Neuroscientist: If You Don’t Have These 3 Things After 40, Your Brain Is at Risk For Dementia

1. 0:00 – 2:26

   How 45–70% of dementia could be preventable (and what those numbers really mean)

   1. RCDr. Rangan Chatterjee0:00

      You state that 45 to 70% of dementia cases may be preventable. You also state that when you say that to people, there's often disbelief-

   2. TWDr. Tommy Wood0:11

      Mm-hmm

   3. RCDr. Rangan Chatterjee0:13

      ... and/or resistance.

   4. TWDr. Tommy Wood0:14

      Yeah.

   5. RCDr. Rangan Chatterjee0:16

      Where does that statistic come from, and why do you think so many people push back at it?

   6. TWDr. Tommy Wood0:22

      That statistic comes from two separate studies. 45% comes from The Lancet, uh, Commission on Dementia Prevention report. There have been two now. The first was in 2020. Uh, most recent one was in 2024. They upgraded the, uh, the number from 40% of dementias potentially being preventable to 45%. The 70% number comes from a study using UK Biobank data performed by Professor Ying Kai Yu's group. Um, and they sort of looked at all the different modifiable, uh, factors and risk factors for dementia to estimate, you know, if we removed all of these risk factors from the population, what proportion of dementias would we expect to, you know, n- no longer happen? And this is what, essentially what The Lancet Commission report does as well. So they have these statistical ways of estimating how much a given risk factor translates to a proportion of dementia in the population. It is an artificial way of doing it because we know that risk factors to any chronic disease are not a one-to-one thing, right? And people often have multiple risk factors together and they compound and they interact. But that's the, the best way to, to truly estimate right now how, um, different aspects of the environment and society impacts dementia risk. And so it's things like 7% of dementias are thought to be preventable if everybody got access to high quality education, um, and, you know, high levels of educational attainment. And then there are, um, uh, risk factors related to smoking, head trauma, obesity, um, hearing loss, et cetera. And the, the 45% number from The Lancet, uh, Commission report, I think that could be conservative because they didn't include things like poor sleep, which we know is a risk factor. They didn't include things like, um, late, uh, later life cognitive stimulation, which we know is important as well. So that's why potentially this, you know, 70% could be the, the upper limit perh- perhaps, um, of

2. 2:26 – 6:17

   Avoiding blame: prevention is about probability, not personal fault

   1. TWDr. Tommy Wood2:26

      dementias that are preventable. But you're right that when you say something like that, first of all, people are surprised. I think this is, this is new information. Um, and then people, especially those who have some kind of relationship with dementia, they have a loved one or family member with dementia, they have a family history of dementia. If you say that dementias are potentially preventable, they might interpret that as if there's some blame on an individual who previously suffered from dementia or is currently suffering from dementia, when that's absolutely not the case, right? We've just said that we're only just starting to appreciate that dementia may be preventable or, you know, a certain proportion of dementias may be prev- preventable, certain types of dementia may be preventable. And we know it's very complicated, right? Multiple risk factors may come together in an individual, uh, genetic risk factors, environmental risk factors. Um, and I truly believe that each person is doing the best with the information that they have and the things that they can do at the time. So it's more an idea of hope, right? Should we be able to modify our environment? Should we be a- be able to make societal change to remove some of these risk factors? 'Cause some of them are related to socioeconomic factors. There is, um, the possibility of dramatically de- decreasing dementia burden in the population. And yes, individually we can take that on and, and, uh, decrease our own risk of dementia. But it's, it's really, um, sort of an idea of, of what's possible rather than saying, "Oh, because somebody, uh, got dementia, they did something wrong."

   2. RCDr. Rangan Chatterjee4:07

      Yeah. It's... It-- That whole thing about blame is something I think a lot about on this show 'cause each week we're trying to empower people with the things that you might be able to do in your own life. It doesn't mean though that if you get something, you failed in some way.

   3. TWDr. Tommy Wood4:25

      Yeah. Yeah.

   4. RCDr. Rangan Chatterjee4:25

      Do you know what I mean?

   5. TWDr. Tommy Wood4:25

      Yeah.

   6. RCDr. Rangan Chatterjee4:26

      It's, it's a tricky one, isn't it?

   7. TWDr. Tommy Wood4:27

      It's also hard for us to, to think about this as individuals because we're talking about probabilities, right?

   8. RCDr. Rangan Chatterjee4:35

      Yeah.

   9. TWDr. Tommy Wood4:36

      So it would be impossible to say that any individual case of dementia is preventable. It would be very possible to say, were you to address certain risk factors, you will decrease your risk of getting dementia. But I could never say I can guarantee that one individual won't experience dementia. They may experience it later. They may have, you know, less of a decline, fewer symptoms. They may not experience it at all. But it's sometimes hard to wrap our head around the fact that when you're talking about statistics, you're talking about probabilities rather than certainties, and often in the health sphere we're sold certainties and black-and-white stories, and it can be difficult to understand that there's some nuance in, in what we're trying to, to get across and what we could potentially do.

   10. RCDr. Rangan Chatterjee5:19

       I think those statistics, firstly, they're very empowering, but I think they're empowering on a couple of different levels. I think firstly it means, "Oh wow, just 'cause Mom had it-

   11. TWDr. Tommy Wood5:30

       Mm.

   12. RCDr. Rangan Chatterjee5:31

       "... maybe it doesn't mean that that's my fate."

   13. TWDr. Tommy Wood5:34

       Yeah.

   14. RCDr. Rangan Chatterjee5:35

       And so, "Oh, let me learn more to see what I can introduce into my life." So I think it's hopeful on that level, but I think deeper to that, it, it more broadly to me speaks to our collective attitudes towards aging.

   15. TWDr. Tommy Wood5:52

       Yeah.

   16. RCDr. Rangan Chatterjee5:53

       Right? Are we expecting our brains to get slower, weaker, poorer, whatever that might be, as we get older?

   17. TWDr. Tommy Wood6:02

       Yeah.

   18. RCDr. Rangan Chatterjee6:02

       Or do we actually think that that doesn't necessarily have to be the narrative? And, you know, in the new book, The Stimulated Mind, you very clearly make the case that that does not need to be the case. Let's talk a little bit about mindset-

   19. TWDr. Tommy Wood6:13

       Mm

   20. RCDr. Rangan Chatterjee6:13

       ... and attitude to aging, 'cause I th- I think that's quite key, isn't it?

3. 6:17 – 11:53

   Mindset and aging: how expectations can become a self-fulfilling decline

   1. TWDr. Tommy Wood6:17

      Yeah, I, I think so.And this is something that we've embodied as a society almost, that we expect a certain amount of decline as we get older. And I, uh, I lay some of this blame at the feet of Sir William Osler. If anybody's heard of him, he's a, a very famous physician. Um, he's a... Was a Canadian physician, helped to found Johns Hopkins Hospital in the US and then he was a professor of medicine at the University of Oxford. And in the early 20th century, Osler helped to popularize the idea of retirement, because before then, other than sort of like military pensions, it wasn't normal for people to, to retire. But he gave this famous address at Johns Hopkins where he said that at the age of 60, the, uh, average adult is useless and should be put out to pasture. [laughs] And this then is something that we have internalized as a society, and this is essentially what we expect. I will give him a little grace by saying that at that time, average life expectancy in the US was in, you know, late 50s. So maybe he was right that once you were 60, you know, the average individual wasn't in great health.

   2. RCDr. Rangan Chatterjee7:32

      Mm-hmm.

   3. TWDr. Tommy Wood7:33

      But that's no longer the case, right? With the advancement of, of medicine and ev- everything we've been able to do to extend both lifespan and healthspan at the population level. And despite that, I think we expect some level of decline, and because of that, we do things or stop doing things that then make that inevitable. So, uh, there's this, uh, idea of stereotype embodiment theory, um, based on, uh, some of the work, including like Ellen Langer's-

   4. RCDr. Rangan Chatterjee8:07

      Yeah

   5. TWDr. Tommy Wood8:08

      ... work. You know, you know her work well.

   6. RCDr. Rangan Chatterjee8:09

      She's great.

   7. TWDr. Tommy Wood8:10

      Um, and she talks about the fact that if you expect decline, then you embody this idea that you will decline and therefore you stop doing the things that prevent decline, and therefore it becomes a self-fulfilling prophecy. So if we expect to lose physical function and we expect to lose cognitive function, then we stop doing the things that help us to maintain function. "Oh, I'm too old to learn a new language. Oh, I'm too old to pick that up. Oh, you know, I might get, might get injured. I don't want, I don't wanna do that." Um, and we stop doing those activities that challenge our physiology, which are inherently the things that help us maintain function, and as a result, um, we, we see decline. So I think the most important thing to, to realize, and we can certainly go into the, uh, into the evidence that decline ha- doesn't have to be inevitable, but the first thing we have to realize is that there is this huge possibility to enhance function, physical function, cognitive function at essentially any age-

   8. RCDr. Rangan Chatterjee9:13

      Yeah

   9. TWDr. Tommy Wood9:13

      ... as long as we engage in these processes and, uh, skills and challenges that, that help that to, to happen.

   10. RCDr. Rangan Chatterjee9:22

       Yeah. When I think about how our attitude influences the reality of our lives, I, I think about two, two cases or, or two sort of examples where there are some South American tribes-

   11. TWDr. Tommy Wood9:36

       Hmm

   12. RCDr. Rangan Chatterjee9:37

       ... uh, running tribes where you grow up, from, from what I understand, with the belief that as you get older, you get faster.

   13. TWDr. Tommy Wood9:45

       Yeah.

   14. RCDr. Rangan Chatterjee9:46

       Right? And look, I haven't seen the physiological data. I haven't seen the VO2 maxes-

   15. TWDr. Tommy Wood9:50

       [laughs]

   16. RCDr. Rangan Chatterjee9:50

       ... that they've measured or not measured, but apparently in your 60s and your 70s, they are the fastest runners.

   17. TWDr. Tommy Wood9:57

       Mm-hmm.

   18. RCDr. Rangan Chatterjee9:58

       Right? And it, and it... You know, we can look at the science and go, "Yeah, but we know you lose muscle mass from the age of 30, and we know that this is gonna decline," right? Or whatever it might be. And also, let's also not forget that if you grow up in a culture where it's believed that you get faster as you get older, how much of an impact does that have?

   19. TWDr. Tommy Wood10:17

       Yeah.

   20. RCDr. Rangan Chatterjee10:17

       There's also some research I saw where if you live in a culture where older women are looked up to-

   21. TWDr. Tommy Wood10:27

       Mm-hmm

   22. RCDr. Rangan Chatterjee10:27

       ... right, and they're really valued, I think in some of those cultures they have, uh, less reporting of menopausal symptoms.

   23. TWDr. Tommy Wood10:35

       Mm-hmm.

   24. RCDr. Rangan Chatterjee10:36

       Now, I'm sure there's multiple complexities there. You know, are they reporting them enough? Are they, are they doing them the same way? Whatever it might be, I just find this whole idea that our mindset and the influence it has... And of course, Ellen Langer's work is hugely saying-

   25. TWDr. Tommy Wood10:49

       Yeah

   26. RCDr. Rangan Chatterjee10:49

       ... your mindset is massive. It is kind of interesting, isn't it?

   27. TWDr. Tommy Wood10:53

       Yeah. There's so many examples of how what we think and what we expect drives our physiology as well as driving our behavior, and then essentially creates the, the reality that we, that we expect. And you, and you can measure this in many different ways and, and, you know, Ellen Langer's work is, uh, critical to that. Uh, be that, um, you know, manipulating how people think about their sleep then affects how they perform the next day, day regardless of how they actually slept, or manipulating clock time and, um... Or how people think about, uh, the food that they ate, which then affects their blood sugar responses to it, even if, you know, it's a standardized meal under, under different conditions. And so we know that what we think drives physiology as well as behavior, and then you sort of get the outcome that you expect, uh, to a, to a certain degree. And therefore, I think we need to understand that this doesn't have to be the case when it comes to cognitive decline I- in particular, and there's a, a few different ways that we can approach that. But the, the, the

4. 11:53 – 14:13

   What the data actually shows: most people maintain cognition longer than we think

   1. TWDr. Tommy Wood11:53

      first thing, if people think about cognitive function, you think about a graph, right? So on one side you've got cognitive function, like on the le- on the Y axis on the left-hand side, and then along the bottom you've got age. And everybody might expect some... They've seen some curve where, you know, it peaks around, uh, your 20s or early 30s. This is like exactly the same with physical strength and muscle mass. And then sort of just like declines from, from there. And then eventually at some point you'll lose enough function that you might reach a threshold that we call dementia.When you're doing those kinds of studies that result in those kinds of graphs, what you tend to do is you just sample a whole bunch of people, maybe thousands of people, and you measure their cognitive function. And you see that on average, yes, as you get older, the func- function is lower, right? You add up, add up everybody's cognitive function, divide it by the number of people, right? You get the, the, the average. And yes, some people, as they get older, do lose function, so there are people who are sort of dragging the average down. But asking what the average function is or the change in function in an average population over time is not the same as saying, "What's my function gonna be in 10, 20, 30 years' time?"

   2. RCDr. Rangan Chatterjee12:56

      Mm.

   3. TWDr. Tommy Wood12:56

      And so when studies have looked at that, there was a, a classic study, I think it was one of the first studies to do this. It was called the Seattle Longitudinal Study-

   4. RCDr. Rangan Chatterjee13:03

      Mm

   5. TWDr. Tommy Wood13:03

      ... uh, run by, uh, Warner Shaw. And he took individuals starting in the '50s, um, and he measured their cognitive function every seven years for multiple decades. And every seven years, he would bring back the old participants and add new participants. So in, in the end, he had data from people in their 20s up to people more than 100 years old. And what he saw was that the, um, the majority of people, so like more than half of people, maintains cognitive function into their 50s, 60s, and 70s. So yes, there were some people who lost function. They dragged down the average. But the, the norm, you know, more than 50% of people, was to maintain function over time, even into s- your 70s and 80s. And those data were actually used to raise the retirement age in the US because, you know, he showed actually that we can expect that most people will maintain function later into life. But if we don't understand that as individuals, then all those things we just talked about come into play, right? Because we stop doing the things that help to maintain function because we expect function to decline as we get older.

5. 14:13 – 18:52

   Messaging traps: when health information creates stress and reduces benefit

   1. RCDr. Rangan Chatterjee14:13

      I think about that through the lens of public health messaging, and, you know, let's, let's take what you do or what I do on this podcast. You're trying to share information that people can then absorb and then if they choose to, take on in their life.

   2. TWDr. Tommy Wood14:30

      Yeah.

   3. RCDr. Rangan Chatterjee14:31

      But there's a, there's a fine balance, isn't there? Because if you spend two hours talking about the problems of sleep deprivation-

   4. TWDr. Tommy Wood14:39

      Yeah. [laughs]

   5. RCDr. Rangan Chatterjee14:40

      ... right? On one hand, y- you're being honest, you're trying to educate people, but also, you're also probably infusing this idea that it's really, really bad, and actually, as you beautifully write about in your book, you know, w- we're pretty resilient.

   6. TWDr. Tommy Wood14:58

      Yeah.

   7. RCDr. Rangan Chatterjee14:58

      You can deal with a couple of nights-

   8. TWDr. Tommy Wood14:59

      Yeah

   9. RCDr. Rangan Chatterjee15:00

      ... where we don't sleep.

   10. TWDr. Tommy Wood15:01

       Yeah.

   11. RCDr. Rangan Chatterjee15:01

       But I, I, I've changed my messaging around sleep over the years. I, I... Let me put it, I've evolved it because I've realized actually that when you do these deep dives, it's great, and for many people, it's like, "W- wow, I better start taking my sleep seriously."

   12. TWDr. Tommy Wood15:14

       Yeah.

   13. RCDr. Rangan Chatterjee15:14

       Right? But then you of course get new parents who then send me messages saying, [laughs] "I'm really worried," you know, "after that last podcast. You know, I'm... I haven't slept well for the last three months 'cause my young baby needs feeding through-

   14. TWDr. Tommy Wood15:26

       Yeah

   15. RCDr. Rangan Chatterjee15:26

       ... half the night," et cetera, et cetera.

   16. TWDr. Tommy Wood15:27

       Yeah.

   17. RCDr. Rangan Chatterjee15:27

       And then the unintended consequence is you're trying to help and empower people, but sometimes that same message can be very disempowering a- and frankly, quite stressful.

   18. TWDr. Tommy Wood15:39

       Yeah. There's... So that particular example, I... There's a, a study that, that I reference in the book that showed... This is, uh, using UK Biobank data again, showed that the more children that parents had, both men and women, the lower their risk of dementia. And [laughs] I thought this was fascinating because on the face of it, having kids should be devastating for your cognitive function, right? Stress, sleep, you know, all the, you know, all these things that you don't get to do. You don't, don't get to look after yourself anymore because you're so, you know, busy-

   19. RCDr. Rangan Chatterjee16:14

       Yeah

   20. TWDr. Tommy Wood16:14

       ... by wor- worrying about this, this, um, this new human that, that now has to navigate the world. Um, but this is what happens when we focus on, on the downside, right? Downside of stress, down- downside of poor sleep, downside of, you know, what are the, you know, contaminants in seafood, or is your food organic or not? In general, so many of these things, the benefits massively outweigh the downsides. So when you think about kids, right, they come with opportunities for joy, cognitive stimulation, social connection, pro-social behavior, which is just such a critical component of, um, humans-

   21. RCDr. Rangan Chatterjee16:52

       Mm

   22. TWDr. Tommy Wood16:53

       ... and their evolution and what it takes to, to, you know, make them healthy. Um, you know, looking after other people and, you know, building a community. And so those benefits seem to massively outweigh the, the potent- the potential downsides. And, like, this is then I think the important thing for us to remember. A, we are incredibly resilient and adaptable, and B, usually the things that we're doing, we want to try and get the, the, the most benefit out of them as possible. So when we're then worrying about those minu- minutiae as far as the potential downsides, we're actually offsetting some of the benefits that we're getting from all these amazing things that we're doing. And I think a study that maybe we've talked about previously, but is worth bringing up again, is, um, a study where they looked at, um, physical activity, both actual physical activity and perceived amounts of physical activity. This was, uh, done by Ardia Crump, who actually trained with Ellen Langer, um, and now she's a professor at Stanford. And what they found was that people who, um, felt like they were doing less exercise than people like them, you know, you know, similar demographically, they had a higher risk of mortality. And there was another study that found a similar thing for cognitive function. So if you, if you thought you weren't doing as much exercise as people like you, they ended up having, you know, on average, lower, lower cognitive function. Um, and this was after adjusting for how much exercise people were actually doing.

   23. RCDr. Rangan Chatterjee18:20

       [laughs]

   24. TWDr. Tommy Wood18:20

       As well as a whole bunch of, you know, health related confounders. So what that says is, if you spend all your time thinking, "I'm not doing enough. I should be doing more-"You are then essentially creating a situation where you're not getting benefit from the things that you are doing, and creating this, this chronic stressor that's, that's having ne- negative health effects. So I, so I'm much more in favor of celebrating all the amazing things that we do do because those are probably offsetting any of the sort of like the minor things that we, we would otherwise worry about.

6. 18:52 – 24:32

   Comparison and social rank: why social media can become a physiological stressor

   1. RCDr. Rangan Chatterjee18:52

      Yeah. And of course, in the modern age now, we'll maybe talk about modern technology and social media later, but one of the things, of course, that many of us have experienced is comparison.

   2. TWDr. Tommy Wood19:04

      Mm-hmm.

   3. RCDr. Rangan Chatterjee19:04

      Right? And so, you know, maybe 100,000 years ago, you're, you're kind of comparing yourself to your tribe.

   4. TWDr. Tommy Wood19:12

      Yeah.

   5. RCDr. Rangan Chatterjee19:13

      Maybe 150 people max, maybe less. Who knows? Now, we can compare ourselves to the best in the world at anything, right?

   6. TWDr. Tommy Wood19:22

      Yeah.

   7. RCDr. Rangan Chatterjee19:22

      So you go for your 30-minute walk around the block, but then you go on Instagram and someone's just done an ultramarathon, right?

   8. TWDr. Tommy Wood19:29

      [laughs] Yeah.

   9. RCDr. Rangan Chatterjee19:30

      And so you, you know, your 30 minutes around the block is fantastic for your mental wellbeing, your physical wellbeing, emotional wellbeing, your stress levels.

   10. TWDr. Tommy Wood19:39

       Uh-huh.

   11. RCDr. Rangan Chatterjee19:39

       Brilliant. But there is a risk that you think, "Oh, gee. Yeah. Man, I did 30 minutes. They've just done 30 hours," or whatever it might be.

   12. TWDr. Tommy Wood19:47

       Yeah, yeah, yeah. There's, um, a really nice paper or, or set of papers and essentially work done by, uh, George Slavich and Steve Cole. They're, they're at, uh, UCLA. And, um, myself and, uh, Julian Abel, who's a retired palliative care physician, we recently, um, curated and edited a set of scientific papers on the importance of community and social connection and health. And one paper was written by, um, Steve Cole and George Slavich, and they talk about social stress and the effect that has on our physiology. And one thing that was, like, particularly impactful to me was reading it, and, and you, you kind of... They talk about social, social rank, perceived social rank, right? How we see ourselves compared to others. And, and as you sort of like read... As, as, you know, I'm reading what they've written, I'm like, "This is why [laughs] social media is so bad for our health." Because what happens is that you spend all your time seeing people who are doing more than you, more successful than you, richer than you, better than looking, looking than you, w- b- whatever, like, however you would perceive that of, uh, compared to yourself. And what we do is then we rank ourselves. Like, where are we in, in the, in the world? And we do- demote ourselves internally because we see all these people who we think are better than us or doing more than us. And being demoted in your, in your perceived social rank creates a social stress. And so it creates the ph- a physical, a physiological response similar to when we're socially isolated. And we know that when we're socially isolated, we see shifts in our physiology. It changes our immune function. It changes baseline levels of inflammation. This is a evolutionarily conserved response, right? So if you're isolated, then your immune system shifts away from being better at dealing with things like viruses, respiratory viruses, because, you know, you're not surrounded by anybody to give you a cold or a flu, and it shifts more towards, uh, an acute response that makes you better with, like, wound healing, for example, which is survival. That's important, right? There's nobody to look after you if you get injured. And these things are... you know, we can measure them in our physiology. However, that comes with a baseline lower level of inflammation because your body's, like, ready to respond to an injury. If you continue that long term, you then see an increased risk of many chronic diseases, heart disease, dementia, because of this immune system shift, and that is driven by social isolation. But it's also, uh, driven by other social stresses, such as a lower perceived social rank.

   13. RCDr. Rangan Chatterjee22:24

       Yeah. I remember reading, uh, that in... I think it was in the adapt chapter-

   14. TWDr. Tommy Wood22:27

       Ah

   15. RCDr. Rangan Chatterjee22:27

       ... in the book, which is one of my favorite chapters.

   16. TWDr. Tommy Wood22:29

       Nice. [laughs]

   17. RCDr. Rangan Chatterjee22:30

       Um, that whole idea that the immune system shifts, uh, I think is really interesting. So I just wanna clarify something 'cause, um, I think... I don't know if you said lower inflammation or higher inflammation.

   18. TWDr. Tommy Wood22:44

       Hmm.

   19. RCDr. Rangan Chatterjee22:44

       When it shifts because you're lonely, the cost of that is a higher-

   20. TWDr. Tommy Wood22:51

       Yeah

   21. RCDr. Rangan Chatterjee22:51

       ... background level of inflammation.

   22. TWDr. Tommy Wood22:52

       Yeah.

   23. RCDr. Rangan Chatterjee22:52

       So it makes us inflamed basically-

   24. TWDr. Tommy Wood22:54

       Yes

   25. RCDr. Rangan Chatterjee22:54

       ... being lonely.

   26. TWDr. Tommy Wood22:54

       Yeah. Exactly.

   27. RCDr. Rangan Chatterjee22:55

       Yeah. And some of that being a perception's quite interesting. I, I once had a, a very successful author on the podcast, uh, Will Storr. He's written some brilliant books. And we chatted about status, and I remember chatting to Will, and it came up, this idea that Will is more successful than most authors-

   28. TWDr. Tommy Wood23:15

       Mm-hmm

   29. RCDr. Rangan Chatterjee23:15

       ... in the whole scheme of things.

   30. TWDr. Tommy Wood23:16

       Yeah.
7. 24:32 – 27:57

   Quitting vs curating social media: timeline effects and ‘what you do instead’

   1. TWDr. Tommy Wood24:32

      There are... Well, there are actually trials that, that do look at that, right? And it's interesting because the-The, the, the timeline matters, right? If you, if you ask somebody how they feel about quitting social media after just a week or two, they might not feel that good about it. You still get, you know, FOMO and these other things because you're, you're not, uh, interacting in that world. It's like asking how a smo- how a smoker feels two days after they quit.

   2. RCDr. Rangan Chatterjee24:58

      [laughs]

   3. TWDr. Tommy Wood24:58

      Um, they don't feel great. Um, but if you go out long enough, four weeks plus, there seems to be an overall, uh, increase in, in wellbeing, and this is also driven by what people do instead, right?

   4. RCDr. Rangan Chatterjee25:11

      Yeah.

   5. TWDr. Tommy Wood25:11

      And this is where a l- a lot of the issue, uh, with social media comes from, I think, because it can be, um, a way to increase social connection and social contacts that you wouldn't have had otherwise. And we see this in studies in older adults-

   6. RCDr. Rangan Chatterjee25:25

      Yeah

   7. TWDr. Tommy Wood25:26

      ... where they're using Facebook for the first time. They can communicate with family members that they wouldn't, wouldn't have done otherwise, you know, share photos, that kind of stuff. That is a net benefit. But if you're using social media to consume content instead of going and meeting people in real life, that's a net negative, and we see that very clearly in terms of, uh, wellbeing. So, yes, you, um... There is maybe some benefit from at least decreasing our, our exposure to social media, but you can also curate the way that you use it-

   8. RCDr. Rangan Chatterjee25:55

      Yeah

   9. TWDr. Tommy Wood25:55

      ... such that it becomes a net positive. Plus, you need to think about, what am I doing instead? Um, and then there are multiple different ways to navigate that, but just appreciating that these, um, these are potential issues based on the fact that if you're, you're constantly, you know, uh, being ex- being exposed to, to content from people, that makes you feel less than, either consciously or, or unconsciously. Um, it might be having a, a, a net negative effect on your health.

   10. RCDr. Rangan Chatterjee26:23

       Yeah. It's the tool, right? A- a- and like all tools, it depends how you use it. I agree, and at the same time, I think something has happened recently which makes that even harder.

   11. TWDr. Tommy Wood26:35

       Mm-hmm.

   12. RCDr. Rangan Chatterjee26:35

       So a few years ago, I thought, "Right, I'm gonna cul-..." Everyone I f- when it was still called Twitter, I thought, "I'm gonna unfollow everyone and just follow the people who I think really are giving me value."

   13. TWDr. Tommy Wood26:47

       Yeah.

   14. RCDr. Rangan Chatterjee26:47

       Right? So some of these, you know... There's a few endurance, uh, coaches who I really like following. A lot of... They share research papers on exercise physiology and their experience coach- you know, the things that I really enjoy looking at.

   15. TWDr. Tommy Wood26:59

       Yeah.

   16. RCDr. Rangan Chatterjee27:00

       And I did that, and for a while it worked. I thought, "Okay," 'cause whenever I go on, all I'm seeing is stuff from people who actually I want to see stuff from.

   17. TWDr. Tommy Wood27:06

       Mm-hmm.

   18. RCDr. Rangan Chatterjee27:06

       But I think algorithms have changed now where you don't only see stuff anymore from people you follow.

   19. TWDr. Tommy Wood27:11

       Yeah.

   20. RCDr. Rangan Chatterjee27:11

       In fact, that's only a very small percentage of who you see. So I do think it's getting harder, and you do talk about this in the book, right? You talk about the halcyon days-

   21. TWDr. Tommy Wood27:19

       [laughs]

   22. RCDr. Rangan Chatterjee27:20

       ... of social media.

   23. TWDr. Tommy Wood27:21

       Yeah.

   24. RCDr. Rangan Chatterjee27:21

       And I, I... You know, you were very early 'cause I think your uni-

   25. TWDr. Tommy Wood27:24

       Yeah

   26. RCDr. Rangan Chatterjee27:24

       ... was, like, the third uni to get Facebook or something like that.

   27. TWDr. Tommy Wood27:27

       Yeah, one of, um, one of the first unis to get, uh, Facebook outside of the US. In 2004, I think we got it. Yeah.

   28. RCDr. Rangan Chatterjee27:35

       Yeah. But I remember back sort of, I don't know, 2007, 2008, Facebook was great.

   29. TWDr. Tommy Wood27:39

       Yeah.

   30. RCDr. Rangan Chatterjee27:40

       You'd, you'd, you'd... It was a way of staying in touch with mates. You know, you'd share photos. You'd see what your mates are doing. You might follow a few people and see their content, and it was, I think, unless I'm looking at it through rose-tinted glasses-
8. 27:57 – 33:03

   PRIME and the attention trap: why algorithms hook us with prestige, morality, emotion

   1. RCDr. Rangan Chatterjee27:57

      I think for many reasons which we don't necessarily have to go into on this show today, but you write about, is it PRIME in the book?

   2. TWDr. Tommy Wood28:03

      PRIME, yeah.

   3. RCDr. Rangan Chatterjee28:03

      But just explain what PRIME is.

   4. TWDr. Tommy Wood28:04

      Yeah, so this is information that we prioritize as humans, um, which, um, me- So the PRIME stands for prestigious, in-group, moral, and emotional, and this is because we prioritize information that tells us something about our social environment because that's gonna help us survive, right? And we are inherently social beings. And so this then is what's, I th- I, I think, leveraged by the algorithms to have us stay engaged or, you know, continue scrolling. And so they know that information that you will respond to, either positively or negatively, in a large way is the kind of information that's gonna keep you, keep you hooked in because your brain thinks, "This is important information about my social environment that I need to gather such that I will then survive better in my environment." And so that will include the things that you want to see, right? But it might also include stuff that they know will elicit a negative emotional reaction because you get these large swings in dopamine that then drive learning, right? That dopamine, dopamine, um, is largely, um, responsible for learning what's important. Um, and that's, that's done on, that's done on purpose. And so, like, I think that social media takes advantage of our need for social information whilst giving us social disconnection, but we keep going back 'cause we're like, "Well, next time-

   5. RCDr. Rangan Chatterjee29:34

      Yeah

   6. TWDr. Tommy Wood29:34

      ... I'll learn something that will really help me." Um, and that's how you get sort of, uh, stuck in the loop.

   7. RCDr. Rangan Chatterjee29:40

      Okay. Tommy, so, so far-

   8. TWDr. Tommy Wood29:41

      [laughs]

   9. RCDr. Rangan Chatterjee29:42

      ... we're basically up to the point where we're saying that a lot of dementia cases are preventable-

   10. TWDr. Tommy Wood29:48

       Mm-hmm

   11. RCDr. Rangan Chatterjee29:48

       ... which is a very empowering message. You've mentioned that the brain can adapt at any age.

   12. TWDr. Tommy Wood29:53

       Mm-hmm.

   13. RCDr. Rangan Chatterjee29:54

       Again, very empowering. Doesn't matter how old you are when you're listening to this. Um, I don't know if we'll get to your owl story or not today-

   14. TWDr. Tommy Wood30:00

       [laughs]

   15. RCDr. Rangan Chatterjee30:00

       ... but you start the, start the book with a beautiful story about owls, which really highlights this point, right? That, that the brain can adapt at any age. I'm delighted to announce that AG1, the daily health drink that has been in my own life for over six years now, have updated and improved their formulation based upon the latest science, and to celebrate by giving my audience a very special offer. Some of the upgrades include more magnesium, which supports muscle function and improves the ability of your nervous system to relax, and also five strains of bacteria instead of just two to reflect the latest advances in microbiome science. It also contains key nutrients like vitamin C, biotin, niacin, vitamin B6, riboflavin, thiamine, zinc, and folate in bioavailable forms the body can easily and readily utilize, maximizing their potential benefits.Nutrition can often seem really complicated. What diet should we be following? What supplements should we be taking? And I think that's one of the main reasons I really like AG1. They make it really simple for you to be the best version of you. Over 70 ingredients, one scoop, once a day, for less than a cup of coffee. So if you wanna support your health seven mornings a week, get started with AG1, and right now we have a very special limited time offer. Get a free AG1 Flavour Sampler and AGZ Sampler to try all the flavors, plus free Vitamin D3+K2 and AG1 Welcome Kit with your first AG1 subscription order. See all details at drinkag1.com/livemore. I've been using BON CHARGE wellness products for over five years now. From red light therapy to infrared sauna blankets to blue light glasses, Bon Charge make it really easy to get healthy while staying at home. Now, one of my personal favorites is their Demi Red Light Therapy device. I absolutely love it and use it on most days, and I personally have this device on when doing my morning meditation. And I also tend to read in front of it in the evening before I go to bed. And I've noticed some quite significant changes, improved relaxation, enhanced focus, and deeper sleep. Now, there are so many studies out there showing the potential wide-ranging benefits of red light therapy, including better eye health, pain relief, reduced inflammation, enhanced recovery, improved sleep, and even better skin. So if you're looking to take charge of your health at home, I highly recommend you consider adding the Demi Red Light Therapy device into your daily routine. Bon Charge are giving my audience 20% off all of their products on their website. Just scan the QR code on screen

9. 33:03 – 39:18

   The 3S model: Stimulate, Supply, Support—brain health beyond just nutrition

   1. RCDr. Rangan Chatterjee33:03

      or go to boncharge.com/livemore and use the coupon code LIVEMORE to save your 20%. We're talking a lot about social connection, and I wa- I wanna really talk about the 3S model that you, you put forward-

   2. TWDr. Tommy Wood33:21

      Uh-huh

   3. RCDr. Rangan Chatterjee33:21

      ... in The Stimulated Mind, okay? Because, well, firstly, I do have to tell you, I think this is one of the best health books I've ever read.

   4. TWDr. Tommy Wood33:26

      Thank you.

   5. RCDr. Rangan Chatterjee33:26

      It's absolutely fantastic, and it's so thorough. It's... Well, I'll tell you what I like about it the most. Not only is it grounded in a lot of scientific research, it's very clear that you've got a lot of practical knowledge about the application of it as well.

   6. TWDr. Tommy Wood33:45

      Mm-hmm.

   7. RCDr. Rangan Chatterjee33:46

      And that's not always the case. You know, there are sometimes books from researchers which are great, and you see all the science. But, you know, as someone who's spent many years practicing, I'm like, yeah, but that doesn't... That, there is a different skill, I think, to application of these things for real-life people who are busy.

   8. TWDr. Tommy Wood34:05

      Yeah. Mm-hmm.

   9. RCDr. Rangan Chatterjee34:05

      So it's a beautiful blend of that. You also, and I know this whenever I talk to you, you seem to know a study for absolutely everything.

   10. TWDr. Tommy Wood34:10

       [laughs]

   11. RCDr. Rangan Chatterjee34:10

       I can literally say anything. And, um, you know a lot of studies, don't you?

   12. TWDr. Tommy Wood34:17

       Uh, yeah, that's part of... It's an occupational hazard at this point. Um, I think the, the book has a reference list of, um... It will, it'll, it'll be about 2,000 studies, um, 99.9% of which are in humans, um, that people can have access to if they're interested [laughs] in, in, in digging in further.

   13. RCDr. Rangan Chatterjee34:32

       Yeah, it's, it's very rigorous, um, which I think is great.

   14. TWDr. Tommy Wood34:37

       Mm-hmm.

   15. RCDr. Rangan Chatterjee34:38

       But I, I really love this 3S model that you put forward in the, in the sort of the final third of the book, as it were.

   16. TWDr. Tommy Wood34:45

       Yeah.

   17. RCDr. Rangan Chatterjee34:46

       Stimulate, Supply and Support. And I'll just... Before you, you sort of go g- you know, outline it for us, something I read last night, which I, uh, which I've been thinking about ever since, is this idea that nutrition, of course, is important, but I think it's only one of the S's.

   18. TWDr. Tommy Wood35:06

       Yeah.

   19. RCDr. Rangan Chatterjee35:06

       And I think that's quite novel because we think, "Well, what can I eat to support my brain?" You're making this case throughout the book that actually stimulus to the brain is perhaps the most important thing. So it made me think, well, hold on a minute. If you think about physical health, right? We can talk about eating protein for your muscles, but if you're never stimulating your muscles with movement or with lifting weights, is that protein really going to translate to muscle growth?

   20. TWDr. Tommy Wood35:40

       Mm-hmm.

   21. RCDr. Rangan Chatterjee35:41

       And then I thought about it through the lens of the brain. We can have the right diet, the right omega-3s, and, you know, the, all the things you talk about, right? We, we, we can, we can have them in our diets, but that seems to be only one of the S's.

   22. TWDr. Tommy Wood35:54

       Yeah.

   23. RCDr. Rangan Chatterjee35:54

       If we're not also stimulating our brain, we're perhaps not getting the, the full benefit. So I said a lot there.

   24. TWDr. Tommy Wood36:01

       [laughs]

   25. RCDr. Rangan Chatterjee36:02

       I think it's interesting. Can you walk us through the model then comment on anything I've just said that you feel is important?

   26. TWDr. Tommy Wood36:07

       Y- yes. So, so what you say is exactly right, and where the model comes from is all the different pockets of neuroscience that I've worked in or coached in over the years. So I'm thinking about the developing brain, um, thinking about individuals who suffer some kind of brain injury during life, like a traumatic brain injury or concussion, or trying to help, um, elite athletes perform at their absolute best. Um, and then also thinking about, you know, what are the factors that contribute to long-term cognitive decline and dementia? And you see the same things pop up again, and again, and again, which sort of makes me feel like there are these core foundational inputs that the brain requires in order to perform at its best, both on a day-to-day basis but then also long term. So things that you can do right now to improve how your brain functions today or tomorrow then translate into, uh, a longer term, um, lower likelihood of dementia and, you know-... you're much more likely to maintain the function that you do have or maybe even improve it, right, in your 60s, 70s, 80s, and beyond. And there are a whole host of factors that we can talk about. We've already talked about several of them, right? But they, for me, they, they coalesce around these three common areas, which is what, which are the three S's, so stimulus, supply, and support, like you said. And I think that stimulus is something that we, we inherently know is important, right? Everybody said use it or lose it at some point, right? But I don't think we've quite understood w- what that, what that truly means in order to give our brains the stimulus that, that, or the stimuli that they, that they benefit from the most. But I do relate it to this idea of physical performance and physical health because people... We kind of inherently understand that, right? If I want to get, uh, if I wanna get bigger and stronger, right, I want bigger biceps, the most important thing to do is to do bicep curls, right? I can improve my response to my training with a higher quality diet and making sure I attend to sleep and recovery, but I can't just drink protein shakes and nap and hope that my biceps get bigger.

   27. RCDr. Rangan Chatterjee38:15

       Okay. Th- this is great. So, so in that physical health example-

   28. TWDr. Tommy Wood38:21

       Yeah

   29. RCDr. Rangan Chatterjee38:22

       ... right, you're making the case that the three S's are still important, but the stimulus is the most important-

   30. TWDr. Tommy Wood38:31

       Yes
10. 39:18 – 50:13

    What counts as ‘good’ stimulation: complex learning, social interaction, multisensory skills

    1. TWDr. Tommy Wood39:18

       Sure. So the, the stimu- the stimulus that I think that we need more of... And I will acknowledge that I quite like the title of the book, The Stimulated Mind, because it's provocative in a, in a way because right now we are at the same time understimulated and overstimulated.

    2. RCDr. Rangan Chatterjee39:39

       Yeah.

    3. TWDr. Tommy Wood39:39

       Everybody feels overstimulated, right? So Tommy, how can you tell me that my brain isn't stimulated enough? Like, I'm, I'm constantly feeling stimulated. And so it's the type of stimulus that really matters, and I think we can talk about, and, you know, social media is one of those things. We can talk about how you can decrease these other stimuli that make us feel overstimulated or stressed because that's an important part of it that, that will end up in our support bucket. But the, the, the kind of stimuli that drive the development of the human brain are learning, knowledge acquisition, skill acquisition, social interaction, pro-social behavior, are, you know, languages, music, um, complex, uh, movements in sports, uh, social connection. These things that require us to learn a skill and apply that skill, um, in a way that involves processing information quickly, in a way that involves responding to the environment, responding to other people, um, and, you know, through multiple senses, right? Our hearing and vision and touch, taste, smell. Like, all of these things actually can, can be important stimuli for maintaining cognitive function, and it's that kind of complex, um, skill development and expression, uh, across all those domains, you, you know, including arts, including computer games. Like, like complex computer games can even improve cognitive function because it's the same thing. A, a multisensory complex cognitive stimulus. These are the things that I think we need more of, and we need to spend time really attending to them and, and focusing on them.

    4. RCDr. Rangan Chatterjee41:14

       I- is it the complexity of the stimulation? I- is... You know, you, you mentioned this kind of the paradox o- uh, of the time in which we live. You know? The book is called The Stimulated Mind. As you say, many of us go, "Yeah, but most people are overstimulated."

    5. TWDr. Tommy Wood41:26

       Yeah.

    6. RCDr. Rangan Chatterjee41:26

       But is it that it's almost like a... We've got too much of the wrong kind of stimulation, like the, the unidimensional perhaps, like the, the scrolling. 'Cause, you know, let's say you wake up and you go onto your social media platform of choice for an hour whilst drinking coffee.

    7. TWDr. Tommy Wood41:46

       Yeah.

    8. RCDr. Rangan Chatterjee41:46

       Okay? You're getting stimulation, right? You might in that hour see more information in that hour than maybe your ancestors would see in a year-

    9. TWDr. Tommy Wood41:55

       Yeah

    10. RCDr. Rangan Chatterjee41:55

        ... or maybe even longer, right?

    11. TWDr. Tommy Wood41:58

        Yeah.

    12. RCDr. Rangan Chatterjee41:59

        Okay. L- let's, let's just work this 3S model.

    13. TWDr. Tommy Wood42:01

        Mm-hmm.

    14. RCDr. Rangan Chatterjee42:01

        Let's say for that one hour you got all of this stimulus in, right? And then we go to the supply and go, yeah, and, and you... Let's say you've got an exceptional diet and you're moving your body regularly, so you're getting supply, and you're sleeping well that night to allow that learning. In theory, could that stimulation be beneficial for the brain?

    15. TWDr. Tommy Wood42:23

        To an extent. So if you're using Instagram and you're c- consuming educational content such as you're, you know, learning important facts-

    16. RCDr. Rangan Chatterjee42:34

        And thinking

    17. TWDr. Tommy Wood42:35

        ... and thinking-

    18. RCDr. Rangan Chatterjee42:36

        Yeah

    19. TWDr. Tommy Wood42:36

        ... absolutely. That can, that can be an important stimulus. Um, we know that education and the environment are the primary drivers of brain development, and educational attainment is one of the best predictors of long-term cognitive function and cognitive decline. So that's literally just every day your job is learning, right? You're learning and you're applying that knowledge. That's why attainment is important, right? You're actually remembering things, applying that knowledge in exams or, or, or however that, that knowledge is, is tested.

    20. RCDr. Rangan Chatterjee43:06

        So, so okay. So attainment, that's... So it's not just going to schoolAnd passively, uh, consuming stuff, you have to actively engage in some way.

    21. TWDr. Tommy Wood43:16

        Yeah. So the... To kind of like really simplify that is, is the difference between, you know, you spend 10 years at school and you, you know, pass your A levels or you, you spend another few years and you get an undergraduate degree, right? That those levels of attainment versus you spend 10 years retaking the same year in school because you never pass an exam, right?

    22. RCDr. Rangan Chatterjee43:37

        Right.

    23. TWDr. Tommy Wood43:37

        Those are two ve- you spend the same time in education, but those are two very different outcomes in terms of applying your brain and making sure that you're, you know, using the knowledge that you, that you've, that you've gained.

    24. RCDr. Rangan Chatterjee43:49

        A- and can the stimulation that we need, like the primary stimulus [chuckles] to the brain, um, we don't all need the same. 'Cause, 'cause you, you, when you've been on the podcast hall, you, you have spoken a lot about, you know, when do we have peak cognitive status? Is it, is it after university or-

    25. TWDr. Tommy Wood44:08

        Yeah

    26. RCDr. Rangan Chatterjee44:08

        ... in your late 20s maybe in, in kind of the modern Western world in terms of how people who go through education and then they might go and study beyond that. But then it made me think about hunter-gatherer communities and I, and I thought, well, do we know in these traditional societies whether they have high rates of cognitive decline if they've not done the same type of education? But then I, then I think, well, but they would be getting stimulated in other ways. Maybe not in the conventional or the modern academic stimulus. You know, there's... Stimulus can come in a variety of different forms, can't it?

    27. TWDr. Tommy Wood44:44

        Yeah. So I think that's an important, um, clarification to make because these studies are done in a typical West, you know, Western environment. We're doing specific tests of cognitive function, you know, relates to a whole bunch of different, um, functions of the brain that could involve memory, attention, um, decision-making, um, processing speed, like how quickly you can process information. But this is, these are just the data that we have access to.

    28. RCDr. Rangan Chatterjee45:11

        Yeah.

    29. TWDr. Tommy Wood45:11

        This is how we understand it, right? And what that, what those data show is that the cognitive function peaks around the time that you leave formal education. So the, the later you, the later you leave education, right, so the longer you spend at school or you're getting degrees, the higher and later your peak of cognitive function because I think you're just getting this stimulus on a day-to-day basis. But that doesn't mean that that's the way that you have to do it, right? This could happen outside of a formal educational setting. You know, in, in those, you know, traditional hunter-gatherer groups, they will actually constantly be learning, and then at some point they'll transition from learning to teaching, right?

    30. RCDr. Rangan Chatterjee45:48

        Yeah.
11. 50:13 – 57:17

    Supply: neurovascular coupling, metabolic health, and brain-critical nutrients

    1. TWDr. Tommy Wood50:13

       Yeah. So, so that's... And I think to, to, to fully unpack that, we can, like, flesh out the model a bit more, 'cause then you kind of understand how, how this, how this works, which then gives us a lot more agency, and it's a lot simpler, um, in terms to start applying this stuff and benefiting from it. So we have stimulus, right? You've stimulated your brain doing, doing something, right? Starting to learn a new language. When the areas of the brain that are related to that skill, uh, that you're learning are activated, they ask for more blood flow. There's this thing called neurovascular coupling, where the, the neurons and the astrocytes in that area stimulate the local blood vessels to bring in, uh, they need more oxygen, right? They need more glucose or whatever fuel you're fueling your brain with. Um, and so those blood vessels dilate, you know, they widen, they bring in more blood flow. This is then... So now we're in our supply bucket. And so that's where, like, cardiovascular health becomes important. We know that, um, things like high blood pressure, high blood sugar are important risk factors for long-term dementia, and that's at least partly because they, um, affect the health of those blood vessels. If you want your brain to be able to react and adapt and do a whole range of different things, then our blood vessels need to be healthy and respond accordingly.

    2. RCDr. Rangan Chatterjee51:28

       So, so you've stimulated your brain, and now we're going to the second S, supply. When you have chronically high blood sugar or you have poor metabolic health, you are negatively affecting the supply.

    3. TWDr. Tommy Wood51:41

       Yes.

    4. RCDr. Rangan Chatterjee51:41

       And the supply is important to get the most out of the stimulation that you just gave your brain.

    5. TWDr. Tommy Wood51:48

       Exactly.

    6. RCDr. Rangan Chatterjee51:49

       And is this why perhaps we read things where, let's say, we've done a 90-minute bout of work, um, and, you know, 'cause my son's in his GCSE year, I'm talking a lot to him about how he revises and how important it is to move his body and, you know. Um, so, you know, you do the stimulus. Let's say you've revi- your, whatever, whether it's a child or an adult, you've... Let's say you've worked for 60 minutes on something quite cognitively challenging. Is it overly simplistic to say that if you then go for a walk or a run, you've done the stimulation with a one-hour work, the run and the walk has basically got your blood flowing, so your, you know, your supply from nutrients, from oxygen, everything is increased? Is... That's correct, right?

    7. TWDr. Tommy Wood52:35

       Yeah. So one of the reasons why, um, movement is so beneficial for the brain in the, in the very short term is because it improves blood, blood flow to the brain. Um-

    8. RCDr. Rangan Chatterjee52:45

       So the supply, the second S

    9. TWDr. Tommy Wood52:46

       ... the sup- improve, improves supply. Exactly. And then that also translates long term, right? Long term, the more ac- you know, if you're more physically active, you main- maintain better physical fitness there and physical health, metabolic health. Then you maintain good, good blood flow to the brain, brain because your blood vessels are, are healthier. Um, the, the other part of that is that, and, uh, we may get to this more later, is that you inc- if you increase, uh, arousal, uh, which exercise does, you increase some of the neurotransmitters that are related to learning and focus and attention, and that then afterwards, once you've taken a chance to recover and adapt, you, you remember things better. So we know that if you do exercise before or after learning something, partly due to blood flow, partly due to, um, arousal and neurotransmitter release, you will then remember those things better. So that's why, um, movement around learning can be really important. Plus, if you've been learning, 'cause you've been, you, you've been sat in a chair the whole time, we know that if you, if you sit, um, very still for long periods of time, blood flow to the brain starts to decrease, and that can decrease mood and attention a little bit. So it's another way to just kind of reactivate, uh, everything, you know, related to that learning process.

    10. RCDr. Rangan Chatterjee54:00

        We all know that moving our bodies more is good for us, but despite that knowledge, many of us find it hard to actually implement. That's where the new Peloton Cross Training Bike+, powered by Peloton IQ, can really help. It's built for fitness breakthroughs with real-time insights and endless ways to move. And you can go from cycling on the Bike+ to strength training off it with one spin of the swivel screen. While you lift, Peloton IQ counts reps, corrects your form, and suggests new weights so you're always making progress towards your goals. And Peloton's movement tracking camera provides real-time feedback so you can train safer, lift smarter, and make every move count more. With over 15 types of workouts, expert instructors to keep you motivated, and a personalized plan tailored to your goals, the Cross Training Bike+ takes the guesswork out of working out so you can move freely and let Peloton handle the rest. Let yourself ride, lift, stretch, move, and go. Explore the new Peloton Cross Training Bike+ by clicking on the link below or by scanning the QR code on screen.Okay, so let's go back to the three S's

    11. TWDr. Tommy Wood55:21

        Yeah

    12. RCDr. Rangan Chatterjee55:22

        We- we've stimulated the brain, and now you're talking about supply

    13. TWDr. Tommy Wood55:25

        Yes. So you've stimulated a, a, an area of the brain or the networks in the brain. We're now bringing in more blood flow, um, right? So we've talked about why, uh, physical health becomes really important there to maintain healthy blood vessels, maintain a good, uh, uh, glucose supply to the brain. And we know that in individuals with Alzheimer's disease in particular, um, there's a, there's a, a decrease in, in glucose getting into the brain that, that may be... There's two parts to that. One may be due to decreased stimulus, right? If you're not using your brain in the same way, the brain is gonna ask for less glucose, but there may be also an issue with the glucose getting in if we have poor physical health, metabolic health. So then the final part of supply is nutrients. The, the critical nutrients that we know are important, um, both for cognitive function on a day-to-day basis, but also in terms of long-term dementia risk. So the ones that we have the best evidence for are vitamin D, iron, uh, omega-3 fatty acids, uh, B vitamins, especially the B vitamins related to methylation-

    14. RCDr. Rangan Chatterjee56:21

        Mm

    15. TWDr. Tommy Wood56:22

        ... like, uh, B12, folate, uh, B6, and riboflavin. Um, other things that we, uh, see are important for, uh, long-term cognitive function are like the antioxidant, um, vitamins, like vitamin C and vitamin E. Um, antioxidant polyphenols. There's very cool things that you can get from... You know, that make, uh, berries purple and red, or that make, um, you know, fruits and veggie- veggies orange and red, so like lutein, um, zeaxanthin. Astaxanthin, that's what makes, uh, shrimp, um, uh, and salmon pink. These antioxidant polyphenols, um, seem to have really, uh, interesting benefits for the brain, both in the short term and the long term. Um, and then some other minerals like, uh, magnesium and zinc, things like that be- become important too. So those are the critical nutrients that we're hopefully getting from the diet that then get directed to the parts of the brain that are building new connections, building new synapses, as it sort of cements the things-

    16. RCDr. Rangan Chatterjee57:17

        Mm

12. 57:17 – 1:02:36

    Support: sleep, recovery biology, and removing inhibitors (stress, smoking, alcohol, inflammation)

    1. TWDr. Tommy Wood57:17

       ... that you're learning, right? And so th- that's, that's, that's the final part of supply. And then, right, you've stimulated a part of the brain. You've brought in all the resources it needs to do the thing that you've asked it to do. Then we know that for a tissue, including the brain, to adapt to a stimulus, it needs, uh, a period of time to do that, and that's usually during rest, right? So, um, it's the same if we, uh, if we, if we're going training for something, like a marathon, right? You don't get faster while you're running. You get faster while you recover after the training run that you did. And so the brain is the same. This is where sleep is really critical, so now we're in the support, the third S. Um, so sleep is a big part of support. That- that's when all those connections that we've made are cemented. That's when, um, you know, we're building that function in the brain based on the, based on the stimulus that we've applied. Um, but we can also further support that adaptation through a variety of different things. So that's where hormonal status can become important. That's where other factors that get released, uh, by the body can support, um, the neuro- neuroplasticity and development in the brain, things like brain-derived neurotrophic factor, which is released during, during exercise. These can kind of help to support the direction and, and creation of new connections in the brain. Um, and then, uh, sort of the other side of support is we want to avoid things that inhibit that process. So, um, smoking, excessive alcohol, um, air pollution, uh, other things that can cause, um, chronic increases in inflammation. So already talked about the social side, but that could include, like, uh, uh, dental, dental health and oral health is, is a, an increasingly recognized risk factor for dementia because, uh, either 'cause of the direct effect of the bacteria, but also maybe the inflammation that they create. Um, and then chronic stress, uh, plays a role here too because we know that if you never get a chance to fully switch off, um, because you're chronically stressed, then that can, that can sort of like impair our ability to, to, to, to adapt. So then you, you realize that all these different buckets are interconnected, right? So, um, stimulus drives supply, and stimulus also drives support. So when somebody, um, does a cognitively challenging task, they then have a greater need for sleep that evening. So they actually s- they, they may sleep better because they have the greater, uh, drive for it.

    2. RCDr. Rangan Chatterjee59:41

       So, so just... Sorry to pause you there-

    3. TWDr. Tommy Wood59:43

       Yeah

    4. RCDr. Rangan Chatterjee59:43

       ... ju- but that could mean if someone's listening to this and they sometimes struggle to sleep-

    5. TWDr. Tommy Wood59:49

       Mm

    6. RCDr. Rangan Chatterjee59:50

       ... and there's many reasons for that, one of the reasons might be that you're not stimulating your brain enough.

    7. TWDr. Tommy Wood59:56

       Yes. So, uh, one of the ways that we know, know that, um... One of the, uh, ways we understand that the best is through exercise. We know that exercise improves sleep, uh, can improve, uh, sleep onset as well as sleep quality. But there, there are really interesting studies in older adults where they have them do a brain-training program, uh, for a few weeks, and what they see is that compared to a control group who are just, um, doing much less cognitively stimulating stuff on a computer... They were using, like, um, Paint to just, like, you know, make some things, but it's not the same as, like, really challenging your, your cognitive function with some of these brain-training programs. Those who are cognitively stimulated, they ended up sleeping better because they're creating greater sleep drive. And so I often wonder if part of the reason why as we get older we sleep less is 'cause we're not using our brains in the same way. We're not stimulating them. We're not asking as much of them.

    8. RCDr. Rangan Chatterjee1:00:51

       Mm.

    9. TWDr. Tommy Wood1:00:51

       So we're not creating that, that pressure, uh, that sleep pressure, that drive to sleep. And so because all of these things are connected, that then means exactly what you said earlier, which is when you change one thing, you change everything. So we know that if you start to sleep a bit better, then your blood pressure improves, and your blood sugar improves, um, and the next day you feel more sociable. So you're more likely to engage with other people in, like, some kind of social interaction. We also know that if you're less fatigued 'cause you've slept better, you're more likely to engage in a cognitively stimulating task because we avoid cognitively challenging things when we're tired. Um, and the, the same is true, right, if you stop smoking, right? Blood pressure improves. Uh, inflammation improves. You're more likely to exercise. You're more likely to make, um, a more, like, nourishing meal choice. If you start to, um, exercise, then you sleep better, and all those other things, um, kind of come off that. So-If we understand that these are, th- these are not a long list of things that... Or all these things we have to do, but instead, even just within one bucket, you would identify something where you're like, "Oh yeah, I could start to make a small change there." We know that benefits tend to be linear, right? A little bit more is gonna have, is gonna have some benefit, right? You don't have to do four hours of exercise in order to see benefit, right? Anything is gonna start to be beneficial. But you pick the thing that you feel like you can make some change in, you enj- you would enjoy doing or, you know, you're able to do. The whole network starts to shift in your favor, and then you can start to come in from other places as well. But understand that it's not a, a, a long to-do list that's overwhelming. It's a network that allows you to come in pretty much anywhere and start to see big benefits.

13. 1:02:36 – 1:15:21

    Make it doable: the ‘one change’ principle, high ROI actions, and process over outcomes

    1. RCDr. Rangan Chatterjee1:02:36

       That has huge practical application. I think back to earlier on in my career, and I very quickly learned that if I was to tell a patient or give them loads of things that they could do, you know, say, "Hey..." And I'd give them the research, say, "Hey, you know what? If you do this, it's gonna do that. If you do that, it's gonna do that." And they come back four weeks later and say, "I haven't done anything."

    2. TWDr. Tommy Wood1:02:59

       Yeah.

    3. RCDr. Rangan Chatterjee1:03:00

       Right? I was like, "Oh, I've actually just overwhelmed them." Have you found that to be true yourself in, in your own sort of coaching-

    4. TWDr. Tommy Wood1:03:07

       Yeah

    5. RCDr. Rangan Chatterjee1:03:07

       ... in, in your own, in your own life?

    6. TWDr. Tommy Wood1:03:09

       A- a- absolutely. I, I think that right now it's very common on social media to see, "Here's a list of things to do for your brain health." And they can all be very evidence-based, right? Could be all the things we've talked about today. But I've seen time and time again, you give somebody a list of 37 things, they will do zero things-

    7. RCDr. Rangan Chatterjee1:03:27

       Yeah

    8. TWDr. Tommy Wood1:03:27

       ... right? For those exact reasons. And my, my favorite personal experience is the first time I worked in Formula 1. I, um, you know, had sort of interacted with the team a little bit before. This is... I do all of my Formula 1 work through a company called Hintsa Performance. Um, and I was invited to go to the, the US Grand Prix in Austin, and I was gonna be in the paddock, you know, meeting with coaches and drivers and team principals and all this, you know, all these amazing people. And, like, I was a big Formula 1 fan, so this was like a... This was a big deal for me.

    9. RCDr. Rangan Chatterjee1:03:56

       Were you nervous?

    10. TWDr. Tommy Wood1:03:57

        Very nervous.

    11. RCDr. Rangan Chatterjee1:03:58

        [laughs]

    12. TWDr. Tommy Wood1:03:59

        And then I did what any good nerd would do, and I massively overprepared. I was like... I went in armed with 100 things and 200 studies to be like, "I'm ready. I've got all these things-

    13. RCDr. Rangan Chatterjee1:04:12

        [laughs]

    14. TWDr. Tommy Wood1:04:12

        ... that people could do, right, to, to improve performance and health and all this kind of stuff." And I, I remember having a, a conversation with a coach. Um, a- and so the, the way that, um, Hintsa works is the majority of the drivers that we work with, they have a Hintsa coach. This is usually somebody, they have, like, a master's degree in strength and conditioning or they're a, a physio or a... You know, some of them are, are... have a psychology background, just depending on what the driver needs. But they're there, like, inserted into the, into the life and world of the driver. They're there every day. They hold the helmet next to the car, hold the umbrella. They're doing all the warmup drills. They're doing all the training and y- they're looking after diet, all this kind of stuff. They're sort of, like, organizing their lives. And these are, these are the individuals that I spend most of my time interfacing with. Like, how can I help the coach do their job better? And so I'm meeting with this coach for the first time, and I think I probably start throwing out all these different ideas, and he, he's like, "We've got time for maybe one thing."

    15. RCDr. Rangan Chatterjee1:05:08

        [laughs]

    16. TWDr. Tommy Wood1:05:08

        "Maybe." Right? What you don't realize or maybe you don't think about is that, first of all, you know, drivers are essentially jet lagged nine months of the year because they're constantly-

    17. RCDr. Rangan Chatterjee1:05:18

        Yeah

    18. TWDr. Tommy Wood1:05:19

        ... flying from place to place. Plus, you have to do all the, um... Well, there's the races, but then there's all the preparation in between. There's media days. There's... You've got to go and schmooze the sponsors, right, because everybody wants their piece. Plus, you've got a million people like me showing up and being like, "Hey, try this thing. Do this thing. Hey."

    19. RCDr. Rangan Chatterjee1:05:35

        [laughs]

    20. TWDr. Tommy Wood1:05:35

        Right? And so, so then it, it, it come... He's like, "Right. We've got time for one thing. What's the one thing that you think would have the biggest impact?" And so, like, ever since then, that's the mindset that I've had to take in. Like, if we... We can start with a big net, but first of all, like, where's the biggest potential anchor or issue that's affecting this one individual? What's the highest return thing that that person could do with the time and resources and things that they have available? And that's what... That's where you start. Um, and yeah, sometimes you get it wrong. Um, and that's true for all of us, right? We try and learn-

    21. RCDr. Rangan Chatterjee1:06:10

        Well, you need to experiment.

    22. TWDr. Tommy Wood1:06:11

        Yeah. Yeah.

    23. RCDr. Rangan Chatterjee1:06:11

        Yeah, yeah.

    24. TWDr. Tommy Wood1:06:11

        And like, of course, like, some of, some of this requires some trial and error. But starting with the one thing that you think is most likely to have an effect is always gonna be much more likely to actually start to move the needle because you'll actually start to do it-

    25. RCDr. Rangan Chatterjee1:06:25

        Yeah

    26. TWDr. Tommy Wood1:06:25

        ... rather than thinking about 100 things that I've suddenly thrown at you. Like, well, I just don't know where to start, so I won't do any of it.

    27. RCDr. Rangan Chatterjee1:06:31

        Yeah. You mentioned Formula 1, and I, I know we've... I've always wanted to delve deep with you about your experience there because it's super fascinating. Um, as you were describing the drivers there and the pressures on them, the pressures to compete, to perform at a high level, to deal with jet lag, sponsors, everyone wanting a piece of their time, I thought, "Wow, that must be quite stressful."

    28. TWDr. Tommy Wood1:06:54

        Uh-huh.

    29. RCDr. Rangan Chatterjee1:06:54

        And perhaps some of these extra commitments that they have potentially are gonna get in the way of their ability to perform, which is ultimately what they're paid to do.

    30. TWDr. Tommy Wood1:07:03

        Yeah.
14. 1:15:21 – 1:27:09

    Practical downregulation: cognitive gears, break design, and mental offloading for sleep

    1. RCDr. Rangan Chatterjee1:15:21

       So I know you've sort of... There's a whole chapter on this in the book, but have you got some sort of practical guidance for people who might be experiencing that at the moment?

    2. TWDr. Tommy Wood1:15:32

       I think one of the thing, things that ends up being very common is because of the way we structure our workday, we get to the end of the workday, and we're still sort of stressed about what we have and haven't done. Plus, we're sort of desperate for some kind of way to, to switch off that w- that we end up, um, spending a lot of time on screens, social media, right? And, and those things can be beneficial if we, if we... Or, you know, they, they don't have to be that detrimental if we, we, if we craft our experience with them. But a lot of what happens when people can't sleep, you know, this sort of like t- tired and wired thing, I think is downstream of our, um, lack of structuring how we spend our days. So in, uh, you know, one of the, one of the first people that I met when I was working, when I started working with Hintsa is a guy called, uh, James Hewitt. Um, he's, uh, he, he used to be a professional cyclist, and now he's a sort of a, a cognitive performance specialist. And he wrote a book with Aki Hintsa, who founded Hintsa, called Exponential, where they, they outline this idea of cognitive gears, and it sort of, again, relates to the sort of like the physical side and physical training. And, but basically, we have three gears in which we can use our brains. Um, high gear is sort of really deep, focused work. Like, this is when we're paying attention to one thing at a time. We're doing something complex. We're learning. We're problem-solving, um, you know, these big tasks that we have to get done in our days. Um, low gear at the other end is, you know, when we're fully, you know, switched off, relaxed, you know, our brains free associate, right? You know, this is why we have, uh, moments of inspiration in the shower because, you know, we're, we're not sort of constantly having to deal with other, other inputs, or this is, you know, often happens when I'm in the gym. Like, that's when I'm not thinking about anything else, and sort of like ideas kind of appear. Same when you go for a walk, right? And ideally, your brain spends a lot of time in this kind of mode because you need that mode to recover from this, like, complex-

    3. RCDr. Rangan Chatterjee1:17:54

       Mm

    4. TWDr. Tommy Wood1:17:55

       ... cognitive work that, that you've been doing even during the day, like, in, in addition to sleep. Where we spend most of our time, if not all of our time, is in the middle gear. So think about high gear as, like, sprinting, low gear as, like, walking, and middle gear as kind of like jogging or running.

    5. RCDr. Rangan Chatterjee1:18:10

       Mm.

    6. TWDr. Tommy Wood1:18:12

       And we basically spend our entire day running, and if you imagine, like, how exhausting is it to run all day? You couldn't do it, right? But you just, like, keep trying to keep, keep going. Um, and this is essentially what we're doing to our brains in the modern work environment, and it's, uh, the middle gear is meetings, uh, emails, dealing with Slack and Teams and all these different inputs, multitasking or task switching across multiple... like trying to deal with multiple things at the same time. So like you're trying to do some work, and then an email comes in or a message comes in or... And we, you know, we get to the point where we're so used to distractions that we distract ourselves. There's some really nice work from, from Gloria Mark, fantastic book called Attention Span if any, if anybody's, um, interested in this. But basically, if we're distracted a lot, our brains get used to distractions, and then we go looking for distractions. You know, like-

    7. RCDr. Rangan Chatterjee1:18:59

       Mm

    8. TWDr. Tommy Wood1:18:59

       ... when you go to pick up your phone even though it hasn't gone off.

    9. RCDr. Rangan Chatterjee1:19:01

       Yeah.

    10. TWDr. Tommy Wood1:19:01

        And there's no... I mean, you, you, I mean, you have your, your framework. Like, why now? Why am I doing this? Like, what, what, what is it for? But we basically get to the point where our brain gets used to distraction and goes, goes looking for it. And so we know that when we're forced to multitask or, you know, we're interrupted in our work, which is essentially everything we're doing in the modern work environment, it's inherently stressful. It, it creates this low level of stress. And then you layer on top the fact that you never get a chance to do the really high quality work that makes you feel useful, right?

    11. RCDr. Rangan Chatterjee1:19:35

        Mm.

    12. TWDr. Tommy Wood1:19:35

        The, this, this is what I'm good at. Like, this is, this is the job that I'm here to do. Um, and it could be, right, researching or writing a book. It could be, uh, you know, preparing presentations for, uh, a, a board. It could be, you know... Luckily, um, you know, if you're like a, a surgeon, right, they get to remove all the distractions and actually do their, their, their work, but that's the kind of thing that we wanna be doing, like, focused. Th- this one thing that we're doing. This is the thing that we're good at, really applying ourselves.

    13. RCDr. Rangan Chatterjee1:20:02

        But we'll, but we'll do that with a surgeon because-

    14. TWDr. Tommy Wood1:20:03

        Yeah

    15. RCDr. Rangan Chatterjee1:20:04

        ... we know that someone's life depends on it.But without being flippant, you could kind of make the case that all of our lives depend on it.

    16. TWDr. Tommy Wood1:20:13

        [laughs]

    17. RCDr. Rangan Chatterjee1:20:13

        Right?

    18. TWDr. Tommy Wood1:20:13

        Yeah.

    19. RCDr. Rangan Chatterjee1:20:13

        Like if, yes, we're not surgeons, or many of us listening are not surgeons. I'm sure there are a few surgeons listening.

    20. TWDr. Tommy Wood1:20:19

        Yeah.

    21. RCDr. Rangan Chatterjee1:20:19

        But, you know, the quality of your life probably does depend a lot on how you're spending each day.

    22. TWDr. Tommy Wood1:20:28

        Yeah.

    23. RCDr. Rangan Chatterjee1:20:28

        Right?

    24. TWDr. Tommy Wood1:20:29

        Yeah.

    25. RCDr. Rangan Chatterjee1:20:29

        So, yeah, a surgeon has a reason-

    26. TWDr. Tommy Wood1:20:31

        Yeah

    27. RCDr. Rangan Chatterjee1:20:31

        ... to do that, but we kind of need to give ourselves that reason as well, I think.

    28. TWDr. Tommy Wood1:20:35

        Exactly. And w- so we want to feel, we want to feel useful and productive, right? We're no longer... You know, as a s- as a species, our history was largely, you know, our productivity was largely due to physical work, right? Hunting, gathering, farming. But now, the product of our work is due to our brains, right? We're knowledge workers. Um, I'd like to call us all cognitive athletes, right? And so, like, that's important because the best athletes, like I was saying earlier, they know... They have very targeted training, they have very targeted stimulus, and then they focus on recovery adaptation, how... G- getting the most out of their training. Whereas we just spend all day jogging and never think about the recovery that our brains need in order to perform at our best. So well, then what happens is, uh, at the end of the day, you've felt very busy and very stressed because you're constantly bouncing around between all these different things. You know, you're in Z- in Zoom while you're also writing an email, but you're, like, not paying proper attention to either of them. Um, and so that is... That process is inherently stressful. Um, and we know that people make, make more, more mistakes and errors and feel more stressed when they're interrupted or they have to multitask. And then you're stressed about the fact that you didn't actually do that really high quality focused piece of work that you needed to do because you were so busy in meetings and multitasking. Um, and so then when you get to the end of your day, you're like... You're stressed about the fact that you didn't do, do those things. Um, and then you have to try and somehow wind down and go to sleep. So you then may rely on other things that could... That you feel like are allowing you to relax, but could, could compound that. So it could be social media, or it could be, you know, a glass of wine, which then, you know, impairs your, im- im- impairs your sleep and then... Or, you know, two glasses of wine. And then the... You're right, then the next day, the whole kind of cycle starts again. So I kind of start by thinking about, how can I structure the, how can I structure the workday so that even if it's just for 30 minutes, I can just get the, get the thing that I need to get done today done? And you do that by, if, if you can, structuring your day so that whenever you feel best, e- and, like, each of us feels most focused, mo- most alert, most at- you know, attentive at one specific time of day, and it could be in the morning, it could be in the evening, right? Depending on chronotype and other things. During that period of the day, like, just get... Just set aside half an hour to, like, do the thing that you need to do. And then you can also set aside time to do the m- the, do the meetings and other things, right? And the emails. We all, we all have to do that. But in between those things, allow yourself time to get... To, to have a break. Can you go for a five-minute walk? Right. Can you just, like, look outside at something green, right? There are studies that show that we can, um, become reinvigorated and less, uh, cognitively fatigued just by looking out a window-

    29. RCDr. Rangan Chatterjee1:23:13

        Yeah

    30. TWDr. Tommy Wood1:23:13

        ... at greenery for 90 seconds, right? So it doesn't necessarily take that much. There are also some nice studies where, uh, people feel reinvigorated after five minutes of watching comedy clips on YouTube.

Episode duration: 1:27:10