Best Diet to Improve & Maintain Brain Health | Dr. Tommy Wood & Dr. Andrew Huberman

Diets for Dementia Prevention

00:00in these studies, these large-scale uh trials, uh what was the diet intervention? Can we distill it down to some things that um everyone should do or ought to consider? Most interventions in the sort of um cognitive and psychological space are focused on some version of the Mediterranean diet.

00:18Um there's uh the mind diet, um Mediterranean intervention to prevent neurogenerative delay. It came out of the Rush U memory and aging project and it's basically just a version of the um Mediterranean diet kind of focused on um dementia prevention and the way they initially created it was they looked at foods that people ate more or less of and created a score and those who had a higher score tends to you know had a lower risk of later de dementia.

00:47It wasn't an intervention when it was when it was first um developed but that was kind of the version. It's kind of combination of the Mediterranean diet and the DASH diet which is um like a a anti-hypertension blood pressure treatment type diet.

00:59So it's uh you know seafood, vegetables, berries, whole grains, that kind of stuff. Not too much uh saturated fat or animal protein. Yeah. And so this is very similar to the diet they used in the SMIS trial which was the first randomized control trial in depression that showed significant improvements in in mood symptoms.

01:17I think the the principles are useful, but there's not necessarily a huge amount of evidence to say that like this is the way that you you should or you have to eat uh to maintain cognitive health. There was actually um a big trial of the of the mind diet.

01:33It was published in the New England Journal of Medicine a couple of years ago and they compared uh the mind diet to standard caloric restriction. Um and actually they saw similar benefits in both in both groups. There have been big observational studies that have looked at how much their diet looks like a Mediterranean diet.

01:51And those whose diets look more like Mediterranean diets, yes, they have a lower risk of dementia. Of course, right, this is observational data, right? So, it's not you can't say it's causal. But what's interesting in some of these studies, there was a big one that came out of the UK bio bank was that they um took out individual uh foods or food components of the Mediterranean diet to see if that changed the relationship between the Mediterranean diet and dementia risk.

02:16And there was no food or you know olive oil or food group or you eating more or less meat that changed the relationship between the Mediterranean diet and dementia risk. So what that tells me is

Nutrient Density & Whole Foods

02:26it's much more about whole foods. they're nutrientdense rather than avoiding any you have to eat you have to consume lots of olive oil right or you have to restrict meat because if those things are eaten in the context of all this other stuff it's really that bigger context of diet quality and nutrient density that really matters so the the parts of diet that I think about are the you know there's three so there's energy there's nutrients and then there's overall dietary pattern.

02:58So, one of the confounding things about that trial I told you about the mind diet versus caloric restriction is you're like, well, the mind diet should win out,

Caloric Intake & Brain Volume

03:08right? How does caloric restriction do just as well? And in the kind of average population, we tend to have some issues with metabolic health and have been in a state of chronic energy excess for some period of time. There's been some very nice studies that have looked at brain aging and brain volume or brain reserve um across different populations.

03:30There was um there was uh one group that looked at different um tribes in Bolivia, the Bolivian Chiman who are hunter gatherer group, the Metan who are kind of an intermediate group between sort of the Chiman and like a standard kind of industrialized group and then industrialized humans in the US and Europe.

03:49And what they found is there's kind of this um bell-shaped curve between energy availability and brain volume. And in general, brain volume, right, the more the better, right, we think. And so if you're chronically calorically restricted, your brain is smaller um because you just don't have the resources to invest in, you know, the structure um and to maintain it.

04:08At the other end, you see the same thing. So if you're chronically in a chronic state of chloric excess, you also tend to have a smaller brain on average. And this is related to metabolic disease um you know and you know potentially and what comes with it um higher levels of inflammation high blood pressure things like that that we know can negatively impact the brain.

04:29[snorts] So the most important thing and I think this is where some of the benefits of caloric restriction happened in that in that trial compared to the mind diet was that you know people's cognition improved just because they decreased their energy intake to a point that was you know more you know was essentially kind of what their brain kind of needed or you know kind of supported their overall physical health which then affects you know cognitive health and and brain volume and and brain function.

04:54So the first thing to do is to make sure that you're eating enough but not too much right and that's very simplistic but like energy is really critical energy availability not too low not too high then the next thing that you need is there is is

Critical Nutrients for Cognitive Function

05:10nutrients we know there are several critical nutrients for related to cognitive function and risk of dementia um the ones that we have the best evidence for are vitamin D iron omega-3 fatty acids uh the B vitamins uh involved and the B vitamins involved in methylation so particularly B12 and folate also potentially B6 and riboflavin although that might depend a little bit more on on the individual.

05:32Then there are some other nutrients that you know have some pretty good evidence for them. So many of the antioxidant uh polyphenols things that you get from berries, coffee, tea, chocolate, the carotenoids that make things orange, yellow and red.

05:44Um lutein zeazanthin aazanthin if it comes from seafood that's that's what makes shrimp and salmon pink. Um and then you know some other aspects like dietary fiber seems to have you know some some benefits as well. Not magnesium. So magnesium is absolutely absolutely in there in there too.

06:00Um and in general I think um and the so magnesium uh zinc um then there's some of the structural lipid components things like choline and ethanolamine that you might get from um nuts and seeds or eggs. They have some slightly less you like less evidence.

06:20you really when you're looking at um brain changes over time and dementia risk, but they certainly do seem to be related to to cognitive function. So, there are some studies that show that those who have lower magnesium intakes tend on average to perform less well on some some cognitive function tests.

06:34So, all of those do seem to be important. I have two questions about nutrients and brain health in [clears throat] short and long term. And they have to do with interactions between nutrients, which at least to my understanding are rarely explored.

06:50You know, you'll see studies of supplementing omega-3 or having people eat some fatty fish or or less and so on, but rarely in the presence or absence of some other vitamin that, you know, that can potentially impact the same pathways. So there's synergy.

07:05There's also, you know, necessity. So that could impact results. The other piece is on what time scale are these nutrients needed and on what time scale are they metabolized? So maybe to just kind of drill into the second question first. So you know I'm not out here as

The Role of Dietary Supplements

07:22like the defender of supplements, but I've been taking supplements in various forms and eating whole foods and eating as generally healthily. You know, less so when I was younger, but still pretty healthy and more so as I get older. But here's where my brain goes.

07:36Wait, whole food is great, but let's say dark leafy greens have a bunch of things in them that are fundamentally important for brain and bodily health. Great. And they have fiber, etc. How many times a week am I eating dark leafy greens? Let's say I do Monday, Tuesday, Wednesday, I'm great.

07:56But then I'm traveling on, you know, Thursday, Friday. Should I be just supplementing Thursday, Friday? Am I good until the next week? I think one of the reasons why eating really well, I think everyone knows what that means, not enough calories, not too many, mostly whole foods, etc., enough vegetables, fruits, and high quality protein and quality fats.

08:19I think the reason why supplements still become enticing to me, maybe even necessary, is because you can take them every day very easily. So, you can make sure that you're in range and maybe above range. So, let's take one of these things, okay?

08:34Omega-3 fatty acids. I I believe that the data are pretty compelling. They can be helpful for health, maybe even brain health. Certainly, I believe that. But let's say the early part of my week is omega-3 rich and the later part of my week is omega-3 poor.

08:53Am I good? Versus, you know, spreading it out across the week. It just becomes difficult to eat in a truly healthy way. I if uh if it's the case that it has to be consistent every 24 hours. So what do we know? So again I think we're often tempted to over complicate this and try and think oh you know I have to hit all these things at this interval and if I can't do that then I have to supplement.

09:18And in reality we probably have more buffer in the system than than we realize. So

Omega-3 Absorption & Storage

09:27um omega-3 fats is a really good example. your adapose tissue, your fat tissue is a depo, you know, it kind of stores excess omega-3s. I actually wrote a paper on this with a colleague of mine, Rory Heath, a few years ago. The longchain omega-3s that we have in our in our fat stores um may help to explain why supplementation does or doesn't work in some of these trials because some people just have more kind of hanging around.

09:54And if you eat more than you need on one day, um especially in a state of caloric excess, um that's going to be stored in your fat tissue. And then when uh you're sleeping or when you uh initiate uh lipolysis, the breakdown of fat. So particularly during periods like you're doing exercise, those then get released and they the brain then has access to them.

10:15So there's some studies that um show that when you this relates to the form of the omega-3s as well. So many people will tell you that you have to take omega-3s in the phosphoipid form uh which is like a a special it's a special supplement.

10:28Um you can get it from krill. Um and the the form is with that the fat is attached to like a a phosphoipid head group just like it would be if it was sitting in in a cell membrane and there's a specific pathway for those to get into the brain.

10:44It's only krill or it's fish oil also. Uh no. So fish tends to be the triglyceride form uh which is your glycerol and then three fatty acids attached. When you compare a single dose of phospholipid versus triglyceride form then more of the phosphoipid form gets into the brain.

11:00Some of this you most of this comes from rodent studies. But what's interesting is if you supplement over several days, it all kind of comes out in the wash because the triglyceride form um cycles through the adipose tissue as a depo and then it gets released and the brain can then use it.

11:16So if you're going to take just one day of supplement and you want to get as much of that omega-3 in your brain, yes, you should take the we think we should you should take the phosphoippid form. But the form that comes in seafood, which is primarily the trig trigide form, is regulated through the body's fat stores.

11:32So, this is a really long way of me telling you if you eat some fish early in the week, you don't then have to supplement later in the week as long as you got kind of enough. And especially if you've consistently eaten seafood across your entire life because you probably have a bit of a depo.

11:44And so, what you see in several trials where they've given omega-3s to decrease dementia risk or improve cognitive function. So, many studies of like that have been done. There was actually a very recent one that just came out of of USC where they gave omega-3s for a long period of time.

12:04They measured omega-3 levels in the in the CSF, right, in the spinal fluid of these people to show that this the omega-3s were getting into the brain. They didn't see any changes in terms of cognitive function or um brain structure on an MRI scan.

12:18So, everybody's like, well, omega-3s don't work. But when you kind of squint at the data and and they didn't quite give me the data that I wanted. But when you look at it, those the people in the trial just didn't seem that omega-3 deficient in the first place.

12:31So, right, if this isn't something that you need more of to start with, giving a load more of it isn't going to make that much of a difference, right? And this is the case for all of these different supplements. So, the best advice if you have access to it is to test your levels.

12:46Test your vitamin D levels. test your hemoglobin and iron levels, test your omega-3 levels, test your homocyine levels, which is as is a marker of B vitamin status, which we know is a a risk factor for cognitive decline dementia as well. So, if um if

Testing Nutrient Levels for Risk

13:02you can test your levels and it shows that you need more and yes, there are the the normal ranges that you have on a blood test are not necessarily the same as the risk ranges. So um homoyine is a good example. A normal range for homocyine which goes up if you need uh some of these methylation dependent B vitamins.

13:20The normal range might go up to like 15 or 16. But we know that risk is definitely elevated above 13 and is probably elevated above sort of 10 to 11. So what your target range really might be is is probably lower than what the normal range might be.

13:35But we have very good evidence that if you then supplement when somebody is above that range and you bring that down, you see significant improvements in in cognitive function or slowed cognitive decline. That is particularly the case for omega-3s and B vitamins that lower homocyine.

13:54And so this is the interactions that you were talking about earlier and this is the best one that we know of although I'm sure there are many more. Like I said, there are lots of trials that have given omega-3s or have given u B vitamins to lower homocyine and just haven't seen much of an effect.

14:09And everybody goes, "Oh, well, they don't work." But there are now at least three randomized control trials that have shown that omega-3 status and B vitamin status interact and they're dependent on one another. So, if you give uh B vitamins to somebody who has elevated homocyine, you bring down their homocyine, but they have poor omega-3 levels, you don't see any benefit.

14:26And [snorts] that's been shown in two trials. It was originally shown in the Vitocog trial that was run out of the University of Oxford. Um it was then uh replicated in the Broof uh trial. Then the other side has also been shown. There was a in the Omega AD trial they showed that supplementing with omega-3s didn't result in any benefit if people had elevated homocyine.

14:46So that's just one example and you can imagine like you kind of said there are probably lots of these and if we're not you know going into a study actually looking like well what nutrients does this person need and then supplementing with them um you you you're not going to find any effect.

Multivitamins & Cognitive Health

15:05You're like you shouldn't be surprised when there's a when when the study doesn't show anything. potentially the one recent um example of kind of just giving a broadbased kind of set of nutrients with a multivitamin that seemed to work fairly well was the Cosmos study people may have heard of.

15:27It was thousands of people of older adults um and they were given either a multivitamin or a a flavoronoid supplement. It's like a sententrum type vitamin. Yeah, it was it was Centrum silver, right? The most basic multivitamin, just 100% of the recommended daily allowance, not like no multi no like massive doses of anything.

15:45And in [snorts] that study, those who got the mil got the multivitamin saw, you know, changes in cognitive function that suggested some like some some improvements and but that was literally just covering the bases, right? No massive doses, the most basic multivitamin.

15:58So in the kind [snorts] of general population, I think you could say that something like that is probably a reasonable strategy. But what they also showed was that um supplementing with this antioxidant cocoa flavonol was only beneficial in those who tended to have a poor quality diet to start with.

16:14Right? So they just weren't getting many of these kind of compounds from their diet. If you're drinking a lot of coffee, eating a lot of berries, seeing a lot of fruits and vegetables, you probably don't need it cuz you're already getting it.

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