Feel Better, Live More with Dr Rangan Chatterjee - Protect Your Brain, Extend Your Life: 7 Mistakes to Avoid for Better Cognitive Health with Dr Tommy Wood #681

Episode Date: September 22, 2026

Why would you want to live longer, if not to spend more time with the people you love? That question sits at the heart of this conversation with brain health expert Dr Tommy Wood. And today, we tackle the biggest mistakes people make when it comes to protecting their brain and longevity. Tommy is Assistant Professor of Paediatrics and Neuroscience at the University of Washington, where his research spans brain development, cognitive decline and dementia prevention. He’s also worked with elite athletes and Formula One drivers as a performance coach. And in his must-read book The Stimulated Mind, he combines that breadth and specialism to make understanding brain health easier – and more fun – than you might think. We start with mindset, and the surprising research findings that how you feel about ageing can shape how you go on to age. As someone in his 40s, I was delighted to hear Tommy cite a paper called Humans Peak in Midlife, showing that increasing wisdom, emotional intelligence and moral reasoning could make age 55 to 65 my best brain decade yet! We talk about the risk of becoming so focused on optimising your own health that you neglect what matters most, your relationships with other people. And Tommy points out why chasing longevity without that connection is missing the entire point. From there we get practical. We discuss mistakes like ignoring your blood pressure (and the implications for dementia) and what testing markers like homocysteine early, rather than waiting until something goes wrong, means for your long-term brain health. I also ask Tommy which supplements are worth considering, including the latest evidence on creatine and basic multivitamins. And he reveals the surprisingly strong link between your oral health and your brain. Finally, we consider the toxic load of modern life, from microplastics to air pollution, and whether you should filter your water. Tommy’s balanced, evidence-based perspective avoids scaremongering while still taking these issues seriously. Whether you’ve listened to every one of Tommy's previous appearances or you’re new to the podcast, this conversation is packed with practical ideas you can act on today, whatever your stage of life. As Tommy reminds us, it is never too late to start. The Thrive Tour: Transform Your Health and Happiness, a live show: Book Your Tickets https://drchatterjee.com/live   Thanks to our sponsors: https://drinkag1.com/livemore https://thewayapp.com/livemore https://exhalecoffee.com/livemore https://dohealth.co/livemore   Show notes https://drchatterjee.com/681   DISCLAIMER: The content in the podcast and on this webpage is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor or qualified healthcare provider. Never disregard professional medical advice or delay in seeking it because of something you have heard on the podcast or on my website. Learn more about your ad choices. Visit podcastchoices.com/adchoices

It's never too late to start thinking about dementia prevention. Studies in individuals in their 60s, 70s, 80s, they start an exercise program. They start with some dietary change. They do some cognitive training. You know, they start language or dance classes or they start to improve their sleep. You start to see benefits. So start wherever you are. And even just starting with one thing can have significant benefits.

Hey guys. How you doing? I hope you having a good week so far. My name is Dr. Rongan Chatterjee, and this is my podcast, Feel Better, Live More. For many of you listening, today's guest needs no introduction.

Dr. Tommy Wood has been on this podcast more times than almost anyone else. This is his fifth appearance, and every time we speak, he gives us something new to think about when it comes to brain health and meaningful longevity. Now, if you're new to Tommy, he originally trained as a medical doctor,

and now he's a world-leading neuroscientist and performance coach, whose research spans brain development, traumatic brain injury, and dementia. His very first book, The Stimulated Mind, came out earlier this year, and is honestly a fantastic weed for anyone who's interested in brain health, focus, and longevity. In this conversation, Tommy and I explore seven common mistakes that many people are making when it comes to protecting their brains. Now, some of them may surprise you, but honestly, there's no need to worry because, as ever, Tommy is full of practical ways to address them.

We talk about mindset, and while your beliefs about aging, shape how you go on to age. We get into blood pressure, blood testing, supplementing, oral health, microplastics, and whether or not you should be filtering your water. And perhaps most importantly, if all, we debate the risk of becoming so focused on optimizing your own health that you forget about other people. As Tommy says, social connection does not just make life feel richer.

It helps protect our brains and extend our lives as well. So, if we chase longevity but lose our connection to others along the way, well, maybe we've missed the entire point. This is a really empowering and practical conversation that at its call has the message that it's never too late to make the simple changes that can improve the health of your brain. You are back. This is number five. I think that's a record.

Yes. Thank you. Just gone ahead of Gabon Mase number five. Well, hopefully it's not a competition we have to keep having because I'm sure he'll win out. But while I'm ahead, I will enjoy it.

What I was thinking about how to go about our fifth conversation, I was trying to think of a different framing. And 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. So are you up for this?

Sounds great. Different kind of format. Yeah, yeah, let's do it. Mistake number one, I think, relates to mindset. We neglect how much our perception of aging impacts how well we age. And in your latest book, which I love, you quotes the Ohio longitudinal study of aging, And you write that those with a more positive perception of aging were found to live on average seven 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 like that. And those who had a higher level of the positive perception of aging tended to live longer, like I said, seven and a half years longer on average. And 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 reverse causality, right? So if you're already feeling like you're experiencing the process of aging, you've lost some of your health, 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 a positive 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 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 think that that's what we're seeing some of in that particular study. 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 aging is bad, right? Because in order to fight against aging, you have to think that aging is inherently detrimental. And yes, 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, when 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 focuses on preventing 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 fight the aging process, stop 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, right? It is just a truth of life. And we see this, I think I mentioned to this, and maybe one of your previous appearances, there's quite a bit of research showing that cultures where women aging is seen as a good thing reports less menopausal symptoms. I think that a lot of what we experience we know 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 called Humans Peak in Midlife. And actually talking about the fact that when you look at just individual factors, and we're talking about cognition and personality here primarily,

then you might look at something like how quickly can you process complex information? and maybe do some kind of nonverbal reasoning, something like that. Yes, that peaks early in life, 20s and 30s, and then on average tends to decline. 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 other things increase over time.

And maybe even into our 60s and 70s, things like crystallized intelligence, which is a fancy word for wisdom, but also emotional intelligence 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, 6-year-old, because they have more experience, they've kind of integrated all these different things. So, when you look across all those different factors, then on average, people sort of tend to peak somewhere between 55 and 65,

sort of like you have, you still have a good cognitive function, Plus, you've built other aspects of wisdom and emotional intelligence and sort of they integrate. And that's actually when people tend to peak. And so that's after the men are pausal transition in women. And obviously it's a similar age as seen in men. So we can continue to grow cognitively, emotionally, and see benefits from that. Much later maybe than people might otherwise think. Yeah.

What's the practical take-home 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 think maybe it's worth just talking for a minute on the process of aging and what aging is. And there are lots of different theories of what aging is. And so 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 continued decades later, they actually drive a functional decline.

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

to whatever it is that you're doing. So that would fit with the developmental theory of aging. But there are other theories like the information theory where damage accumulates and DNA doesn't replicate as well. And then that kind of drives these aging processes. But regardless of what aging actually is, which people don't actually agree on what aging is, one thing that most people do agree on is that we may not be able to slow aging down, but we can accelerate aging. And that's by not sleeping and eating a poor quality diet.

not moving and not being socially connected. So when we're thinking about 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 satisfaction with life and happiness as you get older. And that's probably a downstream effect of all these things kind of integrating and coming together. So maybe the main takeaway is in that kind of middle port, 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 any kind of major benefit of it. And so it's just acknowledging that it's happening, acknowledging that actually there is some benefit to it, and at the same time you're doing, 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 I think just knowing that it happens and knowing that actually there's some net benefit to it 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. 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 because then you may be more likely to see the benefits of the things that will happen as we change every 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 reframing that stress in particular ways can change the way that our bodies respond. Yeah. So where we've gotten to right now, and there's actually been a lot of 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. And that might be psychological, it might be physical. 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 why historically, I'm, sort of like the kind of the father of the modern stress response, right, is hand cell you.

Yeah. 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 stress hormones like noradrenaline in the brain. But it's your brain diverting resources to say, hey, I need to change my structure and my functioning so that I can adapt to this thing that I'm being exposed to.

And exercise is the same. If you did somebody's blood pressure and measured their heart rate and measured their glucose and cortisol, right? Measure that in you after a paddle game. You'd be like, God, paddle is terrible. Just look how stressful it is for your body. But as a result, your body adapts, right? Resting heart rate improves. inflammation improves, strength and speed and power improve, V-O-2 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 happen if you're not, stressor isn't you're 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.

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 work is done, has been done by Alia Crum. She's at Stanford. she, as a PhD student, she worked with Adam Langer, who I know we both love, love her work. And so it's very much in a, like, Alia's work is very much in a similar vein, but has obviously taken it and built an amazing career in her own right.

And what she research is, or one of the things she researches this idea that stress is enhancing. And they've done randomized controlled trials where you take a group of people, and one group you say, just think about how terrible stress is, right? It sort of, it breaks you down, it impairs your decision making, right?

It's just really, really bad for you. Stress is debilitating, right? It prevents you from being able to perform your best. And in 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 Hudson, your famously. Think about all the times that you've performed under stress. Think about how amazing you can be even when you're stressed. And then you put them in a stressful situation. And there are experimental ways to do this. One is called the Tri-Ssocial 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 five minutes on this topic that you haven't prepared at all. And while you do that, the audience just sits there completely. passively just like staring at you, which is like very stressful. And what you see is that those, you're both groups, they get stressed, right? Cortisol goes up the same in both.

But you see a few other things that happen in those who are told that stress is enhancing. So you see other hormones increasing at the same time. So one of them is DHA, which is a steroid hormone. And that, like, DHA is part of that adaptation process. It kind of helps to facilitate growth and the building and the adaptation of tissues. And that goes up in the stress-enhancing group, whereas it doesn't in the stressor 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 DHA when stressed tend to make better decisions under stress.

It may not be the DHA, it may be this whole physiological kind of setup of thinking that stress is enhancing that you can then, or being 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 in 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 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 making us bigger and stronger and smarter. And then acknowledging and thinking about the fact that, yeah, actually, I probably can perform under stress. 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. Mistay 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. 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 five hours of zone two and do your Norwegian four by four and, um,

and 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 think that this is, in particular, a risk for those who are very hyper-focused on this area. And 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 themselves 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 think that it's possible they could undo or even go in the other direction because by being so hyper-focused on optimizing everything, which I think is a misnomer in the first place,

you miss out on this core part of human biology, physiology, which is the connection to others. And we know that is health-promoting and health-driving, as well as just being a part of how humans evolved. So one of 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 are individual for themselves and it's just like this battle to survive and reproduce. And, right, that's how you win. But 12 years after he wrote on the origin of species, which is like the, you know, the set of essays that kind of came, that founded this theory of evolution.

Supposedly, Darwin thought, well, actually, survival of the fittest as an idea doesn't explain human evolution. And so he wrote another set of text called the Descent of Man. And essentially came up with this idea instead that the group that was the most, he called them sympathetic, like the group of humans that were most sympathetic, 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 survive and that kind of better explained human evolution. And then Dacher Keltener, sort of much later, ended up calling this survival of the kindest. And there's now a huge amount of science to show that when we act pro socially, like we connect with others,

particularly when we're helping others. And this is where some of those ideas of why purpose and meaning can have such a big effect on our health. You can see, again, physiological responses. So you see activation of the vagal nerve and like heart rate variability improves and, you know, stress responses decrease. And all these things that we know are, again, tied to long-term health. 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 the benefit of others or the benefit of things outside of ourselves.

And I think we miss out on that when we're so hyper-focused on optimizing everything for ourselves individually. And I've seen this a ton with clients that I've worked with over the years where they stop going out, they stop seeing friends, they stopped having meals and restaurants because they're so worried about the food that they'll eat

or whether they won't get to bed in time. you know, everything else will kind of fall out of kilter because they're not at home to kind of get their perfect routine. And I think their health suffers because of it. And like there's almost, I imagine everybody who works in our fields, right, I don't see patients clinically. I haven't for a long time. But, you know, 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 mate. again and all of their health problems improved. And yeah, there's maybe exceptions to the rule because 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 we're so hyper-focused on, you know, getting everything else perfect.

Yeah. Your book, Tommy, The Simulated Mind, which you know how much I love it. You know how much I want people to get it. 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 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'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, come 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 I think it's maybe worth first thinking about... Toronto, I'm so excited to be finally coming your way this September. for those of you who don't know me, I'm Dr. Ronan Chatterjee, Dr. Author and host of Europe's biggest held podcast, Feel Better Live More. I'm bringing my Thrive tour to the Queen Elizabeth Theatre for a live evening all about health, happiness, and what it means to truly thrive in the modern world. 20,000 people came across the UK and Australia to the show last year.

And when I asked people where they'd like me to visit next, Canada was top off the list. I haven't to Canada since I was a kid, so I'm genuinely thrilled to be coming back. Health and happiness are skills we can all learn. Throughout the evening, I'll be sharing powerful stories, practical tools, and life-changing insights that will give you everything you need to thrive. Last year's shows were incredibly special, and I hope to see you in Toronto this September. Tickets are on sale now at Dr.chatterjee.com forward slash live. Today's episode is sponsored by The Way, the only meditation app with a single long-term pathway.

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For listeners of my podcast, The Way is offering 30 free days to establish your own meditation practice. All you have to do is go to the way, app.com forward slash live more to get started. What's the point of living longer and maintaining cognitive function for long periods of time, right? Because I don't think it's to stay at home by yourself for more time, right? More Netflix watching by yourself, mate. You don't think that's why we evolved.

I mean, you know, I absolutely love a good Netflix binge. Of course. But from the vast majority of people, and actually, yes, the sort of the extreme optimizes and biohackers, I think it's almost like theater. It's interesting. I'm glad people are doing it because, you know, maybe we'll, I'm sure we'll find out some useful stuff. But the vast majority of people don't want to just live longer. They want to get to 80-something. 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 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'll never actually get the thing that you're trying to live longer for in the first place. So I think that for most of us, that should kind of like frame why are we even doing this

in the first place. To go to the 3S model. So this is kind of my idea of how we bring together all these different aspects of lifestyle and the environment that affects cognitive function. But it's actually the same principles work for physical function and many other aspects of our health. And so the 3S is a stimulus supply and support.

So stimulus being essentially how we're using our brains. The idea is that how we use our brains is the primary determinant of how our brains function, just like how we use our bodies is the primary determinant of how our bodies function. And that could be learning, skill building, languages, music, but of course, like social interaction. And there are many examples where there's an outsized benefit from something that includes doing it with other people,

be that volunteering or sports, you know, dancing. And like similarly, languages, music often happen with other people, right? That's why you do it, is to play with other people or 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 in order for those networks to do what you're asking them to do. You need a supply of various things. So that's our second desk. So it's blood supply, energy supply, and then nutrient supply.

So these things come from physical health, cardiovascular health, diet quality. And 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 kind of major part of support. But then we can support adaptation in other ways. Hormonal status is important as well as avoiding, you know, another 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 can kind of increase inflammation or oxidative stress, some of which I think will 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, we. learn and do with other people or where we want to express them and use those skills and abilities with other people or cognitive functions be able to play with our grandkids or

do any kind of sort of sport or other activity with them and that's why we're trying to maintain function in the first place so I really think that that part of human connection is critical to all of this and I will say that I wrote a paper on the this with my colleague Josh Turkner 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 and then when i spoke to my friend julian able who is um you know famous for his work in compassionate communities and um you know the importance of social connection on health his response is like we

was, yes, this is great, but of course it's all driven by the human need for social connection because so much of this happens through our connections with other people. And he's absolutely right. That is sort of like fundamental to so much of this. Yeah. Can we say that social isolation is a form of stress? So, yes, on multiple levels. We see in controlled studies that being social isolated increases stress responses,

which you can 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 send them to Mars? Right. So there have been some Mars simulation projects where you put people either on their own or a very small group in a tight, confined space for extended period of time. And even that for just weeks significantly increases stress responses. We know it's inherently stressful. Even if there are other people there, you're relatively isolated because there's only one or two other people.

And we also know that when you look at people, when you look sort of across a big population, those who are more socialized, particularly those who feel lonely, they have other markers of a heightened stress response. so you can measure these stress responses in people who are isolated in a variety of different ways, either experimentally or just as part of their, you know, unfortunately where they are in the world right now. 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. They're also responsible for some of our most complex cognitive functions. Areas like the prefrontal cortex, the lateral lobe,

the lateral temporal lobe. So kind of like the front and sides of the brain, essentially, which are responsible for things like decision-making, focus and attention, memory, language, vision, or visual processing. social cognition, things like that. These areas of the brain are essentially completely undeveloped at birth. Their development is driven by the environment and how you engage with it 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. 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, you know, kind of doing complex activities. 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 simulated Mars trip studies or people who were polar explorers, right, on their own, off, you know, on some snowy glacier for months on end or in prisoners who 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 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 kinds of stuff, right? Even with that kind of stimulation, you're missing out on a very important part of simulation 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 Ward, 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 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 think that, 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 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 it up. Exactly. And you can be connected to a lot of people and still feel lonely. And some people only did a very small amount of human connection to feel like they're getting everything they need. My friend, Dr. Ben, Ryan, who wrote an excellent book called Why Brains Need Friends. It talks about a flower in a pot. And like some people, 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 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 some kind of your life has some meaning 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 helps 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. I'm going 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.

share. Do you agree with that statement, Dr. Wood? Yes. 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 controlled trials that have been put into meta-analyses to show that if you address, this risk factor, you see a significant reduction in dementia. 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 modify this risk factor, you'll see benefit. But blood pressure actually has really high quality evidence. So when we talk about blood pressure normally, we're usually thinking about heart health, right, and heart disease risk. And it's obviously important there too. But if I've learned one thing 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.

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 probably fine. When you then realize that this is a critical risk factor for the majority of dementias, both Alzheimer's disease and vascular dementia, which have a lot of overlap, and between them and make up 70 to 90% of dementias,

often that's the key maybe for people to think about it. But we don't really think about the brain when we think about blood pressure. But we know that once your blood pressure goes, you're much above sort of 120 over 80. And you really, once you get into the sort of the metabolic syndrome, criteria level of blood pressure, which is usually over 130, over 85, you see a significant increase in the risk of dementia. And if you can reduce it,

you see a significantly reduced risk of dementia. And the average benefits, 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 there are multiple ways to do that. We know we can do it through physical activity. We can do it through other lifestyle changes

to improve mental health. 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 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 potential problems with blood pressure is that people often don't feel anything wrong. Yeah. They used to call it. the silent killer, right? Yeah, I think.

Certainly 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 trialing the Hilo band. 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? But of course, you know, there are 24-hour monitoring, that you can get on the NHS. So there's all kinds of ways. But I guess 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 model, was it 20 or 30 quid? Yeah. It's probably not that much. Probably not anymore. And if you do it two or three times a day at home, 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. But just like, like you said, having some idea what's in the morning, what's in the afternoon, take it two or three times a day, 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, that feels kind of weird and, you know, getting stressed about what it might be. And I think now it's gotten to a point where, you know,

relatively regular blood pressure monitoring is something that's easy for all of us to do. And, you know, we should be doing. Yeah. I think that's a good segue to get into the fourth mistake, 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. One thing I've noticed since I started playing, and you've got to bear in mind, it wasn't as if I was sedentary beforehand. I was already, I would say, pretty healthy before I start a plane 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 as well as being a brain health, that's what you're a performance coach for Formula One drivers and a lot of high-level athletes. What is the benefit of a resting heart rate going down? In this context. Yeah. There are several metrics that you can sort of track physiologically that do seem to correlate with longevity, chronic disease risk, you know, heart disease risk in particular. And resting heart rate is one of them. Heart rate variability is another.

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

And when your resting heart rate is lower, your heart is essentially more efficient, right, 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 have fewer chronic diseases, less heart disease. And that's probably a combination of, yeah, improved fitness, decreased stress responses and all those kind of things are related to that.

So having lower resting heart rate is absolutely like a measure of better sort of like overall health and fitness. Like you said, in this context, there are times when low resting heart rate can be a bad thing. later risk of things like heart disease, heart failure. And so by improving efficiency and improving heart function, 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 idea of not doing any form of blood testing until you get sick. And I guess underpinning this as a mistake, it's an idea that I don't think is widely known with the public. And 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. 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

is being 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. Oh, no, you've got type of diabetes.

Let's talk about metformin and insulin and softened ulureas and all that kind of stuff, right? So this idea that HBA1C, for example, your average blood sugar marker here in the UK at 6.0, in old money, it becomes pre-diabetes. At 6.5,

you're called a type-to-diabetic, but that does not mean that 5.7 and 5.8 and 5.9 is fine. And 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 kind of a 20th century approach, even though we're now at 2026, 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. 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, it's relevant to blood tests.

I mentioned cognitive tests previously, like just in passing earlier, because nowadays you can't get cognitive tests from a neurologist or an old-age psychiatrist or whoever would be doing it until somebody suspects you have cognitive impairment. There had to be some trajectory of decline, but we'd 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 cognitive function test. Because we don't track these things over time.

A charity that I work with Food for the Brain that has an online cognitive function, that people can do for free if they're interested, but more importantly, they just got a big 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, and then they can track their own function over time. But 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, here. At 48, I've just gone down a bit. Jesus, hey, Doc, what can I do here? So it might motivate people to start these changes earlier. Yeah, absolutely. I think that's the case for many, you know, very basic blood tests, just like it was, just like it is for blood pressure. We have to have diagnostic cutoffs, like the ones you mentioned for pre-diabetes and type to diabetes when it comes to blood sugar. You have to have some decision-making point where you

They don't say, right, right now it's time to treat with the medication. I completely understand why we have those. That's very important. But blood sugar is a good example, so HBA1C, because two people can have the same HBA1C but have very different blood glucose or blood sugar trajectories or experiences over the day. Because HBA1C 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 HB-A-1C is this. Your average blood glucose was this. But actually, there's a huge amount of error in that. Two people with the same HB-1-C can have very different average glucose levels. And one may be problematic, but the other may not be. And so where HB-A-1-C is most useful is tracking your own changes over time. But again, you can't do that unless you have a baseline. What was my HB-B-1-C 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 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 now's the time or, you know, I should be doing something to intervene. Yeah. This is one of the reasons that I have created something called Doob Health here in the UK initially. And the truth is, I never had any aspirations to do something like this, a health app, a preventative health act

to help people get on top of the 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. Sedge, I get all this, but I'm going to my doctor and I can't get this, right? And some of the tests that you talk about, like fasting insulin or homocysteine,

I just can't get it. I might be able to get an A1C, but I can't get it regularly. I can't track it. And I've been wanting the NHS to do this in the UK for years. I mean, my honest hope with due health is that within a few years, we'll have proved the case that the NHS take it. And 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 coaching built in and all this kind of stuff, 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 love your take on. And I really pushed hard for these two because you can't really get these easily on the NHS. It's fasting insulin and homocysteine. Both are very important. Homocysteine, we'll start with. So homocysteine is a marker related to methylation in the body, particularly related to the status of B vitamins related to methylation.

So B12, folate, B6, and riboflavin for most people, and there may be a genetic component there as well. So the two most important are B12 and folate. And we know that having elevated homocysteine is associated with a higher risk of cardiovascular disease, but also in particular dementia. So it also influences the trajectory of cognitive decline. So those who have elevated homocysteine have a more rapid rate of brain atrophy, right? Their brain shrinks faster and they lose cognitive function faster or their cognitive function declines. more rapidly.

There's sort of the threshold based on the randomized control trials that have been done is probably somewhere around 10 or 11. So ideally you'd get your home assisting below 10. You'd definitely want to below 13 because that's considered elevated and you'd see a more rapid

cognitive decline associated with that. And then the intervention that you would do is supplement with B vitamins or make sure that you get enough B vitamins in your diet. The proportion of people who have very high homocysteine has come down a bit in countries that have started to fortify white flour with folic acid.

So there's a big population study is done in the US where they started to fortify flour with folic acid in 1998. The proportion, the number of people who had elevated homocysteine did decrease after that. So we know that getting more of this in the diet definitely brings homocysteine down. Randomized controlled trials have used folate and B12 and then plus or minus B6 as well.

And we also know people, in particular, people who have MTHFR polymorphisms, they have elevated homocysteine if they don't get enough riboflavin. But by enough, I just mean the recommended daily allowance. I know what you mean when you say that, but a lot of people will hear mtHFR polymorphism and go, come again? So could you just try and explain in layman's as well? what that means. Today's episode is sponsored by Exhale Coffee,

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free bag of coffee. Today's episode is sponsored by Do Health, the preventative health app that I have helped to create to transform the way we think about health. Now, as you've probably heard me say before, there are specific blood markers that can show you're at elevated cardiovascular risk years before you ever feel a symptom. In fact, 46% of Do Health members had hidden cardiovascular risk they potentially had no idea about. Over 25% of members had suboptimal homocysteine levels, which is linked to an increased risk of Alzheimer's.

And this is exactly why I decided to build due health, to help people understand when things are starting to move in the wrong direction inside their bodies, instead of waiting until they get sick. Do health takes everything I know about health, including my four pillars, and makes it personal to you. An initial blood test screens for over 50 biomarkers, then zeros in on the 11 core markers that relate to your metabolic health.

Every four months, we retest your blood to see what's changing and what is not. And in between tests, you have unlimited coaching with our in-app coach joy. And together, we help you build a lifestyle plan personalized to you. You can sign it to the wait list today. All you have to do is go to dohealth.co forward slash live more and use the code live more. Yeah, so unfortunately, you'll actually, you know, I imagine a lot of people who've listened to this podcast will have heard about MTHFR. It's a gene, methylene tetrahydropholate reductase. There'll be a test later.

That is involved in this sort of methylation pathway, which is essentially what methylation is, maybe let's talk about that. methylation is this process of moving carbons with some hydrogens attached, is one carbon with three hydrogens as a methyl group, moving them around the body. And when you move methyl groups, you turn on genes, you activate proteins. It's like this really important signaling molecule that we use to kind of control biological processes. And there are, you know, the B vitamins are involved in kind of providing the, the methyl groups for our body to do that, just to kind of move these signals around,

to turn things on and off. And so one of 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. And we're often, you know,

if you go out into the world and you look up MTHFR, it's 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 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.

Because most of us, actually, the majority of people have, one of these polymorphisms that changes activity a little bit. But what these polymorphisms do, and they absolutely have some kind of benefit, right? because most of us have at least one, is that changes how that enzyme binds to a co-factor, a co-factor being the thing that just allows that enzyme to run. And that co-factor is made from riboflavin,

which is vitamin B2. And there are studies, the randomized controlled trials that show that if you just get enough riboflavin, which you can find in whole grains and liver and things like that, 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 homocysteine and methylation

are driven by your genetics, they're not. They are largely determined by nutrient status, just getting enough B vitamins. So if you just get the recommended daily allowance, you've ticked that box. But if you do measure homocysteine and it's elevated, then the other B vitamins are a great place to start. There are some other things that you can think about

as well, but those core B vitamins are really 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 due health blood tests. And he tests me yesterday, say, mate, I've got my results. And I'm loving it, loving the whole thing and their app and the explanations. And so, mate, if you're open to sharing, send me them and I can give you some advice if you want. Now, you know, he gets advice on the app anyway, but his home assisting was 15.

Okay? Now, 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 home assisting can increase your risk of cognitive decline as you get older. He has a family member who has got dementia.

Now, it could, well-be for this individual that this elevated homocysteine 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 home-assistine checked, which is the norm at the moment, I was saying, in the NHS, then you don't know a critical piece of information that it's actually quite easy to address. Yeah. I said, 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, you know, that's will directly impact his behavior. And when he re-checks the bloods in four 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 homocysteine and sort of my friend and how he can meaningfully reduce his risk of getting sick in the future? Yeah.

So one of the reasons why homocysteine isn't routinely measured is because homocysteine had a moment 20 years ago in cardiovascular disease and neurological disease. or neurodegenerative 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 homocysteine 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 actually makes perfect sense that if you take,

If you take a person and they have insufficient levels of one B vitamin, they're probably, or one vitamin, one nutrient, they're probably going to be insufficient in others, right? Not everybody, but in general, these things don't come one at a time. And when we've done 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've done the same thing with omega-3s, actually.

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? In order to like a send a signal in the brain, you need B vitamins, right, for mitochondrial functions, right? For your brain to make the energy to send the signal in the first place. And then you need, you need, you need, you know, 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 a fat around it

to kind of allow that signal to be transmitted faster called myelin. And it's like iron status is really critical for myelin. And then you get to the end, and you're trying to send the signal, if it's like a serotonin neuron, 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.

neuron at the synapse that sends the signal to the next neuron, like DHA, which is a long chain omega-3, kind of concentrates there because it's really important to kind of make the little sort of envelopes or vesicles of neurotransmitters to send them, right? So you need all of those things for that to happen at its kind of best. And so for this reason,

when you look at sort of multi-component interventions or you look at the status of multiple neutral you see that they interact. So the first time this was found, this was the Vitacog study run by David Smith at the University of Oxford. And this was the first study to show that if you have people with high homocysteine

and you give them B vitamins, you slow their rate of brain atrophy and cognitive decline. But only if they have adequate omega-3 status. 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. So, this is one of, you know, thinking about this as like a single variable nutrient problem

is one of the reasons why it's hard to get a homocysteine test today because those previous trials didn't kind of address this full picture. But that's the kind of hangover of the kind of reductionist approach to health that we've taken, right? Which is obviously how we test pharmaceutical interventions. You know, 100 people, 50 get the drug, 50 don't. is there a difference? But of course, as you're saying, you know, and I love the vice-contrad, this idea that, yeah,

lower the homocysteine, and it will lower your risk of cognitive decline if you have sufficient Amiga-3. If you don't, it won't. I think it's very, very empowering, which is why I told my buddy. So, like, let's say, yeah, Amiga-3 needs to be there as well, right? So, of course, testing Amiga-3 is a little bit harder.

Yeah. Do you think people need that? or if they're, I guess, if you're eating fatty fish two to three times a week, do you really need an Amiga 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 tests, right?

A large costs for all of these tests. But I will say that, so food for the brain, the charity that I mentioned, does have an at-home blood test called the Drift test that includes HB.O.C. D, homocysteine, and omega-3 status. You have to pay for it. It's somewhere between 1 and 200 pounds, so it's not cheap. And I'm not saying that everybody needs to do that test. But if somebody wants to test the mega-3s, right, that is an option.

When you then think about testing omega-3 status, dementia risk, if you're regularly eating fatty fish, cold water fish, sardines, macrull, salmon two or three times a week, you probably don't need, you probably don't need to test. Equally, if you're not doing those things and you'd rather just take a high quality fish oil or omega-3 supplement, I think that's fine too. And often, you know, when I talk about this, yes, those who are vegetarian or vegan, they certainly have questions. I would recommend like an algal, you know, an algae-based omega-3 supplement. So it's not, an animal-based supplement,

but you can still get those fats in your diet, and then you take one to two grams of omega-3s a day. That's probably going to cover your bases. That's going to, I think that's going to be enough for most people. Yeah. On DoHad, we don't actually test amoeia 3. Maybe it's something we'll bring in at some points. In fact, one thing I was very clear on

is that over-testing 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 interestingly, and interestingly, And I can't remember the exact statistic. Just on home assisting, 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 home asistine, which is quite interesting. There's been some recent discussion about where these blood tests fit

in dementia prevention in particular. So I think last time we talked about the Lancet Commission report on dementia prevention run by Professor Jill Livingston. They identified 14. Modifiable risk factors for dementia, estimated that 45% of dementias may be preventable. But diet wasn't in that, was it?

And that's 14, I don't think. No, it wasn't. And so there were actually letters written to the Lancet where it was published. And this was actually discussed in the sort of popular media as well, that B vitamins and omega-3 status weren't discussed, you know, even though we have some fairly good evidence for those, I absolutely don't want to put 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 building an evidence base around them. But I think you're right, particularly as people get older, 10 to 20% of individuals at least may have elevated home assisting. So that's like a significant chunk. Previous analyses done by other groups suggested that potentially up to 20% 20% of cases of dementia were related to elevated homocysteine and low levels of mega-3s. So that's, you know, even if it's not 20%, it's still a meaningful.

Significant. It's a meaningful contribution to future risk. So yeah, I think to kind of go to your original point about what's it worth testing, I also agree that just like more testing 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 rather than just like doing a scattergun, test everything. And right, in medicine, we have this idea of a pre-test probability.

Like, how likely is it that you're going to find something that you can address it? Yeah. And I think that's really important. So we focus on metabolic health. We know that the vast majority of adults have at least one risk factor for metabolic things. Right? So it's very likely. that you're going to find some kind of modifiable metabolic health.

That's why we focus on mental health. And I had a criteria when choosing the 11 that's got to be a good evidence space behind them. And we've got to be able to do something with the results. And I guess in answering some of the stuff around homocysteine in Amiga 3s, we've slipped into mistake number 5, which is thinking all supplements are a waste of money. Okay.

So, 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 thought, 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 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 it's a common mistake. You've already mentioned the potential benefits of B vitamins and Amiga-3s. 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. Yeah. And what your take is on that trial?

Because I thought it was really quite illuminating. Yeah. So the Cosmos trial was a recent trial run in the United States. Thousands of people. It's a massive trial. older adults, randomizes to four different groups. So they had a control group, and then they had a group that took a basic multivitamin. Centrum Silver was the multivitamin.

Centrum Silver essentially just has 100% of your RDA of, like, the basic vitamins. Another group got cocoa flavonol supplements. So cocoa flavonols are like the polyphenols, like the antioxidant polyphenols that are in cocoa. So you have similar compounds in coffee, tea, chocolate, berries, for example, things that make berries sort of purple and red. And then one group got both, right? So we call it like a two by two design. And what they found was that in the two groups they 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 two years younger.

So you kind of saw this slowing of brain aging by taking a multivitamin. And this is the most basic multivitivit. Like you go to boots and you get an over-50s multivitamin. That's essentially what it is. And I'll also say this about the Vitacog study. The Vitacog, you know, often when we're sold supplements and vitamins were like, you have to have this fancy version

and this bioavailable version is going to cost X amount of money. the best evidence that we have for multivitamins, for B vitamins, is the most basic version, you know, the essentials version, some folic acid and cyanocabalamin. There's a form of B12, it's like the cheap, the cheap version of B12. That's what showed benefit in Vitacococ. Just like the most basic, low, essentially low dose multivitamin showed benefit in Cosmos.

And there may actually be a thing where 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. In the sort of the cocoa flavanol 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 or drink much, coffee or tea because actually coffee is the most, for most people is their primary source of antioxidants in their diet. If you had a low quality diet, lots of processed foods, just like processed fats and carbohydrates and few nutrients, a nutrient poor diet, then taking the cocoa flavonol 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, as much of an effect,

which I think makes sense. Yeah. There's often been a negative view with doctors, supplements, possibly because the industry has been unregulated, which I get. But the truth is, is that I have seen so many patients over the years where the right supplement can be game-changing. But I think the Cosnos trial just showed us that actually across a broad population, there can be a benefit with the brain for a multivitamin and mineral. Okay, so I think is a really good take home. We've covered B vitamins in Amiga 3, the supplement of the moment 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 for this from, I was actually on a panel with Jeff Bland, who 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's safe, then you can try it with very little risk.

Yeah. If we don't have good safety data, then the will it work for me becomes much riskier. Yeah. Right. And so. So chemotherapy, right? Yes. It's like, you want really good evidence that this is going to help.

you before you expose yourself to the downsides. Because there are a lot of downsides. Yeah. 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 your 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 could take it. Vitamin D, trickier because, again, in very high doses, a fat soluble vitamin, you don't want to overdose on vitamin D. There's some downsides there. But we know people who are vitamin D deficient, absolutely.

What you said is prescribed on the NHS for people who are deficient. We know it's important brain health, bone health, et cetera. 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. It's been tested in probably thousands of clinical trials at this point, randomized controlled trials for various people in various conditions. Low doses, high doses, years at the time.

Recent meta-analysis found essentially no side effects with creatine compared to placebo on average. And that's probably because it's something that we can get from the diet. Maybe not quite are the doses that some people might take, but close. So we know, assuming that you're getting a high-quality source, it's not contaminated, that kind of stuff. All right, so you want a reputable supplement maker. Hopefully they've done something we call third party testing. It's been tested for impurities. They can send you a certificate to show that they've done that.

Every good supplement, some company would be able to do that. But we know that creatine is incredibly safe, even in sort of like frail older populations. So then we might say, well, is there a possibility that it might benefit me? So creatine has been used for decades as a supplement in like sports performance. particularly strength and power. It helps you do an extra rep or two in the gym, and then if you do that over time,

you can build more muscle, you can build more strength. The effect isn't huge, but it is statistically significant and meaningful, right? It's not magic, but it helps you do a little bit more work in the gym and that compounds over time. It's become of particular interest in the brain world recently because there have been some studies to show that, 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 be of some benefit there. So for the average person who thinks of their brain is working really well, there might not be that much of an effect. So when you look at method analyses, studies of many studies of creatine, it tends to benefit older people,

and particularly is beneficial for memory. That's kind of where it's been shown to have some benefit. In other populations, there's some evidence, there's actually better evidence in like kids with concussions, but there's some evidence that taking creatine after like a traumatic brain injury may help with some elements of recovery. In the kind of the really flashy study

that got a lot of press recently was in individuals who were sleep deprived, and they took a high dose of creatine. It was kind of the equivalent of sort of 20 to 30 grams of creatine when maybe a standard dose is like five to 10 grams. And they saw that people maintained brain energetics. You can do a brain scan.

You can measure 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 deprivation. And there was an older study in rugby players actually that showed that when they were sleep 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. So in those kind of settings, when sleep-deprived, maybe creatine can help to maintain some elements of cognitive function. And then there were a few randomized controlled trials now, although some people have suggested that, you know, they were done in countries

where maybe the quality of the science isn't as good is in the UK or the US. 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, adding creatine to, say, a medication regimen, if they haven't had full, you know, remission of symptoms, may improve, like, symptoms of mood and well-being 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. Across a wide range of doses, a lot of people are now saying that you 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 grams.

Which is 5 to 10 grams. 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 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 effects. There was one study in individual with Alzheimer's disease where they gave them creatine and saw some improvements in cognitive function. However, 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.

Even though some of their cognitive function may be impaired, they do better at the test the second time. They start to 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 say there may be some benefits for creating for the brain,

just because it was no control group. We know in studies that look at cognitive function, it's really hard 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. 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 know, maybe you have been diagnosed with depression

and you 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. We know it's safe. It's cheap. 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 definitely can tell that I just a little bit stronger, a little bit faster in the gym when I'm taking it. I find creatine to be mildly stimulating for me.

And that is the case for some people. Like I kind of mentioned that rugby player study, seeing similar benefits with creatine versus caffeine in the setting of sleep deprivation. And so I definitely noticed that I take it later at night, I don't sleep as well. And so for the same reason, I do feel like I get a bit of a cognitive 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 often over-stimulate people where, so say, if you had several espressoes before you played paddle, you might be sweaty, anxious. you don't quite have the accuracy because you're sort of over-stimulated. Creatine could give us a mild stimulating effect and it doesn't happen to everybody,

but those who experience it, if you're one of those people, maybe it's useful then. But in terms of the strength and the power effects and the fact that, you know, paddle is more of a sort of aerobic cardio-type sport, 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 crockative effects. And 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 of that is going to do something as well, which is, I guess, the kind of hidden glue with all the same. If you believe something's helping you, it probably will. 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. because 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 perhaps we can sort of zoom through oral health, you know, point number six. What's the relationship between oral health and brain health and oral health and longevity? It's been known for maybe 10,000, 10 or 20 years at this point, that there is a connection between oral health and cardiovascular health. I think that was probably found first. In fact, there are some of the bacteria that you get when you have gum disease or what we would call. So gum disease has two stages. The first is ginger vitus. And then if it starts to affect kind of the underlying bone, then it would be called periodontitis. I think we can call it just gum disease more broadly.

some of the bacteria that tend to overgrow in the setting of gum disease, things like pseudomonas gingervalis and streptococcus mutants, you can find those bacteria in atherosclerotic plaques in the heart, which we know sort of trigger heart disease. And some of the thought is that because you sort of like have all this inflammation around the gum disease and you know, bleeding and things like that, actually those bacteria can get from the mouth into the blood. stream and then can trigger systemic inflammation, might trigger the formation of some of these

plaques in heart disease, and they've actually been found in amyloid plaques in the brain of certain individuals. And some people argue that one of the reasons why we accumulate amyloid is, you know, one of the parts of kind of the process of developing Alzheimer's disease is because it has antimicrobial effects. So it's accumulating around, say, bacteria that, you know, that's, that might have gotten into the brain. And one way that happens and does seem to happen is through gum disease. This doesn't mean that if you have gum disease, you're definitely going to get dementia, right?

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 in multiple sort of perspective, as in sort of like you follow people over time studies. And then in at least one study, 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 would do, they then decrease their risk of dementia over the next several years compared to those who don't get treatment. There have been other studies that show that the amount of antibodies you have circulating in your blood against those bacteria that tend to accumulate because of gum disease,

the more antibodies you have kind of, suggesting that you've had a higher exposure, those people tend to have a higher risk of dementia as well. So, like, from multiple different directions, it seems that gum disease 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 ignore your oral health. And in terms of xylitol gum, are you a fan? So, yes. And the... My favorite story about xylitol is actually a colleague of mine, 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. But his work is looking at ways to decrease preterm birth.

So there's nothing to do with dementia, although people who are born preterm do actually have an increased risk of dementia. So it could sort of have this full kind of lifespan effect. But we know that having gum disease is a risk factor for preterm birth because it creates this inflammatory effect. And we know that chronic inflammation is a potential trigger for preterm birth. So babies being born too soon. The more preterm you're born, the higher your risk of both death, but also neurodevelopmental impairment, multiple long-term health issues. Obviously not everybody born preterm experiences those, but it's just on average.

So he's run multiple clinical trials. He's running them in the US right now, but the clinical trials he ran already are in Malawi in Africa. Malari has the highest rate of preterm birth in the world, and the majority of pregnant women in Malawi have gum disease. And so one trial they did was this large cluster randomized trial where they had different villages in Malawi, and they gave them some of the village of Zylautol gum

to chew like three times a day. throughout the last chunk of pregnancy. And they saw significant improvements in gum disease and a statistically significant reduction in preterm birth rates, which to me, it's just mind-boggling. Amazing. And the design of the trial wasn't perfect.

They didn't have a placebo gum and that kind of stuff. Those are the trials he's running right now. But even that you would see that kind of effect is just incredible to me. 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 an imbalance in the microbiome that drives a lot of gum disease without having negative effects. So other types of mouthwashes, for example, like a alcohol-based or a chlorhexstein-based mouthwash, they can actually get rid of good bacteria that you want 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, zylotol gum 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 the same, ignoring the toxic load in the modern world. Now, I don't want to scare people, okay, because I think one of the problems with health these days is people get quite scared. And I think we've 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 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 issue with all of these is that there's absolutely. some important signal as it relates

to these exposures 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 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 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. Microplastics. I've certainly gotten a lot of press recently. And these are essentially the breakdown products of plastics

that we use for packaging for food or utensils or other things. So our primary exposure is from the food that we eat. You can get some from like skincare products. and things like that. But there have been some recent studies that suggest that maybe our primary exposure is through food, food and drink. And a couple of years ago,

there was this study that said, you know, the average human consumes a credit card's worth of plastic a week or something. And then everybody lost their minds. Then some more recent studies, they got a lot less press. 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, yeah, the decimal place went in the wrong spot. The decimal place was like miles out. Like several, like, I can't remember exactly how many. It was like six or seven places in the wrong place. Like it was, it was huge, the difference. And so that's one part is yes, we do consume. these things, but the amount that we've been told

that we're consuming is probably a lot less than we've been told. Then the next part is there have been studies that have looked at microplastics in the body, in tissues of people who are deceased, and, like, looked at them in, say,

artery plaques, look to them in the brain, and, you know, they've looked at them in, like, testicles and other organs and basically suggested that in those who have a higher disease burden, say higher heart disease burden or higher dementia burden, they have higher, so people who have a higher dementia burden or people with dementia have more microplastics in their brain. 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 might be in your bloodstream.

So the dementia is probably driven, at least partly by the blood flow issue, the vascular disease, and then microplastics just kind of accumulate they come along for the ride. We also have a big issue in terms of how microplastics are measured in these studies. So, 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. And so what they do is they essentially vaporize, the plastics and then measure it in something called a mass spectrometer. 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. It breaks down into the same compounds as plastics do. So there have been some papers that say that, 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, maybe some of like what we're measuring in tissues is overblown. However, we do know that some of the compounds that come in plastic, some of the plasticizers, thallates, bisphenols, right? People who've heard of BPA, right,

with the lining of cans. And there are many other breakdown products of plastics. They are certainly linked to some changes in cognitive function, issues with neurodevelopment in kids, higher rates of heart disease. So these things aren't, you know, completely benign. 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 really say that it's this primary driver, but we also know that they're not benign, and we should try and minimize our exposure where we can. There was a recent trial where they randomized individuals to multiple different groups where they changed different plastic exposures and then tracked their sort of levels, levels in the urine of different plastic breakdown compounds. And the biggest driver seemed to be the food. So they gave people that,

So they stopped them using canned or reduced their canned foods, reduced storage of foods in plastic, yeah, reduced plastic utensil use. So, you know, if you're kind of like stirring a pot and you've got a plastic spoon, 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 they actually controlled a lot of the food production process so that at no point were foods kind of stored in plastic for long periods of time. So 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 or getting things that are that you can buy loose rather than things that were sort of like pre-chops and stored in plastic, that kind of stuff. I would say that if you're 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 the reason why 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're going to throw them in a pot and then make dinner quickly. Do that, right? That has a much bigger signal in terms of benefit.

But if you can, you know, don't store your leftovers in plastic, get a wooden spoon, minimize the amount of foods that you get that are kind of stored in plastic, right? Wherever that's possible, drink fewer drinks out of plastic bottles or cans, 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 what? 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 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 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 Bredison came on recently to talk about dementia risk and brain health, 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 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 eight hours and actually, you know, I'm thirsty, right? I personally no longer, haven't done this for a while, will get a takeout coffee in one of those containers. Yeah.

You know, because the heat and how that interacts with the cars. Again, for me and my life, that's not that difficult to do. Yeah. You know, and certainly at home, we don't store on plastic anymore. We store in glass containers when we overcooked 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 with the science how much of an impact this is having on health. Okay, I'm sure we could talk for an hour on plastics, but let's leave it there on plastics.

What should take on filtering drinking water? Yeah. So I'd start by saying that, you know, luckily for, I imagine everybody listening to this podcast, are like water supply is very safe, right? And so the... In many countries. Yeah. In the vast majority of countries, not all, but right, I would expect that wherever you're listening to this,

your water supply is safe and it's not, it shouldn't be a primary concern. However, 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 tap water and there's a significant amount of lead in it. We also know that there are other things ending up in the water that are very hard to remove, like the PFA's and the forever chemicals. And plastics.

And plastic. Microplastics. So thylates and things like that can end up in the water as well. And we know that these have some potentially negative health effects. So the way that I've approached this is that I do filter my water. I have an in-fridge filter. You can get a jug filter, although the main thing with the 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've probably undone the good work of filtering your water. Right. You're probably adding your own contaminants. Yeah, exactly. And then you can scale that up to under, you know, some people have, you know, you can get under sync filters and stuff like that. But I think about it very similarly to how I think about microplastics.

And actually, this is how I think about this, like, whole topic in general, is that wherever you're able to do, do that and you're almost certainly decreasing your exposure over time, right? So 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 thylates and other things if they are if they are in your water 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 a thing it's low low risk high potential for benefit not particularly um cost intensive depending on which filter your filtration system you go for so i that's that's generally how how i approach it there's probably a level of water filter that each of us could do. 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 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 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. 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 heavy lift to have a lot. water filter at home. Yeah. So I've got something, I think, I think it's called Aquitru. It's a reverse osmosis filter. I bought it about two, three years ago. It reminds you when you filter needs changing.

You know, it's just, we have a habit now in the house, so we fill it up and you pop it on in it, you know. But yeah, it is, you could call it a hassle if you want because it takes out lots of good stuff as well. Yeah, it takes out the minerals. So we have to put some drops to remineralize it. Now, someone might call that a fath. It possibly was a fath three 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 one thing I always like about you tell me. It's 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. 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. What can you feel that you have an element of control over? What should you take on 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 compounds that you get. So exercise, of course, would do that as well. Yeah, so I think that sweating is important. It is 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 excrete things that our body doesn't want inside. urine, fecese skin, right?

Yeah, exactly. Yeah. So I do think sweating is probably beneficial. We know that some of these compounds can be excreted in sweat. exercise that cause you to sweat is free. Right? So I don't, and actually many of the benefits of sauna, particularly dry sauna, sort of like a finish hot sauna.

Many of the benefits of sauna actually overlap very significantly with aerobic exercise. The pathways that get activated, right, the sweating. So, yes, I think sauna 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 a similar way.

So, yes, I would think about sweating, but however you achieve that sweating, I think matters a lot less. That's a great message. However you achieve your sweating, it's so to you. You choose the activity you want. Absolutely, yeah. Okay.

And because I mention it, let's just touch on pollution in the air. Because when I think about how 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, yeah, external air pollution, I know there's a link to B vitamins

and how we're going to tell you our risk. So what's your sort of top-level take on pollutants in the air? Yeah, so it's very similar to the others. Yeah, I guess we can touch upon that, the B-Vitamin study, this was done 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 PM 2.5. It's like 2.5 microns, that's the size particles

that are released from cars and roads. and things like that, that seemed to be, there were other aspects of air pollution as well that are linked to human health, but they're kind of the most frequently studied and associated with increased risk of heart attacks 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 dementia. Of course, this is not a randomized controlled trial, But it's thought that exposure to air pollution increases homocysteine, which we were talking about earlier. And so if you measure your homocysteine 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 maybe offset a lot of the risk from the air pollution by supplementing with B vitamins. I think that makes sense. So it's just another reason to maybe consider getting enough B vitamins in your diet. Then a lot of the... the sort of inside air

well it's obviously connected to the outside air but because where you've got closed windows things sort of like accumulate over time and so often the 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 for that reason and so I think that again especially if you live somewhere 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 the air outside is filled with smoke the house smells of smoke and we know that's linked to poor health you know uh effects 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 And there was one recent study where they actually did a randomized controlled trial of air purifiers in people who have high exposure to air pollution. And they saw that having an air purifier on significantly reduced blood pressure. So again, a meaningful 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 something worth considering.

But again, right, we can't, you know, it's often very, there are many people who can just move because they have a lot of air pollution, right? So I think that if you can address that by just, you know, if there are rooms you spend a lot of time in, say the bedroom, get an air purifier. Again, over time, you're dramatically decreasing your exposure with a relatively simple intervention. Yeah. And of course, something we have covered before is the socio-economic sort of input here in the sense that, you know, in many places in the world, your socioeconomic status hugely influences how polluted your environment is, right? So, you know, the middle classes and the wealthy people can live out in the suburbs and have 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. Tommy, I love chatting to you. As you know, you're one of the doctors and the health commentators who I respect the most. I love your balanced, nuanced, but also open-minded approach to health. I think the book, The Stimilar Amad, is fantastic. And I really would encourage people

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've 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.

what would your final words for that individual be? I would say that it's never too late to start and we actually have really good evidence for that. 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 one of the world's premier medical journals, it's never too late to start thinking about dementia prevention.

That's because they were focusing on dementia. But then your brain health more broadly. Studies in individuals in their 60s, 70s, 80s, they start an exercise program. They start with some dietary change. They start to improve. They do some cognitive training 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 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? Because you sort of 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 the all you can do right now, but you set it and forget it, or you know, you start a B-vitamin supplement. These things we know have significant impact through very high-quality trials,

regardless of the age that you're at, 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 would ideally make multiple changes over time, but these things, you know, just one thing is the place to start and then build from there. 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, these are some of the comments that came in on the back of that.

Artie has told her she started playing netball and paddle. Cool. Lara started figure skating. Lynn started reform of Pilates. Dorothy started, tap dancing classes. Soce started a heels dancing class. Heather started playing pickleball. Louise started ballet after a recent Parkinson's diagnosis. And Darrell started playing table tennis and badminton. And honestly, that's all because of the information you shared on my show. So I think

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

on the side. So, like, pick something that, any of those things, fantastic, I'm so happy people are doing it. I really appreciate your time as always, and thank you for having me on. Really hope you enjoyed that conversation. Do think about one thing that you can take away and apply into your own life. And also have a think about one thing from this conversation that you can teach to somebody else.

Remember when you teach someone, it not only helps them. It also helps you learn and retain the information. Now before you go, just wanted to let you know about Friday 5. It's my free weekly email containing five. simple ideas to improve your health and happiness. In that email, I share exclusive insights that I do not share anywhere else, including health advice, how to manage your time better, interesting articles or videos that I'd be consuming, and quotes that have caused me to stop and reflect. And I have to say, in a world of endless emails, it really is delightful,

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