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The Neuro Experience
I Asked a Neuroscientist How to Avoid Dementia. His Answer Changed Everything | Dr. Tommy Wood
00:58:52
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- [00:00]
A
You say that most people are literally poisoning their brains by treating them like trucks instead of Formula one cars. What does that mean?
- [00:08]
B
It would be unfair to say that cognitive decline is a choice. Most people don't know that they have a huge amount of control over that. Looking at the different factors that influence cognitive function, there are a huge number of things that we have control over.
- [00:22]
A
When people spend $500 a month on supplements and nootropics for their brain, you're saying they're literally flushing their money down the water. Is that correct?
- [00:31]
B
The majority supplements don't have a huge amount of evidence behind them. And the core functions of the brain are much better supported by manipulating lifestyle and the environment. It's not this long list of things you need to do. It's identifying some individual things where you can start to make a change. And then when you make a change, the whole network shifts in your favor.
- [00:54]
A
Consistency is key. You can dramatically decrease your risk of cognitive decline, but you can also be a happier person. I'm Louise Nicola, and this is the neuro experience. 70% of people watching this will experience cognitive decline. But you say that's a choice, not a destiny. In fact, you worked with Formula One drivers whose brains process information at 200 miles per hour, and you discovered something that changes everything we know about the brain. You say that most people are literally poisoning their brains by treating them like trucks instead of Formula one cars. What does that mean?
- [01:33]
B
I guess I should start by saying that right now it would be unfair to say that cognitive decline is a choice because most people don't know that they have a huge amount of control over that. And there are also factors that influence cognitive trajectory over the lifespan that people don't necessarily have control over. But as a society say, we could. We could say that the majority of cognitive decline is basically optional. Were we to put everything in place, that would change the factors that affect cognitive function. What people traditionally think is that as we get older, we're just destined for our function to decline. And that's true for physical function, it's true for cognitive function. But we've actually known for several decades now that the average. And by average, I mean there are many different ways to measure an average, but by median. So, like the middle, or. Actually, for most people, cognitive function can stay relatively stable from your 50s into your 80s and maybe even further. This is not what people expect. What they expect is you might have seen some of these graphs and you'll see them on social media, you might see them in scientific papers where you have on one the Y axis, the side, you have cognitive function of some kind. And there's lots of different types of cognitive function that we can measure. And then age along the bottom, you just see this essentially steady decline from your 20s or 30s, and you assume that that's what happens to everybody, but that's actually just again, an average. It's a mean average of everybody in the population. But most people can stay relatively stable, while a few people do experience decline, and that drags down the average. So it's very different to think, what is my cognitive function going to be in 30 years time versus what is the overall average population's cognitive function going to be? Looking at the different factors that influence cognitive function, there are a huge number of things that we have control over. This is relevant to formula one drivers, just like it is relevant to the rest of us, because it's related to how we use our brains, how we then recover from cognitive stimuli, which are a really important part of developing and maintaining cognitive function, just like physical activity and physical stimuli are really important for maintaining physical function. So then how we recover from that. So sleep, nutrition plays a huge role, as do a whole bunch of other things that we might expose ourselves to or be exposed to, which actually means that we have a huge amount of control over the factors that influence cognitive function across our lifespan. But the first thing we need to realize is that we do have control, because then we may actually do something about it.
- [04:26]
A
Why don't we define for everyone what cognitive functions are? You know, I say this often, and I think that a lot of people are like, does that mean thinking like, let's explain what that is and the difference between, like, cognition and the actual structural part of the brain.
- [04:43]
B
The majority of neuroscience focuses on the physical structure of the brain. And historically that has been, how did this brain look under a microscope after this person died? More recently, it's been, how does it look on an MRI scan or a variety of other scans? We can look at different structures and functions of the brain in real time, though cognitive functions do then map onto that structure. How the brain looks under a microscope is almost completely unrelated to how that brain functioned in real life, because, like.
- [05:15]
A
The neurons, like, how they're like cell bodies, all of that.
- [05:18]
B
Yeah. So you can, you can look at. So particularly if we're talking about cognitive decline, we might think about proteins that accumulate in the brain as we get older, like amyloid and tau, and that tells us something about that brain, but it tells us actually quite little about how that person, you know, was in the world and how their brain functioned, doing the things that they wanted to do every day. And. And we've spent decades trying to map these two pieces together, but we still don't really know fully how the structure of the brain maps onto how that brain functions in real life. And this is important because each of our brains is completely different and does completely different things. It's been exposed to completely different things. And we're still trying to reconcile how those things map onto each other. But we can look at the structure in different parts of the brain. We can think about the frontal lobe at the front, which is often. Think about how that's related to executive function or decision making. We can think about parts like the hippocampus, which is sort of in the middle, kind of slightly underneath, kind of near your ears, which is very important for memory. We can think about the back of the brain, the occipital lobes, very important for vision, as well as various other things. The cerebellum, all the way at the back, which does emotional control, motor control. So when we talk about cognitive function, I talk about it quite broadly, mainly because each of us wants our brains to do slightly different things. And so part of it is very personal, Though there are also some core features that we might all want. Like, we want to be able to make decisions in the moment when we have to. We want to be able to remember important things and our family members. We want to be able to sort of react and respond to the environment as things happen around us. And these are some of the core basic functions of the brain that we can measure. But when we sort of talk about cognitive function more broadly, we can talk about those sort of individual core features and different things you might do with your lifestyle preferentially affect different cognitive functions. But I'm also just thinking about brain health overall, which is some measure of. Is your brain doing what you wanted to do when you want it to do it?
- [07:26]
A
Yeah. Or performing even better because those cognitive functions decline. And there's a reason may decline. Okay. But there's a number of reasons. Factors that may decline. For a woman, it may be hormonal, it could be genetic, or you could be hit in the head. You know, if you're an NFL player, it's a. There's so many reasons as to why your cognitive functions may decline, but what you're setting out to prove and educate the world on is the fact that it doesn't. Like we've got more agency, then. Okay, I love that. Why don't we move into this world of nootropics and supplementation, because I think that that's where most people think, you know, what I'm seeing online is like, how can I take this supplement to make me think better, make me more sharper? There's a. What's the limitless? You know, there's a limitless drug. There's a movie about it. And we all think as a society, if I just take this supplement, maybe it's choline acetylcholine. If I just take this, it'll make me think faster. So when people spend $500 a month on supplements and nootropics for their brain, you're saying they're literally flushing their money down the water. Is that correct?
- [08:39]
B
It's hard for me to say that, and I wouldn't necessarily say that all those things are a waste of money, but I would say that the vast majority are not necessary. Many of the supplements that might work tend to be core, basic nutrients that the brain needs that you might not be getting enough of from the diet. Things like B vitamins, vitamin D, omega 3s. If you're not consistently getting them from the diet or you do a blood test and you see that your. Your levels are maybe not where you would want them to be, and we know sort of cutoffs as they relate to risk of cognitive decline and dementia, then I think supplementing with those can make a lot of sense. But everything else, the majority of supplements don't have a huge amount of evidence behind them, and the core functions of the brain are much better supported by manipulating lifestyle and the environment as much. As much as we're able to. So physical activity, for example, and there are many different types of physical activity, and different types of physical activity affect different parts of the brain and different functions of the brain. And so the evidence there is much greater than, say, for most supplements. But I understand that people are looking for an answer. The problem is that for some of these supplements, those that do have been shown to affect cognitive function in a beneficial way, what they're often doing is they're supporting one aspect of cognitive function at the expense of others. So the brain doesn't just improve everything at the same time, right? When you're using one part of the brain, then other parts of the brain sort of decrease their activity. And one of the best examples of this is the broad category of stimulants. So you can think about caffeine, but they've done similar studies with the stimulants that they might use for adhd. Things like methylphenidate and what you see is that certain very basic types of cognitive functions are particularly reaction time. Sometimes you do a test called psychomotor vigilance, which is a way to measure reaction time. You will often see improvements in that kind of very basic cognitive function with stimulants. But what you then see at the same time, partly is because you become overstimulated and partly just because of the sort of the different parts of the brain that are being activated. You can see decreases in performance in more complex cognitive functions like working memory or response inhibition, like executive function and decision making. So often we're taking these supplements and we think, oh, I'm just going to improve my brain function. But you may be improving one part of function at the expense of another. Now, if that means that you can do the thing that you need to do better at the time, that's not necessarily a bad thing. But you shouldn't think that you're sort of overall just improving everything at the same time.
- [11:35]
A
So how does that relate to the Formula one drivers that you've worked with? Why are their brains more unique? Do they have a greater capacity for processing speed and reaction time than the general population?
- [11:47]
B
I could say how that particular example relates direct directly to Formula one drivers, because probably every driver and their coach has a story of a time when they overached the caffeine before a race. And so to kind of really boil it down to what you might see at the most basic level is your reaction time will improve. So your, your start time off the line might be better, even though that's actually quite complex because you have to do multiple things at the same time to launch an F1 car. But maybe this happened in a lower category, F1, F2 or F3 or something. Go karts. So you might be faster off the line, but then because you're sort of over aroused, complex cognitive functions can sort of diminish. There's this idea of the arousal curve that says that there's a peak amount of arousal that's ideal for a complex cognitive function. You've sort of like too far over on that curve. Complex cognitive functions have maybe diminished a little bit because you're sort of so anxious and overstimulated and so you fast off the line and then you crash in the first corner when you're trying to navigate all these things, things happening around you. So that's something that I think most drivers have probably seen and it still relates to us as well. Like you might feel a more alert after you've had Several shots of espresso. But then, you know, you got that crash. Yeah. Or you react very negatively to something, sort of, because you're not processing things and taking just, like a beat to think about them. Then we think about the brains of Formula one drivers. I'm not sure there have been that many Formula one drivers who've been in an MRI scanner. I'm not sure why we could even say that their brains are unique. There's probably a genetic component, Right. We know that things like reaction time do have a genetic component to them.
- [13:22]
C
Really?
- [13:23]
B
Yeah. There's, you know, everything exists on a. On. On a bell. On a bell curve. And there's probably some. And it could be a combination of genetics, epigenetics. You know, not everybody has exactly the same reaction time. There's going to be some variation, and maybe they're sort of like at the upper end of a bell curve or something like that. But that's probably not what differentiates them. Like, largely what differentiates them is they've spent their entire lives driving and racing cars. So it's that stimulus, that skill development, that they've spent huge amounts of time investing in that really separates them apart. And then, of course, there's the opportunity and being able to go to all the races that they have to go to. And they need lots of financial support, which is why, you know, there's not necessarily a ton of diversity in Formula one racing, because, you know, opportunities aren't equal to everybody. But I don't think that it's because these guys started out with very special brains. They've just been trained and funneled in that direction. And so you have this huge amount of stimulus. I think that's the primary driver of cognitive function. I think that's the primary driver of function in them. Plus, then they'll have had to focus on recovery and sleep and adaptation. And hopefully they've had a good nutritionist and physio who's worked with them and worked on their biomechanics and all these other things that sort of stack up over time.
- [14:41]
A
What you're saying is not so outside of the box. Okay. In terms of cognitive functions. Right. It just means if you're doing something for a long period of time, and that could be peak performance. Right. You know. You know, people are always trying to look for, like, how do I reach my peak? And what you're pretty much saying is, it's just time. It's a lot of time doing one thing, neuroplasticity, which we know it's the same For NBA players. People think like, what's the difference other than height that separates LeBron from an average person? It's like, well, you know, he's probably spent, you know, from the age of two doing jump shots. Like, who knows? It's just time, right? Skill development. Then how do we then move in to discuss dementia? Right. Demented cognitive states. So what is dementia? Because I know in your book you have five rules that can cut your risk of getting dementia by almost 50%. You mentioned the Chicago Health Study which proved this with 2,500 people. Your Rule 5 really was really astonishing to me, which I want you to get into later on, about being kind to yourself, which I thought was just so interesting. I've never. It wasn't until I saw your book, you know, you hear this often. Be kind to yourself. I didn't really think that this could relate to cognitive capacity, cognitive functions. Can you convince me on why this is all amazing and not just bs?
- [16:05]
B
There are several parts to that that we can kind of, we can kind of go through. So first of all, it's worth mentioning. So dementia, as your listeners will know, is, is the loss of cognitive function to the point where you get a clinical diagnosis because you are unable to sort of look after yourself on a day to day basis. That's sort of like the basic.
- [16:28]
A
And that represents. Because people get still confused, like, oh, my grandmother died of dementia or was it Alzheimer's? It's like, well, let's just, let's confirm what. Dementia.
- [16:36]
B
Yes, so dementia is an umbrella term for that significant loss of cognitive function. And so there are many different types of dementia, and Alzheimer's disease is the most common form. The next most common form is vascular dementia. Alzheimer's makes up something like 50, 60, 70% of dementia cases. Vascular dementia, sort of 10, 20%, maybe a little bit more. And there's actually a huge amount of overlap. So most individuals who have Alzheimer's disease also have some evidence of vascular disease in their brain. So between the two of them, they make up the vast majority of dementia, somewhere between 70 and 90%. And it's those dementias that are generally considered to be preventable at a, at a population level. And not all of them, but somewhere around, you know, some estimates say 45%, others say maybe as much as 70%, but potentially the majority of those of those dementias. And all dementia cases are preventable through manipulation of diet, lifestyle and the environment. So then when we sort of get to the, the next part of your question, which is as it relates to being Being, being kind to yourself. So, so I, I have. So in my book, the middle portion, I lay out the rules to the brain game that you refer to. And the last one is be kind to yourself. And this, I think, is, is really underappreciated in the world that you and I exist in, which is the worlds of, you know, optimizing everything, you know, health, maxing, doing everything you can to kind of be the best and work the hardest at your health. Right. That's, that's, those are the kinds of people that we tend to, tend to work with. And what's interesting is that there's actually quite a lot of evidence that continuously telling yourself that you're not doing enough or that you're not good enough, which I think is essentially that same version of, well, you know, oh, I'm not sleeping enough, I'm not doing enough exercise, right? I need to do more, I need to do more. There are a few studies that show that thinking like that, thinking that you're not doing enough is actually associated with worse long term health and worse cognitive function, in fact. And so one nice study used data from the NHANES cohort. So this is not like a randomized controlled trial. I can't randomize somebody to think poorly of themselves or think that they're not doing enough. But what they did is they asked people, how much exercise do you think you do compared to people like you? And there was like about as much or less or more. And what they found was that those who said that they thought they did less exercise than people like them had worse cognitive outcomes. And this is two separate studies, but they essentially use the same methodology. Worse cognitive outcomes and a higher risk of overall mortality regardless of how much exercise they actually did. So they adjusted for actual activity because they had them wear activity monitors, and they adjusted for socioeconomic status, physical health, all these other things. So the idea is that constantly thinking, I'm doing less than other people, I'm not doing enough, then can have a negative impact on our health. And this relates to some really interesting work that's done by George Slavic and Steve Cole and their group at ucla where they look at social stress. And chronic social stress, we know, creates a sort of a chronic inflammatory, sympathetic activation kind of picture that can negatively impact our health. And it's evolutionary. It's an evolutionary adaptation. So when we're socially isolated out, you know, in the world, right, we've been lost from our tribe and we're sort of stumbling through the wilderness by ourselves. Your immune system and your nervous system shift so that you're actually slightly, slightly more alert. You have better wound healing because you've sort of activated some of these clotting factors and some of these other inflammatory factors, so you'll actually heal wounds faster. But if that's stimulated for long periods of time, that then contributes to something we might call our allostatic load, chronic inflammation, which we know is associated with increased long term risk of cognitive decline and dementia. So how this then ties to this be kind to yourself picture to kind of sort of wrap it all together, is that when you think you're not doing enough or you think you're doing less than other people, right. You're constantly seeing social media, listening to podcasting, oh, you know what I need to do four hours of zone two, and then I need to do resistance training, and then I need to do my sprint, and then I need to sleep for nine hours tonight. Right. And that constant trying to do more. What you're doing is you're demoting your social rank. You're like, I'm less good than these other people. Your body internalizes that as a sort of like a chronic inflammatory stress response because you've created a social stress within yourself to see that. So, and you can measure these things like physiologically.
- [21:45]
A
And that's interesting because you see the state of social media right now, which we're all competitive, right? And you know, you've got high rocks and everyone just wants to compete with one another, whether it's, you know, in every category. It doesn't just mean sports. So that's. So that was mind blowing to me that the more unkind you are to yourself, the more things that you put yourself down for psychologically can increase your risk of dementia and all cause mortality. Does that mean, is that where manifestation and, you know, journaling and positive attitudes come into play?
- [22:19]
B
Then again, there isn't like a really good study that says so. These were observations, these are observational. Plus you have to think about some of the mechanisms. And we know that high allostatic load and these chronic stressors contribute to the risk of long term cognitive decline. And we know that we're activating these same physiological processes when we have these thought processes. So we kind of have to put the pieces together. But it certainly makes sense from this kind of bigger picture of how we're thinking about where we exist in the world and what we're doing for our health.
- [22:49]
A
That just made me think that the type A high achievers listening to this, the ones who are tracking every biomarker could be accelerating their brain aging process.
- [23:00]
B
It's certainly possible. Yeah. I can't say that it's definitely doing that, but I know that at a population level and certainly with a lot of the people that I've spoken to and worked with, you can see this negative impact that it's having on them. Constantly trying to do more and thinking that they're not doing enough.
- [23:17]
A
I've heard you mention allostatic load. You just mentioned it. And it was at Bruce McEwen's research that showed this is why people who can do everything right and still get dementia. If I'm a 5 year old, can you explain what allostatic load is?
- [23:34]
B
Allostatic load is all the things that happen to you or are happening to you that make you feel stressed or anxious.
- [23:45]
A
Oh, hello. I mean, Jesus. So I'd have a huge allostatic load then, depending on who.
- [23:52]
B
Well, so the thing is that kind of depends because it also depends on your ability to tolerate stress. So we know that there are other things that you can do to increase your ability to tolerate stress. So one way that you might think about chronic stress, whether it is truly chronic, is, say, if it's impacting your sleep, right? You're constantly worried about something, and then that's causing you to not sleep well. That's then impairing recovery. It's causing a whole bunch of other downstream effects. If you're sleeping really well, you're much less likely that you have this very high burden of chronic stress that's going to be negatively impacting your health. We also know that physical activity can help to buffer many of the different types of stress that we're exposed to. That could be cognitive or psychological stressors, some physical stressors. This is something called the cross stress adaptation hypothesis, that by training yourself to deal with one type of stress, you're actually better capable of dealing with other stressors. So if you're somebody who is very physically active and you're sleeping well, you can probably tolerate a lot more than somebody who isn't. So it all comes down to how those different things interact within a given person.
- [25:13]
C
One of the biggest drivers of aging, especially brain aging, is oxidative stress. And the body's main defense against that is glutathione, which is often called the master antioxidant. I'm such a huge fan of RO nutrition. Because they use liposomal delivery, this protects nutrients, so they're actually absorbed and used by your cells Instead of being broken down in digestion. They have liposomal glutathione and it's the one I recommend most often because when glutathione levels are strong, everything improve detox pathways, immune resilience, skin health, energy and cognitive function. And sometimes if you go and get tested like a methylation test, you may find that you are not a good methylator of glutathione. I'm one of those. That's why I have to supplement with glutathione. It's one of those supplements where you don't just read about the benefit, you actually feel it. So if you want to try it out or explore rose other liposomal formulas like NAD or curcumin and resveratrol, you can get 20% off with code Neuro that is R H O-Nutrition.com Neuro for 20% off team I want to talk to you about creatine because I get asked so often, what is the best creatine on the market? One with no fillers, no additives, no junk. It is Piori P U O R I. Their creatine plus combines pure creatine monohydrate with taurine, which supports both muscular and neurological function. Women in particular have significantly lower creatine stores and that affects everything from strength to mood to mental stamina. I love peori because I have spoken to the founder myself and I've really dug deep into their manufacturing process. So I also use their whey protein. It's PW1 whey protein. It's part of the clean label project. It's been certified, it's tested for over 200 contaminants, something most protein powders can't say. I know that you guys all read that study about lead being inserted many protein powders. This one is so clean, it's the only one I put in my body. It's one of the cleanest ways that I found to support my daily protein intake without guessing. So if you need to meet your protein stores every day, if you're not getting at least 100 grams and you're getting to the end of the day and you've only had about 60 to 70 grams of protein, hit yourself with a whey protein smoothie. If you want to try this one, you'll get 20% off. Just go to peori.com neuro or just put code neuro at checkout.
- [28:00]
A
So allostatic load. If we can imagine a vase, right, and one glass represents one area of your life, like a glass of water. You fill up that vase and maybe that's work stress. Another glass is what environmental Toxins can.
- [28:16]
B
Be environmental toxins, so it could be air pollution, could be smoking, could be.
- [28:21]
A
It all adds to this allostatic load. And when that vase gets full, you're at the tipping point. Things just start to fall apart.
- [28:29]
B
This is probably something that takes several years, if not decades to really come out. So when you look at studies on measures of allostatic load, sometimes they call it, they might sort of have some kind of threshold. So they say nowadays we might say burnout. Other studies might say vital exhaustion. That was sort of a term that came into the, that was in the literature before sort of burnout became to the forefront. So once you're experiencing this really defined or definable effect on your mood, on your cognitive function, you can measure this in blood tests. So in general, a high allostatic load looks a lot like metabolic syndrome. So high blood pressure, high blood sugar. Often people have, you know, their body composition has changed. They have high levels of crp, so C reactive protein or inflammation. They often also have lower levels of vitamin D. We don't know whether that's because they're, you know, everything that's going on means that they're less able to attend to, you know, getting enough vitamin D. Or if the, the stress that they're exposed to is increasing their requirement of vitamin D, they're often also more likely to smoke and drink. So, like, all these things are coming together, but you can.
- [29:51]
A
It's often invisible, right?
- [29:52]
B
Yeah. So, well, it's, it's invisible if you don't measure some of those things. So you might notice that somebody's, you know, because of the, because of the stress that are exposed to, their eating behaviors and physical activities have changed. Therefore their body composition changes. You might, you might notice that. But high blood pressure, high blood sugar, low vitamin D, high crp, those aren't things that you can see unless you actually measure them.
- [30:17]
A
How does vitamin D specifically affect, relate to stress, though?
- [30:21]
B
Because of the way these studies are done, you sort of look at individuals where you're like, this person has high allostatic load, or they have these psychological symptoms that we would associate with burnout or chronic high allostatic load. And then we look at, like, what do they look like physiologically? And those people are more likely to have low levels of vitamin D. So you can hypothesize that chronic stress has changed the way the vitamin D is metabolized. And, you know, maybe you have higher requirements, but that's all kind of like, it was kind of like testing, testing the ideas that we Just know that on average, those people are more likely to have low vitamin D. Why that is, we don't. Don't really know yet.
- [31:02]
A
Yeah, it's more so observational. Maybe they're just not going out in the sun enough.
- [31:06]
B
Yeah. Yeah, maybe.
- [31:07]
A
I want to still. I want to still talk about cognitive functions and explain to everybody that over time, you know, if you look at something new for the very first time, you create a new connection in the brain, right? So you're constantly. If you see new things, you're constantly creating new connections. But if you stop seeing these things and you stop doing activities and we call this retirement. I saw this in my parents. You know, you stop doing new things, therefore you stop. You stop the progression of your brain. And, you know, you say that retirement is somewhat killing our brain. And we've got data from the UK Biobank on 400,000 people which shows that cognitive function drops 40% faster after retirement. Retirement? That can't be right.
- [31:49]
B
This has been shown in several population studies in several countries, particularly early retirement. But just retirement in general. People have modeled this in different ways. Retirement seems to be the point at which cognitive function starts to accelerate or at least declines most rapidly. And there are studies in China, France, Sweden, in the US that shows something similar. I wouldn't put an exact number on it, but we know that that's when risk of decline starts to. Starts to increase. The reason for this is thought to be because you're removing the stimuli that you get from work. And those are cognitive stimuli, right?
- [32:31]
A
Social.
- [32:32]
B
And the social, like the social environment of the work that you're doing. Usually when I talk about this, I think about how the brain develops in the first place. So the development that occurs after we're born, the parts of the brain that develop the most after we're born are actually the parts of the brain that are most uniquely human compared to other species. Parts of the prefrontal cortex, parietal lobe. And what drives that development is going out into the world, learning social interaction, learning language, learning motor skills, and then going to school and learning all the things that we learn in school. And cognitive function, on average, peaks around the time that we leave formal education. That doesn't mean that you have to go into formal education to develop your brain. It's just by being in formal education, what you're doing is you are a professional learner. All you're doing is exposing your brain to new things every day that then drives brain development. Then, on average, as soon as we leave school, cognitive functions start to decline. Not all cognitive functions, but things like executive functions, memory, processing speed, other things like short term or working memory, other things like sort of historical memory, other aspects of critical thinking, something that we might call crystallized intelligence, which is like a fancy word for wisdom. Those things actually might continue to increase as we get into our 40s, 50s, 60s, and remain relatively stable. So our brains don't necessarily get worse over time. They're just how they work kind of shifts. But in general, cognitive function, you know, you might think that cognitive function declines from when you. That's what you hear, like from your 30s, cognitive function is already declining. And some of that is a process of aging that we don't yet have a way to completely stop. I think we can accelerate it by having less than ideal lifestyles and environments, which then means that we can slow it down by changing those things. The other part of it, I think that maybe gets less attention is that that decline is probably driven by what we're doing with our brains after we leave school. So there are studies that show that if you have a high amount of complexity in your work, lots of learning new skills, problem solving, critical thinking, social interaction, then you have a decreased risk of cognitive decline and a decreased risk of dementia. So what that tells us is that by continuing to learn new things, interact with the world, engage our brains as we get older. And a lot of that comes from the work environment. That's actually the place where it's just easiest to measure it. That seems to then be protective for brain function. So when you leave school and then you go to work and you just do the same thing again and again and again and again, what you're doing is you're no longer providing those new critical inputs to the brain.
- [35:33]
A
And this is why education is a lifelong. Education is one of the modifiable risk factors for Alzheimer's disease. And it's interesting. I've got a newsletter going out today that's actually talking about being bilingual or learning a new language, which, by the way, I'm learning Farsi. Okay. And it's the most. I gotta tell you, during my lessons, my brain feels like I'm just. I want to cry. I don't know what it is. It just gets to this place where it's so hard when they ask you to repeat. So learning a new language, especially in your mid-30s, is really, really difficult. But I know every time I'm doing it, that stress in my head, I'm like, I'm building new synapses. Just keep going. But this is why work and Hobbies are so good for cognitive functions as we age.
- [36:17]
B
Yeah. And there is evidence that individuals who grow up bilingual have a lower risk of dementia later in life. There's also evidence that even in older adults in their 60s and 70s, if you start to teach them a new language, then you see improvements in certain aspects of cognitive function. I actually have very good friends and colleagues at the University of Washington, Andrea Stocco and Chantal Pratt, who have studied this. And it basically shows that by your brain having to juggle multiple languages, you essentially get better at juggling multiple streams of information, which then translates to certain aspects of improved executive function and decision making. And what's interesting is what you said there. You know, when you get into your 30s or, you know, maybe even later, it's harder to learn a language. And you're right that as we get older, our brain is more fixed, which is a good thing, because your brain has adapted to the things you've exposed it to, and you want it to sort of have fixed abilities and skills, which then means you just need to give it good reason if you want it to change further. But one of the reasons why I think we stop engaging with these things is because we're like, oh, too old. I just can't learn it. It's too hard. When I was young, I could do this. I can't do this anymore. And I think that a lot of that is just expectation and it's reality. Because when you're in your 30s, 40s, 50s, you have a job, you have family, you have responsibilities, you're no longer a professional learner. Like, your job isn't to learn every day like it was when you were a kid. So I think a lot of the struggles that people have when they're adults to learn things, it's just they don't have the same time to invest in it. And that's not a bad thing. That's just a fact. So I think that when we think about engaging with these new skills, your brain can do it just fine. It's just finding the time and to be able to engage in this process and learn and then accept that you're going to suck at it. And it's actually in the sucking that the magic happens. That's what drives neuroplasticity, is making failures, failing, making mistakes. So just, like, really leaning into that discomfort, I think, is really important above everything.
- [38:23]
A
You know, if we could do one thing to help our brain. I know. And this comes down. You know, you and I have collaborated on a paper together, which proved that exercise can slow the rate of cognitive decline. Specifically, looking at resistance training, you know, I know you have a love affair with resistance training. You've got your own home gym, right? And what do you think is the biggest takeaway when it comes to exercise and cognitive functions? Like, how does exercise specifically. Let's look at resistance training. How does that specifically help decrease your risk of dementia?
- [38:56]
B
Again, there are multiple different types of studies that we can look at. So the paper that you wrote focused on interventional studies as much as possible, where they actually took individuals in their 50s and older, did resistance style training programs as part of a randomized controlled trial, and then looked at the effects on cognitive function and. And brain structure as well. And we know sort of there's a natural trajectory of how these structures change with age and that those changes accelerate in individuals who end up experiencing dementia. So when you then see reversal or improvement in those areas in those structures, you would say, well, you've created a buffer there that's either going to slow, prevent, or at least delay dementia if it's going to occur. That it was very difficult to do resistance training studies for decades, right, to actually see if you're preventing dementia, but you're seeing improvement in structures in the brain and their functions. So a resistance training in particular seems to benefit the white matter more than any other part of the brain. So, very simply, you can break the brain into gray matter and white matter. Right? So gray matter is the cortex on the outside. It's kind of like that wrinkly bit that everybody knows about. There's more gray matter. Like deep inside, there's a deep gray matter. In between is the white matter, which is myelinated, so it has lots of fat around it. That's what makes it white. And humans have more white matter than any other species by a reasonable amount. The human brain is about 60% white matter or more. Non human primates are around 50%. Your rodents, which is where we do most of our neuroscience work, have 5 to 10%.
- [40:35]
A
This is why they say that the brain is mainly fat.
- [40:37]
B
Yes. And the white matter is really critical for fast connections between different parts of the brain. It explains a lot of the cognitive complexities that humans are capable of. And what you see is that resistance training seems to preferentially benefit the structure and function of the white matter, and as a result, seems to be particularly beneficial for things like executive function and decision making. Although when you look at sort of overall global cognition, which is basically, you measure a bunch of different things and then add them all Together and see what's. What is your sort of overall cognitive function. Resistance training seems to be particularly beneficial for that. For that as well. And this is probably because of some of the things that are released when we do resistance training. So the one that's best studied is IGF1 or insulin, like growth factor one. This is really critical to the development of white matter in the first place. This is a, you know, IGF1 is really important in babies and then toddlers, and as our white matter is developing, and then it seems to be really important as we get older to maintain the structure and function of the white matter of the brain. So compared to other types of exercise, we release more IGF one when we do resistance training compared to, say, aerobic training. So that's probably one of the key. There's others like osteocalcin, which is released when we kind of stress the bones. But that's. As we're putting ourselves underweight, we kind of have that same effect. So things that are released during exercise that seem to. During resistance exercise, that seems to preferentially benefit those parts of the brain that then result in improvements in things like executive function.
- [42:15]
A
So these myokines that get released from the cells of the muscles go into the bloodstream, and when they go into the brain, they have an effect on the white matter tracts, which can decrease something called white matter lesions.
- [42:27]
B
Yes. So white matter lesions tend to. Which is basically you do an MRI scan, and you see in the white matter, there's these kind of changes in the structure. The white matter isn't as sort of tightly organized as you would normally expect it. And these sort of accumulate with age. It's probably related to all the different lifestyle factors that we've already mentioned. We know that changes in white matter actually seem to better predict cognitive decline and dementia, like Alzheimer's disease, than even the amount of amyloid or tau that you have in your brain. So your white matter is really critically connected to cognitive function as you get older. And like you say, when you look at the studies that have looked at this, if you do a resistance training program, you seem to see improvements in white matter structure and maybe reversal of some of these white matter lesions.
- [43:20]
A
Because the white matter lives on the axon. Right. So this is where, you know, you said information processing speed occurs. Is this where we get demyelinating diseases like multiple sclerosis? And do you think that there's a correlation between white matter lesions and cognitive decline and the fact that 80% of autoimmune diseases are female? Do you think that there's a correlation between all of this?
- [43:46]
B
That's a very good question. And the answer is I don't know. So you're right that women are more likely to get autoimmune diseases in general. That includes multiple sclerosis. Why that might be a particular target, I don't know. It's a great question.
- [44:01]
A
I think that too. I don't know whether it's, you know, they just, they have hypothesis about living close to the equator. Maybe it's a hormonal.
- [44:08]
B
So vitamin D is obviously a critical component of multiple sclerosis risk. So that may be playing a role too.
- [44:15]
A
Yeah, which I'm not at risk at the moment. I just did my blood test. For some reason my vitamin D came back as 81.
- [44:20]
B
That's pretty, pretty good.
- [44:22]
A
It was very high. And I struggled for so long at 20. And you know what I did? I was taking 5,000 IUs per day and it just wasn't coming up. So then I started taking the drops of K2 under my tongue. That's all I changed. And look, it shot up to 80. I don't know how healthy that is. It should be 60.
- [44:40]
B
Yeah. So 40 to 60 is usually where. And, and so this is in like US units. So if you're in using international units, so you're in the UK, then you multiply by 2.5. So in the US we target maybe 40 to 60. In the UK or Europe will it would be sort of like 100 to 150. But there are a number of reasons why that, that might. So you're kind of on the upper end. You could probably dial back the supplement. I think you can, you can get vitamin D toxicity. You're not at that. No, not at risk of that. Certainly at that level. But there are a lot of other things that can come into play. So other fat soluble vitamins. You know, magnesium is really critical for processing vitamin D. Maybe there's some additional sunlight, other things. Maybe you decrease your allostatic load and that's allowing your vitamin D to come up with something.
- [45:31]
A
I did. Well, let's keep on the theme of white matter because I'm really interested, by the way. I just want everyone to know that the paper said that we just have to do two days. Well, minimum two days a week of resistance training. That's not big. No, two days a week. We often think because we see Instagram. I'm actually at the mercy of this, even though I know this information. I follow so many fitness women who are in fitness And I look at their bodies, I'm like, that's it, I gotta be doing the gym every day. But you don't need to for the brain effects. Right, but what about diet effects? I love my red meat, but unfortunately as I look at the data, it shows that a diet more rich in plants and vegetables are more beneficial for the brain as it relates to cognitive decline.
- [46:20]
B
Yes, that's true, but those things aren't mutually exclusive. A lot of the signal for red meat being associated with worse health outcomes is. And there have been studies that have kind of like picked this apart, looking particularly at cancer. But also all cause mortality is probably related to the absence of other things in the diet or the other things that you're eating at the same time. So you can eat meat and you can also eat plants at the same time. What they don't, they don't have to be, they don't have to be mutually exclusive. And I think that, that if you are doing that, the minimally processed red meat may be, particularly in certain groups, beneficial. So there are studies that show, including some unprocessed red meat in the diet, so there was a study from the UK Biobank was associated with a lower risk of dementia. There have been similar studies that have shown that including some unprocessed red meat in the diet is associated with a lower risk of depression and other mental health conditions. This is all observational data. However, it certainly makes sense because again, unprocessed red meat is a, is a good source of protein as well as B12, zinc, a whole bunch of other nutrients and vitamins that you might not be getting elsewhere in the diet. So I am less concerned and I think you can absolutely include red meat in a brain healthy diet as long as you are also eating a wide variety of minimally processed, nutrient dense plant foods. That's kind of the ideal in my mind. It was a very interesting study again sort of using data from the UK Biobank, where they looked at Mediterranean diet patterns and risk of dementia. And what they did first is they looked at how well does this person's diet, they do these diet diaries, how well does this person's diet map onto a Mediterranean style diet? And you can kind of score these. There were scores for Mediterranean diets and then what they did is they removed one by one these different rules for the Mediterranean diet to see what effect that then had on the likelihood of getting dementia later in life. So like if the scoring system for a Mediterranean diet was less red meat, what happens when they remove that variable from the model from the score, and they found actually there was no difference in terms of dementia risk. What this tells me is that it's not. Not these individual foods which we get so focused on. It's your overall dietary pattern. So the Mediterranean diet, as a pattern is nutrient dense. It's less calorie dense, it's less easy to overeat, it's generally minimally processed. I think those are the things that we should focus on. And if you're eating red meat in the context of all those different things, I think, you know, any risk is massively reduced.
- [49:12]
A
I think it's just biomarkers, like, in terms of, like, you know, what we. There's this on Instagram right now. There's the camp of, no, LDL does not increase your risk of dementia. And then you've got the other band. It's like, no, we need to bring down LDL, especially if you're an APOE 4 carrier to below 80, right? Or below 100. And I just think of the fact that, okay, well, maybe remove red meat if you've got a really high APOB and ldl. So I think about it as biomarkers in terms of, like, vitamin B, you know, B12. You know, you want to have all these vegetables because you're getting all of the vitamins and minerals. But then I think about, you know, cholesterol levels as well.
- [49:54]
B
So I think. I think you're right that without knowing how a specific food is affecting your own physiology, it's very difficult to say you should eat more or less of this. This is tricky because not everybody has access to these tests. So you do need some general rules that everybody can apply just because they can't go and measure their APOB easily or you afford to get regular blood testing. And I think that's important to remember that. I think those kind of those general, minimally processed, nutrient dense, less calorie dense, whatever that looks like, that's a perfect starting point for most people. And then, yeah, if you have the ability to tinker from there, that's great. So there's a big network meta analysis that looked at different types of fats on LDL cholesterol. The specific fat that was actually that raised LDL cholesterol, more than beef fat, more than coconut oil. These other sources of saturated fat was butter. So if you have high LDL and you consume a lot of butter, that's a very simple switch to make if you're concerned about your cardiovascular risk or stop eating croissants. Well, yeah, if your croissants have butter in them rather than, you know, hydrogenated vegetable oils. Knowing these things and then tinkering with your diet as you need. So increasing dietary fiber also decreases LDL cholesterol, improving insulin sensitivity through physical activity or, you know, decreasing overall energy availability. If you have evidence of metabolic syndrome, that that improves LDL cholesterol. So we often get very focused on these individual foods, but I'm much more focused on, like, what are the nutrients that you're getting from your diet? Are you hitting all your nutrient needs? And then just like you say, what is the physiological effect that it's having? And that's not going to be the same for everybody. You can have some people who could eat huge amounts of very fatty meat has no effect on their lipid markers whatsoever. So why would you then say to that person that that's increasing their cardiovascular risk? It probably isn't. So it very much depends on how a given one person is responding to a certain part of the diet. And then all that other stuff comes into play as well, like how are you sleeping, how are you exercising? These things have an effect as well.
- [52:05]
A
So nuanced. I want to end very quickly with your new book, the Stimulated Mind. I. Oh my God, it's like a bible to me. I'm so blessed. Tommy's my mentor and I'm blessed with it. But what are the biggest. When's it out, by the way?
- [52:24]
B
March 24 in the US, March 26 in the UK and elsewhere.
- [52:28]
A
Can you just quickly, as we end, tell me in your book, you've got this 3S model for brain health. What are the 3S's?
- [52:36]
B
The 3S's are stimulus, supply and support.
- [52:40]
A
That'S going to build the best performing brain.
- [52:42]
B
So it's how I think about all the stuff we talked about today, plus a whole bunch of stuff that we didn't talk about. You can imagine these hugely long lists. You can go on social media. So here are 40 things you need to do for your brain. First of all, that's an incredibly overwhelming thing. And you look at all those things, you're like, well, here are all these things I'm not doing. That's where you need to be kind to yourself and appreciate that actually maybe you are doing more than you think. And the reason for that is because these lists aren't lists. They are variables that kind of fit into these core common mechanisms of what's happening in the brain that support cognitive function. And they overlap. And lots of these things can have a similar effect. So you don't need to think about 40 things. Think about these different variables in these kind of three buckets. So the first bucket is stimulus. So how are you using your brain? Are you socially active? Are you learning new skills? Are you playing sports? Sudoku is fine. It's not really kind of what I'm thinking, because sudoku and crosswords fit into something that Gloria Mark calls rote activities. So they require focus, but they're not cognitively challenging, really cognitively challenging. So they're actually great for like, a nice mental break. It's sort of like something you can kind of do and feel, you know, it's kind of nice to complete them. Definitely fit into the bigger picture of a brain. Healthy activities. But what we're really thinking about is these things that are truly cognitively challenging. Where are you failing? Where are you making mistakes? Where are you learning? Where are you kind of like really leaning into that discomfort of. Of this. That drives neuroplasticity, right? As you. As you make mistakes, that's when you release noradrenaline and dopamine. And that's where you get some of that friction and you kind of feel uncomfortable.
- [54:28]
A
Gotta be mentally hard.
- [54:30]
B
There's gotta be. It's gotta be hard. So that's, you know, where are those stimuli coming from? And they can be all of those things. And so there's no one way to do it. It's, what are the things that you want to be good at? Then when you stimulate a part of the brain or a network within the brain, that part of the brain needs blood flow, it needs oxygen, it needs energy metabolites, so glucose or ketones or lactate, right? And these things are intimately connected. So when you activate a part of the brain, something happens called neurovascular coupling, where those neurons and the astrocytes, they ask for more blood flow. So you need a healthy cardiovascular system, right? That's where LDL and APOB is important. That's where aerobic exercise and cardiovascular exercise is important. Then you need a healthy energy metabolism to get the necessary energy to those parts of the brain. So that's where we know that prediabetes and diabetes and metabolic syndrome increase the risk of dementia. So maintaining a healthy metabolism is important so that your brain can get the energy it needs. And then you need the nutrients that kind of run that whole system. You need. Need long chain omega 3 fatty acids like DHA, really important for synapses. You need B vitamins and you, because methylation is really important for getting those fats in the right places. You need iron and vitamin D, because vitamin D is important for the synthesis of neurotransmitters. So that's kind of the supply bucket. It's cardiovascular health, it's metabolic health and it's sort of nutrient status. And then you've stimulated a part of the brain, you've brought in all the necessary nutrients and supplies and then you need to actually adapt to that stimulus, right? So that's where support is critical. Like any good athlete knows, you don't get stronger in the gym, you get stronger when you recover at home afterwards, right? And the brain is essentially the same. So sleep is really critical, but then we want to avoid things that impair adaptation that kind of fit into that bucket too. So chronic stress impairs adaptation because it creates this like hyper metabolic state in the brain that stops us from being able to adapt to all these stimuli. And then there are other things we might be exposed to that can impair that process as well. So we do talked about smoking, air pollution, excessive alcohol. So that's kind of the support bucket. Now all of these things interact, right? So when you stimulate the brain, you have greater sleep drive afterwards. And when you stimulate the brain, you have greater supply being drawn in. So they're all intimately connected. And this is important because what that means is when you change one thing, you change everything. So when you sleep better, then you're more social, you're more likely to engage in physical activity, right? You've decreased stress and inflammation, that may impair adaptation. You've improved your blood pressure, so that improves supply. If you start an exercise program, you've been sedentary previously, again, you start to sleep better, you sort of improve cardiovascular health as well as directly stimulating the brain. When you stop smoking, blood pressure improves and sleep improves and inflammation decreases. So it's not this long list of things you need to do, it's identifying some individual things where you can start to make a change. And then when you make a change, the whole network shifts in your favor. And then you can start to add things on top of that.
- [57:44]
A
Consistency is key. And if you can keep the three S's throughout your time, you can dramatically decrease your risk of cognitive decline. But you can also be a happier person. And when you are happier, you're more mentally fit and you have a better performing brain, you can probably show up better at your work, in your relationships, just for yourself. So I loved that and I loved the book so much. I'm going to link it below. Dr. Tommy Wood, thank you for being part of the new experience. Podcast.
- [58:13]
B
Thanks so much for having me. It was so fun to see you, as always. And Doug, here we have the Limu Emu in its natural habitat, helping people customize their car insurance and save hundreds of hundreds with Liberty Mutual. Fascinating. It's accompanied by his natural ally, Doug.
- [58:40]
A
Limu is that guy with the binoculars watching us?
- [58:43]
B
Cut the camera. They see us. Only pay for what you need@libertymutual.com. liberty. Liberty. Liberty. Liberty Savings Ferry. Underwritten by Liberty Mutual Insurance Company Affiliates excludes Massachusetts.