgust, it's an avoidance.

10:57 And so we can break down the discussion about emotions

11:01 into these simpler versions of themselves,

11:04 but at the core of that of attraction or aversion

11:07 is an important theme that you might realize already.

11:11 But most people tend to overlook

11:13 which is that there's an action there

11:16 you're either moving forward

11:17 or you're moving away from something.

11:19 And any time you're talking about action

11:21 in the nervous system, you're talking about motor behaviors.

11:24 You're talking about literally the contraction

11:27 of muscles to move you toward or away from things.

11:29 And any time you're talking about nerve

11:31 to muscle and action, you're talking about the brain

11:35 and the body, because the brain can't move itself

11:38 that the brain has a body so that the organism can move.

11:43 And the body has a brain so

11:45 that the organism, you, can move toward or away

11:47 from things that you deem to be good or bad for you.

11:51 Now, some of these things that we're attracted to and some

11:53 of them that we avoid are what we call innate or hardwired.

11:57 You know, when we taste bitter compounds,

12:00 I'm not saying about bitter

12:01 like a little bit of a bitters in your drink

12:04 or something like that, but really bitter compounds.

12:06 We tend to avoid those

12:07 because they're associated with poisons.

12:09 When we taste things that are sweet or that are savory

12:12 we tend to pursue more of those.

12:15 We tend to lean toward those so to speak

12:17 and we tend to not avoid them.

12:20 So there are circuits in the brain

12:21 for aversion and for attraction toward things.

12:24 And the body is governing a lot of that.

12:27 And so immediately in this conversation

12:29 I want to raise an important point

12:31 which is about a nerve pathway that many,

12:34 many people have heard of that gets discussed all the time.

12:37 And that is one of the most kind of oversold

12:39 for the wrong reasons and undersold, unfortunately,

12:43 for its real power, which is the vagus nerve.

12:46 So the vagus nerve is one, not the only,

12:50 but one way in which our brain

12:52 and body are connected and regulates our emotional states.

12:56 Now, many of you have probably heard about polyvagal theory.

12:59 I'm gonna talk about this today.

13:01 Polyvagal theory was popularized by Stephen Porges

13:04 and it's an interesting theory,

13:06 certain aspects of it, frankly, hold up to the science,

13:10 some of it doesn't.

13:11 And I'm gonna discuss all of that today.

13:14 A lot of the vagus and the excitement

13:17 about the vagus, V-A-G-U-S,

13:19 is because it's somehow got into the mind of the public

13:23 that the vagus is involved in calming us down.

13:27 So what is the vagus nerve?

13:28 Okay, we're gonna make this really simple,

13:30 in particular for those that are just listening,

13:33 you can just imagine this,

13:34 for those are watching I'll point to the various areas,

13:36 but basically vagus is the 10th cranial nerve

13:40 which basically means that the neurons,

13:43 the control center of each of those neurons

13:46 in the vagus lives just kind of near the neck, right?

13:50 And a branch of the vagus goes into the brain.

13:52 They send a little wire into the brain.

13:54 The other branch goes into the periphery

13:56 but not just the gut.

13:57 It goes into the stomach, the intestines

14:00 the heart, the lungs, and the immune system.

14:02 So this vagus nerve is incredible

14:04 because it's taking information

14:06 from the body and it has two directions.

14:08 The first is what we call sensory.

14:10 So it's sensing things that are happening in the gut

14:13 in the lungs, everything, for example, in the lungs

14:15 when our lungs are distended, the vagus nerve senses that

14:20 and sends that information up into the brain.

14:22 It also consents things in the gut like how distended

14:25 or empty your stomach happens to be,

14:27 it can sense heart rate.

14:30 It can sense your immune system, whether or not

14:32 you have bacteria or things invading you in your body.

14:35 So it sends that information up to the brain.

14:37 So it's a two-way street

14:38 and sensory information is going up to the brain.

14:40 That's all vagus.

14:42 So it's like a super highway sensory information

14:44 going one way and in the other direction is motor control.

14:48 So the vagus is not just for sensing things.

14:50 It's actually for controlling things.

14:51 It's got a sensory pathway and a motor pathway.

14:54 So that's the first thing I think everyone should know

14:56 about the vagus.

14:58 In fact, it's so important that I feel like this is as

15:01 important as people knowing

15:04 that walking involves flexors and extensors.

15:05 And if you don't think that's important, it's as important

15:08 as walking, frankly, because the vagus is the way

15:10 in which you can govern the brain body connection.

15:13 And in which you can steer various aspects of your mood

15:17 and wellbeing, but most people

15:18 just don't understand how to use it.

15:20 So first you got to understand what it is.

15:21 So you've got sensory information coming

15:23 from all these different organs of the body up to the brain.

15:25 You've got motor information going

15:27 from the brain back to the body.

15:29 And so you've got this super highway within you.

15:31 Now what actually regulates the vagus.

15:34 Oftentimes you'll hear things

15:35 like, oh this particular behavior

15:39 rubbing your face at a particular location or breathing

15:42 in a particular way, or a warm bath or something

15:46 stimulates the vagus.

15:48 Well, right now, I want everyone to know that,

15:49 quote unquote, stimulating the vagus broadly speaking

15:53 is a terrible way to think about the vagus

15:55 because do you know what,

15:57 if you have a contaminant inside your body

16:00 the vagus senses that and projects that information

16:03 to your brain, and you start to generate a fever

16:06 you start to try and kill that contaminant in your body.

16:10 So I don't know that you want to stimulate the vagus just

16:12 as a general theme today, we're going to get specific

16:14 about how you can activate particular circuits,

16:17 certain pathways from certain organs to the brain

16:21 in order to feel better or relieve certain conditions.

16:24 But you certainly don't want to just stimulate the vagus.

16:28 Now excitement about the vagus in part

16:30 is because of what quite honestly,

16:34 was a fairly pioneering theory about the vagus

16:37 which is his polyvagal theory.

16:39 So polyvagal, the word poly means many,

16:42 is cool because it acknowledges

16:45 that the vagus has a lot of different branches.

16:48 It's not just one thing.

16:49 And so I really liked that.

16:51 I liked the naming polyvagal.

16:53 The idea that Porges has put forward was that there's

16:56 a dorsal vagus, which is kind of runs in the back

16:58 of the spinal cord, which is involved in alertness

17:00 and activation and kind of fight or flight type stuff.

17:03 And that there's a ventral pathway

17:06 and that that's involved in more kind of empathic behaviors.

17:09 That is not quite in agreement

17:13 with the modern anatomy,

17:14 but he was doing the best with what he had at the time.

17:16 So, okay.

17:18 The problem I have with the polyvagal theory

17:20 is the way that it's discussed people often say,

17:23 oh if your dorsal vagus is too active

17:27 then you tend to be someone who's a little too keyed

17:30 up and people who are kind of in a state of freeze

17:32 or kind of flacid and kind of

17:35 like just not really active

17:37 and they're just lethargic.

17:40 Well, then that pathway is hypoactive.

17:42 It should be more active.

17:43 So there are a lot

17:44 of theories about how psychology maps onto the vagus.

17:46 That as far as I know, don't map to any real physiology.

17:50 Now, the other problem with this kind

17:53 of the way that the polyvagal theory is discussed

17:55 probably not by the real experts, but by a lot of people

17:58 is that people start to diagnose different psychological

18:02 and physical manifestations through the vagus.

18:05 They would say things like, Oh

18:07 this person is hyper flexible at the joints

18:10 and therefore their dorsal vagus isn't active enough

18:13 or something like that.

18:14 And it's really kind of gone way outside the lane lines.

18:17 So today we're gonna clean up a lot of that.

18:19 Let's make it really simple

18:20 about how the vagus actually works.

18:22 At least as we understand it today in 2021.

18:26 First of all, as I mentioned, you have sensory information

18:29 the same way that you detect light with your eyes

18:31 or you hear sounds with your ears, you have sensors

18:34 in your gut that sense how full or empty your gut is.

18:38 It can also sense how acidic your gut is.

18:41 It can sense various things within your gut.

18:44 Your heart is doing the same.

18:45 It's informing the brain how fast your heart is beating,

18:47 how full your lungs are has been communicated

18:50 and then the status of your immune system.

18:52 So the way to think

18:53 about the vagus is the same way I would think

18:55 about the eyes.

18:56 The eyes are looking at colors, they're looking at motion

18:59 they're looking how bright it is.

19:01 And each one of those things,

19:03 those features is telling the brain something different.

19:05 So the brain can decide when to be awake or asleep

19:07 whether or not it's looking

19:08 at somebody's attractive or unattractive.

19:11 The vagus nerve is also analyzing many features

19:14 within the body and informing the brain

19:17 of how to feel about that and what to do.

19:20 So a really good example that I think is an exciting one is

19:24 as it relates to sugar.

19:26 So we all know that sweet things generally tastes good.

19:30 I'm not particularly a fan of very sweet things.

19:33 You know, I'd much rather have

19:35 cheese or pizza or hamburger or steak.

19:38 I like savory fatty foods, but I do like sweet foods.

19:41 And most people find sweet foods to be attractive.

19:45 They want them, they might

19:47 or they might not be able to regulate their behavior

19:49 around them, but they want them.

19:51 And what's really interesting is that for hundreds of years

19:54 people have thought that that's

19:56 because of the way that sweet foods taste.

19:59 So that makes sense, right?

20:00 You eat something that tastes sweet.

20:02 You want more of it.

20:03 Well, it turns out

20:04 that it's much more interesting than that.

20:06 When you eat something sweet

20:09 within your stomach, you have cells, neurons,

20:13 that sense the presence of sugary foods

20:16 independent of their taste and signal to the brain.

20:19 So those sensors, those neurons send information

20:23 up the vagus to your brain

20:25 goes through a series of stations.

20:26 And then you release dopamine.

20:28 This molecule that makes you want more

20:31 of whatever it is that you just ingested.

20:34 In fact, this pathway is so powerful

20:37 that they've done experiments

20:38 where they completely numb all the taste

20:41 and feeling in somebody's mouth they're blindfolded.

20:44 So they don't know what they're eating

20:45 and they're eating a food.

20:46 That's either sugary or not sugary.

20:48 And what they find is

20:50 that even though people can't taste the sugary food

20:52 they crave more of the food that contains sugar

20:56 because of the sensors in the gut, that sense sugar.

21:00 So to put this differently, you actually have sensors

21:03 within your body that make you crave sugar

21:07 independent of the sweet taste of those things.

21:10 Now that's incredible.

21:11 And what it does, and what it tells us is

21:13 that we have circuits in our body that are driving us

21:16 towards certain behaviors and making us feel good

21:19 even though we can't perceive them.

21:22 Now, for those of you that are really interested

21:23 in gut intuition and kind of gut feelings

21:26 this is a gut feeling except this is a chemical gut feeling.

21:30 This is a particular set of neurons detecting that something

21:34 in your body has a particular feature,

21:36 in this case the presence of sugars,

21:38 and sending information to the brain

21:41 essentially to control your behavior.

21:44 And I find this remarkable,

21:45 because what it means is that what we call attractive

21:49 isn't always coming from our thoughts

21:51 about that or our feelings, or even our perception.

21:54 We are drawn to particular foods and we're drawn

21:57 to perhaps also to particular people, places

22:00 and other things because of information

22:03 that's coming from our body.

22:04 And we're gonna talk about

22:07 what one can do with this information.

22:08 I know many people are thoughtful or concerned about sugars

22:11 these days thinking we all ingest too much sugar.

22:13 There's sugar snuck into all the things we eat.

22:17 And indeed, that's true.

22:18 I mean, this should completely reframe the way that we think

22:20 about the sort of so-called hidden sugars in foods.

22:24 What this means is that even if a food is very savory

22:26 like a piece of pizza or a piece of bread

22:29 or even like a salad dressing

22:32 if there's sugar snuck into that and you can't taste it

22:36 you will still crave more of that thing

22:39 without knowing that you crave it because it has sugar.

22:42 In other words,

22:44 you might find yourself wanting certain foods

22:45 and not knowing why you want those foods.

22:47 So I find this to be a fascinating aspect

22:49 of our biology and yes, it relates to mood and emotion.

22:52 And we'll talk about how that is in a moment.

22:55 So let's just back up a bit and ask the question

22:57 why do we eat certain things?

23:00 And why do certain foods make us feel good?

23:03 And other foods actually make us feel anxious.

23:06 I think some people may be familiar with this.

23:07 Other people might not,

23:09 but most people don't realize that as you approach eating

23:13 there's an anxiety associated with that.

23:16 It's an alertness.

23:17 Remember in the previous discussions,

23:19 or even if you don't and you haven't seen those,

23:22 all of your moods and feelings of wellbeing are anchored

23:25 on this continuum of alertness versus calmness.

23:28 And we hear so often about rest and digest.

23:30 You know that, oh, after we eat, we feel really nice

23:33 and full, hopefully comfortably full and not too full.

23:36 And we're relaxing.

23:37 And we feel satiated, it's associated with serotonin

23:41 this molecule of satiation.

23:43 That's all true.

23:45 But what most people don't know is that there's an area

23:47 of the hypothalamus.

23:48 So deepen the brain kind of in the middle deep portion

23:50 of the brain called the lateral hypothalamus.

23:53 And the lateral hypothalamus is really interesting

23:56 because it controls feeding, but it inhibits feeding.

24:00 It stops us from feeding.

24:02 And there's another area in the brain.

24:05 If you want names, I'll give them to you.

24:06 If you don't want names, just ignore them,

24:08 delete them from your memory and awareness,

24:10 called the locus coeruleus,

24:12 now the locus coeruleus sits back further

24:14 in the brainstem and it releases norepinephrine

24:16 which is essentially adrenaline.

24:18 It makes us feel alert.

24:19 Now, locus coeruleus has a lot of different functions

24:22 in the brain, but when we are going to eat

24:24 let's say we walk into a restaurant, we sit down

24:27 or we're preparing a meal,

24:28 locus coeruleus is known

24:30 to release noradrenaline in the brain.

24:33 It's creating a kind of alertness.

24:35 This has ancient utility, but it's creating this alertness.

24:39 And for many people, they experience

24:40 that as they approach food as stress as anxiety.

24:45 But what's interesting is that as we approach food

24:48 locus coeruleus is releasing all these molecules

24:51 that make us feel more anxious and alert

24:54 sometimes it's felt as excitement.

24:56 And that asks probably to do with how we feel about food

24:58 generally, are we happy with our relationship with food?

25:00 Are we trying to restrict our relationship to food,

25:02 are people coming over for dinner, all that will play

25:05 in of course, but there's a certain stress

25:08 and anxiety upon approach to food.

25:10 And as we approach food and we feel that anxiety

25:15 locus coeruleus activates the lateral hypothalamus

25:18 in a way that inhibits feeding

25:20 that makes us not want to eat.

25:23 So a lot of people who have kind

25:24 of pre-meal anxiety or anxiety around food

25:27 and they can't seem to just calm down

25:29 and have a good meal to access that later rest and digest.

25:33 A lot of that is because

25:34 of this heightened stress upon approach to food and a lot

25:37 of the tools that are out there, both for eating disorders

25:40 and for just kind of the general public who isn't suffering

25:43 from eating disorders, things like mindfulness around meals.

25:48 You know, they always tell you

25:48 you should never eat when stressed.

25:50 I'm sorry, but my life is not organized

25:52 in a way that I can do that.

25:53 I would never eat.

25:54 Right because I eat when I'm awake

25:56 and I don't know if I'm stressed,

25:58 but I don't think I am but I tend to

26:00 run around a lot during the day.

26:02 I don't generally take time to do two

26:04 or three deep breaths before I eat.

26:06 I generally will just eat.

26:09 That can be healthy

26:10 or unhealthy depending on the quality of your digestion.

26:13 I think using digestion as a guide is good,

26:15 but a lot of people aren't aware that this interaction

26:19 between locus coeruleus and lateral hypothalamus

26:21 is a basic mechanism where we are supposed to

26:24 get a little bit alert and anxious around mealtime.

26:27 And then as we eat, the mechanisms

26:30 for calming and satiation are supposed to kick in

26:33 and those mechanisms involve

26:35 as I mentioned earlier, two things.

26:37 One is how things taste, digestion starts in the mouth.

26:40 Of course, we taste our food.

26:42 Everyone tells us we should chew our food more.

26:45 Yes, that can improve digestion.

26:46 We're not supposed to drink too many fluids as we eat.

26:48 That's true too, but a lot of how we feel while we eat

26:53 and after we eat is because

26:56 of this vagus sensing of what's in our gut.

27:00 It's sending information all the time.

27:02 Is there sugar?

27:04 Are there fats?

27:06 Are there contaminants?

27:08 There are a lot of information.

27:09 These so-called parallel pathways that are going

27:11 up into our brain that regulate whether

27:13 or not we want to eat more of something or not.

27:15 And there are accelerators,

27:16 things that make us want to eat more, like sugar and fats

27:20 because those are nutrient dense.

27:22 And they helps generally, at least in the short term

27:24 support the survival of animals,

27:27 but also amino acids.

27:29 And this is very important.

27:30 There are a lot of data,

27:33 but much of what comes from the data on what people eat

27:38 and how much they eat is from a subconscious detection

27:42 of how many amino acids and what the array,

27:47 meaning the constellation of amino acids is in a given food.

27:50 And it's fair to say that the sum total

27:53 of these studies pointing in a direction where

27:55 people will basically eat, not until their stomach is full

28:00 but until the brain perceives

28:04 that they have adequate intake of amino acids.

28:07 Now, this is a conversation that comes up in the context of

28:12 you know, the meat, only the keto,

28:14 the kind of zone diet,

28:16 the Mediterranean diet, the vegan diet.

28:18 I'm largely going to ignore the kind of strict camps today.

28:23 I will talk a little bit about it,

28:25 because I think each one of them actually taps

28:26 into something important about this brain

28:28 body relationship that the other ones don't.

28:31 But I don't want to get into a discussion about

28:33 the ethics of different foods

28:35 of animal based or non animal based.

28:36 'Cause that's not the topic today.

28:38 It's really about nutrient sensing and amino acid sensing.

28:41 So we generally will eat

28:44 until our gut tells our brain that we have adequate amounts

28:47 of these amino acids.

28:48 Amino acids of course are important

28:50 because they are the building blocks of sure, muscle,

28:53 and the other things in our body that need repair.

28:56 But what most people don't realize

28:58 is that amino acids are what the neurochemicals

29:02 in the brain are made from.

29:04 Now, this is vitally important.

29:06 Okay, so we've heard dopamine is this molecule

29:10 that makes you feel good.

29:11 Actually dopamine is a molecule that makes you feel good.

29:13 It's released within the brain.

29:15 And it does feel very good when you have dopamine release,

29:18 dopamine releases caused by surprise, excitement,

29:22 events that you're looking forward to and they turnout well,

29:25 it is inhibited by events you're looking forward

29:28 to that don't work out when someone says

29:30 they're going to call that you're really

29:31 really excited to talk to, and then they don't,

29:33 or you thought a movie was gonna be really great

29:35 and it's not, or you expect a meal to be really delicious.

29:38 And it's kind of, eh, and we actually

29:41 there's a name for that.

29:42 It's called reward prediction error.

29:44 And you can actually use this in the context

29:47 of meals and plans in a way that's very useful

29:49 with yourself and people you know,

29:51 essentially if you expect something to be really terrific

29:57 it really does place a higher expectation

29:59 at the chemical level.

30:01 So if you don't get as much dopamine

30:03 as you're expecting from something,

30:05 so you you hear about a really great restaurant

30:07 or a place that has a really, in my case,

30:10 I have, I wouldn't call it an addiction.

30:12 I would call it more of an affliction for croissants.

30:14 The best vegetable of course, is the croissant.

30:16 And I get really excited

30:17 about the fact that someone will tell me,

30:19 oh there's this place and they have incredible croissants.

30:21 You gotta go there.

30:22 So I get really excited, and I'll go.

30:24 And just them telling me

30:25 that it's gonna be really terrific

30:27 raises an expectation, a dopamine expectation.

30:30 And unless those croissants are amazing

30:35 chances are I'm going to experience them

30:37 as less good, less satisfying.

30:40 I will truly release less dopamine than I would

30:44 had they just said, oh yeah,

30:45 I think that there are croissants down the street.

30:47 Or if I just tried one at random,

30:48 and that's because of this reward prediction error

30:51 your expectation of something releases dopamine

30:54 and the actual event releases dopamine.

30:58 And if the event related dopamine does not

31:01 exceed the expectation or

31:03 at least match it, there's a much higher tendency

31:06 that you won't pursue that thing again.

31:08 So dopamine is really powerful

31:10 and it's not just the molecule of reward.

31:12 It is the molecule of desire.

31:14 It's the molecule of wanting

31:15 not just the molecule of having.

31:18 And a book, since people often ask for book recommendations.

31:21 I don't know the author personally, but I love the book.

31:23 It's called "The Molecule Of More".

31:25 It's a terrific book.

31:26 I wish I had written it, frankly,

31:28 but if you want to learn more

31:29 about dopamine reward prediction error

31:31 and how dopamine regulates various aspects of your emotional

31:34 and motivational life, it's a terrific read.

31:38 Dopamine is what's going to lead us to want to eat more

31:42 of something or to not want more of something,

31:45 because dopamine really is about craving.

31:48 It's about motivation and it's about desire.

31:51 And as I mentioned, these amino acid sensors

31:53 in our gut are detecting how many amino acids

31:56 but they're also detecting which amino acids.

31:59 And there's a particular amino acid called L-tyrosine

32:02 which comes from food.

32:03 You can look up online, which foods contain L-tyrosine.

32:06 It is in meats.

32:07 It is in nuts.

32:08 It is also in some plant-based foods.

32:10 L-tyrosine is the precursor to a couple other molecules

32:16 like L-DOPA, et cetera, that make dopamine.

32:19 And so there's a misconception out there that most

32:22 of the serotonin is in our gut.

32:25 And most of the dopamine is in our gut.

32:27 And therefore our mood is in our gut.

32:29 That's not quite the way it works.

32:31 Okay. we'll talk about serotonin in a moment

32:33 but dopamine is synthesized

32:36 from the amino acids that you eat.

32:38 However, the dopamine neurons that give rise

32:42 to these feelings of good or wanting more

32:44 or desire and motivation, those reside in the brain.

32:48 So we don't want to get too confused.

32:49 We want to respect and honor the power

32:52 of the gut and this vagal pathway, but it's really neurons

32:55 within your brain that drive the pursuit

32:57 and decision-making, so what does this mean?

32:59 Well, some people make too little dopamine.

33:03 Some people make so little dopamine that they

33:05 need prescription dopamine.

33:07 They need L-DOPA, people with Parkinson's take L-DOPA

33:10 and other compounds to increase dopamine

33:12 because Parkinson's is associated with deficits in movement,

33:16 starts as a tremor,

33:18 actually starts with some other things that are interesting.

33:20 We'll talk about in a moment,

33:21 but Parkinson's is a depression.

33:25 It's a blunting of motivation

33:27 and mood and effect, and it's a tremor.

33:29 And then eventually in severe conditions

33:31 it's challenges in speaking and walking so

33:33 that some famous examples would be Muhammad Ali,

33:36 Michael J. Fox, the great boxing trainer, Freddie Roach,

33:41 like these people have Parkinson's and they

33:44 at least later in their life had challenges speaking.

33:46 Now it's not just fighters that develop Parkinson's as far

33:49 as I know, Michael J. Fox wasn't a fighter.

33:54 People can develop Parkinson's

33:55 and Parkinson's is a depletion

33:57 of dopamine neurons in the brain.

33:59 And it's not just movement challenges.

34:01 It's challenges with mood.

34:02 Now, hopefully most of you

34:03 all of you don't have Parkinson's,

34:05 but it's clear that dietary L-tyrosine

34:09 supports the healthy production of things like dopamine

34:14 and as well as other factors within the brain.

34:17 Now, some people immediately ask,

34:19 well should I supplement L-tyrosine?

34:20 So let's just talk about that

34:22 because that's gonna come up.

34:24 Full disclosure, I sometimes take L-tyrosine.

34:26 I'm not taking it right now,

34:27 but I take it only occasionally,

34:29 you can buy this in capsule form.

34:31 It does increase kind of a mood and elevation and alertness.

34:35 It is over the counter.

34:36 You have to check with your doctor.

34:37 I'm not responsible for your healthcare

34:39 and I'm not a doctor, whether or not it's safe for you,

34:42 people with preexisting hyper dopaminergic conditions

34:44 like mania should probably not take L-tyrosine.

34:48 The other thing

34:49 about taking L-tyrosine is there is a crash, okay?

34:52 It's not a massive crash if you take it

34:53 at appropriate doses and it's right for you

34:56 but it can produce a crash and a lethargy

34:59 and a kind of brain fog after the next day or so.

35:02 And so L-tyrosine however can be ingested through foods

35:07 or through supplementation to increase dopamine levels.

35:09 That's well-known, taken chronically however,

35:12 it can disrupt those dopamine pathways.

35:14 Now there are other drugs that will increase L-tyrosine

35:18 and dopamine as well.

35:19 But those are severe enough

35:20 that they generally tend to have addictive properties.

35:22 So things like methamphetamine,

35:24 things like cocaine are terrible because they really ramp

35:27 up the dopamine system so much

35:29 that people really can't achieve dopamine release

35:32 through any other mechanisms.

35:33 But food and the ingestion

35:35 of L-tyrosine has a profound effect

35:37 on our levels of dopamine.

35:38 It takes a little while

35:39 but that really will impact level of mood.

35:43 Certain antidepressants fall

35:44 into the category of dopaminergic antidepressants.

35:48 One of the most famous ones of course is Wellbutrin.

35:51 Wellbutrin with developed

35:52 because a lot of the other antidepressants

35:54 tend to make people feel kind of lethargic

35:57 or they had side effect profiles that people didn't like.

35:59 So they developed this thing that,

36:02 the generic name is different,

36:04 but it's generally called Wellbutrin.

36:05 Wellbutrin activates dopamine

36:07 and epinephrin, which is a substrate of dopamine.

36:10 And both of those are involved

36:11 in motivation and alertness and effort.

36:14 So you might say, wow, this sounds like a great drug.

36:16 However, this drug,

36:18 the side effect profile tends to be the things

36:20 that are associated with elevated mood and alertness.

36:23 So this isn't like taking some L-tyrosine.

36:25 This isn't like eating some tyrosine rich foods.

36:27 This is really a much greater release

36:29 of dopamine and epinephrin, and it increases things

36:32 like anxiety, sweating, the pupils dilate.

36:36 It has certain effects on, in particular people

36:39 with epilepsy, it's been used somewhat successfully

36:42 for smoking cessation, but again, it's not for everybody

36:45 and I'm not here to encourage the use of these things.

36:48 I'm just describing the biology

36:49 and the rationale for why these drugs were developed.

36:52 So let's back up a second.

36:55 Let's just kind of take stock of where we're at.

36:57 We have a brain body connection.

36:58 There are many of them, but one

36:59 of the main ones is the vagus nerve.

37:01 The vagus collects information

37:03 about a lot of things, breathing, heart rate stuff

37:06 that's happening in the gut, et cetera,

37:08 and gut by the way, includes the stomach and the intestines,

37:10 sends that information up to the brain.

37:12 The brain is using that information

37:14 to decide one of two things,

37:16 move toward something or move away.

37:18 It can also pause,

37:19 but essentially pausing is not moving toward.

37:22 So that's the dopamine pathway and foods rich

37:25 in L-tyrosine generally give us an elevated mood

37:28 and make us want to do more

37:29 of whatever it is that we happen to be doing as well

37:32 as other things, motivation, generalizes

37:34 to other things it's not unique to just ingesting foods

37:37 but foods that give us a big pulse

37:39 of dopamine will make us crave more of that food.

37:42 It will make us crave more

37:44 of the activity that led to the ingestion of that food.

37:47 And as I mentioned earlier, a lot of that is happening

37:50 at a subconscious level that you're not even aware of.

37:53 And this is why I think the concern about hidden sugars

37:55 and over ingestion of sugars

37:57 is serious because it's not just

38:00 that the sugars are impacting

38:01 our blood glucose in negative ways.

38:04 Although often it is,

38:05 it's not just the obesity crisis that's happening.

38:08 It's also the fact

38:09 that it's disrupting our dopamine systems.

38:12 Now that doesn't mean all sugar is bad.

38:14 Some people have a quite healthy relationship to sugar

38:17 but I think most people are just not aware

38:19 that sugar isn't just operating at the level

38:21 of taste it's operating at the level

38:22 of neurochemicals and it's doing it subconsciously.

38:25 So I'd like to talk about some of the other pathways

38:28 between brain and body that regulate our moods and emotions

38:31 but also are actionable.

38:33 So the other neuromodulator that's really interesting

38:35 in the context of the vagus is serotonin.

38:39 Serotonin, just to remind you is a neuromodulator

38:42 therefore it creates a bias in which neural circuits

38:46 which neurons in the brain and body are going to be active

38:49 and it makes it less likely the other ones

38:51 are going to be active.

38:53 I think it's fair to say without ever having measured it

38:55 that my bulldog Costello, just his brain

38:58 and body must be swimming in serotonin,

39:01 because he's very calm and he eats a lot

39:05 but he generally feels pretty sated.

39:07 He's kind of an animal that's obsessed with comforts.

39:10 He's a bit of a hedonist, and serotonin when it's elevated

39:13 tends to make us feel really comfortable

39:16 and kind of blissed out wherever we are.

39:19 And that contrast with dopamine and epinephrin

39:22 which mainly put us in pursuit of things.

39:25 Motivation is pursuit.

39:27 Serotonin is more about feeling really comfy

39:29 where we are.

39:31 The conversation around the brain body relationship and mood

39:34 and serotonin for many years was, well, you eat a big meal.

39:37 The gut is distended.

39:39 You've got all the nutrients you need

39:40 you rest and digest and serotonin is released.

39:43 That's sorta true, but there's a lot more going

39:46 on and a lot more that's interesting

39:48 and actionable that's going on.

39:51 First of all, some of you,

39:52 but perhaps not all have heard that more

39:55 than 90% of the serotonin that we make is in our gut.

39:59 And indeed we have a lot of serotonin in our gut.

40:01 We have neurons in our gut that makes serotonin.

40:04 We have neurons in our brain that make serotonin,

40:06 but here's the deal.

40:08 Most of the serotonin that impacts our mood

40:11 and our mental state is not in our gut.

40:14 Most of it is in the neurons of the brain

40:16 in an area called the raphae nucleus of the brain,

40:19 there are a few other locations too,

40:20 and those are the neurons that control

40:22 whether or not we feel satiated or not.

40:24 Whether or not we feel happy and calm.

40:27 You can't have a discussion about serotonin

40:29 without having discussion about antidepressants.

40:32 Because during the late eighties and early nineties

40:35 there was this explosion

40:36 in the number of prescription drugs that were released.

40:39 Things like first one and most famous one is Prozac, Zoloft

40:42 and Paxil, a number of other ones that are so-called SSRI

40:46 selective serotonin re-uptake inhibitors.

40:50 That's a long acronym, but basically those drugs work

40:53 by preventing the gobbling up of serotonin or re-uptake

41:00 of serotonin into neurons after it's been released

41:03 which leads to more serotonin overall

41:05 which means to elevate serotonin.

41:07 And indeed those drugs were and can be very useful

41:11 for certain people to feel better in cases

41:14 of depression and some other clinical disorders as well.

41:17 So I really don't want to dismiss them

41:20 as useless or dangerous for everybody.

41:22 They can be quite useful for many people.

41:25 Not everyone responds well to them

41:27 as I'm sure you've all heard.

41:29 And their side effect profile has affects

41:32 like blunting affect.

41:34 It can make people feel kind of flat,

41:36 kinda meh, it can reduce appetite for food.

41:39 It can reduce appetite for sex.

41:41 It can do all sorts of things, or it can work really well.

41:44 Sometimes it's a dose-related issue, et cetera.

41:47 Serotonin is fascinating however,

41:50 because how well those neurons

41:52 in the raphe work is impacted by some events within the gut.

41:55 Although you might be surprised to find

41:58 out what those events are.

42:00 So let's go a little bit deeper into the gut.

42:03 And again, the gut includes the stomach

42:05 and then the small intestine in the large intestine

42:07 and ask like, what is going on with serotonin in the gut?

42:09 How is it impacting serotonin in the brain?

42:13 And let's think about this in the context

42:16 of how some of us might want to increase

42:18 or decrease our serotonin levels.

42:20 So as far as I know, there aren't any really good

42:25 at home blood tests for things like serotonin and dopamine.

42:29 There's some commercial products out there.

42:30 But to me, just to me, I'm not particularly impressed.

42:34 You know, it's not the same

42:35 as getting your hormones levels measured

42:37 or your metabolic factors measured, that's can be daunting.

42:41 It can be done rigorously.

42:42 There are tests out there.

42:44 There are even some, believe it or not.

42:46 There's some questionnaires that,

42:47 and I think actually last year it made some

42:49 of the bigger newspapers,

42:50 are you more of a dopamine or a serotonin?

42:52 Are you a this or that?

42:54 I find that stuff to be a little silly

42:55 although I do appreciate, and like the fact

42:58 that people are thinking about and talking

42:59 about neuromodulators there aren't really

43:02 great ways to measure these things outside the clinic.

43:05 There's some great clinical tools that you can get inside

43:07 of a hospital or from a proper endocrinologist

43:09 or neurologist, but no great at-home tool.

43:12 So maybe that's a call to arms

43:13 for some of you entrepreneurial folks

43:15 out there to create these tests, accurate tests please,

43:19 that could be done at home.

43:20 But some people feel like they're too anxious

43:23 or they're always in a motivated state

43:25 and they're trying to adjust their serotonin.

43:27 Many people adjust their serotonin by just eating more food

43:31 and carbohydrate rich foods will increase serotonin.

43:35 I've talked about this on a previous podcast

43:36 but I personally am a big fan

43:39 at least for me is I usually fast

43:41 and exercise in the early part of the day

43:43 I eat a relatively high protein and moderate fat zero carb

43:49 or low carb meal at lunch in the afternoon to stay alert

43:53 because those foods tend to favor dopamine production

43:56 acetylcholine production,

43:57 epinephrin production and alertness.

44:00 My mood is generally pretty good most of the time.

44:03 And then as evening comes around and I'm concerned

44:06 about sleep and a good night's sleep, not concerned

44:08 in an anxious way, but I want to get a good night's sleep.

44:11 I will ingest foods that promote serotonin release

44:14 because they contain a lot of tryptophan.

44:16 So if I do eat meat,

44:17 it would be like a white meat, turkey meat.

44:19 I don't tend to, I've never liked turkey.

44:21 I don't mind the animal

44:22 but I don't like ingesting the meat,

44:24 but starchy carbohydrates will increase serotonin.

44:28 Some people also will take serotonin.

44:32 You can now buy 5-HTP supplements.

44:34 This is a little bit tricky.

44:36 5-HTP supplements can of course increase 5-HTP.

44:40 It is 5-HTP or serotonin

44:43 but that sometimes can create problems

44:46 in endogenous or self-made production of serotonin.

44:49 So I'm never a fan

44:50 of taking things very close to the chemical

44:53 you're trying to increase for very long periods of time.

44:55 Maybe for occasional use.

44:57 I have the problem that

44:59 if I take serotonin supplements, 5-HTP, I fall asleep.

45:02 The sleep I have is very intense

45:04 and I wake up three or four hours later.

45:05 And we know based on sleep studies with good measurements

45:09 in the lab that serotonin release tends to be

45:12 in the later part of the night.

45:13 And so by taking it early in the night

45:15 it really can disrupt the pattern

45:16 of sleep in the depth of sleep.

45:18 Nonetheless, some people are interested

45:20 in taking serotonin to get some

45:21 of the more blissed out effects.

45:23 You can achieve that with foods.

45:25 As I mentioned, that are carbohydrate rich.

45:27 So as you're seeing this

45:28 isn't really a discussion about nutrition per se.

45:30 This is discussion about food

45:31 which contains amino acids, amino acids

45:34 being the precursors to neuromodulators and neuromodulators

45:37 having a profound effect on your overall state

45:40 of alertness or calmness, happiness, sadness, and wellbeing.

45:44 So there are a number of things that one can take.

45:47 As I mentioned, one of them being 5-HTP itself.

45:50 Now I'm not recommending people take anything,

45:52 but if you're interested

45:53 in what this does and you want to explore this

45:56 of course you'd want permission from your doctor.

45:58 You can go to this free website.

46:00 I love this resource.

46:01 They don't pay me to say that,

46:03 but I just love this resource.

46:04 I've followed it for a long time called examine.com.

46:07 Thank you folks at examine.com

46:10 for putting this free resource

46:11 out on the web that has links

46:13 through what they call the human effect matrix.

46:16 So it's links

46:16 to all the PubMed studies for particular effects

46:19 of particular compounds that one combined

46:20 and just incredible as well as important health warnings.

46:23 So I'm not gonna read through everything

46:25 but if you were to go to examine.com as I have now

46:27 and you put in 5-HTP

46:30 they're only looking at things that have strong evidence.

46:32 PubMed articles,

46:35 articles that are in the PubMed archive.

46:37 So for instance, I didn't know this,

46:39 but 5-HTP produces a notable decrease in appetite,

46:44 three studies.

46:45 And this appetite suppression makes sense, of course,

46:48 because we ingest foods to get serotonin.

46:51 And if we have enough serotonin

46:52 then there's no reason to ingest more foods.

46:55 It tends to have a blunting of appetite.

46:58 It probably does that also through other mechanisms.

46:59 So I'm not saying you should do this

47:01 but if someone's trying to blunt

47:02 their appetite could be a interesting route,

47:05 although I don't recommend chronic use,

47:08 not surprisingly there's a decrease in body weight

47:11 as a consequence, an increase in cortisol.

47:14 So that's kind of important to note

47:15 that when you typically in biology, if you pull

47:18 on one string really hard and other one moves

47:20 it's a little bit like a puppet in there.

47:22 It's more than one string on the puppet.

47:24 So it does seem to increase cortisol though

47:26 they report as a minor effect.

47:27 Again, links to all those are there

47:29 which is why I'm not listing them out in our caption notes.

47:32 You can go and get them at examine.com,

47:34 put in serotonin and you'll find that.

47:36 So I find it fascinating

47:38 that nowadays there are things that are somewhere

47:42 between doing nothing, getting serotonin

47:45 from tryptophan and foods and prescription drugs.

47:48 There's this other category

47:50 of supplements that are really interesting

47:52 for modulating these chemicals in the body.

47:55 And I should mention before I move on,

47:57 because I mentioned L-tyrosine

47:59 I neglected to mention earlier

48:00 in our discussion about dopamine, if you're interested

48:02 in the dopamine pathway, go to examine.com,

48:05 put in Mucuna pruriens, it's M-U-C-U-N-A,

48:11 separate word, P-R-U-R-I-E-N S.

48:17 It is a velvet bean that grows from vines

48:20 and is very itchy to touch due to serotonin on its surface.

48:23 Amazing, this bean has serotonin on its surface

48:25 and indeed serotonin at if you were to put it

48:28 on your skin would cause

48:29 some irritation of the skin, amazing.

48:31 Inside the bean is L-DOPA, Mucuna pruriens is not

48:36 just something that promotes dopamine release

48:39 because of some weird mystical

48:41 ancient thing or whatever, or sorcery.

48:44 It is chemically L-DOPA the precursor to dopamine.

48:49 It contains some other molecules as well

48:51 and low levels of other psychoactives.

48:53 This stuff is available over the counter.

48:55 Incredible. I personally find it incredible.

48:58 Its effects are really interesting.

49:00 I'm not gonna read them all off

49:01 but I mentioned these effects

49:03 not because I'm encouraging you to take it

49:05 but because you get a window

49:06 into what dopamine, acute dopamine increase does

49:10 in the non-Parkinsonian context.

49:12 And you can start to think about foods that are rich

49:15 in L-tyrosine as biasing certain effects or not others.

49:20 So when you hear food is medicine,

49:21 food isn't really medicine.

49:22 Food is food, but food has these chemical effects as well.

49:25 So first one listed is three studies

49:29 with very high rigor that overall have a minor effect

49:35 on of all things, sperm quality.

49:37 So it appears that sperm motility itself,

49:39 I'm assuming when they say sperm quality

49:42 I don't know what features of sperm of quality

49:44 they looked at with sperm,

49:45 that's not discussion I want to have,

49:45 but I'm assuming it's motility

49:47 because I know enough about reproductive biology

49:49 to know that sperm ability to swim depends

49:53 on some proteins that are present

49:54 in the front of the sperm, et cetera

49:56 things like contractions and sperm motility

49:59 is generally associated with sperm quality.

50:02 Sperm that don't move are generally not very useful sperm.

50:05 Symptoms of Parkinson disease are

50:07 are notably degraded with Mucuna pruriens.

50:10 So fascinating. That's not surprising.

50:12 And there are a lot of other effects here.

50:13 Feelings of subjective wellbeing,

50:15 testosterone, reductions in prolactin, not surprising.

50:18 Prolactin is a hormone that's involved

50:21 in milk letdown, it's in lactating mothers.

50:24 It's involved in feelings of peace and generally

50:28 is antagonistic to sexual desire in both men and female.

50:33 So it's really interesting that things like Mucuna pruriens

50:37 which are L-DOPA reduce prolactin, increased sperm motility,

50:40 increased testosterone, subjective wellbeing.

50:42 So you're starting to see a theme, right?

50:44 Dopamine really makes us motivated.

50:46 Feel in pursuit, makes us feel good.

50:48 Serotonin makes us feel more relaxed and calm.

50:51 Now this whole month is about emotion.

50:53 So you might be thinking, well, wait

50:54 where are we going with all this as it relates to emotions.

50:57 But in the last episode I said something

51:00 I'm gonna repeat it now briefly, which is that much

51:02 of what we talk about is good emotions or bad emotions.

51:06 There's a context to that.

51:07 There's a social context.

51:08 We can't really say an emotion is good or bad.

51:11 Grieving at a funeral is healthy.

51:13 Being happy at a funeral,

51:16 assuming you loved the person that died

51:18 is most people probably wouldn't think that was healthy.

51:21 So we can't really say that certain

51:23 emotions like sadness or happiness are healthy.

51:26 It's context is important.

51:28 Cultural context is important.

51:29 Many of you have asked for book recommendations.

51:31 This is an opportunity to raise a mention of another book.

51:35 Again, I don't have any financial affiliation or anything

51:38 but if you want to read more about emotions

51:40 and how the context and cultural things impact our emotions

51:44 I'm a huge fan of Lisa Feldman Barrett.

51:46 I learned about her from the Lex Fridman Podcast.

51:50 I've had discussions with her on my Instagram Live,

51:52 she's at Northeastern University,

51:54 a world expert in emotions.

51:56 Her first book is "How Emotions Are Made"

51:58 This is not a book she sent me.

51:59 I paid for this with my own money years ago,

52:02 bought it, read it, loved it long before I met Lisa,

52:05 I'm just delighted

52:06 that we've got to known each other a little bit.

52:08 It's a really interesting read into the psychology

52:10 of emotions and some of the subjectivity of emotions.

52:13 So, whereas I'm talking about mainly the biology of emotions

52:16 this gets a little bit more into the psychology

52:18 and the biology as well.

52:21 And Lisa's just terrific.

52:23 She's also putting a lot

52:24 of information out into the world about emotion.

52:25 So if you want to learn more about that

52:28 check out her work, again, it's Lisa Feldman Barrett.

52:32 And that book is "How Emotions Are Made"

52:33 Hopefully she'll continue to write many more books.

52:37 So now you understand the relationship

52:41 I hope between foods and dopamine, foods and serotonin

52:46 and that they're both being communicated

52:47 to the brain via the vagus, right?

52:49 We ingest these foods,

52:51 these supplements are things people take,

52:53 they don't put them directly into the brain.

52:55 They put them in our gut.

52:56 So yes, there's a gut brain connection

52:58 but it's not about the serotonin

53:00 in the gut that makes you feel calm and placid.

53:04 It's not about the dopamine in the gut.

53:07 It's just been oversold that way

53:09 because I think there's something really attractive.

53:11 And I understand about the idea

53:13 that because certain things about our experience

53:17 of life and our emotions is happening in our body.

53:19 That maybe we have a little more control, right?

53:21 Because this thing is a hard container.

53:23 We can't just stuff some dopamine in there.

53:26 I could probably take a Mucuna pruriens bean

53:28 and stuff it in my ear, please don't do that.

53:30 It'd make my ear itchy

53:31 because of the serotonin on the outside.

53:33 But you can't get stuff in there.

53:34 What you have to do is ingest things that are metabolized

53:37 in certain ways that communicate to the brain

53:39 or so maybe they pass into the brain themselves

53:43 across what's called the blood brain barrier.

53:45 I'll talk about the blood brain barrier in a minute.

53:48 It's actually called the BBB.

53:49 So it ends up sounding like baby, BBB.

53:53 I guess that's like BB, anyway,

53:56 BBB, but they're also nerves

53:59 in the gut that are sensing the nutrient contents of food

54:02 and then saying, oh, you should feel better and want more.

54:05 Oh, that's got a lot of bitterness and acid taste to it.

54:09 You should want less of that.

54:11 So as I transitioned out

54:13 of the discussion about dopamine and serotonin in the gut

54:16 hopefully you've got some actionable items there

54:19 under your belt, pun intended,

54:21 where you can understand how certain foods

54:24 and certain nutrients

54:24 and you can look these up, might impact your mood.

54:27 If you're somebody who's really anxious and really wired.

54:30 Well, then the dopamine adrenaline pathway

54:32 epinephrine pathway is probably not one that you

54:34 want to lean on any harder.

54:36 If you tend to be someone who's pretty passive

54:39 and you're having trouble with motivation.

54:40 Well then think about ramping

54:42 up the dopamine pathway through, I always think behaviors

54:45 and proper food choices is the best way to start.

54:48 And behaviors include things like exercise, et cetera.

54:51 But one of the problems

54:52 with the discussion around mood and exercise

54:55 or mood and meditation is that it's so subjective.

54:59 It's like, I love certain forms of exercise and not others.

55:01 Certain ones are aversive to me.

55:03 Certain ones are attractive to me,

55:05 and it's never really clear.

55:06 No one's ever told me.

55:06 Okay, you have to do 10 minutes

55:09 on the bike at X number of RPM at so-and-so

55:12 or on the skier in order to get your dopamine up.

55:14 But we can actually say, if you ingest more L-tyrosine

55:18 there's a high probability that you're going

55:20 to make more dopamine.

55:22 And I'm talking about ingesting it

55:23 through food or through supplementation if you like.

55:25 Mucuna pruriens, I've tried.

55:27 I should just mention it was too dopaminergic for me.

55:30 I got really, really jazzed up

55:33 and then a severe crash for me the next day.

55:36 But that's, I think because I tend to ride pretty high

55:39 on the kind of alertness and motivation scale.

55:41 I'm always being told by Costello and other people

55:44 in the podcast studio to slow my speech down.

55:46 This is me uncaffeinated, and I could probably

55:48 afford a little more serotonin in my life.

55:51 So, whereas Costello,

55:54 he can afford to wake up every couple of days

55:57 and just say hello to us.

55:58 This dog sleeps more than any other creature.

56:01 It's remarkable.

56:03 So there are things that we can do and they're actionable.

56:07 And they are in some ways they're quantitative

56:09 because you can regulate dosages

56:11 and you can regulate amounts and you can regulate timing.

56:13 And everyone has to play with these things

56:14 and figure out what's right for them in terms of feeding.

56:17 And everyone has to explore

56:19 and understand what's safe and right for them.

56:21 But, and of course, exercise is still very important.

56:25 I talked about social connection in the last episode

56:27 super important for activation of serotonin

56:30 but when it comes to this gut brain,

56:32 body brain relationship, what we eat really matters

56:36 in terms of the neurochemicals that we make.

56:39 So let's talk a little bit more about things that we ingest

56:41 in our body and then allow our body to inform our brain

56:44 to shift our mood.

56:46 And this is something I've been doing for years.

56:48 And I just want to say

56:50 I've found to be a complete game changer.

56:52 There's excellent science to support it.

56:54 And I think most people are familiar

56:58 with it in a different context

57:00 but I don't think most people know this simple fact

57:03 which is that the omega-3 to omega-6 fatty acid ratio

57:09 has a profound effect on depression.

57:12 It has a profound effect on mood so much so

57:15 that in a double-blind placebo controlled study

57:20 that I will provide the link too,

57:21 this was a study first published in 2008

57:23 but there've been many others as well.

57:26 First of all, an experiment done in animals.

57:29 They found there's a model

57:31 of learned helplessness in animals.

57:33 It's not very kind to the animals,

57:35 but they put rats or mice in a jar.

57:36 They let them swim and they'll swim, swim,

57:38 swim to try and save their life.

57:40 And eventually they give up, it's a learned helplessness.

57:41 They don't let them drown, they take them out.

57:44 Adjusting the omega-3 omega-6 ratio so

57:47 that the omega-3's are higher led to less

57:51 learned helplessness, meaning these animals

57:52 would swim longer.

57:53 Now that's an animal.

57:54 That's a rat, not a particularly kind study,

57:56 but that same study was essentially done in humans

58:01 although they didn't have them swim to the point

58:03 of near drowning.

58:04 What they did is they took people who were clinically

58:08 depressed, major depression.

58:10 Major depression is severe maladaptive state

58:14 meaning it inhibits job, relationships, appetite,

58:16 all sorts of negative health effects.

58:20 And they did a comparison of

58:23 a thousand milligrams a day of EPA.

58:26 So EPA is one of the elements that contains high levels

58:30 of omega-3's that's in things like fish oil,

58:32 I'll talk about other sources in a little bit

58:35 but it wasn't a thousand milligrams of fish oil.

58:38 It was a thousand milligrams of EPA.

58:41 Compared that to 20 milligrams of Fluoxetine

58:45 which is Prozac, okay.

58:47 Really increases serotonin.

58:49 And in this study of 60 individuals, again,

58:52 I'll provide the links to the study.

58:55 They found that they were equally effective

58:59 in reducing depressive symptoms.

59:01 So imagine that,

59:02 a food-based compound that you can't make without,

59:07 right, this is not a situation

59:09 where you can make your own omega-3s.

59:11 You have to get them from food sources

59:12 or from supplementation, was as effective as 20 milligrams

59:16 of fluoxetine over the course of eight weeks.

59:19 And what was really interesting in addition

59:21 to that is that the combination of a thousand milligrams

59:25 of EPA and Fluoxetine had a synergistic effect

59:28 in lowering depressive symptoms.

59:30 I find this remarkable.

59:31 I heard about this when it first came

59:33 out and I wasn't sure what to make of it.

59:37 'Cause there are a lot of studies that come out

59:39 and I generally like to focus my changes in behavior

59:41 around things where there's a large center of mass.

59:43 There's a lot of information.

59:46 A couple years later, I did in fact

59:47 start taking a thousand milligrams

59:50 per day of EPA in fish oil.

59:53 Now there are a few side effects of fish oil.

59:56 People who have blood, who are bleeders

59:59 who have Factor V Leiden mutations

1:00:02 or in women who are taking birth control,

1:00:05 which can affect blood clotting and things

1:00:07 of that sort really should talk to your doctor

1:00:10 make sure it's okay for you.

1:00:12 Fish oil also can give people fishy breath

1:00:14 which is pretty gross, frankly,

1:00:17 but there are now fish oils that

1:00:18 either because of the Encapsulations or because

1:00:21 they put some lemon flavoring in there

1:00:25 doesn't have that effect.

1:00:26 In any event, a thousand milligrams per day of EPA.

1:00:29 I started ingesting that regularly.

1:00:30 I just felt better.

1:00:31 I wasn't clinically depressed, but I generally,

1:00:34 I did feel at least for me, an increase in mood and affect.

1:00:37 And a number of other things

1:00:39 it's supposed to reduce inflammation.

1:00:40 The cardiovascular effects are controversial

1:00:42 for a long time everyone thought the effects

1:00:44 on platelets were really terrific.

1:00:47 Then there were articles that came

1:00:48 out in major newspapers saying maybe not so much

1:00:50 but the effects on mood are really profound.

1:00:53 And now there are lots of studies.

1:00:56 If you go into PubMed

1:00:57 and you were to put EPA or fish oil and depression

1:01:01 you would find that there were a number

1:01:03 of really impressive results showing

1:01:05 that it's at least as effective

1:01:06 as certain SSRI antidepressants at these dosages

1:01:10 and it can amplify or improve the effect

1:01:13 of low dosages of some of these SSRIs.

1:01:16 So I feel like more people should know about this.

1:01:18 This is nutrition, but it's profoundly affecting mood

1:01:21 and depression is terrible, right?

1:01:23 Depression can have a component

1:01:25 of anxiety in some cases where people are

1:01:28 they feel lousy and very uncertain.

1:01:30 That's kind of how I talk about depression with anxiety

1:01:32 is you talk to someone who is anxious

1:01:34 and you can tell them everything's gonna be okay.

1:01:36 And they're always concerned

1:01:37 about what they might not know.

1:01:39 You don't really know the plane isn't gonna crash.

1:01:41 You don't really know that life is gonna go okay.

1:01:43 And in some sense, they're right,

1:01:44 no one has a crystal ball or can predict the future,

1:01:47 but they tend to perseverate or fixate on the uncertainty.

1:01:50 And then of course there are the versions

1:01:52 of depression that involve certainty.

1:01:55 People are lethargic and they're certain they say, yeah,

1:01:57 I'm certain, I'm never gonna get another job.

1:01:59 I'm certain, I'm never gonna meet anyone new.

1:02:00 I'm certain I'm gonna fail.

1:02:01 So there's this kind of a divide in the sphere

1:02:04 of depression around certainty and uncertainty.

1:02:06 But what's interesting is this thousand milligrams per day

1:02:10 or more of EPA has been shown

1:02:12 to relieve both forms of depression.

1:02:16 Now, does that mean it's gonna work for everybody?

1:02:18 No, I'm not here to try and play psychiatrist.

1:02:20 I want to point you in the direction of these manuscripts

1:02:23 so that you can make informed choices for yourself.

1:02:26 You can discuss it with your doctor

1:02:27 and family and make the choices that are right for you.

1:02:30 But here's what's especially interesting

1:02:32 about the heart effects,

1:02:33 because we've heard that these omega-3s,

1:02:36 which of course you can get from other sources too,

1:02:38 you can get from fatty fish,

1:02:40 they're in flax seeds, hemp seeds.

1:02:44 There are a number of chia seeds, these kinds of things

1:02:47 but the levels of EPA that are required are quite high.

1:02:51 So this thousand milligrams

1:02:52 per day is that's pretty hard to get from food

1:02:55 although it can be done depending

1:02:56 on what you're eating.

1:02:58 What's interesting is that the heart effects that are solid

1:03:03 that really stand up in the literature

1:03:05 have a lot more to do

1:03:06 with something we talked about in a previous episode.

1:03:08 And I'll mention again, which is heart rate variability.

1:03:11 So we know that having a heart rate that's really high

1:03:14 or heart rate, that's really low.

1:03:15 Neither of those are good.

1:03:16 A lot of people think, oh

1:03:17 you just want a low heart rate, big stroke volume.

1:03:20 You know, if you're running a lot

1:03:22 you may have 30 or 40 beats per minute.

1:03:24 That's great to be in shape

1:03:25 but you still want heart rate variability.

1:03:27 It has a lot to do with the tone

1:03:29 of the autonomic nervous system talked about last time.

1:03:32 How, when you inhale, it speeds up heart rate.

1:03:34 When you exhale, it decreases heart rate.

1:03:35 That's called respiratory sinus arrhythmia.

1:03:38 That's the basis of heart rate variability.

1:03:40 We'll maybe do a short post about this.

1:03:42 So you can get all the mechanism

1:03:44 and the behaviors that spill

1:03:46 out of that that might be useful for you.

1:03:48 But the point is heart rate variability.

1:03:50 HRV is good.

1:03:51 And what's interesting is that there was a study

1:03:53 in 2009 that showed that people who eat a diet where they

1:03:59 fail to supplement in a way that there's

1:04:01 a high omega-6 to three ratio,

1:04:03 so not enough omega-3s, not only are there markers

1:04:06 of an inflammatory cytokines, elevated things like IL-6

1:04:09 and TNF-alpha,

1:04:11 but they tend to be non-responders to antidepressants.

1:04:16 Shifting that omega-3 omega-6

1:04:18 ratio did a couple things.

1:04:19 First of all, increasing the amount

1:04:21 of EPA shifted the ratio.

1:04:23 So it was higher omega-3 to omega-6 ratio, which was good,

1:04:27 lowered the inflammation markers,

1:04:29 and then allowed antidepressants to have their effect,

1:04:32 even at low doses.

1:04:34 And here's the really interesting thing.

1:04:36 It worked by increasing heart rate variability,

1:04:40 and you think, well, how in the world would this happen?

1:04:42 But you know how I mean, that's a ton of effects

1:04:45 but the way it works is because of the way that these things

1:04:49 are impacting the gut and the autonomic nervous system.

1:04:52 Remember earlier, I said, the vagus includes connections

1:04:55 from the heart signaling about sensory information

1:04:57 about how fast the heart is beating to the brain

1:05:00 not just stuff on the lungs, but information from the heart

1:05:02 and the brain then adjusts heart rate

1:05:05 by heart rate variability.

1:05:07 So it's incredible that there's a way that one

1:05:09 can use the gut, the ingestion of more of these EPA's,

1:05:13 either through food or supplementation

1:05:15 to increase rate variability

1:05:18 and thereby to improve symptoms,

1:05:21 meaning reduce symptoms of depression,

1:05:25 and to even make low levels of antidepressants

1:05:28 that wouldn't otherwise work work.

1:05:30 And I think I like this study so much

1:05:32 because a, it's super cool.

1:05:34 It bridges the brain body access.

1:05:36 It incorporates nutrition and micronutrients in the brain

1:05:39 but also because it really points to something

1:05:42 that we hear all the time,

1:05:43 which is our body is a whole system.

1:05:45 It's working as a whole system and the brain isn't working

1:05:47 in isolation up there in the skull.

1:05:49 It's reacting to things that are happening in the body

1:05:51 in the gut and in the heart rate and heart rate variability.

1:05:54 And that the things we ingest can have

1:05:57 a profound effect on them.

1:05:57 Now, of course, I really want to emphasize something

1:06:00 which is that no one compound or nutrient

1:06:04 or supplement or drug or behavior for that matter

1:06:08 is going to be the be all end all

1:06:11 of shifting out of depression

1:06:13 or improving one's mood or improving sleep.

1:06:16 It's a constellation of things.

1:06:18 And this is especially true

1:06:20 when people start to get excited about supplements and drugs

1:06:22 of all kinds and their potential for various things.

1:06:25 Right now, there's a lot of excitement about psychedelics

1:06:27 and their therapeutic uses.

1:06:28 And I think great, but as a good friend of mine

1:06:30 who's a physician clinician says

1:06:33 better living through chemistry

1:06:36 still requires better living.

1:06:39 You cannot expect to take a compound

1:06:41 regardless of source or potency

1:06:43 and have it completely shift your experience of life

1:06:46 without having to continue to engage

1:06:48 in the proper behaviors, all the things we know

1:06:50 proper sleep, exercise, social connection, food, et cetera.

1:06:53 There are many others as well.

1:06:56 So I still find that this collection

1:07:00 of studies about omega-3 to omega-6 ratios

1:07:02 to be profoundly important so much so that it's completely

1:07:05 changed the way that I think about food,

1:07:07 the foods I eat, I do supplement.

1:07:09 I don't necessarily that think that's for everybody

1:07:11 but I really think it's incredible

1:07:14 that there are these compounds

1:07:15 that have these robust effects

1:07:17 on our feelings of wellbeing.

1:07:18 And there are others too.

1:07:20 So that thousand milligram per day

1:07:22 threshold of fish oil that's beneficial

1:07:25 requires that one take a reasonable amount

1:07:28 of these things, either through food

1:07:29 or through supplementation.

1:07:31 I acknowledge that not everyone wants to take fish oil.

1:07:34 There are a couple of reasons

1:07:35 why one might want to avoid that.

1:07:37 One would be for ethical reasons.

1:07:39 You have an emotional relationship or a relationship

1:07:43 to the environment that makes you not want

1:07:44 to ingest fish related products.

1:07:47 There's krill oil.

1:07:48 Krill is still an organism.

1:07:50 It's a little tiny thing that whales eat a lot

1:07:52 of and people generally eat very little of.

1:07:54 So krill is out there, I personally, just me,

1:07:57 I don't know why, I didn't react well to krill.

1:08:00 It didn't make me feel very good.

1:08:02 I had some like kind of skin itches and things like that.

1:08:04 And they stopped when I stopped taking it

1:08:06 but I don't want to bias you against it.

1:08:09 If that's your preference.

1:08:09 Some people really like krill oil

1:08:11 as a source of omega-3s.

1:08:13 I did mention some of the other sources

1:08:15 like chia seeds and flax seeds, but as you'll notice

1:08:19 these are not things that we tend to ingest a lot

1:08:21 of on a regular basis.

1:08:22 It is possible to get omega-3s from meats.

1:08:25 If the animals have grazed

1:08:26 on grasses that contain a lot of omega-3s.

1:08:29 So for those of you that ingest meat

1:08:33 you're the source of those meat is gonna

1:08:36 be very important as it relates to omega-3s.

1:08:38 Even within the category of fish oil

1:08:41 there's a concern sometimes

1:08:44 about mercury and other contaminants.

1:08:46 You want to go with a brand that emphasizes

1:08:49 that they've gone to really good sources

1:08:52 and that they decontaminate regardless.

1:08:55 And so you have to search out those brands.

1:08:58 There is a test that you can do as

1:09:00 to whether or not the fish oil is a rancid or not.

1:09:03 Some people take it in liquid form.

1:09:05 Some people take in capsule form.

1:09:06 The liquid form is gonna be more affordable.

1:09:08 The capsule form is more

1:09:09 is a little easier and a little more portable.

1:09:13 You can actually just chew one of the gel tablets.

1:09:18 And if it tastes really fishy kind of rancid,

1:09:20 you'll know it's disgusting.

1:09:22 You want to spit it out.

1:09:23 And if it doesn't and it's tolerable

1:09:25 then you'll know that that it's okay.

1:09:26 Unfortunately you have to buy it first in order to do that.

1:09:28 Although, I don't know, maybe you can get them to open

1:09:31 up the bottle for you in the store

1:09:32 and tell them you want to try it.

1:09:34 Someday perhaps fish oil and omega-3,

1:09:37 it'll be like tasting wine

1:09:38 at a restaurant where you can send it back for now.

1:09:40 I think you have to purchase it first,

1:09:42 but find a brand you trust in like, and then work with them.

1:09:46 If you decide to go that route of course.

1:09:48 There are other compounds that are also interesting

1:09:50 for mood elevation that are essentially like foods

1:09:56 or are supplement based that now, fortunately,

1:10:00 there are really good data from peer reviewed studies.

1:10:03 And the next one I want to mention

1:10:05 because I think it's really interesting is L-carnitine.

1:10:08 Now, L-carnitine has been around a long time

1:10:11 and it's been discussed in the context

1:10:12 of heart health and a number of other things.

1:10:14 It was actually being touted as a bit of a weight loss agent

1:10:17 in the early nineties, but L-carnitine actually

1:10:21 has some really impressive effects on depression.

1:10:25 And again, we will look to PubMed

1:10:29 because looking at examine.com is essentially for me anyway

1:10:32 looking at PubMed, what is L-carnitine okay.

1:10:34 L-carnitine is most prevalent in meat

1:10:36 and in beef in particular.

1:10:38 Now for the vegans, please know that L-carnitine

1:10:41 is available through non-meat sources as well.

1:10:44 Although it's not as enriched in non-meat sources.

1:10:46 It's a really interesting molecule because acetylcarnitine

1:10:50 is essentially what's made from L-carnitine

1:10:53 but it's acetylated.

1:10:55 If you're interested in the biochemistry,

1:10:56 you can look that up,

1:10:57 it's acetylated into a form that can cross

1:11:00 the blood-brain barrier.

1:11:01 The blood-brain barrier or BBB is a barrier.

1:11:04 It's a wall around the brain and you have this barrier

1:11:08 because the brain is so important.

1:11:11 And it has this feature that the neurons there

1:11:13 don't recreate themselves after injury,

1:11:15 like other organs of the body.

1:11:17 There's not a lot of turnover of cells despite

1:11:19 what you might've heard.

1:11:20 And so nature has created this BBB,

1:11:22 this blood brain barrier to make sure that certain molecules

1:11:26 in particular, large molecules don't get across

1:11:28 the blood-brain barrier.

1:11:29 'Cause it can be damaging to those tissues.

1:11:31 Incidentally,

1:11:32 you also have a very rigid or stringent barrier

1:11:36 around other organs, which are the gonads.

1:11:39 So the ovaries and the testes

1:11:41 and the brain are the organs

1:11:43 of the body that nature has gone out

1:11:45 of its way to protect, give this additional layer

1:11:49 of the blood-brain barrier

1:11:50 or as you might imagine for the testes

1:11:53 and the ovaries, it's going to be

1:11:55 the blood gonadal barrier.

1:11:57 So these barriers exist

1:11:59 to make it such that just because you eat something,

1:12:02 just because you ingest it doesn't mean it's going

1:12:04 to cross the blood-brain barrier,

1:12:05 but L-carnitine when taken is

1:12:07 acetylated and converted into this form

1:12:10 that gets across the blood-brain barrier.

1:12:12 And it has a lot of effects, it's involved

1:12:14 in mitochondrial activation of long chain fatty acids

1:12:17 which that's a big mouthful,

1:12:18 that we'll get into some time when

1:12:20 we're talking about metabolic,

1:12:21 but it has some interesting effects on the neuro side.

1:12:24 So if you decide to check it out on examine.com

1:12:28 you'll see some really interesting things,

1:12:29 lots of effects on ammonia, C-reactive proteins,

1:12:32 things of that sort, blood glucose is lowered, et cetera.

1:12:36 That's all stuff that's the level of blood and periphery,

1:12:39 slight effects in lowering cholesterol.

1:12:41 Here's some interesting ones.

1:12:44 Rates of pregnancy go way up when people

1:12:48 are taking L-carnitine both the father and the mother

1:12:52 but the source of sperm and the source of egg are affected

1:12:57 in ways that favors pregnancy.

1:12:59 It does increase,

1:13:00 here we go again with sperm quality sperm motility

1:13:03 in males and it seems to have positive effects

1:13:07 on females that have polycystic ovary syndrome.

1:13:11 So check that out.

1:13:12 You know, the effects are very strong.

1:13:14 There are three studies listed there.

1:13:16 Again, I'm not promoting this,

1:13:17 but that that people take L-carnitine,

1:13:20 especially if you're trying to get pregnant

1:13:22 but check it out because the effects there

1:13:24 and the studies that are mentioned are published

1:13:27 in peer reviewed rigorous journals.

1:13:29 In terms of the neural effects.

1:13:32 Those are quite interesting.

1:13:34 The effects on depression are still emerging

1:13:37 but they do seem to exist

1:13:38 that people feel a notable decrease in depressive symptoms.

1:13:42 There are seven studies listed on examine.com

1:13:45 that it has a notable benefit

1:13:47 in a variety of circumstances where participants

1:13:49 have heightened depression already.

1:13:51 They start taking L-carnitine and they start feeling better.

1:13:55 And they talk about dosages in those various studies.

1:13:57 It also has been shown to have a notable decrease

1:14:01 in the symptoms of autism, which I find fascinating.

1:14:04 Also again, the things we ingest impact

1:14:06 the chemicals in our brain

1:14:09 and how they impact the rest of our body.

1:14:11 There's other things that's been used to treat certain forms

1:14:14 of alcohol dependence.

1:14:15 I think this is going to be a very exciting emerging area.

1:14:18 We're gonna do a whole month about addiction.

1:14:20 I've got a great guest lined up for that month,

1:14:23 but there's now an emerging field about what people can take

1:14:28 and supplement to help ease the cravings

1:14:31 and the withdrawal when trying to quit drugs of abuse,

1:14:34 like cocaine, alcohol, heroin, and smoking

1:14:37 and things of that sort.

1:14:39 So really interesting area.

1:14:41 This is, I like to think is the early days

1:14:43 and we're gonna discover a lot more.

1:14:44 There's a huge list of things here.

1:14:46 Since we talked about pain on a previous episode

1:14:49 and I know a lot

1:14:50 of people have written to me about fibromyalgia.

1:14:53 It does L carnitine has been shown

1:14:54 to reduce symptoms of fibromyalgia.

1:14:57 Again, all the links to studies are on examine.com,

1:15:00 totally free site.

1:15:02 And that was my bulldog being a battering ram.

1:15:05 There's nothing graceful about this bulldog.

1:15:07 He's decided he wanted to leave to go get a drink of water.

1:15:09 And so please forgive the noise.

1:15:12 Okay.

1:15:12 So now let's turn to another aspect

1:15:15 of the gut-brain relationship that will surprise you,

1:15:19 in some cases might shock you.

1:15:22 And that has some really cool and actionable biology.

1:15:25 And that's the gut microbiome, probiotics and prebiotics.

1:15:31 I know today we're talking about emotions and not pain

1:15:34 but I'd be remiss if I didn't mention another effect

1:15:36 of acetylcarnitine that's been reported

1:15:38 and that you can find listed with link

1:15:40 to study on examine.com

1:15:42 which is its effect in reducing the symptoms of migraine.

1:15:47 This was a randomized controlled trial

1:15:49 with 133 participants who had frequent migraines.

1:15:52 They were taking 500 milligrams

1:15:55 of L-carnitine or nothing for 12 weeks.

1:16:00 So the control is a little bit,

1:16:02 the control experiment there is a little bit tricky

1:16:04 but it had a significant effect

1:16:06 on reducing the number of migraine attacks per month.

1:16:08 So I find that really interesting

1:16:09 and there's a lot more listed there about the study.

1:16:12 And I think these compounds are powerful.

1:16:16 They carry risks for certain people, not for others.

1:16:19 So again, you have to find out what's right for you

1:16:22 but I do think they are super interesting

1:16:25 as potential therapeutics for various people.

1:16:29 So what's the deal

1:16:30 with the gut microbiome and the gut brain axis.

1:16:34 Today we've actually been talking a lot already about

1:16:36 the gut brain axis that has nothing to do with microbiomes.

1:16:40 We've been talking about this vagus nerve

1:16:42 that connects providing sensory information

1:16:46 from the body to the brain.

1:16:48 And then the brain also sends in the same nerve motor

1:16:53 information to control the motility that got the heart rate

1:16:56 how fast we breathe and deployment of immune stuff

1:17:01 killer cells and things of that sort.

1:17:03 But oftentimes when we hear about the gut brain axis

1:17:08 these days, it's a discussion about the gut microbiome.

1:17:13 And once again, we're in a situation where

1:17:15 there's incredible biology,

1:17:16 I'm very happy there's so much discussion

1:17:19 about the gut microbiome.

1:17:21 I am somewhat dismayed and concerned that most

1:17:24 of what I hear out there is either false or partially false.

1:17:29 So we're gonna clear up some

1:17:30 of the misconceptions, first by understanding the biology.

1:17:34 And then we're going to talk

1:17:35 about some of the actionable items.

1:17:38 It is true that we have a lot of these little

1:17:42 microorganisms living in our gut.

1:17:46 They're not there because they want to help us.

1:17:49 They don't have brains, they are adaptive however,

1:17:52 they try and find and create environments

1:17:56 that make it easier for them to proliferate.

1:17:59 So they don't care about you and me

1:18:01 but they are perfectly willing to exploit you

1:18:03 and me in order to make more

1:18:05 of themselves the same way viruses are,

1:18:06 viruses don't have a mind, they infect cells,

1:18:10 they hijack the genome,

1:18:11 and they use that genome to make more of themselves.

1:18:16 The microbiota that live in us

1:18:19 vary along the length of our digestive tract.

1:18:22 But let's just take a step back

1:18:23 and think about how our body plan is made.

1:18:26 We are actually a series of tubes.

1:18:28 Our brain is actually a tube.

1:18:29 You see, it's all squishy on the outside.

1:18:31 And then it's got that long thing.

1:18:33 The spinal cord that goes down to the base of the spine.

1:18:35 That's the central nervous system

1:18:36 that all started out as a tube.

1:18:37 It just looks like a cauliflower on the other end

1:18:41 up in the brain because the tube is so big

1:18:45 and it has to be crammed into the skull.

1:18:46 So it gets all wrinkled up.

1:18:48 But if we were to splay it out

1:18:49 you'd find that it's just one big tube.

1:18:51 Similarly, our digestive tract

1:18:54 and our airways are essentially one big tube.

1:18:57 It starts with our mouth, also our nose.

1:19:00 And then we have all these other tubes.

1:19:01 They go down through our throat and then

1:19:03 into our stomach and then into our various intestines.

1:19:07 And then the tube ends out the other end.

1:19:10 So we are one long tube for digestion.

1:19:12 And inside of that tube is a mucosal lining.

1:19:16 It's these little microvilli, tiny, tiny, tiny little

1:19:19 like velvety ends of cells that are able to move

1:19:24 and move things along and mucus mucosa.

1:19:29 And the conditions

1:19:30 of that mucosal lining set a number of different things.

1:19:34 It sets the rate

1:19:36 of our digestion and the quality of our digestion.

1:19:38 It sets for instance, our immune system.

1:19:41 Most people probably don't realize this, but most infections

1:19:43 in the environment have to get into our body somehow.

1:19:47 Some of them are inhaled.

1:19:49 A lot of them go into our mouth

1:19:51 and lodge in the mucosal lining of the mouth.

1:19:53 And then infection start there.

1:19:56 You probably had the experience, unfortunately,

1:19:58 of you know, feeling like you have a tick in your throat,

1:20:00 like something's irritating your throat.

1:20:01 And then it kind of migrates up into a head cold

1:20:03 or runny nose.

1:20:06 Sometimes it'll start as headache.

1:20:07 Sometimes it won't, but things that are inert

1:20:11 can migrate down into the gut.

1:20:12 So we're ingesting things all the time.

1:20:14 Think about air, bacteria, viruses,

1:20:17 they're making their way into our gut.

1:20:19 And some of those bacteria live in the gut.

1:20:21 And some of those bacteria bias the mucosal lining

1:20:26 in the gut, stomach and intestines

1:20:29 to be more acidic or more basic

1:20:33 so that they can make more of themselves

1:20:36 so they can replicate.

1:20:37 They like a particular comfort.

1:20:38 It's like they like a particular kind

1:20:41 of bedding to lie down in and create more of themselves.

1:20:44 Now, some of those those mucosal linings

1:20:48 that they promote make us feel better.

1:20:50 They make us feel more alert.

1:20:51 They bolster our immune system

1:20:52 and others make us feel worse.

1:20:54 So first rule, the microbiome isn't good or bad.

1:21:00 Some of these little bugs

1:21:01 that live in us do bad things to us.

1:21:03 They make us feel worse.

1:21:05 They lower our immunity.

1:21:06 They affect us in negative ways.

1:21:08 Some of them make us feel better and they do that mainly

1:21:11 by changing the conditions of our gut environment.

1:21:16 In addition to that, they do impact

1:21:19 the neurotransmitters and the neurons that live in the gut.

1:21:25 And that signal up to the brain to impact things

1:21:27 like dopamine and serotonin

1:21:28 that we've been talking about previously.

1:21:31 So there's a vast world now

1:21:34 devoted to try and understand what sources of food

1:21:38 what kinds of foods are good or not good

1:21:41 for the gut microbiome?

1:21:42 So let's just talk about some general rules of thumb related

1:21:45 to the research quality research that's peer reviewed.

1:21:48 And then in a future episode

1:21:49 we will go far deeper into the gut microbiome

1:21:52 and gut brain axis.

1:21:54 But here's a few things

1:21:56 that I think you might find surprising.

1:21:58 First of all,

1:22:00 supporting a healthy gut microbiome is good for mood,

1:22:04 great for digestion and great for immune system function.

1:22:09 However, that does not mean maxing out

1:22:13 or taking the most probiotic

1:22:15 and prebiotic that you can possibly manage.

1:22:18 As I mentioned many times before

1:22:19 I do believe in probiotics, I take probiotics

1:22:22 but there are studies that show that

1:22:24 if you take lots and lots of certain probiotics

1:22:27 like lactobacillus and you really ramp up the levels more

1:22:30 it is not a case of more is better.

1:22:32 There are things like brain fog that can come from that,

1:22:37 brain fog is just this inability to focus.

1:22:39 People feel really not well generally.

1:22:41 Some of those studies are a little bit controversial

1:22:43 but I think it's fair to say

1:22:44 that if people really increase the amount

1:22:48 of probiotic that they're taking beyond a certain amount

1:22:52 then they start feeling foggy in the mind.

1:22:55 Now what's too much?

1:22:57 Well I get probiotics

1:22:59 I mentioned before from Athletic Greens,

1:23:01 you can get them from fermented foods

1:23:03 like sauerkraut, pickles, kimchi natto,

1:23:07 these are different sources from around the world.

1:23:09 Actually, I'd love to hear some

1:23:11 of the other sources that people know other foods

1:23:13 from around the world.

1:23:14 I'm fascinated by the way

1:23:16 in which different cultures have all arrived

1:23:19 at these foods that provide

1:23:22 and support healthy microbiomes because they're fermented.

1:23:26 I have a colleague at Stanford, Justin Sonnenberg,

1:23:28 and he and I have talked about this.

1:23:29 I don't want to quote him inappropriately,

1:23:33 but we've had discussions about it,

1:23:35 and they've published that the ingestion

1:23:37 of fermented foods is one

1:23:39 of the best ways to support healthy levels

1:23:41 of gut microbiota without exceeding the threshold

1:23:45 that would cause things like brain fog.

1:23:47 So foods and fermented foods

1:23:50 are going to be the best source.

1:23:51 And there are a number

1:23:53 of different ways that one could do that.

1:23:54 Some people don't like fermented foods,

1:23:56 however some people supplement it.

1:23:58 So it isn't a case of more is better.

1:24:00 So we know that.

1:24:02 The other is that it is true

1:24:04 that healthy gut microbiota have been shown to

1:24:07 improve symptoms of certain psychiatric illnesses

1:24:11 as well as certain conditions like particular features

1:24:15 along the autism spectrum, which is interesting.

1:24:17 And those effects are probably due to not just improvement

1:24:21 of immune system function,

1:24:24 but to the the conditions in which the neurons

1:24:27 that sense nutrients convey information to the brain

1:24:30 and increase levels of serotonin and or dopamine.

1:24:34 So gut microbiome provides kind of a foundation

1:24:37 for healthy gut and healthy gut brain access

1:24:41 so much so that some people report

1:24:42 that when they start eating small bits

1:24:45 'cause it doesn't require a lot of fermented foods,

1:24:47 that their overall mood is better,

1:24:49 not unlike the effects of EPA.

1:24:50 Although I don't think it's been looked

1:24:51 at directly in the context of clinical depression yet.

1:24:55 And if someone knows of a study

1:24:57 please mention it in the comments.

1:24:58 That would be terrific.

1:25:01 There are some things that you can do to really

1:25:02 damage your gut microbiome.

1:25:04 And this is where there's a huge misconception

1:25:06 that I want to clear up.

1:25:08 There was a study that was published in "Nature",

1:25:09 which is among the three top journals

1:25:10 that we have in science.

1:25:13 You know, "Nature", "Science"

1:25:15 and "Cell" are considered the top tops,

1:25:17 but excellent journal that showed

1:25:20 that artificial sweeteners

1:25:21 but a particular artificial sweetener

1:25:23 which was saccharin can disrupt the gut microbiome

1:25:28 in ways that is detrimental

1:25:30 to a number of different health markers,

1:25:32 increasing inflammatory cytokines

1:25:34 and all the other bad things that happen when

1:25:36 the gut microbiome is thrown off kilter.

1:25:41 That study was widely discussed

1:25:43 but there were a few things that were not

1:25:46 mentioned there that are really important.

1:25:47 That study was about saccharin in particular.

1:25:52 Saccharin is not the most typical artificial

1:25:56 sweetener that's used, the most typical

1:25:58 artificial sweeteners that are used are things

1:26:00 like aspartame, so-called NutraSweet or Sucralose,

1:26:04 or these days Stevia, there's monk fruits, to my knowledge

1:26:07 and please correct me if anyone knows of any studies,

1:26:10 to my knowledge, the negative effects

1:26:13 of these artificial sweeteners

1:26:15 on the gut microbiome were restricted to saccharin.

1:26:20 Now there is enough chemical similarity

1:26:22 between saccharin and some

1:26:23 of the other ones that I mentioned, but not all of them.

1:26:25 For instance, Stevia, monk fruit are distinct

1:26:29 in their chemical makeup so that they probably don't have

1:26:34 if they have any, have lower effects, negative effects

1:26:37 on the gut microbiome, but it should still be tested.

1:26:40 So saccharin is really, it was shown in this study

1:26:43 and several other studies can really negatively

1:26:46 impact the quality of the gut microbiome.

1:26:51 Interestingly, the narrative around artificial sweeteners

1:26:54 and gut microbiome is incorrect.

1:26:58 Most people thought,

1:26:59 oh, saccharin is bad for the microbiome.

1:27:02 It must kill the microbiome.

1:27:04 And so you hear people saying,

1:27:06 oh, artificial sweeteners kill the microbiome.

1:27:08 That's not true at all.

1:27:09 In fact, in that very same study published in nature

1:27:11 they showed that the negative affects

1:27:13 of saccharin on the microbiome could be blocked

1:27:16 or eliminated by giving antibiotics.

1:27:19 So what happens is certain artificial sweeteners

1:27:22 in particular saccharin disrupt the microbiome

1:27:25 and make the environment

1:27:28 within the gut that mucosal lining more favorable

1:27:32 to bacteria microbiota that are not good for the organism.

1:27:38 This is an important distinction.

1:27:40 It's not just a language thing where people say,

1:27:42 oh, you know, it kills the microbiome.

1:27:44 It doesn't kill the microbiome.

1:27:45 It shifts the microbiome and shifts

1:27:49 in the microbiome can be good or they can be bad.

1:27:51 And that takes us to another topic

1:27:52 that's a bit of a hot button topic

1:27:54 but I'm willing to go there.

1:27:55 'Cause I think it deserves conversation,

1:27:58 which is nowadays there are many examples out there

1:28:01 where people have switched from a kind of standard diet

1:28:04 or even a vegetarian diet to a vegan diet, to a keto diet.

1:28:09 Now keto doesn't necessarily have to mean

1:28:11 the ingestion of meats, but it can.

1:28:13 And they experience positive effects for themselves.

1:28:17 Not everybody.

1:28:17 And I've talked previously about some of the

1:28:21 kind of the incorrect,

1:28:23 what I believe is incorrect marketing of keto

1:28:25 as it relates to the cosmetic effects

1:28:28 and some of the challenges with sleep that some people have

1:28:30 but some people love keto and it works great for them.

1:28:32 But the ketogenic diet is interesting

1:28:35 because when one shifts to the ketogenic diet

1:28:37 there is a shift in the gut microbiome.

1:28:39 And some people end up feeling better.

1:28:41 Some people end up feeling worse.

1:28:44 Likewise, some people go from ingesting animal products

1:28:49 including meat or they're vegetarian and they go to vegan

1:28:52 and they experience positive shifts in mood and affect.

1:28:58 And we know that the transition to a more

1:29:00 plant-based diet and especially the enrichment of fiber

1:29:04 that's present in those diets also creates dramatic shifts

1:29:08 in the gut microbiome.

1:29:09 Some people feel better doing that.

1:29:11 Some people feel worse.

1:29:12 And of course, it's gonna depend on whether

1:29:14 or not you're ingesting a lot of processed foods or not.

1:29:16 There was a paper published in "Cell",

1:29:18 "Cell Press" journal obviously, excellent journal,

1:29:21 showing that ingestion of processed foods,

1:29:23 regardless of whether or not they come

1:29:25 from animal sources or non-animal sources

1:29:27 the processed foods themselves tend to create activity

1:29:31 within the body and this surely has roots

1:29:34 in the nervous system that lead

1:29:35 to over-consumption of calories and weight gain.

1:29:38 Even some weight gain that couldn't be explained

1:29:40 by increased calories.

1:29:41 In other words, processed foods are bad, regardless of

1:29:44 whether or not you're talking about animal products

1:29:45 or non animal products, probably not surprising

1:29:48 given what you know about these sugar sensing

1:29:50 and other amino acid sensing cells

1:29:52 in the gut that we talked about earlier.

1:29:54 So the point of all this is that when I say you have to

1:29:58 find what's right for you, that's not a throwaway statement.

1:30:00 Some people's microbiome and the lining

1:30:04 of their mucosa, excuse me,

1:30:09 their mucosa lining of their throat,

1:30:10 of their gut, of their nose,

1:30:12 everything is improved by diets that are heavily meat based

1:30:16 and don't have many plants.

1:30:17 Other people do much better on a plant-based diet

1:30:19 without many meat products or animal products.

1:30:22 It's highly individual.

1:30:23 And this probably has roots in genetic makeup.

1:30:26 This probably has roots in what people were raised

1:30:30 on because remember the nervous system of course

1:30:32 is set up by your genetic, your genes, your genetic program

1:30:35 but your nervous system adapts early

1:30:38 in life to your conditions.

1:30:40 That's what it's for,

1:30:41 the reason you have a nervous system is to move

1:30:43 your body appropriately towards things that are good

1:30:45 for you and away from things that are not.

1:30:47 But also it was designed to adapt.

1:30:50 The early life period has this incredible thing

1:30:52 about plasticity that we spent a whole month

1:30:54 on so that it can change so that yes

1:30:56 indeed some people may like certain foods

1:30:58 and react to certain foods better than others

1:30:59 because of the way that their nervous system was wired.

1:31:03 This enteric as it's called nervous system

1:31:05 that lines the gut and the communicates with the brain.

1:31:08 So most of what I've talked

1:31:09 about today is kind of black and white.

1:31:12 These are things that are present in all of us,

1:31:14 the sugar sensing neurons of the gut,

1:31:15 the way the vagus is wired.

1:31:17 The fact that omega-3 omega-6 is tend to improve.

1:31:20 The ratios tend to impact mood with high omega-3.

1:31:22 omega-6 ratios improving mood.

1:31:25 We talked about all sorts of things in the gut brain

1:31:28 and body brain axis, but when it comes to the microbiome

1:31:31 the key thing is that we all have a microbiome.

1:31:34 You want a microbiome, but you want to

1:31:36 promote the microbiome that is right for you.

1:31:40 And that can be shifted and steered

1:31:42 by ingesting certain categories of foods and not others.

1:31:46 And one thing that really frustrates me is when

1:31:49 the people show up with an agenda,

1:31:52 like all meat agenda or a vegan agenda

1:31:54 or a keto agenda, and they talk about these positive effects

1:31:57 on the gut microbiome.

1:31:58 And it's all true, frankly.

1:32:00 And so it's highly individual.

1:32:01 Now this doesn't get to any of the ethical issues

1:32:03 around animals or the planet,

1:32:06 and you hear rabid debates about that on both sides.

1:32:10 And I am not qualified or equipped to talk

1:32:13 about whether or not regenerative agriculture,

1:32:15 animal products, or farming or any of these things,

1:32:18 how those actually impact the environment,

1:32:20 that is not my expertise,

1:32:21 but when it comes to your health and your microbiome

1:32:24 you want to support the microbiome.

1:32:26 It's very clear

1:32:27 that these fermented foods support the microbiome

1:32:30 that we should be ingesting at least two servings per day.

1:32:33 Which is quite a lot that supplementation

1:32:36 at low levels can be good.

1:32:38 Supplementation at high levels can create this brain fog

1:32:41 even though some people say that result is controversial.

1:32:43 I've experienced this myself and the data looked

1:32:46 to me pretty darn solid.

1:32:49 So that's one thing to think about as well.

1:32:52 And the other thing about the gut microbiome

1:32:55 is that it's highly contextual based

1:32:57 on other things that you're doing.

1:32:58 So even things like exercise and social well-being

1:33:01 and connection, those things are also impacting

1:33:03 the gut microbiome.

1:33:05 So find the diet that's right for you.

1:33:06 And that works for you in the context of the other ethical

1:33:09 and lifestyle choices that are important to you.

1:33:12 That's my advice.

1:33:13 A note about fasting.

1:33:15 I have a colleague at Yale, who's an expert

1:33:16 in the gut microbiome.

1:33:18 And he told me something really interesting,

1:33:20 which is when we fast,

1:33:24 we actually digest certain components

1:33:27 within our dietary tract.

1:33:30 It actually depletes a good amount of the gut microbiome.

1:33:33 And this is interesting.

1:33:35 I've had good results

1:33:36 from I guess you would call it intermittent or kind

1:33:38 of circadian type fasting where I've never done long fast,

1:33:41 but where I push out my first meal by a few hours

1:33:43 my first meal is generally around lunchtime or so

1:33:46 but the longer periods of fasting that go for a day

1:33:50 or two or three days are known to deplete

1:33:52 the gut microbiome in major ways.

1:33:56 But that's not always necessarily a bad thing

1:33:58 because when it's replenished, it often is replenished

1:34:02 at levels that exceeded its previous level.

1:34:05 But I think that some of the GI tract and even some

1:34:09 of the mental effects of returning to eating after feeding

1:34:12 sometimes people don't feel so good when they start eating.

1:34:14 They really want food, but then they start eating again.

1:34:17 They don't feel as good as they did on the fast.

1:34:18 Some of that may be related to the depletion

1:34:20 of the microbiome that occurs during long fast.

1:34:23 So again, this is something to think about and talk about

1:34:25 with your doctor, but the idea that fasting

1:34:28 across the board is good.

1:34:30 There may be some merits to that, and certainly

1:34:32 in some cases, but it does deplete the microbiome

1:34:36 and that depletion of the microbiome is significant

1:34:39 because it means when you return to eating, you're actually

1:34:41 not in the same position to digest

1:34:43 and assimilate those foods.

1:34:45 And those foods are not in the same position to

1:34:47 impact your brain and body the same way

1:34:48 they were prior to the fast.

1:34:50 And this is, I think why people suggest a kind

1:34:52 of gradual transition back

1:34:54 to consuming nutrients after a fast.

1:34:58 So as we round up, I want to share some results with you

1:35:00 That without question will impact the way that you respond

1:35:05 to food mentally and even physically.

1:35:08 And I know that because that's the central theme

1:35:11 of the studies I'm about to tell you about.

1:35:13 I have a colleague at Stanford, Alia Crum,

1:35:16 who's done some remarkable experiments on mindset.

1:35:21 And some people could think about these as placebo effects

1:35:24 or belief effects,

1:35:27 but they actually go way beyond those terms.

1:35:29 And there are a number of different examples

1:35:31 of this that Aaliyah's lab

1:35:33 and her coworkers have demonstrated.

1:35:35 But two that are particularly interesting to me

1:35:38 I Want to share with you now

1:35:40 because they really emphasize how

1:35:42 our beliefs can really impact the way that our brain

1:35:45 and body work together.

1:35:47 I think the most famous of these is an experiment they did

1:35:50 where they had two groups of individuals.

1:35:52 They were each given a milkshake and they had some factors

1:35:58 measured from their blood by an IV while they

1:36:01 ingested the milkshake.

1:36:02 And then afterwards as well.

1:36:04 And one of the factors that they were looking

1:36:06 at was something called grehlin, G-H-R-E-L-I-N.

1:36:10 Grehlin is a peptide that increases with hunger.

1:36:13 So the longer you haven't eaten that grehlin goes up.

1:36:16 And I know some of you say, well, I fast, I fast, I fast

1:36:18 and I eventually lose my appetite.

1:36:20 Well, grehlin still goes up and then it drops.

1:36:22 So if you were one of these people that eats every three

1:36:25 hours regularly, grehlin kind of gets a little pulse

1:36:28 as you get to that two hour and 50 minute mark.

1:36:30 So it's a little bit of a timer as well.

1:36:32 It's really interesting peptide.

1:36:34 In any event, what they did is they gave people milkshakes,

1:36:39 two groups, one group got a shake that they were told

1:36:42 it was a low calorie, healthy shake.

1:36:44 The other got a milkshake that they were told

1:36:48 it was the very decadent high calorie shake.

1:36:52 I think it was something like two or maybe even two

1:36:54 and a half times as many calories as the other.

1:36:57 Perhaps even more, I don't recall the details,

1:36:59 but you got a high calorie

1:37:00 and a low calorie condition.

1:37:02 And then they drank the shake

1:37:04 and then they measured grehlin in these subjects' blood.

1:37:08 And what they found was that the high calorie shake

1:37:12 had a much more robust effect

1:37:13 on blunting grehlin and reducing grehlin.

1:37:18 But the interesting thing you probably guessed already is

1:37:21 that it was the exact same shake given to both groups.

1:37:24 So people's belief about the content

1:37:27 of something impacted their physiology.

1:37:30 And this speaks to the so-called top

1:37:33 down mechanisms or modulation of our physiology.

1:37:36 In a previous episode about pain

1:37:38 we talked about the effects of obsessive

1:37:41 believe it or not, it was an obsessive infatuation

1:37:44 and love on pain responses and pain thresholds.

1:37:47 This is yet another example where beliefs

1:37:49 or subjective feelings can impact physiology

1:37:52 at the level of the periphery,

1:37:54 because grehlin is released in the periphery in the body.

1:37:57 Now, these beliefs affects

1:38:00 extend beyond examples like this,

1:38:01 another good example that I'd like to share

1:38:03 is Alia, Dr. Crum,

1:38:07 and her colleagues did an experiment where

1:38:09 they took housekeepers,

1:38:11 they were essentially hotel workers,

1:38:13 divide them into two groups.

1:38:15 They had them watch a short film.

1:38:17 In one case, the film was about how

1:38:18 their work was important to help people feel comfortable

1:38:21 in the hotel, et cetera, et cetera.

1:38:23 The other group heard that the activity that they were

1:38:26 doing cleaning and taking care

1:38:27 of the hotel was good for them.

1:38:29 It was good for their health, et cetera, et cetera.

1:38:32 They controlled very nicely in the study

1:38:34 for health parameters, for individual differences.

1:38:39 And for the behaviors of these people in the period

1:38:41 that followed this short tutorial.

1:38:43 And what they found was eight weeks later,

1:38:47 the group that had been told that the activity was good

1:38:51 for them showed lower blood pressure.

1:38:53 They had lost a significant amount of body fat

1:38:56 and they reported enjoying their work far more

1:38:59 than the other group.

1:39:00 The same work, simply biased mentally

1:39:03 by the information that they were given,

1:39:06 but their physiology followed that information.

1:39:10 And so this is not just the placebo effect.

1:39:14 This is an incredible set

1:39:15 of findings that illustrate the extent to which whether

1:39:18 or not we believe a food is gonna be good

1:39:20 for us or not good for us.

1:39:22 Well, we can't escape the reality.

1:39:24 You can't tell yourself that a poison is gonna be good

1:39:26 for you and ingest that poison

1:39:27 and expect it to not kill you,

1:39:30 nor can you tell yourself that eating 12 croissants,

1:39:34 I confess I've done it,

1:39:36 it was after a very long run, a long time ago

1:39:39 but you can't tell yourself

1:39:40 that that's necessarily going to be good

1:39:42 for you or that it's gonna make you lose weight.

1:39:44 These belief effects are not about lying

1:39:47 to yourself in these cases, in these experiments

1:39:49 as you'll notice that subjects didn't have prior knowledge

1:39:53 about grehlin or about the effects

1:39:55 of their daily routine on weight loss and blood pressure.

1:39:58 So in order for them to work

1:40:00 you have to be naive to the information, right?

1:40:03 You can't simply lie to yourself

1:40:05 and tell yourself what you want to believe

1:40:07 and that's important, but also important is that the mind

1:40:12 and the body are in this fascinating interplay.

1:40:14 And today we've talked mainly about how the body

1:40:17 and things that we put inside this tube,

1:40:20 that runs from our mouth to the other end to our rectum,

1:40:24 basically is impacting all these cells,

1:40:28 these neurons, microbiota in their mucosal lining,

1:40:32 heart, lungs and how all that information is feeding

1:40:35 up to the brain to impact how we feel up here.

1:40:38 But also how we feel up here is impacting

1:40:40 how our body reacts at levels

1:40:43 of very core physiology that you couldn't just tell yourself

1:40:46 that this was gonna work, but what you believe

1:40:49 about certain substances, certain foods,

1:40:51 certain nutrients does have a profound effect

1:40:54 on the magnitude of their impact

1:40:57 and sometimes even the quality and direction of that impact.

1:41:01 Well, first of all,

1:41:02 I want to thank everybody for their support of this podcast.

1:41:05 The response that we've received since releasing

1:41:07 at the beginning of the new year has been tremendous.

1:41:10 And we're so grateful for it.

1:41:11 I know some of you and people I've said,

1:41:14 well, it's a lot of information.

1:41:16 It's like a college lecture.

1:41:18 Indeed, there's a lot of information,

1:41:20 but I believe very strongly that if you learn mechanism

1:41:23 and maybe even if you hear it several times over

1:41:26 eventually those mechanisms become embedded

1:41:28 into the way that you view an entire topic.

1:41:31 As well, I always try and put tools

1:41:33 as I go along that you can look to immediately.

1:41:36 Some of them might be right for you.

1:41:37 Others might not,

1:41:39 try them if you like and don't if you don't want to,

1:41:41 and if they don't work for you, then discard them.

1:41:45 If however, you are finding benefits

1:41:46 from the information and from the tools and you know

1:41:49 others that you think could benefit from it,

1:41:51 please pass along information about the podcast.

1:41:55 Please subscribe to the YouTube channel

1:41:56 if you haven't already,

1:41:58 please subscribe to us on Apple and Spotify,

1:41:59 if you haven't already.

1:42:01 Please leave a review

1:42:02 in the comment section here on YouTube.

1:42:04 Also, if you feel we deserve it

1:42:05 please give us a five-star review on Apple.

1:42:07 All those things really help us.

1:42:09 In addition, if you'd like to support the podcast further

1:42:12 we've set up a Patreon account.

1:42:14 It's patreon.com/andrewhuberman.

1:42:17 It allows you to support the podcast at a variety of levels.

1:42:20 We have the 5-HTP serotonin for $5 a month,

1:42:24 the Costello, $10 a month

1:42:26 in honor of Costello, et cetera.

1:42:28 You don't have to but if you'd like to,

1:42:30 that would be terrific.

1:42:31 In addition, please check out our sponsors

1:42:34 that we've mentioned at the beginning of the podcast.

1:42:35 That's one of the best ways to help support us.

1:42:37 And we do believe in all the products that we support

1:42:41 and our sponsors very much otherwise

1:42:43 we wouldn't be working with them.

1:42:45 So much so that when I mentioned supplements

1:42:48 and I talk about supplements throughout the course

1:42:50 of the episodes, I don't mention specific brands,

1:42:53 but I would be remiss if I didn't mention the fact

1:42:56 that we have partnered with Thorne, T-H-O-R-N-E.

1:43:01 And we've done that because we know

1:43:03 that Thorne uses the highest levels

1:43:05 of stringency in terms of the products they produce.

1:43:09 What they say is in each capsule

1:43:11 and tablet actually is,

1:43:13 they're used by the Mayo Clinic,

1:43:14 by all the major sports teams

1:43:15 because of their level of stringency and rigor.

1:43:18 If you want to know what supplements I take

1:43:20 you can go to thorne.com/u/huberman.

1:43:25 And you can see the supplements that I take

1:43:27 and you can get those as well

1:43:28 as any of the other supplements

1:43:30 and products that Thorne makes for 20% off.

1:43:33 So it's thorne.com/u/huberman to get 20%

1:43:38 off any supplements that Thorne makes.

1:43:41 So in today's episode, we took a full journey

1:43:44 into the brain body relationship

1:43:45 and discussed a lot of the mechanisms

1:43:47 and the actionable items that you can approach

1:43:50 if you want to explore this aspect

1:43:52 of your biology and psychology further.

1:43:54 Last, but certainly not least,

1:43:56 I want to thank everybody

1:43:58 for your time and attention today,

1:43:59 and as always, thank you for your interest in science.

1:44:03 [upbeat music]