Neuroscientist: 7 Habits That Protect Your Brain & Reduce Dementia Risk | Dr. Tommy Wood

Key Takeaway

Make one brain-health change today that gives your brain a reason to adapt: book a dance, language, sport, music, or volunteering session with other people. Dr. Tommy Wood’s key point is that stimulation is not just solitary puzzles or optimization—it is often social, purposeful, and enjoyable. Pick an activity you genuinely like, schedule it this week, and treat sleep, movement, and nutrition as the support system that helps your brain respond to that stimulus.

Episode Overview

Dr. Tommy Wood and Dr. Rangan Chatterjee examine seven commonly overlooked mistakes in brain health and dementia prevention, from negative beliefs about aging to ignoring blood pressure, oral health, social connection, and environmental exposures. Wood emphasizes a practical, non-alarmist approach: maintain brain stimulus, provide the body with adequate metabolic and nutritional supply, and allow adaptation through sleep and recovery. The episode repeatedly returns to the idea that small changes are valuable at any age.

Full Transcript

Transcript of Neuroscientist: 7 Habits That Protect Your Brain & Reduce Dementia Risk | Dr. Tommy Wood from Feel Better, Live More. Auto-generated from episode audio; may contain minor errors.

The framing I thought would be quite fun and useful for people is basically around the common mistakes people make when it comes to brain health and longevity and health span. Mistake number one, we neglect how much our perception of aging impacts how well we age. And in your latest book, which I love, you quote the Ohio Longitudinal Study of Aging, and you write that those with a more positive perception of aging were found to live on average 7 and a half years longer. What's going on?

There's several things going on, and it's difficult to tease them all apart in a study like this, but essentially what they did is they asked people how they felt about the process of aging. So they asked them to rate on a scale of you know one to five how do you feel about questions like when I get older or when people get older they become less useful things you know things like that and those who had a higher level of the positive perception of aging tended to live longer like you said seven and a half years longer on average and then you have to adjust for other things like age and health status and some other things and some of it could be what we call uh reverse causality right so if you're already feeling like you're experiencing the process of aging, you're u you've lost some of your health, um then you might feel more negative about aging and it's the health that's really driving it rather than your perception.

So, some of that is certainly playing a role. But I do think that having um a positive outlook outlook on the processes of aging will then allow you to continue to engage in the world in a positive manner that then drives a whole host of benefits. And we know that mindset and how we feel about our own health and our well-being are important drivers of our physiology and important [clears throat] predictors of our long-term health. So some of that reverse causality is possible there too. But we do know that how you feel about the future and how you feel about your health and then aging as part of that is going to change both how you interact with the world and change your physiology.

And I I think that that's what we're seeing some some of in in that particular study. Um, and where this then becomes really interesting to me is when we think about this idea of chasing longevity in particular, then inherent in that is some idea that um aging is bad, right? Because in [snorts] order to fight against aging, you have to think that aging is inherently detrimental. Um, and yes, we we know that with aging you will lose some function. It just it is what it is.

We can't prevent it entirely. But if you have a negative perception of that, then when you start to see aging happen regardless of your efforts, I think that could then have an even worse effect on your psychology and mindset because you've kind of internalized this idea that aging is bad. Then with aging could come a whole bunch of changes in say cognitive function and other aspects of personality that may be beneficial but we might miss out on that if our primary focus is on preventing it entirely because we think that it's bad.

When we think about changes that we can make to help increase our health span, we can think about individual changes that we can make, but we also need to think about, I guess, collective changes and the influence that culture and society has on us. So, if we're constantly being surrounded by a message that aging is bad, how can you um fight the aging process, stop the aging process? It kind of undermines like a central truth which is you're actually aging from the minute you're born. Yeah.

Right. It is just a truth of life. We see this. I think I mentioned to this in maybe one of your previous appearances that there's quite a a bit of research showing that cultures where women aging is seen as a good thing report less menopausal symptoms. I think that a lot of what we experience we know um is based on how our culture sees these processes of aging. And I really enjoyed there was actually a very recent paper that came out um uh called humans peak in midlife um and actually talking about the fact that when you look at just individual factors and we're talking about you know cognition and and personality here primarily then you might look at something like how quickly can you process complex information and maybe do some kind of non-verbal reasoning something like that.

Yes, that peaks early in life, 20s and 30s, and then on average tends to decline. Um, but that's one very narrow idea of cognitive function, right? So when you look across a whole different range of things that the brain does and they sort of had various scales and ways to integrate all these different things, you think about the fact that um other things increase over time and maybe even into our 60s and 70s things like um crystallized intelligence, which is a fancy word for wisdom, but also emotional intelligence and um and moral reasoning.

Right? On average, a 20-year-old probably isn't as good at sort of like thinking about the moral big picture as a 40, 50, 60-y old because they have more experience. They've kind of integrated all these different things. So, um when you look across all those different um factors, then on average, people sort of tend to peak somewhere between 55 and 65. sort of like you have you still have uh good cognitive function plus you've built um other aspects of wisdom and emotional intelligence and sort of they integrate and like that's actually when people tend to peak and so that's after the menopausal transition in women and obviously it's you know sim similar age is seen in men so we can continue to grow cognitively emotionally um and see benefits from that you much later maybe than than people might otherwise think.

Yeah. What's the practical takehome then for an individual? Is it a bit like gratitude where if you focus on what you lack, you lose what you have? Yeah. I I think maybe it's worth just talking for a minute on on the the process of of aging and what what aging is. And there are lots of different theories of what of what aging is. Um and so like one is actually the developmental theory of aging which is that aging is the continuation of developmental processes that caused growth earlier in life and then as they sort of continue decades later they actually drive a functional decline.

Although what I would argue and this is right the major point point of um my book as well is that it it might be that we stop giving the body inputs that maintain function uh and then that's why function declines. And that would make sense with development because development is all about building function uh relative to inputs. So if you stop giving those inputs then function declines because the body is trying to match function to to whatever it is that you're you're doing. So that would fit with the developmental theory of aging.

But there are other theories like the information theory where you know damage accumulates and you know DNA uh doesn't replicate as well and then uh that kind of drives these aging processes. But regardless of, you know, what aging actually is, which people don't actually agree on what aging is, um the one thing that most people do agree on is that we c we we may not be able to slow aging down, but we can accelerate aging, right? And that's uh by not sleeping and eating a poor quality diet and not moving and you know, not being socially connected.

So, when we're thinking about um aging in general, know that the best place to start is just do those things that I just mentioned, the things that you talk about all the time, because by not doing those things, you could accelerate the process of aging. You probably can't slow aging down, or at least at this point, we're not sure how much we can slow aging down. So then if you tick those kind of boxes, those big boxes that I think each of us can do in our own way and can have a big impact even with relatively minimal effort, then the rest is just acknowledging and understanding that yeah, things will change over time.

But you also see, you know, with this kind of idea that humans peak in midlife, you actually tend to see an increase in um satisfaction with life and happiness as you get older. And that's probably a um a downstream effect of all these things kind of integrating and coming together. So the maybe the main takeaway is in that kind of middle portion as you transition into sort of mid and later life just don't maybe don't fight it as much because then it's just a it increases distress without um you any kind of major benefit of it.

And so so it's just acknowledging that it's happening, acknowledging that um actually there is some there's some benefit to it and at the same time you're you're doing um you know you're kind of covering your bases so that you're not kind of accelerating any kind of biological process associated with aging. But but I think just knowing that it happens and knowing that actually there's some net benefit to it is is probably a starting point because then you're not constantly fighting your biology which is going to win out at some point.

It's interesting. So it makes you think of the stress response and I guess a more spiritual or philosophical explanation of stress is to do with resistance right if you resist what is happening that is what is creating the stress. Yeah. The more you can accept and not resist the less stress you are going to experience. And I guess we could bring that argument in here and go if you try and resist the aging process to a degree. We're not saying don't do the things that are going to help you age well, but the more you resist the fact that your hair's going gray and that you're not going to run probably your 5k PB at 70.

Yeah. And that's okay. Yeah. Yeah. Just not essentially wasting mental and physical energy in resisting something that will happen to all of us. Um because then you may be more likely to see the benefits of the things that will happen as we change over time. Before we move to mistake number two, I've heard you talk before, Tommy, about how we perceive stress changes the physiological stress response. Yeah. And I think, you know, we're broadly talking about mindset here and how the right mindset as we age can potentially help us live longer, improve our brain health, and improve the quality of our lives, right?

So talk to me a little bit about stress, maybe from a less philosophical lens and a more scientific lens, what it is and how refraraming that stress in particular ways can change the way that our bodies respond. Yeah. So where we've gotten to right now and you there's actually been a lot of it in the last couple of years where people are talking about right stress is inherently bad in all situations regardless of what's happening and fundamentally that just is not true. The stress response is incredibly important and it's also a general response to the outside environment changing and your body realizing I need to do something in response to this thing that's outside of me.

That's essentially all the stress response is. Um, and that might be psychological, it might be physical. Um but the initial response you release adrenaline, cortisol, heart rate goes up, blood sugar goes up. Your body is diverting resources to allow you to respond to this change in the environment. And it's it's why um historically the sort of like the kind of the father of the modern stress response, right, is Han cell, right? And he called it general adaptation syndrome initially. And I quite like that because it's like this is your body signaling that adaptation is required.

So when you're focused and learning and maybe failing, we talked about the importance of failure before for building cognitive function and building skills. It's stressful. Your heart rate goes up. You release um stress hormones like noradrenaline in the brain. But it's your brain diverting resources to say, "Hey, I need to change my structure of my functioning so that I can adapt to this thing that I'm being exposed to." And right, exercise is the same. If you did um somebody's, you know, blood pressure and measured their heart rate and measured their glucose and cortisol, right, measured that in you after a paddle game, you'd be like, "God, paddle is terrible, right?

Just look how stressful it is for your body." But as a result, your body adapts, right? resting heart rate improves, inflammation improves, um strength and speed and power uh improve, uh V2 max improves, and that's driven by this stress response. So, the first thing that I hope that people realize is that stress is useful. It's your body's signal to adapt to some change. Yes, chronic stress where it then starts to impact sleep and it impairs your ability to adapt which can which can happen if if you know a stressor isn't you removed or relieved or you're unable to process that stress.

Yes, it can be maladaptive or problematic, but in the moment stress is actually incredibly beneficial. Um, and then we know kind of to get to your question, we know that how we think about stress affects how we respond to it. So most of this u work is is is done has been done by Alia Crumb. She's at Stanford. She um work as as a PhD student. She worked with Alan Langanger who I know we both um love love her work. And [snorts] so it's very much in a si like Alia's work is very much in a similar vein but has obviously taken it and uh built built an amazing career in her own right.

Um and what she researches or one of the things she researches is this idea that stress is enhancing. Um, and they've done randomized control trials where you take a group of people and one group you say just think about how terrible stress is, right? Um, it sort of it breaks you down. It impairs your decision-m, right? It's just you just really really bad for you. Stress is debilitating, right? It it it prevents you from being able to perform at your best. And another group, they sort of show them videos and they prime them with this idea that stress is enhancing.

Think about all the amazing people who've performed under incredible stress. So you might talk about Winston Churchill or Abraham Lincoln or Sully Sullenberger who landed the plane in the in the in the Hudson, you famously. Think about all the times that you've performed under stress. Like think about how amazing you can be even when you're stressed. And then you put them in a stressful situation. Um and there are experimental ways to do this. One is called this try a social stress test where there are different versions of it but essentially you go into a room and there's a panel of people in front of you and they're like you have to speak for 5 minutes on this topic that you haven't prepared at all and while you do that the audience just sits there completely and [snorts] passively just like staring at you which is like very st very stressful.

Um and what you see is that those you both groups they get stressed right cortisol goes up the same in both but you see a few um other things that happen in those who um are told that stress is enhancing. So you see other hormones increasing at the same time. So one of them is is DHEA which is a a steroid hormone and that like DHA is part of that adaptation process. is kind of um helps to facilitate growth um and the you know the the building the adaptation of of tissues and that goes up in the stress-enhancing group whereas it doesn't in the stress debilitating group.

There have been other studies by other groups that looked at hormonal responses to stressful situations and they found that those who release more DHEA when stressed tend to make better decisions under stress. Um it may not be the DHEA. It may be the sort of like whole physiological kind of setup of of thinking that stress is enhancing that you can then um or you know being that in that kind of situation where you don't necessarily think stress is debilitating that allows you to make better decisions under stress.

But this is very interesting that not only does your mindset change your physiology and response to stress, but it may also then change your ability to perform under stress. So I think some of this just requires us to to acknowledge hey stress is actually good. It's a good thing first of all it's for survival but it's also for growth and adaptation and you know making us bigger and stronger and smarter. Um and then acknowledging and thinking about the fact that yeah actually I probably can perform under under stress.

Um and then in doing that you will perform better under stress. Yeah. Okay. Let's get to point two. Okay. So, mistake number one about having the wrong mindset. Mistake number two, and again, I've started with these on purpose because I don't think they're spoken about enough, focusing on solo health habits at the expense of social connection. Mhm. And I guess the point I'm trying to make here is if we consume all the health podcasts and hear the list of things that we could be doing and perhaps should be doing to optimize our health and longevity, you could end up living quite an isolated life.

If you were going to get your 5 hours of zone 2 and do your Norwegian 4x4 and um never eat out late and all this kind of stuff, you could find yourself spending a lot of time by yourself. Yes, you've optimized certain metrics, but potentially at the expense of social connection. Yeah, I I think that this is in particular a risk for those who are very hyperfocused on on this area. And and I I don't think any of us needs to go very far to see examples of this in popular media, social media, where people who are trying to push, say, the edges of longevity essentially live indoors by by themselves um with a very perfected sleep schedule, food schedule, supplement schedule.

And it's very possible that they'll live a little longer. I don't think they're going to live 20 years longer, but I I I think that it's possible they could undo or even go in the other direction because by being so hyperfocused on optimizing everything, which I think is a misnomer in the first place. um you miss out on this core part of human biology, physiology which is the connect which is the connection to others um and we know that is healthpromoting and health driving um as well as just being a part of how humans evolve.

So, so one of my um my favorite stories around this goes back to Charles Darwin because when we think about Darwin, we think about evolution, we think about survival of the fittest, although survival of the fittest was not his term. It was coined by somebody else later. But this idea that like it's every species or individual for themselves and it's just like this battle to survive and reproduce and right that's that's that's how you win. Um but 12 years after he wrote on the origin of species which is like the you know the the set of essays that kind of came that that founded this theory of evolution um supposedly Darwin thought well actually survival of the fittest as an idea doesn't explain human evolution and so he wrote another um set of texts called the descent of man and essentially came up with this idea instead that um the group that was the most he called them sympathetic.

The like the the group of humans that were most sympathetic we would we would call it empathy now that looked after each other the most that cared for each other the most actually they would be the ones that would that would survive and that that kind of better explained human evolution and then Dhaka Kelner uh sort of much later um ended up calling this survival of the kindest. Yeah. Um and there's now a huge amount of uh science to show that when we act pro- socially like we connect with others particularly when we're helping others um and this is where some of those ideas of why like purpose and meaning can have such a big effect on our health.

You can see again physiological responses. So you see activation of the veagal nerve and um like heart rate variability uh improves and you know stress responses decrease and all these things that we know are again tied to to long-term health. Um and so I think that there's this we know there's this core requirement of our biology to be connected with others and especially to act in in the benefit of others or benefit of things outside of ourselves. Um, and I think we miss out on that when we're so hyperfocused on optimizing everything for ourselves individually.

Um, and I've seen this a ton with, you know, clients, uh, that I've worked with over the years where they, you know, they stop going out, they stop seeing friends, they stopped having meals in restaurants because they're so worried about the food that they'll eat or whether they won't get to bed in time. um you know everything else will kind of fall out of kilter because they're they're not at home to kind of get their their perfect routine. Um, and I think their their health suffers because of it.

And like there's there's almost I imagine everybody who works in in our fields, right? I don't see patients clinically. I haven't uh for a long time, but you when you've worked with people as a health coach, everybody has a story of the person who essentially gave up their diet and gave up their exercise and just started hanging out with their mates again and all of their health problems uh improved. Um, and yeah, you know, there may be exceptions to the rule because, you know, those aspects of lifestyle still do matter a lot, but I think there's this critical importance of social connection that we lose out on when when we're so hyperfocused on, you know, getting everything else perfect.

Yeah. Your book, Tommy, The Simulating Mind, which you know how much I love that. You know how much I want people to get it because I think it's one of the books of the year. It's absolutely fantastic. There's two studies in that book that I wrote. I I I sort of wrote down to discuss with you which relates to this topic. Right. A Japanese study of 9,000 adults greater than 65 years old, more frequent social contact was associated with higher brain volumes and less age related white matter injury.

And then you also spoke about the 2025 world happiness report showing that one of the strongest predictors of well-being across 142 countries was the number of meals per week people share with others. I mean this is huge right because as we we're talking about here you can solo optimize but you miss out on all of the social inputs. And if we go back to your 3S model, which I'd love you to just briefly summarize for people who've, you know, coming to you for the first time, well, when we think about stimulating the brain, yeah, it can be learning new things for sure, but you can also argue that having conversations with other human beings, being around other human beings, well, that's also an important stimulus for the brain, isn't it?

Yeah. So, so I think it's maybe worth first thinking about what's the point of living longer and maintaining cognitive function for [snorts] long periods of time, right? Because I don't think it's to stay at home by yourself for more time, right? More more Netflix watching by yourself. Is that you don't think that's why we've evolved? I mean, you know, I absolutely love a good uh Netflix binge, of course. Um but for the vast majority of people and actually yes the the sort of the extreme optimizers and biohackers I I think it's it's almost like theater.

It's interesting. Um I'm glad people are doing it because you know maybe I'm I'm sure we'll find out some some useful stuff. Um but the vast majority of people don't want to just live longer. They want to get to 80 something and be in good health for the majority of that time. And why do they want to do that? Because they want to spend time with family and friends. That's like that's what it boils down to. So it's the spending time with people that is the primary motivator for all of this in the first place, right?

So you don't want to miss out on that in the pursuit of it because you you'll never actually get the thing that you're trying to live longer [snorts] for in the first place. Um so I think that for most of us that should kind of like frame why are we even doing this in the first place. Um to kind of to go to the the 3S model. So um this is kind of um my idea of how we bring together all these different aspects of lifestyle and the environment that affect cognitive function.

But it's actually this the same the same principles work for physical function and you know many many other aspects of our health. And so the 3s are stimulus supply and support. So stimulus being how essentially how we're using our brains. The idea um is that how we use our brains is the primary determinant of how our brains function just like the how we use our bodies is the primary determinant of how our bodies function. Um and that could be you know learning skill building languages music but of course like social interaction and and there are um many examples where there's an outsized benefit from something that includes doing it with other people.

uh be that volunteering or sports, you know, dancing and like similarly languages, music often happen with with other people, right? That's why that's why you do it. Um is to play with other people or uh perform in front of other people or to kind of do something communally. And so that kind of is the driver of adaptation, building structure and function in the brain. And then you kind of activate networks in the brain. Um in order for those networks to do what you're asking them to do, you need a supply of various things.

That's our secondary. So it's blood supply, um energy supply, and then nutrient supply. So these things come from physical health, cardiovascular health, um diet quality. And [sighs] then like we were kind of talking about earlier, right? We know that stimulus drives some version of a stress response. This drives adaptation. So that brings us to our third S support and most adaptation happens during sleep but essentially during periods of rest. So that's the the kind of major part of support. Um but then we can support adaptation in other ways.

Hormonal status is important as well as avoiding you know and other kind of aspects of physical health that sort of support adaptation and then avoiding things that impair that process. So alcohol, smoking, certain environmental exposures that that can kind of increase inflammation or oxidative stress, which some of which I think we'll get to today. So that's kind of the three S's, but so many of like the overall goal of thinking about the 3S model. And then many of the primary inputs in the stimulus bucket come from things that either we learn and do with other people or where we can we want to express them and use those skills and abilities with other people.

Um or cognitive functions, be able to, you know, play with our grandkids or, you know, um do any kind of uh sort of sport or other activity um with them. and that's why we're trying to maintain function in the first place. So I really think that um that part of human connection is is critical to all of this. And I will say that um I wrote a paper on this with my colleague Josh Turknet a few a few years ago talking about how the sort of potentially the primary driver of loss of function with age and this was focusing on cognitive function was stopping doing the things that maintain function, right?

Stopping stimulating the brain. Um and then when I spoke to my friend Julian Ael who is um you know famous for his work in compassionate communities and um you know the importance of social connection and health his response was like was yes this is great but of course it's all driven by the human need for social connection cuz so much of this happens through our connections with other people and you know he's absolutely right that is sort of like fundamental to to so much of this.

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That's when these simple techniques can make a real difference. I explain all of them in my guide, Break Free from Stress, and it's yours for free today. Simply scan the QR code on screen or tap the first link in the description box below and I'll send it immediately to your inbox. With a few small changes, you can feel a little calmer right away. Can we say that social isolation is a form of stress? So yes on multiple levels we we see in controlled studies that being socially isolated increases stress responses which you can you know measure through things like heart rate variability and cortisol levels and there are studies where they've done this for instance NASA and other space agencies around the world have wondered how will people do if we if we send them to Mars right so there have been some Mars simulation in uh projects where you put people either on their own or in a very small group in a in a tight confined space um for extended period of time and even that for just weeks significantly increases stress responses.

We know it's inherently stressful even even if there are other people there you're relatively isolated because there's only one or two other people. Um and we also know that when you look at pe when you look sort of across a big population, those who are more social isolated, particularly those who feel lonely, they have other markers of of um a a heightened stress response. So you can measure these stress responses in people who are isolated in a v variety of different ways either experimentally or just as part of their you know unfortunately where where they are in the world right now.

Um on the other side you can also see a response or changes in the brain with social isolation that look like the removal of stimulus and accelerated brain aging. So when you look at the areas of the brain that are the human brain that are most driven by the environment and are most driven by experience and sort of interaction with the world around you that they're also responsible for some of our most complex cognitive functions. um areas like uh the the prefrontal cortex, the lateral parietal lobe, the lateral temporal loes are kind of like the front and sides of the brain essentially which are responsible for things like decision- making, focus and attention, memory, language, you know, uh vision or visual processing, social cognition, things like that.

These areas of the brain are essentially completely undeveloped at birth. they are their development is driven by the environment and how you engage with it um during childhood and then early adulthood. But these are also the areas of the brain that are most susceptible to the processes of aging particularly the removal of stimuli. Right? I I mentioned earlier that part of the reason why I think our brains age is because we stop doing the things that help build these functions in the first place. interacting with other people, learning skills, focusing on stuff, um you know, kind of doing complex um activities.

[sighs and gasps] And those areas of the brain that I just mentioned, when you look at people who are socially isolated, those areas of the brain are the areas of the brain that tend to either get smaller or tend to lose function. And they've done studies where you look at Yeah. So people from those like sort of uh simulated Mars trip studies or people who um were uh polar explorers right on their own off you know on some snowy glacia for months on end or uh in prisoners who [clears throat] are placed in solitary confinement those same areas of the brain that I mentioned tend to lose structure and function as a result of that loss of social input.

So, not only is uh social isolation and loneliness, not only are they inherently stressful, you're also removing a critical input that maintains these really important structures in our brains. Even if you're a polar explorer, right, and you're getting stimulated by all kinds of things in your environment and you know, you have to be vigilant and all all kinds of stuff, right? Even with that kind of stimulation, you're missing out on a very important part of stimulation or stimulation for the human brain. And it made me think, the brain needs stimulation.

And this, I guess, fits in with this second mistake of focusing on solo health habits at the expense of social connection. Let's say you're an 80-year-old and you live by yourself, okay? And you've heard Tommy Wood or you've read your book and you go, "Yeah, I need to stimulate my brain." So you are learning new skills on your computer. You're competing at chess online with other people. But you're doing it all in isolation. So you're giving it a lot of stimulus, but it's individual stimulus as opposed to social stimulus.

Can we say then or or do you can we hypothesize that even with all of that stimulus, you are still missing a significant primary stimulus that the brain needs, which is social connection. The way that I would answer it is that if that person feels lonely or feels that beyond what they're currently doing, they lack some kind of purpose or meaning, then yes, I I think there's more to be gained. If that life is incredibly fulfilling to them, which for some people it will be, then no, I couldn't say, well, you have to go out and make friends, right?

So I think some of it is going to come down to like fundamentally how do you feel about the kind of setup and your current connection to other people because often when you talk about social connection and and rightly so some people will say this is directed at extroverts who like to spend time with other people. I was literally going to bring that up. Exactly. Um and you can be connected to a lot of people and still feel lonely. Um, and some people, um, only need a very small amount of of human connection to feel like, you know, they're getting everything they need.

Um, my friend, uh, Dr. Ben, uh, Ryan, who wrote wrote a excellent book called Why Brains Need Friends, you know, talks about, um, you know, a flower in a pot and like some people the the soil in the pot needs a lot of watering, right? It needs a lot of social connection for them to feel kind of fulfilled. But like some people are a succulent or a cactus, right? they only need a little bit and they'll and they they they feel just fine. And like wherever you are on that spectrum is absolutely fine as long as you're getting what you need to feel like you're connected, to feel like you're supported, to not feel lonely, to feel like you have, you know, some kind of, you know, your life has some meaning, you know, outside of just yourself.

So I want to make that very clear that it will come down to how you feel about the situation. Yeah, that's a really important point. And I think for those people who were pushing back when they heard social connection, I think that hopefully appeases people and and helps clar clarify things. Okay, we've done two of these mistakes so far. Mindset and this solo health habit focus at the expense of social connection. [snorts] Um I want to go to some areas that I think we haven't spoken about before.

One is blood pressure. So I would say mistake number three that I think gets made a lot is ignoring high blood pressure. Do you agree with that statement, Dr. Wood? Yeah. Uh, yes. Um, and I didn't necessarily realize it until I was doing the research for my book, but the evidence for blood pressure management and dementia risk is actually incredibly strong. It's one of the few interventions where we have multiple randomized control trials that have been put into meta analyses to show that if you address this risk factor, you see a significant reduction in dementia.

Um, most of the other things we talk about come from big population studies, observational studies. Yes, we're pretty sure that that connection is there and if you you modify this risk risk factor, you'll see you'll see benefit. But blood pressure actually has really high quality evidence. So um when we talk about blood pressure normally we're usually thinking about heart health right and you know heart disease risk and it's obviously important there too um but if I've learned one thing over the over the past few years is that even when people are taking cardiovascular disease risk fairly seriously it's not as much of a motivator for behavior change as we might hope.

Um whereas when we think about this in terms of our brains often that's the right somebody wouldn't maybe worry about their blood pressure. Oh it's a little bit high it's it's it's probably fine. Um when you then realize that this is a you know a critical risk factor for the majority of dementias both Alzheimer's disease and vascular dementia which have a lot of overlap and they between them make up 70 to 90% of dementias often that's the key maybe to for people to think about it but we don't really think about the the brain when we think about blood pressure but um we know that once your uh blood pressure goes you much above sort of 120 over 80 and you really once you get into the sort of the metabolic syndrome uh criteria level of blood pressure which is usually one over 130 over 85 you see a significant increase in the risk of dementia and if you can reduce it um you see a significantly reduced uh risk of dementia and the sort of the the average benefit is if you can get your systolic blood pressure down by about 10 points you see a significant benefit in terms of your dementia risk.

So um there are multiple ways to do that um right we know we can do it through physical activity we can do it through other uh you know other lifestyle changes to improve metabolic health but these studies are with blood pressure medications and you see significant benefit in terms of dementia risk. So if you need a blood pressure medication uh or your blood pressure is high and is not fully controlled you know I think that is something that we really should take seriously. Yeah, I guess one of the problems with or or potential problems with uh blood pressure is that people often don't feel anything [clears throat] wrong.

Yeah, they used to call it the silent killer, right? I think in medical school, I'm pretty sure that's what we used to get taught that it's just going on in the background. I'm literally at the moment triing the hyo bands. I think it's the to my knowledge it's one of the only FDA approved continuous blood pressure monitors. The goal is that that is telling you more accurately whilst you're going about your everyday life, what actually is my blood pressure doing? Um but of course, you know, there are 24-hour monitors that you can get on the NHS.

So, there's there's all kinds of ways. But I guess the the message you're sort of I guess trying to give people around brain health is get your blood pressure checked. Yeah. And we've now gotten to a point where you could go to Boots and a blood pressure monitor, was it 20 or 30 quid? It's probably not that much. And if you do it two or three times a day at home, um or you could even get it, you know, your GP could prescribe it for you on the NHS, right?

So, you might not even have to pay for it yourself. Um but just like like you said, having some some idea you what's it in the morning, what's you know, in the afternoon, take it two or three times a day. um that's going to give you a much better picture. Plus, you get used to having your blood pressure taken, so you have less of that kind of anxiety of, you know, it feels kind of weird and, you know, getting stressed about what it might be. Um, and I think now it's gotten to a point where blood, you know, relatively regular blood pressure monitoring is is something that's easy for all of us to do and and and you know, we should be doing.

Yeah, I think that's a good segue to get into the fourth mistake, uh, which is not doing any form of blood testing until maybe until you get sick. Right? Before we just jump there though, I guess this is related to blood pressure. I mentioned earlier on in this conversation that over the last 12 months, I have taken up paddle. [snorts] One thing I've noticed since I started playing, and you got to bear in mind, it wasn't as if I was sedentary beforehand, I was already, I would say, pretty healthy before I started playing paddle.

My resting heart rate has gone down by about four beats, right? That is significant. We've never covered resting heart rate before. There is a linkage here with blood pressure of course, but you know as well as being a brain health expert, you're a performance coach for Formula 1 drivers and a lot of high level athletes. What is the benefit of a resting heart rate going down in this context? Yeah, the there are several metrics that you can sort of track physiologically that do seem to correlate with longevity, chronic disease risk, you know, heart dis, you know, heart disease risk in particular.

Um and resting heart rate is is one of them. Um heart rate v variability is another and I imagine if you're resting heart rate has dropped your heart rate variability has also gone up. Yeah. Um and then um resting respiratory rate is another one that that maybe we don't appreciate uh as much uh which is basically you know how many breaths you take a minute. Um and that also seems to be a good predictor of uh you know stress burden and other things as well as being you know related to some aspects of of um long long-term health.

And when your resting heart rate is lower, your heart is essentially more efficient, right? To to get blood around the body. And we know that those who have a lower resting heart rate tend to be fitter. They tend to live longer. They tend to, you know, have fewer chronic diseases, less less heart disease. And that's probably a combination of Yeah. improved fitness uh decreased uh decreased stress responses and you know all those kind of things uh uh related to that. So having lower lower resting heart rate uh is absolutely um like a a measure of better sort of like overall health and fitness like you said in in this context there are times when lower resting heart rate can can be a bad thing.

you know, later risk of things like um heart disease, heart failure. Um and so by improving efficiency and improving heart function, um you're decreasing the risk of that happening long term. Yeah. And almost certainly had I been tracking my blood pressure, which I was not, I might also see that come down as a consequence, right? Because these things of course don't work in isolation. Let's get to that mistake number four. you know, this this idea of not doing any form of blood testing until you get sick.

And and I guess underpinning this as a mistake is an idea that I don't think is widely known with the public. And you know, I very much appreciate your take on this, which is this idea that the bulk of our medical education and I would say certainly here in the UK, the way that NHS is broadly speaking set up is to diagnose disease and treat it. Okay? And I think it can do that exceptionally well. The creation of health is a little bit different from the diagnosis and treatment of disease.

And one of my frustrations over the last couple of decades or so has been that we in medicine and maybe we could argue there's no resource for that within medicine. But for whatever reason, I feel that people are allowed to deteriorate somewhat. not quite get into a disease category but deteriorate and say everything's fine until actually something happens where we go oh no you've got type two diabetes let's talk about metformin and insulin and suluras and all that kind of stuff right so this idea that hbaw1c for example your average blood sugar marker here in the UK at 6.0 zero on in old money um it becomes pre-diabetes at 6.5 you're called a type 2 diabetic but that does not mean that 5.7 and 5.8 8 and 5.9 is fine.

And [clears throat] many people in the UK, if you go and get an HBA1C test from your doctor, you're told that's normal. Now, there's a resource issue within the NHS. I accept. At the same time, I think our approach to prevention is a little prehistoric. It's it's kind of a 20th century approach, even though we're now at 2026. cuz we're in the 21st century. And so I believe it's much better if we were able to track certain metrics and start to see when things start to go wrong.

So we can say, "Hey, listen. You're not pre-diabetic, but you're not where you were a year ago. You're on the way. Uh would you like some help in making some changes which will perhaps stop this process?" Right. So do you have any sort of thoughts on that initially at least? I completely agree with you. This is relevant to pretty much any chronic disease. It's relevant to we've talked about blood pressure is relevant to blood tests. I mentioned cognitive tests um previously or like just in passing earlier because nowadays you can't get a cognitive test from a neurologist or an old age psychiatrist or whoever whoever would be doing it until somebody suspects you have cognitive impairment.

There had to be some trajectory of decline, but we know no idea where you started. No idea how long that took, no idea how long you've or like how much function you've lost in order to get to the point where somebody diagnoses you with say mild cognitive impairment from a from a cognitive function test. Um because we we don't track these things over time. the a charity that I work with, food for the brain, that has an online cognitive function test that people can do for free if they're interested, but more importantly, they just got a big uh invent UK grant to try and develop it so that it can be used in the NHS hopefully so that people will do it more regularly um and then they can track their own function over time.

Um, but this relates this relates to everything. Why I think it's so important, right, is because if you were doing an annual cognitive test, you may realize at 48, hey, listen, at 45 I was scoring here. At 48, I've just gone down a bit. Jesus, hey doc, what what can I do here? So, it might motivate people to start these changes earlier. Yeah, absolutely. I think that's the case for for many you know very basic blood tests just like it was just like it is for blood pressure we have to have diagnostic cut offs like the ones you mentioned for pre-diabetes and type two diabetes when when it comes to blood sugar you have to have some decision-m point where you then say right this is the this is right now it's time to treat with the medication I completely understand why why we have those that's very important but blood sugar is is a good example so HBA1C because two people can have the same HBO1C but have very different blood glucose or blood sugar trajectories or experiences over over the day because HBO1C is affected by many other things including the life of your red blood cells and there's some genetic components as well.

So what they do is they say your HBA1C is this, your average blood glucose was this, but actually there's a huge amount of error in that. Like two people with the same HB1C can have very different average glucose levels. And one may be problematic, but the other may not be. And so where HBA1C is most useful is tracking your own changes over time. So but again, you can't do that unless you have a baseline. What was my HBO1C when I was young, healthy, everything was good?

Right? Because for some people that might be close, might be not that far from a pre-diabetic cutoff. For from other people, for other people, maybe much lower. And then it's watching that change over time. And when it does start to change, realizing, oh, maybe maybe now's the time or you know, I should I should be doing something to intervene. Yeah, this is one of the reasons that I have created something called Doo Health here in the UK initially. And the the truth is I I never had any aspirations to do something like this, a health app, a preventative health app to help people get on top of their health early.

But what I realized, Tommy, is that I've been talking about this stuff with the public now for maybe 12 or 13 years. And people were saying, "Yeah, Dr. I get all this, but I'm going to my doctor and I I can't get this right." And some of the tests that you talk about like fasting insulin or homocyine, I just can't get I might be able to get an A1C, but I can't [clears throat] get it regularly. I can't track it. Yeah. And I've been wanting the NHS to do this in the UK for years.

I mean, my my honest hope with Do Health is that within a few years we'll approve the case that the NHS take it and go, actually, we want to roll this out. Let's see what actually happens. But this idea that if you can empower people early, you can see certain things early, you can actually do something about it. And there's, you know, there's coaching built in and all this kind of stuff, which so it's not just do it. It's like, let's find out where your current state of health is.

Let's help you make changes and then let's recheck to see if those changes actually made a difference. I don't want to go through all the tests that we're doing, but two I I'd love your take on and and I really pushed hard for these two because you can't really get these easily on the NHS is fasting insulin and homocyine. Mhm. Both are very important. Um homocyine we'll start with. So homoyine is a is a marker related to methylation in the in the body particularly related to the status of um B vitamins related to methylation.

So B12, folate, B6 and uh rioflavin for for most people potent you know and that there may be a genetic component as uh there there as well. So the two mosto the two most important um are B12 and and and folate. And we know that having elevated homocyine is associated with a higher risk of um cardiovascular disease but also in particular dementia. So um it also influences the trajectory of cognitive decline. So those who have um elevated homocyine have um a more rapid rate of brain atrophy, right?

Their brain shrinks faster and they lose um co uh cognitive function faster or their cognitive decline, their cognitive function declines more rapidly. Um the sort of the threshold based on the randomized control trials that that have been done is probably somewhere around 10 or 11. So ideally you'd get your homocyine below 10. you definitely want it below 13 because that's that's considered elevated and and you'd see a more uh rapid cognitive decline associated with that. And then the the intervention that you would do is you know supplement with B vitamins or make sure that you get enough B vitamins uh in your diet.

Um the proportion of people who have very high um homocyine has come down a bit in countries that have started to fortify white flour with folic acid. So in the there's a big population studies done in the US where they started to fortify flour with folic acid in 1998. Um the proportion the number of people who had elevated homocyine did decrease uh after that. So just we know that getting more of this in the diet definitely brings homocyine down. Randomized control trials have used uh folate and B12 uh and then plus or minus B6 as well.

Um and we also know uh people in particular people who have MTHFR polymorphisms they have elevated homocyine if they don't get enough riboflavin but by enough I just mean the the recommended daily allowance. I know what you mean when you say that, but a lot of people will hear MTHFR polymorphism and go say come again. So could you could you try and explain absolutely in layman's what that means? Yeah. So unfortunately um you'll actually you know I imagine a lot of people who who listen to this podcast will have heard about MTHFR.

It's a it's a gene methylene tetrahydropholate reductase. Um there'll be a test later. um that that is in involved in this sort of methylation pathway and in in uh which is essentially what what methylation is maybe let's let's talk about that methylation is this process of moving um carbons with some hydrogen's attached is one carbon with three three hydrogen's a methile group moving them around the body and when you move methol groups you turn on genes you activate proteins you it's like this really important signaling molecule that we use to kind control biological processes.

Um, and there are, you know, the the B vitamins are involved in kind of providing the the the methile groups for our body to do that, just to kind of move these signals around, turn things on and off. Um, and so one of the the enzymes in that pathway, MTHFR, it's very common. Most of us have a polymorphism, which is just a slightly different genetic code that makes this enzyme that just changes how that enzyme functions a little bit. Um, and we're often, you know, if you go out into the world and you look up MT MTHFR, it's uh usually like sold as this disastrous thing like your body can't do these methylation processes and you need all these fancy supplements to overcome it.

None none of that is true. And so if you go out and see a bunch of doom and gloom around MTHFR, I would ignore the vast majority of it cuz most of us actually the majority of people have you one of these polymorphism that changes activity a little bit. But what these polymorphisms do and they absolutely have some kind of benefit, right? Because you know most of them most of us have at least one um is it changes how that enzyme binds to a co-actor. or a co-actor being the thing that just allows that enzyme to run.

Um, and that co-actor is made from riboflavin, which is vitamin B2. Um, and there are studies, the randomized control trials that show that if you just get enough ribboflavin, which you can find in whole grains and liver and things like that, um, then then it's not an issue. So for most people, if you go out and you kind of see what's on the internet, you'll be told that things like homocyine and methylation are driven by your genetics. They're not. They are largely determined by nutrient status, just getting enough B vitamins.

Um so if you if you just get the recommended daily allowance, you've ticked that box. Um but if you do measure homocyine and it's elevated then the other B vitamins um are a great place to start. There are some other things that you can think about um as well. But you know those core B vitamins are really the the the main drivers. This just highlights something that has happened in the last 24 hours. So one of my really good mates has just done their do health blood tests and he texts me yesterday saying mate I've got my results and I'm loving it.

loving the whole thing and the app and the explanations and I said mate if you're open to sharing um send me them and I can give you some advice if you want. Now we you know he gets advice on the app anyway but his home assisting was 15. Okay. Now, why I why I'm so passionate about this, Tommy, is that you've already mentioned, and I don't know if we've covered before or not, but this idea that elevated homocyine can increase your risk of cognitive decline as you get older.

He has a family member who has got dementia. Mhm. Now it could well be for this individual that this elevated homocyine is increasing his risk of cognitive decline like some family members of his. I'm being very careful so it's not possible to identify who this person is I'm talking about. Okay. And so what's really interesting is if you don't have your homocyine checked, which is the norm at the moment, I would say in the NHS, then you don't know a critical piece of information that is actually quite easy to address.

Yeah. I said to him, listen mate, you can try it with diet. If that doesn't work, it's quite easy with relatively simple supplementation of B vitamins and folate to bring that down. I said at the same time mate you've got to be you've got to understand that your omega-3 status is also important here you know but the point is is that that piece of information will directly impact his behavior and when he rechecks the bloods in 4 months we will know has that made a difference if it has great have we bought it down under 13 but ideally under 11 under 10 and that is a meaningful piece of the picture in terms of his risk of getting dementia in the future.

So when I think about prevention, one of the things that led to me doing all the work to try and create this is to go well there is another model out there for prevention that doesn't currently exist. But any comments at all on what I just said about homocyine and and sort of my friend and how he can meaningfully reduce his risk of getting sick in the future? Yeah. One of So, one of the reasons why homoyine isn't routinely measured um is because homoyine had a moment 20 years ago uh in cardiovascular disease and and neurological disease or neurogenerative disease prevention.

And then there were some trials where they gave people B vitamins and they didn't really see much of an effect. And so everybody like if you speak to neurologists now most of them will say oh well we looked at homocyine and we tried it and the supplements don't work. Now the critical part of that then is what you mentioned about omega-3s and this has now been replicated in multiple clinical trials and it it actually makes perfect sense that if you take a person and they have insufficient levels of one B vitamin they're pro or one vitamin one nutrient they're probably going to be insufficient in others right not everybody but in general um these things don't come one at a time and when we've done um clinical trials in the past we haven't looked at a full picture of somebody's nutrient status and kind of addressed multiple things at the same time we just like we just we've done the same thing with omega-3s actually this person's at high risk of dementia we give them omega-3s does it decrease their dementia risk it doesn't seem to have a big effect in most clinical trials because we didn't check whether this person needed more omega-3s in the first place or not plus nutrients don't act one at a time.

Yeah. Right. Um in order for to like a send to send a signal in the brain, you need uh B vitamins, right, for mitochondrial functions, right? To to for your for your brain to make the energy to send the signal in the first place. And then um you need to send that signal down a long kind of arm of the neuron we call an axon. And it's got this sort of wrapping of fat around it to kind of allow that signal to be transmitted faster called myelin.

and and like iron status is really critical for myelin. And then you get to the end um of and you're trying to send the signal if it's like a a serotonin uh neuron um right then we need vitamin D in order to make that serotonin in the first place. And we need omega-3s to kind of sit at the end of that um neuron at the sinapse that sends the signal to the next neuron. um we need like DHA which is a longchain omega-3 kind of concentrates there.

It's really important to kind of make the the little um sort of envelopes or vicles of of neurotransmitters to send them right. So you need all of those things for that to happen at its kind of best. Um and so for this reason when you look at sort of multicomponent interventions or you look at the status of multiple nutrients you see that they interact. So the first time this was found uh this was the Vittocog study run by by David Smith um at the University of Oxford.

Yeah. And this was the first study to show that if you have people with high homocyine and you give them B vitamins, you slow their rate of um brain atrophy and cognitive decline. But only if they have adequate omega-3 status. Um that's now been replicated in multiple clinical trials. You can't just address one or the other. You need B vitamins and you need omega-3s. Um, so this is one of you thinking about this as like a single variable nutrient problem is one of the reasons why it's hard to get a homoyine test today because those previous trials didn't kind of address this full this this full picture.

Um, but that's the kind of hangover of the kind of reductionist approach to health that we've taken, right? Which is is obviously how we test pharmaceutical interventions. you know, you 100 people, 50 get the drug, 50 don't. Is there a difference? Yeah. But of course, as you're saying, you know, and I love the vice culture, this idea that yeah, lower the homoyine and it will lower your risk of cognitive decline if you have sufficient omega-3. If you don't, it won't. I think is very very empowering.

Which is why I told my buddy, I said, listen, your omega-3 needs to be there as well, right? So, of course, testing omega-3 is a little bit harder. Do you think people need that? Or if they're I guess if you if you're eating fatty fish two to three times a week, do you really need an omega-3 test? Yeah. Maybe if you're vegan, it's a good idea. You know, how do you think about this? Yeah, it's an important question because very quickly we can accumulate a large, you know, bill of test, right?

A large costs for for all of these tests. But I will say that so food for the brain the charity that I mentioned does have an atome blood test called the drift test that includes HBO1C vitamin D homocyine and omega-3 status. Um you have to pay for it. It's somewhere between1 and200. So it's not cheap. Um and I'm not saying that everybody needs to do that test but if somebody wants to test omega-3s right that that is an option. Um the when you then think about testing my3 status, dementia risk, if you're regularly eating fatty fish, cold water fish, sardines, mackerel, salmon, um two or three times a week, you probably don't need to test.

Um, equally, if you're not doing those things and you'd rather just, you know, take a high quality fish oil or omega-3 supplement, I think that's fine, too. And often, um, you know, when I talk about this, yes, uh, those who are vegetarian or vegan, they certainly have questions. I would recommend like an alol, you know, an algae based omega-3 supplement. So, it's it's not um an an animal based supp supplement, but you you you can still get those fats in your diet. And then, you know, you take, you know, one to two grams of of omega-3s a day.

That's probably going to cover your bases. That's going to, you know, that's I think that's going to be enough for most people. Yeah, we on do we don't actually test omega-3. Um maybe it's something we'll bring in at some point. In fact, one thing I was very clear on is that overesting is a massive problem. You know, one thing I've I know in America there's loads of companies now who are doing, you know, we're going to do 200 biomass, we're going to do 400, we're going to do 600, right?

And I get that. One thing clinical practice has taught me is that too much data and too much information becomes very very confusing. So our focus really is on what I call the 11 core biomarkers which are I think 11 biomarkers which have a really good amount of evidence and science behind them which are all to do essentially with metabolic health. And interesting enough and I I can't remember the exact statistic just on homocyine Tommy I think so far at the few thousand people who've gone through I think over 25 might even be over 30% of people have got elevated homocyine which is quite interesting.

Yeah there's been some recent discussion about where these blood tests fit in in dementia prevention in particular. So um I think last time we talked about the Lancet uh commission report on dementia prevention run by professor Joe Livingston. They identified 14 modifiable risk factors for dementia. Estimated that 45% of dementias may be preventable if but diet wasn't in that was it in those 14 I don't think no no it it wasn't. Um and so there were there were actually letters written to the Lancet where it was published and then there was this was actually discussed in the sort of popular media as well that B vitamins and omega-3 status weren't discussed you know [snorts] even though we have some fairly good evidence for those.

Um, I absolutely don't want to put like words in people's mouths, but there was some discussion as to whether insufficiencies in B vitamins and omega-3s were common enough that it was worth kind of, you know, building an evidence base around them. But like I think you're right that particularly as people get older, 10 to 20% of individuals at least may have elevated home assistance. So that's like a significant chunk. um you know previous analyses done u by other groups suggested that potentially up to 20% of cases of dementia were related to elevated homoyine and uh low levels of omega-3s.

So that's you know even if even if it's not 20% it's still a meaning it's a meaningful uh contribution to to future risk. So, um, yeah, I think to to kind of go to your original point about like what's it worth testing, I also agree that just like more testing isn't isn't always the answer. And I do agree with this idea that if you're doing a test, you should be answering a specific question like why am I doing this test? So, um, rather than just like doing a scatter gun, um, test everything and right in in in medicine, we have this idea of a pre-est probability, like how likely is it that you're going to find something that you and that you can address it.

Yeah. Um, and I think that's really important. So, we focus on metabolic health. Uh, we know that the vast majority of adults have at least one um risk factor for metabolic disease, right? So, it's very likely that you're going to find um some kind of modifiable metabolic health. That's why we focus on metabol health and I had a criteria when choosing the 11 that has got to be a good evidence base behind them. And we've got to be able to do something with the results. Yeah.

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All you have to do is click on the QR code on screen or go to the wayapp.com/live more to get started. I guess in answering some of the stuff around homoyine and omega-3s, we we've slipped into mistake number five, which is uh thinking all supplements are a waste of money. Okay, so [clears throat] again, the framing here is that Tommy's been on this show four times in the past. So, this is appearance number five. If you haven't heard the first four, please go and listen to him.

There are a wealth of information. The whole point of today is to go through common mistakes that people often make when it comes to uh brain health and longevity. We've done four so far. We've covered mindset, social connection, high blood pressure, and sort of testing. The fifth one, which I think relates to what we've just been talking about, is this idea about, you know, supplements. Thinking all of them are a waste of money, I think is a common mistake. You've already mentioned the potential benefits of B vitamins and omega-3s.

U I want to go through some other supplements with you to get your take on them. But I wonder if it's worth talking about the Cosmos trial and what your take is on that trial cuz I thought it was really quite illuminating. Yeah. So the the Cosmos trial was a recent trial run in the United States, thousands of people. It's a massive trial um older adults um randomized into four different groups. So they had a control group um and then they had a group that took a basic multivitamin.

Uh Centrum silver was the multivitamin. It it centrum silver essentially just has 100% of your RDA of like the basic vitamins. Um another group got uh cocoa flavvenol supplements. So coco flavonols are like the polyphen like the antioxidant polyphenols that are in cocoa. you know, you you have similar compounds in coffee, tea, chocolate, uh berries, uh for example, like the things that make berries sort of purple and and red. Um and then one group got both, right? So we call it like a 2x two design.

Um and what they found was that in the two groups that got the multivitamin, there was a significant reduction in estimations of brain age and cognitive function such that you know on average people's brains acted as if they were 2 years younger. So you kind of saw this slowed slowing of brain aging by taking a multivitamin. And this is the most basic multivitamin like you go to boots and you get an over 50s multivitamin. That's essentially what it is. Um, and I I'll also say this about the Vittocog study.

The Vitto, you know, often when we're sold supplements and vitamins, we're like, you have to have this fancy version and this bioavailable version is going to cost, you know, x amount of money. The best evidence that we have for multivitamins for B vitamins is the most basic version, you know, the essent, you know, the essentials version, you know, some folic acid and cyanocobalamin. If everybody's like, which is a form of B12, it's like the cheap the cheap version of B12. That's what showed benefit in vittook just like the most basic low essentially low dose multivitamin showed showed benefit in cosmos and there may actually be a thing where your massive doses could potentially be detrimental whereas you know cosmos just gave you you hit 100% of your RDA you've got your bases covered that's it and that showed benefit um in the the sort of the cocoa flavonol um supplement was a little bit more nuanced where benefits were largely seen in groups that had low diet quality.

So if you're getting few like plant polyphenol antioxidants because you don't eat many fruits and vegetables um or drink much coffee or tea because actually actually coffee is the most for most people is their primary source of antioxidants in their in their diet. Um if if you had a low quality diet, lots of processed foods just like processed fats and and and carbohydrates and few nutrients who a nutrient poor diet then taking the cocolavinol supplement was beneficial. If you already if you have a high quality nutrient-dense varied diet, it didn't seem to have as much of an effect which I which I think makes sense.

Yeah, there's often been a negative view with doctors around supplements, possibly because the industry has been unregulated, right? Which which I which I get but the truth is is that I have seen so many patients over the years where the right supplement can be gamechanging. But I think the Cosmos trial just showed us that actually for across a broad population there can be a benefit with the brain for a multivitamin and mineral. Okay. which I think is a a really good takehome. We've covered B vitamins and omega-3.

The supplement of the moment um is of course creatine. Okay. You take creatine every day. Should the listener also take creatine every day? I recently heard this nice idea for how to think about supplements that I hadn't really heard before. from um I was actually was on a panel with uh Jeff Bland who you know many people call it you know the father of functional medicine and the first thing that he said we should think about not is will could this work for me is is it safe because if it if it's safe then you can try it with very little risk right if we don't have good safety data then the will it work for me becomes much much riskier yeah Right.

And so, so chemotherapy, right? And it's like you want really good evidence that this is going to help you before you expose yourself to the downsides because we because there are a lot of downsides, right? Um, and so I think that for most people, you know, a very basic level of B vitamin supplement, right, we know it's going to be safe. If you're not taking you massive, massive doses, you're just going to pee out any extra. Yeah. like worth potentially trying especially if you've got some markers to kind of suggest that you you could take it.

vitamin D trickier because um again in very high doses of fats soluble vitamin you don't want to overdose on vitamin D there's some some downsides there uh but we know in people who are vitamin D deficient absolutely well you said it's prescribed on the NHS for people who are deficient we know it's important brain health bone health etc then you come to things like creatine one of the reasons why I think it's actually okay that creatine is the supplement at the moment is because we know it is incredibly safe um it's been tested in probably thousands of clinical trials at this point, randomized control trials for various people in various conditions.

Uh low doses, high doses, years at a time. Uh recent meta analysis uh found essentially no side effects with creatine compared to placebo on on average. Um and that's probably because it's something that we can get from the diet. Um maybe not quite at the doses that some people might take, but you know, close. Um, so we know, you know, assuming that you're getting a high quality source, it's not contaminate contaminated, that kind of stuff. All right? So, you would you want a um a reputable supplement maker.

Hopefully, they've done something we call third party testing. It's been tested for um impurities. They can send you a certificate to show that they've done that. Every every good supplement some company will be able to do that. But we know that creatine is incredibly safe even in sort of like frail older populations. Um so then we might say, well, is there a possibility that it might benefit me? So creatine has been um used for decades as a supplement in like sports performance particular particularly strength and power.

Um it helps you do an extra rep or two uh in the gym and then if you do that over time you can build more muscle, you can build more strength. Um the effect isn't huge but it is statistically significant and meaningful, right? It's not it's not magic but it helps you do a little bit more work in the gym and that compounds over time. Um, it's become of particular interest in the brain world recently because there have been some studies to show that or actually several different studies to show that it might help particularly in what we could call or what I might call cognitively degraded states.

So something has happened that's affected cognition or mood and then creatine may may be of some benefit there. So for the average person who thinks that their brain is working really well, there might not be that much of an effect. So when you look at um meta analyses, studies of many studies of creatine, it tends to benefit older people and particularly is beneficial for memory. That's that's kind of where it's been shown to to have some benefit. Um in other populations, there's some evidence um there's actually better evidence in like kids with concussions, but there's some evidence that taking creatine after like a a traumatic brain injury may help with some elements of recovery.

um in the the the kind of the the really flashy study that got a lot of um press recently was in individuals who were sleepd deprived and they took a high dose of creatine. Uh it was kind of the equivalent of sort of 20 to 30 grams of creatine when maybe a standard dose is like 5 to 10 grams and they saw saw that the people maintained brain energetics. You can do a brain scan. You can measure energy sort of the production of certain energy metabolites in the brain.

And that was and cognitive function was retained better when sleep deprived when taking creatine. This was just like a single night of sleep sleep deprivation. And there was an older study in rugby players actually that showed that when they were sleepd deprived, taking creatine actually a lower dose sort of five to 10 grams helped to maintain rugby specific skills when they were sleep deprived. similar to caffeine actually because they also used caffeine in that study as a comparison. Um so in those kind of settings when sleep deprived maybe creatine can help to maintain some elements of cognitive function.

Um and then there are a few randomized control trials now. Um although some people have suggested that you know they were done in countries where maybe the quality of the science isn't as good as in the UK or the US. So some people have kind of questioned the quality of these trials but it's been shown two or three times that in individuals with depression um supple you know adding creatine to say a medication regimen if they've re if they haven't had full you know uh remission of symptoms um may may improve like symptoms of like mood and well-being or or or depression symptoms and again sort of a five gram kind of dose.

So, lots of different pockets of things suggesting that creatine may be beneficial for the brain uh across a wide range of doses. A lot of people are now saying that you need to take a very high dose for it to benefit the brain. But I don't think we've seen that from the studies. I think we've seen benefit even at sort of a standard lower dose which is 5 to 10 gram which is 5 to 10 grams. Um the and the reason why they say that is because when you look at studies of creatine like increasing creatine levels in the brain that takes longer and higher doses but you may actually see benefits of creatine before you're seeing increases of of like creatine levels in the brain if that makes sense.

Right? You don't need to be saturating the brain with creatine to see benefit for the brain because it could be having other other effects. Um there was one study in individuals with Alzheimer's disease where they gave them creatine and saw some improvements in cognitive function. However, um there wasn't a control group. And we know that when you enroll people with even with cognitive decline in a study, they tend to do better. They get better at the test. [snorts] they they even though you know their some of their cognitive function may be impaired they do better at the test the second time they start to feel a bit be feel a bit better there's a placebo effect of being part of a trial connecting with other people is kind of stimulating in its own way so I tend to not include that trial when I when I say there may be some benefits of creatine for the brain just because it was you know no control group we know in cognitive in in studies that look at cognitive function it's re it's really hard to to look at the effect of an intervention without having a control group because you get better at the test, there's significant placebo effects, things like that.

Um, so but if you're somebody who identifies with any of those things that I mentioned, right, sleep deprivation, maybe some issues with memory when you're older, you you maybe you're you have been diagnosed with depression and you you have have had some benefit from a medication, but you might consider adding creatine on, which is what some of these studies have done, then I think it's worth trying. Um, we know it's safe, it's cheap. Um, it's not, again, it's not going to be a panacea. It's not going to be magic, but you know, I think we're starting to see more and more evidence that it may have some benefits for the brain.

Are you happy to share why you specifically choose to take it? Yeah, I mainly take it from a performance standpoint. So, I train for and compete in strongman. And so I I I definitely can tell um that I just a little bit little bit stronger, you know, little bit faster uh in the gym when when I'm taking it. I find creatine to be mildly stimulating for me and that is the case for for some people like um like I kind of mentioned that rugby player study, right, seeing similar benefits with creatine versus caffeine in the setting of sleep deprivation.

Um and so I definitely noticed that if I take it later at night, I don't I don't sleep as well. And so for the same reason, I do feel like I get a bit of a progressive boost from it when I take it in the morning. But some of it might be placebo, right? I kind of maybe expect some of that. But it could be that if you do get a mild stimulating effect from it, whereas caffeine can can often like overstimulate people where so say if you if you had several espressos before you played paddle, you might be sweaty, anxious, you like you don't you don't quite have the accuracy because right you're you're sort of over stimulated.

um creatine could give us of like a mild stimulating effect and it doesn't happen to everybody but th those who experience it, you know, if you're one of those people, maybe it's useful then. Um but in terms of sort of the the strength and the power effects and the fact that um you know, paddle is more of a sort of aerobic cardio type sport, um it's less likely to give you that kind of performance benefit. But there's a possibility that in some people there may be some kind of cognitive effects.

But then bringing it back to the start, if you bring up mindset, right? And so there's good science on creating, but if you also believe that taking it is helping you and making you sharper, it's hard not to make the case that that is going to do something as well, which is, I guess, the kind of hidden glue with all this stuff. If you believe something's helping you, it it probably will. Yeah. Okay, we've got to find mistakes so far. We're not going to get to 11, but I think the two I would like to get to cuz we haven't talked about them before is number one, neglecting oral health, and number two, ignoring the toxic load of the modern world.

Okay, slightly inflammatory, but I'm talking about things like microplastics and should we filter our water and that kind of stuff. So, [clears throat] perhaps we can sort of zoom through oral health, you know, uh point number six, what's the relationship between oral health and brain health and oral health and longevity? It's been known for maybe 10 or 20 years at this point that there is a connection between oral health and cardiovascular health. Um that was pro I think that was probably found first. Um in fact there are some of the bacteria that you get when you have gum disease or what we call um so so gum disease has two stages.

The first is gingivitis and then if it starts to affect kind of the under underlying bone then it would be called periodontitis. Um but I think we could call it just gum disease more more broadly. Um and some of the bacteria that tend to overgrow in the setting of of of gum disease things like um sudamonus gingivis and streptococcus mutans. Um you can find those bacteria in atheroscerotic plaques in in the heart which we know sort of trigger trigger heart disease. Um and some of the thought is that because you sort of like have all this inflammation um around the gum disease and you know you know bleeding and things like that that actually those bacteria can get from the mouth into the bloodstream and then can trigger systemic inflammation.

Um might might trigger the the formation of some of these plaques in in in heart disease. And they've actually been found in amaloid plaques in the brain of of certain individuals. And some people um argue that one of the reasons why we accumulate amaloid is you know one of the parts of um kind of the process of developing Alzheimer's disease um is because it has antimicrobial effects. So it's accumulating around say bacteria that might have gotten into the brain. And one way that that happens or and does seem to happen is is through um through gum disease.

This doesn't mean that if you have gum disease, you're definitely going to get dementia, right? We're all we're all talking about what increases and decreases risk. So, there are several studies that show that having gum disease is associated with increased risk of dementia um in you know multiple sort of perspective as in sort of like you follow people over time um studies. And then in at least one study uh they also found that in people who have gum disease those who get treatment for that gum disease something like scaling and root planing which your dentist um would do um they then decrease their risk of uh dementia over the next several years compared to those who don't get treatment.

Um there have been other studies that show that the amount of antibodies you have circulating in your blood against those bacteria that tend to sort of accumulate because of of gum disease the more antibodies you have kind of suggesting that you've had a higher exposure um they those people tend to have a higher risk of dementia as well. So like from multiple different directions it seems that uh gum disease uh is associated with an increased risk of dementia and then there's also some evidence that if we treat that gum disease that risk of dementia is decreased.

Yeah. basically don't ignore going to the dentist. Don't go to the dentist. Your oral health. And in terms of xylitol gum, are you a fan? So uh yes and um the my favorite story about xylitol is actually a um a colleague of mine uh Greg Valentine who I work with the University of Washington. He's run several clinical trials. He's still running clinical trials looking at this. Um but his work is looking at ways to decrease preterm birth. Um so this is nothing to do with dementia although people who were born preterm do actually have an increased risk of dementia.

So it could sort of have this full kind of life lifespan effect. Um but we know that um having gum disease is a risk factor for preterm birth because it creates this inflammatory effect. Um that and we know that chronic inflammation is a potential trigger for preterm birth. So babies being born too soon and the more preterm you're born, the higher your risk of both death but also neurodedevelopmental impairment. Um multiple long-term health issues. Obviously, not everybody born pre-term experiences those, but it's just on average.

Um, so he's run multiple clinical trials. He's running them in the US right now, but the the clinical trials he ran already are in Malawi um in Africa. Malari has the highest rate of pre-term birth in the world and the majority of pregnant women in Malawi have gum disease. Mhm. Um and so one trial that they did was this large cluster randomized trial where they had different villages in Malawi and they sort of they gave them z they gave them some of the villages xylitol gum um to chew like three times a day throughout the the last chunk of pregnancy.

Um and they saw significant improvements in gum disease and a statistically significant reduction in preterm birth rates which to me is just like mindboggling. um amazing and right the the the design of the trial wasn't perfect. It didn't have a placebo gum and that kind of stuff. Those are the trials he's running right now. But like even that you would see that kind of effect is just incredible to me. Um and so we know that chewing xylitol gum or using xylitol mouthwashes can address the oral microbiome and it's really the microbiome that kind of and an imbalance in the microbiome that drives a lot of gum disease um without having negative um effects.

So other types of mouthwashes, for example, like a alcohol-based or a chlorhexodine based mouthwash, they can actually get rid of good bacteria that you want uh in your mouth. Whereas xylitol seems to particularly kind of decrease the ones that maybe we would like a little bit less of. So if you do have gum disease, I absolutely go to your dentist, have it addressed, whatever they suggest, but you know, xylitol, xylitol gum is is one thing that you could try at the same time. Yeah. Okay, very very important message.

Okay, the final mistake for this conversation, right, is mistake number seven, ignoring the toxic load in the modern world. Now, I don't want to scare people, okay? Cuz I think one of the problems with health these days is people get quite scared. And I think we got to be careful not to do that. But I think a few things that people often talk about and worry about are microplastics. Should people be filtering their water or not in your view? and air pollution uh inside and outside.

So I wonder if we can just sort of talk about these themes and how they relate to people's lives. Yes. So the the issue with all of these is that there's um absolutely some important signal um and as it relates to these exposures and and our health, but there's also a huge amount of kind of hyperbole and it's overblown and there's a ton of scaremongering, but there is sort of like but but in the middle of those I think there is a way for us to navigate it fairly reasonably without sort of being overly stressed about uh what it might mean or you know overselling the effects of these things on our health.

So I think we can go through them one by one. Um microplastics have certainly gotten a lot of press recently. Um and these are essentially the breakdown products of plastics that you know we use for as packaging for food or um you know utensils or other things. So so our prim our primary exposure is from the food that we eat. Um you can get some from like skincare products and things like that. Um but there there have been some recent studies that suggest that maybe our primary exposure is through food food and drink.

Um, and a couple of years ago there was this study that said, you know, the average human consumes a credit cards worth of plastic a week or something. [snorts] Um, and then everybody lost their minds. um the the then some some more recent studies that got a lot less prep um went back and they redid the calculations and they were like we estimate that this is out by like several orders of magnitude. It's like not it's like a fraction of 1% of the amount that they said previously.

So like the decimal place went in the wrong the decimal place was like miles out um like sever like I can't remember exactly how how many it was like six or seven places in the wrong place. like it was it was huge the the difference. Um and so that's one part is yes we do consume these things but the amount that we've been told we're that we're consuming is probably a lot less than than than we've been told. Um then the next part is there have been studies that have looked at microplastics in the body um in like tissues of people who've dis who are deceased and like looked at them in um say artery plarks looked at them in the brain and and you know they've they've looked at them in uh like testicles and other organs and and basically suggested that um in those who have a higher disease burden say higher heart disease burden or higher dementia burden, they have higher so like people who have a higher dementia burden or people with dementia have more microplastics in their brain.

Um [sighs and gasps] this is certainly possible but there's a few reasons why I'm not yet certain it's like the thing that we have to worry about. So the first is that we know that vascular disease, so issues with blood vessels are present in most people with dementia. If you have issues with blood vessels in the brain, blood flow is going to be slower. You're more likely to accumulate microplastics that that might be in your bloodstream. So the dementia is probably driven at least partly by the blood flow issue.

the the the you know vascular disease and then microplastics just kind of accumulate you know they come along for the ride. Um we also have a big issue in terms of how microplastics are measured in these studies. So when you when you take tissues and then you try and measure the amount of microplastics in them, the typical way you do that is through something called pyrolysis, which is essentially just a fancy word for heating something up a lot. Um, and so what they do is they they essentially um vaporize the plastics and then measure it in something called um a mass spectrometer.

Um, [gasps] the problem is that that doesn't work very well in tissues that have a high fat content, like the brain in particular, because when you vaporize fat tissue, it looks like plastic. Um, it breaks down into the same compounds as plastics do. So, there have been some papers that say that, you know, particularly in tissues that have a high fat content like the brain, pyrolysis is not a valid way to measure microplastics. So it could be that when we're seeing high microplastics in some of these studies, it's actually just an error in the measurement, right, because of the method that's being used.

So I think that some of that is overblown, too. So some of the exposure is overblown. Um maybe some of like what we're measuring in tissues is is overblown. However, we do know that some of the compounds that come in plastic, some of the plasticizers, uh phalates, uh bisphenols, right? Um people have heard of BPA, right? The lining of cans. Um and there are many other breakdown products of plastics, right? They are certainly linked to uh some changes in cognitive function, issues with neurode development in kids.

Um higher risk, higher rates of heart disease. Um so these things aren't, you know, completely benign. Um, and so like I think we can end up down this middle road where we're like, yes, some of it's probably overblown or at least we don't have the data to be, you know, really say that it's this primary driver, but we also know that then that they're not benign and we should try and minimize our exposure where we can. Um, there was a recent um trial where they randomized individuals to multiple different groups where they changed different plastic exposures and then tracked their sort of levels, it was levels in the urine of these different of different plastic breakdown.

um compounds and the biggest driver seemed to be the food. So they so they uh gave people that so they they stopped them uh using canned uh or reduce their canned foods, reduced storage um of foods in plastic. Yeah. Reduced uh uh plastic utensil use. So you know if you're if you're kind of like stirring a pot and you've got a a plastic spoon, right? Swapping it for a metal spoon or a wooden spoon. And then they reduced the number of foods that were just stored in plastic, right?

So you they actually controlled a lot of the food production process so that at no point were were foods kind of uh stored in plastic for long periods of time. So you you go to the supermarket and you're getting your veggies kind of loose and you're just throwing them in your basket rather than kind of packaging them up and stuff, you know, getting things that are that you can buy loose rather than things that were sort of like pre- chopped and stored in plastic, that kind of stuff.

Um, I would say that if you're um going to avoid foods and then not replace them with other similar healthy foods that aren't stored in plastic, I would rather you eat those foods. Right? So, if you're if the reason why you get you you can eat vegetables is because you get them frozen and they come in a plastic bag, but they're already pre-prepared and it's really easy to prepare them and you can just throw them in a pot and then make make dinner quickly. Do that, right?

that is has a a much bigger signal in terms of benefit. But if you can, you know, don't you don't store your leftovers in plastic. Get a wooden spoon. Um minimize the amount of foods that you get that that are kind of stored in plastic or right wherever that's possible. Um drink uh fewer drinks out of plastic bottles or cans. Um then do that. So wherever you can start to move that needle a little bit, just decrease your exposure. I think that's going to be beneficial.

But you know, if if the reason you eat beans is because beans come in cans, I would still eat those beans, right? Because we know that they have a lot of health benefits. So it's all about just reducing your exposure where you can rather than being really really concerned about all the different ways that that you you might be exposed. Yeah, I think that's a reassuring message. I guess importantly I guess we can probably make the case. I think that a thousand years ago humans probably weren't being exposed to plastics in this way.

So it's a it's a new thing. So of course we have to see how the research plays out and if we're going to learn more things. Remember when Dale Bredesen came on recently to talk about dementia risk and you know brain health. um you know he was you know at some point we spoke about microplastics and I think to be fair to Dale he said look we we don't know the full story yet I said to him have you seen enough to make you at least reduce how many microplastics you're exposed he goes yeah so wherever possible I try not to and I guess that's the approach I've taken for a couple of years I'm you know I try you know it's very rare for me to drink out of a plastic water bottle now unless I'm on a plane for 8 hours and actually, you know, I'm thirsty, right?

Um I personally no longer haven't done this for a while, will get a takeout coffee in a um in one of those containers, you know, because the heat and that how that interacts with the cars. Again, for me and my life, that's not that difficult to do. Yeah. Um you know, and you know, certainly at home, we we don't store in plastic anymore. we store in in glass containers when we overcook food and that kind of stuff. So, I think there's a lot of practical things people can do without necessarily worrying, but I guess time will tell uh with the science how much of an impact this is having on health.

Yeah. Okay. I'm sure we could talk for an hour on plastics, but let's leave it there on plastics. What's your take on filtering uh drinking water? Yeah. So I'd start by saying that you know luckily for I imagine everybody listening to this podcast are are like water supply is very safe right and so the in many countries yeah in in the in the vast majority of countries not not not all but right I I I would expect that wherever you're listening to this your your water supply is is is safe and it's it's not it shouldn't be a primary concern.

However, um we do know that for example, you know, several pipes in the UK and the US still contain lead, right? And so there are several places where you drink the the tap water and there's a a significant amount of of lead in it. Um we also know that there are other things ending up in the water that are very hard to remove like uh the PFAS um and like you know the forever chemicals and plastics and and plastics. So, phalates and things like that can can end up in the in the water as well.

Um, and we know that these have some potentially negative health effects. Um, so the way that I've approached this is that I do I do filter my water. I have an infridge filter. You can uh get um a jug filter. Although um the main thing with a jug filter is just remember to replace it because I know there are people who have a jug filter and then it's in there for a year and then it starts to grow stuff and right you you've probably undone the good work of filter of filtering your water.

Um right you're probably adding your own contaminants. Yeah. Exactly. And right and then you can scale that up to under you know some people have you know you can get under under sink filters and stuff like that but the I think about it very similar to to how I think about microplastics and actually this is how I think about this like um whole topic in general is that wherever whatever you're able to do do that and you're almost certainly decreasing your exposure o over time right so um most jug filters will do a decent job of decreasing things like lead if there is lead in your water or they'll do a decent job of decreasing phalates and other things if if they are in your water.

Um, and all of this stuff integrates over time, right? So, if you just continuously do that, you'll be decreasing your exposure over time. And it's sort of like a other than, you know, remembering to change your filter, it's kind of like a set it and forget it thing. It's low low risk, high potential for benefit, not particularly um cost intensive depending on which fil your filtration system you you go for. So I that's that's generally how how how I approach it. There's probably a level of water filter that each of us could do.

I I I don't think you have to do it, but if we're trying to think about something that might give us benefit over long periods of time, it's low risk, relatively low cost, I think um I I think it's worth considering. Yeah, I think all these things, you know, it just depends. Some people get very triggered over water filtration go the tap water is completely safe and it's like yeah compared to you know many countries around the world it it probably is certainly here in the UK you know and I think that's fine and if you are looking to just do a little bit extra as I certainly am you know it's one of those things I didn't do till about three years ago I don't think you know so I lived most of my life drinking tap water yeah Um, and I think I'm doing fine.

And as I learn more, I think, hey, you know what? It's not that much of a heavy lift to have a water filter at home. Yeah. So, I've got something I think I think it's called Aquatue. It's a reverse osmosis filter. Bought it about 2 or 3 years ago. It reminds you when your filter needs changing, you know. It's just we have a habit now in the house. We fill it up and you [clears throat] pop it on and it you know but yeah it it is you could call it a hassle if you want cuz it takes out lots of good stuff as well.

Takes all the minerals. So we have to put some drops to remmineralize it. Now someone might call that a faf. Uh it possibly was a faf 3 years ago when I first started doing it. Now it's just the new norm which is what we do. And so I think that's what one thing I always like about what you told me. a very practical nuanced approach which is you know really at its heart trying not to scare people and go yes things are changing in the world.

It is harder to eat nutrient-dense food. It is we are being exposed to all kinds of new things now which weren't in our evolutionary history. At the same time, going back to point number one about mindset, worrying about this stuff ain't going to help you that much is, you know, what can you feel that you have an element of control over. What's your take on uh sauna use filtering out microplastics because I think there's quite a lot of noise emerging now that that could be a good way of removing it from our system.

Yeah. So you do definitely sweat out some of these uh compounds that you get. Um so exercise of course would do that as well. Yeah. So so I think that sweating is important. Um it is a a detoxification pathway in the most important sense, right? It's one of the ways, right? Just like with our liver and our kidneys, it's one of the ways that we ex excrete things that our body doesn't want um inside. Urine, feces, skin, right? Yeah. So um I do think sweating is probably beneficial.

We know that some of these compounds can be excre excreted in sweat. Um exercise that causes you to sweat is free, right? So I I don't and actually many of the benefits of sauna particularly dry, you know, dry sauna, sort of like a Finnish hot hot sauna. Um many of the benefits of sauna actually overlap very significantly with aerobic exercise. uh the the pathways that get activated, right? The sweating. Um so yes, I think sauna is is is a possible intervention, but I don't think everybody needs to sauna.

If you've got one and you enjoy it, great. But equally, you could go for a jog, go play paddle, and you're probably, you know, sweating out in in in a similar way. So yes, I would think about sweating. Um but however you achieve that sweating, um I think matters a lot less. That's a great message. However you achieve your sweating, it's it's up to you. You know, you choose the activity you want. Okay. Um, and because I mentioned it, let's just touch on pollution in the air because when I think about health, I think about controllables and uncontrollables.

Okay. So, we know that air pollution from planes and cars and diesel and stuff can negatively impact human health and increase risk of dementia. But there's also the pollution inside our home. Again, I don't think we've covered this before, Tommy. So, I think we have covered the big levers a lot. So, um yeah, external air pollution. I know there's a link to B vitamins and how we can attenuate our risk. So, what's your sort of top level take on, uh pollutants in the air? Yeah. So, it it's it's very similar to to to the others.

Um yeah, I guess we can touch upon that that the B vitamin study. Um this was done um actually at the University of Washington where I work and they looked at air pollution exposure. So it's particularly people might have heard of uh PM 2.5. It's like the two like two and a half micron that's the size particles that are released from you know cars and roads and and things like that um that seem to be there are other aspects of air pollution as well that are linked to human health but but they're they're kind of the most frequently studied and you know associated with increased risk of um heart attacks and and dementia.

So this study looked at dementia and they found that those who had good B vitamin status if they were exposed to high levels of air pollution they had that sort of mitigated the risk of of of of dementia. Of course, this is not a randomized control trial, but um it's thought that exposure to air pollution increases homoyine, which we were talking about earlier. And so, um if you measure your homoyine level and it's high and then you supplement with B vitamins and it comes down, if it was the air pollution that's driving that, you've maybe offset a lot of the risk from the air pollution you by supplementing with B vitamins.

I think that that makes sense. So, it's just another reason to maybe consider getting enough B vitamins in your diet. Um then the you know a lot of the sort of inside air um well it's obviously connected to the outside air but because where you got closed windows you things sort of like accumulate um o o o over time and so often the um if you if you look at things like the environmental protection agency in the US they sort of have this big part on their website about how indoor air quality is often worse than outdoor air quality um for for that reason.

And so I think that again uh if you especially if you live somewhere like you live near a main road or so I live in Washington state in Seattle in the summer we have lots of wildfires like often the like the air outside is filled with smoke the house smells of smoke um and we know that's linked to poor health you know uh effects in in the local population like several studies have shown that so I think in those kinds of settings if you do have high exposure to air pollution then I would consider getting an air purifier in the rooms that you spend a lot of time.

Um and there was one recent study uh where they actually did a randomized control trial of air purifiers in people who have high um exposure to air pollution and they they saw that having an air purifier on sign it significantly reduced blood pressure. So again, a meaningful um intervention that's kind of like a set it and forget it thing in people who have high exposure or high risk. You know, definitely, you know, something worth considering. Um but again, right, we can't, you know, it's often very there aren't many people who can just move because they have a lot of air pollution, right?

So um I think that if you can address that by just you know if you're spending if there are rooms you spend a lot of time in say the bedroom get an air purifier um again over time you're dramatically decreasing uh your your exposure with a relatively simple um intervention. Yeah. And of course something we have covered before is the socioeconomic sort of um input here in the sense that you know in in many places in the world your socioeconomic status hugely influences how polluted your environment is right.

So you know the the the the middle classes and the wealthier people can live out in the suburbs and have um less busy roads around them etc etc. So I think we always acknowledge that. I think it's always important to acknowledge that that everyone has a different ability to make changes. Uh Tommy, uh I I I love chatting to you. You know, as you know, you're you're one of the doctors and the health commentators who I respect the most. I love your your balanced, nuanced, but also open-minded approach to health.

Um, I think the book, uh, the stimulating mind is fantastic and, uh, I really would encourage people to to pick it up and take a look at it. I know we haven't covered some of the interventions we've covered before in today's show, but I guess just to finish off for that person who has been listening to us talk and throughout the conversation has realized that they have neglected their brain health for a number of years, maybe decades, and is wondering, well, you know, maybe it's too late, maybe there's nothing I can do.

um what would your final words for that individual be? I would say that um it's never too late to start and we h actually have really good evidence for that. Um I talked to the you know I mentioned the Lancet Commission report again the first time they published that report in 2020. They even said that on the front page of the Lancet like the one of the world's premier medical journals. It's never too late um uh to to to start thinking about dementia prevention and that's because they were focusing on dementia.

Uh but then your brain health more more broadly. Um studies in individuals in their 60s7s 80s they start an exercise program they start with some dietary change. They start to improve they do some cognitive training some or like some kind of you know they start language or dance classes or you know musical instrument or you know they start to improve their sleep. You you start to see benefits you know even at those later ages. So know that start wherever you are and even just starting with one thing can have significant benefits.

Is it taking more steps a day or getting an extra 15 minutes of sleep or volunteering for something? Right. Cuz you cuz you sort of um connected to the stuff that we talked about in terms of social connection. Is it just like getting an air filter and a water filter and those are just that's that's all you can do right now but you set it and forget it or you know you start a B vitamin supplement. Um these things we know have significant impact with through very high quality trials regardless of the age that you're at.

Um and by starting one thing sort of like the whole system we talked about the 3S model that whole system shifts in your favor and yes maybe you have to you would ideally make multiple changes over time but these things you know just just one one thing is the place to start and then build from there. Yeah very very empowering message. I just want to highlight your key message from the last couple of appearances on my show about learning a new thing. Give your brain a reason to grow and adapt.

And I think since our last conversation, which was only a few months ago, Tommy, um, these are some of the comments that came in on the back of that. Arty has told us she started playing net ball and paddle. Cool. Lara started figure skating. Lynn started reformer Pilates. Dorothy started tap dancing classes. Sosce started a heels dancing class. Heather started playing pickle ball. Louise started ballet after a recent Parkinson's diagnosis. and Daryl started playing table tennis in badminton and honestly that's all because of the information you shared on my show.

So I think you're doing wonderful work Tommy. Um thank you for sharing your research so generously with us all and uh I look forward to number six at some point in the future. Um thanks so much for sharing those with me. That's that's um so so cool. I'm so glad that people are just finding like you said right at the beginning find something that you enjoy, right? do it because um do it because it's fun, right? And then oh yeah, it just happens to have all these other sort of health benefits on on the side.

So like pick something that any of those things. Fantastic. I'm so I'm so happy people are doing it. Um I really appreciate your time as always and thank you for having me on. If you enjoyed that conversation, then I think you are really going to enjoy this one. I've been a cardiologist for 30 years and I've tried everything. But when I tried fasting, I started seeing changes. People began to lose weight. Blood pressures came down.

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