DR. TOMMY WOOD

315: Developing Your Brain for a Longer, Healthier Life

This week’s conversation is with Dr. Tommy Wood, a UK-trained MD with a PhD in physiology and neuroscience.

He received an undergraduate degree in biochemistry from the University of Cambridge before attending medical school at the University of Oxford.

After working as a junior doctor in central London, he moved to Norway for his PhD work and then to the University of Washington as a postdoc, where he’s now an Assistant Professor of Pediatrics.

Tommy’s work and research interests include the physiological and metabolic responses to brain injury and how that impacts brain health across the lifespan, as well as developing easily-accessible methods with which to track health, performance, and longevity in both elite athletes and the general population.

So this conversation is far more than just how to “live longer” – it’s about first principles to work from, for health – over time – and we dive deep into best practices to enhance and optimize your brain functioning.

“When you feel you’re committed to something outside of yourself – some process ideally that contributes in a greater way to society – that seems to be one of the best predictors of long term health and even healthy aging.”

In This Episode:

People who retire earlier, tend to die earlier… Why?

The signal that kind of comes out of that [study] and what really sort of brings together threads from multiple areas of both neuroscience and sort of general biology and physiology of longevity or health spam is that essentially the simple concept is: Use it or lose it. And we know that tissues in the body respond to stresses or demands by strengthening, improving their function, improving their regenerative capacity. And if we don’t use them, then they will atrophy and muscle mass is one that people may be familiar with, right? If you don’t use your muscles, they get smaller, they get weaker, they are energetically expensive. So if you don’t need them, your body won’t keep them around. And we could probably think about that for pretty much any tissue in the body and including the brain. That’s the one that I’m the most interested in, but I’m also very interested in muscle tissue because those things are intimately connected. And so if we are not using our brains, if we’re not using our bodies, then they will start to atrophy. They won’t repair as they would otherwise. And bigger picture, eventually that will lead to earlier loss of function and eventually death.

Beneficial stress for the brain

When I think about the stresses that are beneficial for the brain, I like to go all the way back to when you were developing your brain in the first place, which is convenient, because I’m a neonatal neuroscientist. That’s what I do for the majority of my day job. Think about what an infant does as their brain is developing. And they are starting to learn about the world. They spend a huge amount of time learning how to coordinate very fine and gross movements of this meat sack that carries them around, right? And it’s incredibly difficult to learn those processes. Similarly, the process of learning language, right? Learning to speak there’s benefits we could talk about later from learning multiple languages at the same time, but just the act of learning a language, incredibly complex, learning, social interaction, again something that’s very difficult and needs time and effort and practice. Those three things make up the majority of what your brain gets as inputs as it’s developing. And those are the same inputs that can improve/strengthen the brain, the connections function essentially throughout the entire lifespan.

The Pomodoro Technique

The Pomodoro technique is one way to apply focused periods of time to get some productivity done. So there are timers that you can use this, but it’s usually 20 minutes say of focused application and then a five minute break and both are necessary. So even if at the end of 20 minutes, you’re like, I feel good, I can keep going, you stop, you do your defined break and then you get back into it. And there are multiple reasons why this is potentially beneficial. Tasks switching in smaller periods of time seems to be more cognitively demanding, but for less overall benefit. So when you are like checking your email and then doing something else for a couple of minutes, then something else, it takes a lot of cognitive demand, but you get less overall productivity. So you feel busy, but the end output is probably more physiologically, stressful and less overall productivity. So these small focused period of time seems to result in better overall work on average.

Will the average human lifespan extend drastically?

I am certain that we will slowly eek that number out as you know genetics and healthcare and technology improve. So all the models that we have currently, any statistical model is only based on historical data. So it’s impossible to project into the future. So yes, I’m sure that that number will continue to slowly increase, but I think it’s very unlikely that on a large population level, we are going to frequently see the average lifespan be over a hundred years old. Most of that is because of health inequities and societal issues rather than because we cannot do it, but I’m for myself, I’m not convinced that in the next 60 years we are going to dramatically extend human lifespan.

Aspects that help extend lifespan and healthspan

Overall nutrient density food quality will plays a big role. Then there’s a huge social component. So all of the areas of the blue zones, they have meals together. They have some kind of meditative or religious or community practice where they spend time in the moment either together or alone or both. And then that seems to be consistent across a lot of communities that have longevity, then this opportunity for rest and relaxation. So a strong schedule and rhythm being able to actually sleep properly, rest and recover properly, frequent movement practices and that being part of the environment. And again that’s common across all those regions. And so that probably encompasses most of it. Another thing that’s important is meaning or purpose. You have some function in society and that can be your job or it could be something else. And then that’s continues for your entire life, right? In a lot of those communities, whatever it is, you are function, maybe it changes, but you always have one. You’re not just like parked in a nursing home and left there. So you are always a part of the community and you have some meaning or purpose to your work or otherwise. And then the opportunity to rest and recover, interact socially, and move frequently. And any environment that fosters those things, I think provides the environment for a long and healthy human life.

How do we prevent our brains from declining?

So for the declining brain or to prevent the brain from declining, here are the three things we know: we need a good vascular supply of stuff to get up to the brain. So you don’t want your carotid arteries or cerebral arteries to atherosclerosis sort of clogged for want of a better word. We want to maintain good mitochondrial function. And so that’s providing adequate nutrients also, maybe avoiding certain toxins. So there’s interest in pollutants in the water, air pollution, other things that may contribute to this. And then on the other side, you need to maintain demands. So those three things I think are and for different people, different combinations of those will be important, but that’s kind of the framework that I would use in the context of a brain that you want to keep functioning for as long as possible.

Test your body’s reactions to foods

One thing that we’ve learned or the main thing that we’ve learned about blood sugar, in the last five years, is that it is impossible to predict so far how one individual will respond to a certain diet or food. Maybe the original studies or so this sort of really brought this forward, were done by the Weizmann Institute in Israel where they took nearly a thousand individuals. They put continuous blood glucose margins on them. So like measuring their glucose all the time, 24 hours a day. And they fed them a whole bunch of foods. And you take two individuals and they have these nice graphs in their papers. So you take two individuals, one gets a banana, one gets a cookie or they both get banana and they both get a cookie. In one individual, the cookie, no change in blood sugar, looks great, but the banana causes this big blood sugar spike in the other, the exact opposite thing happens. So the first thing to point out at this point is that if you want to know how somebody will respond to a given food, you have to test them.

His concern with the biohacking and constant monitoring

One thing that I’m really concerned about in the biohacking community – continuous glucose monitors a part of this, sleep monitors a part of this – is this kind of pathologization of things that should bring us joy, being sleep and food. So yes, we’re a continuous glucose monitor, test it against things that you eat frequently. If there’s something that you eat frequently that causes a bit blood sugar spike, consider swapping it for something else. And I think that’s as much as most people need to do. Because then and then your arm with that knowledge. Right? So maybe the thing that causes a big swing is ice cream. But you know, every once in a while, you’re like, hey, I’m going to enjoy this ice cream. I’m not going to worry about the blood sugar spike. Because worrying about that blood sugar spike is probably going to be more of an issue than the blood sugar spike itself. And there’s even data suggesting that your expectation of a blood sugar spike causes a bigger blood sugar spike regardless of the meal that you ate.

Expectations vs. reality of your reaction to food

They took diabetics and then they sort of did a crossover study. So they got both conditions: a low sugar milkshake and a high sugar milkshake. And you got to read the nutrition label, understand how much blood sugar is coming. And that’s important for diabetics, particularly if they have to give insulin, right, you need to know what’s coming in. And so, in the high sugar condition, obviously they got a bigger blood sugar spike than the low sugar condition. The thing was, this was the same milkshake both times. So thinking that more sugar is coming in, that’s going to cause a bigger spike, which brings me back to people who have continuous blood sugar monitors all day, every day for everything they eat. You’re going to get to a point where you’re expecting a big spike because of the pizza you’re about to eat. And then you’re going to get a big spike because you’re expecting one. So there’s a lot that comes into this, but yes, the things you regularly eat, understand how you respond to them, be armed with that knowledge, but don’t then, as soon as you quantify something, there’s interesting data this, as soon as you quantify something, you start to lose the joy in it. You start to objectify it and it’s no longer a thing that can bring your joy in the same way. So have the necessary knowledge, but don’t then over complicate or over-focus on it.

How life purpose relates to longevity

In general, if we think about things like that, where you are committed to, or feel you are committed to something outside of yourself, some process, ideally that contributes in a greater way to society, other individuals, that seems to be like one of the best predictors of long term health and even interestingly, healthy aging… it comes back to this feeling of connection or demand, which is that humans require interaction with the physical environment and that’s your movement, singing music, language, and social connection. And so there are multiple ways that you can think about it. There are multiple ways that you can apply it, but our purpose, if we have one, is to think about it from a reproductive standpoint. We are often told that you’re just there to pass on your genes. And then after that, there’s no evolutionary pressure on you as an individual and you will rapidly die off. And you’re essentially just a useless husk that’s taking up space and it’s just your genes that will continue with your children. But I don’t feel that’s necessarily the case because in the reproductive standpoint, as you get older, you have a purpose which is to support and look after your genetic line as it comes behind you. So there is some evolutionary drive to live a successful, longer life so that you can assist backwards in that way. And that for a lot of people, traditionally was their purpose. As you become the matriarch or the patriarch of the family. And you look after your children and their children. And that is kind of one very easy to imagine example of this purpose that you’re contributing to, and it has some kind of evolutionary aspect as well, but it doesn’t need to be that. People may get that through church or CrossFit or volunteering. There are all these things that I think have the same benefit because they are the same connection to society in something more than just looking after yourself. So that’s how I think about purpose. And when you look at the research on purpose, it seems to be protective of a whole host of things. And you can boil it down to that. You are telling your body and your brain that they are useful, that it is required, that it is meaningful, and that it has a distinct physiologic effect that you could measure if you wanted to.

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