Announcing Dexa – The magic of Huberman AI for all your favorite podcasts.
Huberman AI for all your favorite podcasts
Request Early Access


Nutrients For Brain Health & Performance @ 01:08:01

And they and others in their field have done incredible experiments exploring how taste and food value, the nutritional value of food and the impact of that food on metabolism in the brain, drives our food choices and allows us to change our food choices for the better. Their groups have done some really amazing studies involving ingestion of a particular substance that either contains sugar and thereby can elevate glucose, blood sugar, or not, and varying, meaning changing the taste associated with that ingestion of sugar.

Dr. Alia Crum: Science of Mindsets for Health & Performance @ 00:19:49

Lots of studies have shown that believing you're eating different things changes your taste, even your satisfaction and fullness after. But this shows that it has a metabolic or a physiological component. But the second piece was really important as well. And especially for me, this was one study that really transformed the way I think about how I approach eating.

How to Optimize Your Brain-Body Function & Health @ 01:10:58

In fact, it appears is determined by your food eating history, the types of food you eat. And I think this might explain some of the divide and hopefully might bridge some of the chasm between these different groups that are saying it should be one way or it should be another. But at the core of the study was the bigger message.

Using Salt to Optimize Mental & Physical Performance @ 00:06:19

Now, what the downstream consequences of this sensing is, or what they are, isn't yet clear. Now, I believe everyone should be aware of these kinds of studies for a couple of reasons. First of all, it's important to understand that what you crave, meaning the foods you crave and the drinks you crave, is in part due to your conscious experience of the taste of those things, but also due to biochemical and neural events that start in the body and impinge on your brain and cause you to seek out certain things,

How to Enhance Your Gut Microbiome for Brain & Overall Health @ 00:28:43

Now, this brings us to some classic experiments that at least to me are incredible. And these are highly reproducible findings showing, for instance, that even if you bypass taste by infusing sweet liquid or putting sweet foods into the gut and people can never taste them with their mouth, people will seek out more of that particular food.

Nutrients For Brain Health & Performance @ 00:54:28

We take these foods, we break them down in our mouth by chewing them or sucking on them, whatever it is the food happens to be. Those chemicals bind to those receptors and electrical signals are sent into the brain, but they are just electrical signals, just like notes being played on the keys of a piano.

Dr. Alia Crum: Science of Mindsets for Health & Performance @ 01:13:40

And to me, that's interesting and important. It shows that where are we getting this mindset that those unhealthy foods are pleasurable, desirable? What's maybe even more interesting than that is some of the work that he and others in our lab have done to show that the ways people are talking about the foods they're eating really matter too.

Dr. Justin Sonnenburg: How to Build, Maintain & Repair Gut Health @ 01:23:25

So in a way they're a lot more controlled, but it's not food. When you start doing food studies, you can't do a placebo group because people know what they're eating. And the other problem is that it's really hard to just change one thing because as soon as you start adding something, people usually eliminate something else.

How to Optimize Your Brain-Body Function & Health @ 01:06:36

There was a study done by my colleague, Justin Sonnenberg at Stanford School of Medicine. Justin's actually my upstairs neighbor in the building at Stanford where I work. And they explored how different foods or different diets, I should say, impact the gut microbiome and inflammatory markers. And this is a beautiful study because it was done in hundreds of human patients.

ADHD & How Anyone Can Improve Their Focus @ 01:03:43

In addition to that, exploring whether or not they have existing allergies to foods they already consume might be a good idea. At least that's what this paper, the Pelser et al. Lancet paper seems to speak to. And I should mention that that paper was published in 2011. Since then, there have been many dozens of studies exploring the same thing, as well as meta-analyses of all those data.

Nutrients For Brain Health & Performance @ 01:09:32

They've also done experiments where they have no taste, but subjects are being infused with sugar directly into the gut. And not surprisingly, based on everything I've told you up until now, subjects will pursue more of that thing relative to some other taste, either neutral or negative taste, because that sugar in the gut is triggering the activation of the neurons I mentioned earlier, which is signaling to the brain to pursue more of that thing.

Dr. Justin Sonnenburg: How to Build, Maintain & Repair Gut Health @ 01:20:03

leading to better longevity and health over the course of our life. And so we were studying this actually in mouse models and realizing that we really needed to start doing human studies. We needed to start studying microbiome in humans. And because we were studying diet, we knew that this was something we could go in and do right away.

Controlling Sugar Cravings & Metabolism with Science-Based Tools @ 01:13:54

Now, even for people that are of healthy weight and who don't have metabolic syndromes, there may be an additional reason to not want to ingest very sweet foods and highly refined sugars. And this has to do with a new and emerging area of nutrition neuroscience. And I want to point out that these are new data, right? So it's not a lock, the double-blind placebo-controlled studies in large populations have not been finished.

Controlling Sugar Cravings & Metabolism with Science-Based Tools @ 00:42:54

This has been shown over and over and over again in animal models and in humans. This is especially true, I should mention, through the ingestion of sweet liquids. Now, this becomes a very important point to us a little later on when we talk about the proliferation of sodas and sweet drinks, and dare I even say non-sugar or diet sodas.

Controlling Sugar Cravings & Metabolism with Science-Based Tools @ 00:52:09

So this experiment is so crucial because what it says is that the preference for sugar containing foods is in part due to the sweetness of those foods, but in part due to something else. And this something else is what we call the post-ingestive effect. And as I mentioned before, it took about 15 minutes.

Controlling Sugar Cravings & Metabolism with Science-Based Tools @ 00:40:09

They literally change your perception. In fact, there are beautiful neuroimaging studies that show that when people ingest a sugary drink, their perception of images of foods change very much to make those foods appear more appetizing and not just foods that contain sugar. Results of those studies do show that there's an increase, for instance, in the perception of detail and images of ice cream after you ingest a sweet drink, or even put like a hard candy into your mouth.

Dr. Justin Sonnenburg: How to Build, Maintain & Repair Gut Health @ 01:40:19

But it's a super exciting study because it is one of these where people eat a certain way. And what's really beautiful about this is we even got food delivered for part of the intervention. So we had complete control over what they at least had available to eat. And then the second phase, they make the food on their own.

How Our Hormones Control Our Hunger, Eating & Satiety @ 00:50:44

In fact, the data in humans points to this. So what they did is they took inpatient adults, so they had total control over their food intake, and they received either ultra-processed or unprocessed diets for 14 days as a short study. The diets were matched for calories, sugar, fat, fiber, and macronutrients.

How Foods and Nutrients Control Our Moods @ 01:39:00

The same work, simply biased mentally by the information that they were given, but their physiology followed that information. And so this is not just the placebo effect, this is an incredible set of findings that illustrate the extent to which whether or not we believe a food is going to be good for us or not good for us, well, we can't escape the reality.

Nutrients For Brain Health & Performance @ 01:03:01

that leads you to go seek more of those foods. Now, this has profound impact on a number of things. First of all, there's the consideration of so-called hidden sugars. Dr. Robert Lustig, who's a pediatric endocrinologist at University of California, San Francisco, has been among the most prominent researchers to talk about the fact that there are the so-called hidden sugars in foods.

How Foods and Nutrients Control Our Moods @ 01:20:13

So we're ingesting things all the time. Think about air, bacteria, viruses, they're making their way into our gut. And some of those bacteria live in the gut. And some of those bacteria bias the mucosal lining in the gut, stomach and intestines, to be more acidic or more basic so that they can make more of themselves, so they can replicate.

Controlling Sugar Cravings & Metabolism with Science-Based Tools @ 00:39:44

A lot of people don't realize this, but there are a lot of taste receptors on the soft palate and around the mouth, so on the sides of the mouth, where you're actually tasting things, not just with your tongue, but with your entire mouth and your palate. So when you ingest something sweet, very quickly there are signals sent from those neurons in your mouth to brain areas that cause you to seek out, or at least pay attention to the source and the abundance of those sweet things.

Using Salt to Optimize Mental & Physical Performance @ 00:04:26

Your gut is sensing at a subconscious level what's in it and sending signals to your brain that work in concert in parallel with the signals coming from your mouth and your experience of the taste of the food. Now, that alone is incredible and has been the subject of many important landmark papers over the last decade or so.

How Smell, Taste & Pheromone-Like Chemicals Control You @ 01:39:24

So you may actually be eating more of particular foods, not because they taste good, but because they feel good on your tongue and mouth, and because the neurons in your gut, which are totally independent of conscious taste, are triggering the release of dopamine, which is a molecule that makes you seek more of and do more of anything that led to the ingestion of that food.

Controlling Sugar Cravings & Metabolism with Science-Based Tools @ 01:40:58

And those are interacting. If you ingest a substance that's just sweet or mostly sweet, that causes a certain set of effects on your blood glucose, but also your brain, dopamine, and the other neural circuits of your brain. If you also ingest something that's sour, like lemon juice or lime juice, it adjusts the output of those neural circuits in your brain.

Controlling Sugar Cravings & Metabolism with Science-Based Tools @ 00:58:30

And that has to do with how sugar is metabolized in the brain, or I should say how glucose is used. Without getting into too much detail, some of the more beautiful studies of neuroimaging and evaluating which brain areas are active when we eat certain foods were done by Dr. Dana Small's lab at Yale University and in some of her previous work when she was elsewhere.

Using Salt to Optimize Mental & Physical Performance @ 00:56:11

Again, pointing to the challenge in doing these epidemiological studies and really parsing what aspects of a change in some health metric is due to, for instance, the ingestion of more sugars versus more salts or simply because of the ingestion of more salts. It's a complicated, almost barbed wire topic by now, but we can start to pull apart that barbed wire tangle and start to evaluate some of the other people and other conditions that exist out there, maybe for you, that actually warrant more sodium intake

The Science of Vision, Eye Health & Seeing Better @ 01:43:31

But at present, these things are more or less in the kind of experimental or self-experimental phase. There are some good double-blind placebo-controlled studies like the egg yolk buttermilk study of all things, published in really good journals. Journal of Ophthalmology, Journal Investigative Ophthalmology and Vision Sciences.

Nutrients For Brain Health & Performance @ 01:38:11

You can find it very easily online. It was published in 2019. And it's a beautiful deep dive, although quite accessible to most people, about how different foods and the way that we perceive them impacts our brain and body and why we like the things we like and how to reshape what we like. So once again, we've done a fairly extensive deep dive into food and your brain, focusing first on how particular foods and compounds within foods that are available also through supplementation can impact immediate and long-term brain health.

How Our Hormones Control Our Hunger, Eating & Satiety @ 00:49:26

so they can make decisions about what they do want to eat or not want to eat for themselves. Before moving on, I just want to say one more thing about highly processed foods. There was an absolutely beautiful study done by my colleague, Chris Garner at Stanford, exploring whether or not certain diets were better than others.