Future-Proof Your Brain from Dementia & The Lifestyle Levers That Keep You Sharp with Neuroscientist Dr. Tommy Wood

The best way to minimize your risk of dementia is not sit at home by yourself chugging supplements. It's gonna be much more about. Dr. Tommy Wood is a UK trained physician. His research focuses on brain health across the lifespan. How things like exercise affect dementia? If some proportion of dementia is preventable then we must be able to change the trajectory of cognitive function and cognitive decline. What is driving this and what else should I be focused on or thinking about? How we use our brains is the primary determinant of how they will function. Low HDL cholesterol, high triglycerides, high blood sugar or high blood pressure. These are all significant risk factors for dementia and they are effects of... Tommy, so nice to meet you. I am thrilled to have you here. I think your work is vitally important. It touches me personally because I have dementia in my family and it's been a very difficult past couple of years. I've been witness to just how devastating the diseases of dementia, Alzheimer's, etc. have on not just the individual who is victimized by it but also the families, etc. And then the basically inhumane way in which modern healthcare manages this right now. And so I think your book and your message is one that I'm proud to help amplify here and to get into with you today. So thank you. Thanks so much for having me and I appreciate that and I'm looking forward to talking with you about it. Cool. Is it true that the adult brain is destined for an inevitable decline? Yes or no? No. How did you arrive at this conclusion and how do you support that conclusion? Some proportion of dementias are probably preventable. If we think about adult cognitive decline with a terminal decline to the point where you're no longer able to look after yourself on a day-to-day basis, which we would call dementia, if some proportion of dementias are preventable, then we must be able to change the trajectory of cognitive function and cognitive decline in adults. Is this a controversial position to take in neuroscience or in neurology? Not anymore. Potentially 10 years ago it would have been, but if you look at probably the best supported evidence out there formalized as part of the Lancet Commission on Dementia Prevention, spearheaded by Professor Jill Livingston. It's now in its second iteration. It was updated in 2024 where global experts in neurology and neuroscience and the science of dementia and the factors that contribute to dementia risk come together and estimate which risk factors are strongly sort of, we think we can causally link them to dementia risk long-term that are potentially modifiable and they estimate that when you sum up all those different risk factors, it's a sort of a statistical approach that says, imagine that this risk factor didn't exist at all, what proportion of dementias would we expect to never happen? And when you add all those up, the number they currently have is 45% of dementias are potentially preventable. And this is published in the Lancet, one of the premier medical journals in the world. So at least 45% are thought to be preventable and there are risk factors that are strongly linked to dementia risk are also modifiable that they weren't yet able to add into their models that some people think it could even be more than that, potentially the majority of dementias may be preventable. In certain respects, from a non-scientific point of view, like a very basic perspective on this whole thing, issues of cognitive decline are on some level a function of a circulatory problem, much like heart disease, right? These amyloid plaques, etc. that get deposited in your brain are caused, at least in part, by lifestyle choices that produce them, right? So why did it take until 10 years ago to come to this conclusion? That's a great question, potentially the treatment of heart disease. And we've gotten much better at treating heart disease in the last 50, 60 years. That has then changed the age-specific incidents of dementia in the population. And what I mean by that is that at any given age, you are now less likely to be diagnosed with dementia than you were 20 or 30 years ago. So at 70 years old or 80 years old, you're less likely to be diagnosed with dementia now than you would have been done previously. And part of that is thought to be because we've gotten so good at treating cardiovascular disease, which is a risk factor, both for vascular dementia, which makes up something like 10 to 20% of dementia, and Alzheimer's disease, which has a vascular disease component. So and that's Alzheimer's disease is maybe 60 to 80% of dementia. So at least 70 to 90% of dementia do have cardiovascular risk factors as a risk. And that's something that we've actually gotten better at treating. But even if you go back to the 50s and 60s, the Seattle Longitudinal Study, it was one of the first studies where rather than taking a whole population and looking at their cognitive function and seeing, well, the average 70 year old has lower cognitive function than the average 50 year old. And we're talking broad cognitive function, if you test multiple different functions, you sort of add them up. This was one of the first studies where rather than just taking a big population and looking at cognitive function across that group, they looked at the same people over a long period of time. And so he brought people back every seven years and re-measured their cognitive function. And what he found first, one of the papers they published was that cardiovascular risk factors were strong predictors of change over time. So we knew that back in the 60s and 70s when he first published those data. And then the other thing they found was that the average effect, so more than 50% of people maintained cognitive function from their 50s into their 60s, 70s and 80s. Nowadays, we call people who do that super ages, right? Because we think it's so unusual. But actually, we knew even back then that the majority of people, sort of 50, 60%, maintained cognitive function into those later decades. And those data were actually used to raise the retirement age in the US in the 1980s. So we've had some inklings of this for a long time. It's just that getting a big enough set of data, finding a systematized way to really sort of put it together and then frame it as prevention rather than these are just risk factors, right? And knowing that if we treat heart disease, for example, and as a result, a specific instance of dementia comes down, which is what is sort of like part of the hypothesis of that, then for the first time, we can say, oh, yeah, if we do something at the population level, we can see changes in dementia risk. Therefore, we can now start to talk about prevention. The statistics bear out a rapid rise in Alzheimer's and dementia. I looked into this from what I gather. It's due to double in the US by 2060, going from seven to 14 million. There are currently somewhere between 6.7 and 7.1 million people in the United States with Alzheimer's. This is predicted to be 139 million worldwide by 2050. There are 10 million new cases annually. My perception is that maybe it's just my age or because of what's happening with my mother that this is rampant and happening everywhere. So what is driving this and what should we understand? What's vital to extract from those statistics about this condition? The statistics that you give and the ones that I gave are both true at the same time. Meaning there's a high degree of agency in terms of prevention, and yet we're also seeing this rapid rise at the same time. And the age-specific incidents has declined over the last 100 years. So you're less likely to be diagnosed with dementia at 75 years old now than you ever have been, but you're also more likely to ever be diagnosed with dementia because we're going to live much longer. Both of those things are true at the same time. People are projecting that the burden of dementia may double or triple in the next few decades. And that's largely due to an aging population. But some people, such as those who have analyzed the data and shown that age-specific instances has decreased, have suggested that maybe that sort of projection is a bit of an overestimate and that the increase in burden may not be that large. However, things that seem to be contributing to it in particular are the ongoing worsening metabolic and cardiovascular health of the population. So we're still seeing, even though many things have improved, smoking, heart disease treatment, access to education, access to complex cognitive and stimulating jobs, particularly for women, which has sort of massively improved over the last 100 or 50 years or so, that is contributing to some of that decline in age-specific incidents. At the same time, we're seeing worsening in obesity rates and type 2 diabetes rates, and we know that those are significant. High blood pressure is one of the most important predictors of dementia risk. So if we don't manage to change that trajectory, those are one of the things that are expected to continue to drive up the burden of dementia. However, we say that in the age of the GLP-1 receptor agonist and the other therapies in that class, which have huge effects on cardiovascular disease risk, blood pressure, blood sugar. So it's possible that actually we're also changing that trajectory due to the nature of those medications, which if started early enough, you would expect to decrease dementia risk because of the effect they have on metabolic health. Given the high degree of agency that we have to stave this off, let's get into how we can be brain protective and brain health promoting. And what I like about your approach and your work is that it's grounded in the basics. I think when we cast our gaze on the internet, there's a lot of fancy doodads and latest breakthroughs and supplements, etc., which is a lot of cherry on top of the Sunday kind of stuff. We're very dialed in on the connection between things like nutrition, exercise, lifestyle choices, recovery, etc., when it comes to our physical health. And we've gotten a lot better about how we consider our mental and emotional health. But we really don't think about this thing between our ears and the fact that these decisions that we're making every single day actually impact how well this is functioning. So what is your kind of top line thesis on how to enter this aspect of the conversation? One place to kind of transition from what we were talking about to this place is to think about some of the risk factors that we know are in that list of modifiable risk factors for dementia that were included in the Lancet Commission report. So it's things like education. And we know that cognitive stimulus is really important. It's maintaining sensory input. So hearing loss and vision loss are significant risk factors for dementia. It's all the cardiovascular stuff that we talked about, high blood pressure, diabetes, smoking, alcohol, air pollution, obesity, head trauma is another one. And when we think about that, we can very rapidly create this massive list of things that we need to think about. Other things that weren't included in that report, but which I think we have strong enough evidence for to talk about in terms of prevention include nutritional status and the certain nutrients we know are critical for the brain sleep, we know is a critical component. And so the way that I think about it, and it's probably largely because I spent a lot of my time working with athletes and being an athlete myself, I actually draw lots of parallels between physical performance and cognitive performance and long-term cognitive function because essentially the principles seem to be very similar. And many of the things that you would do to improve physical health or mental well-being of physical performance, they actually translate very nicely over to brain health. It's shocking how they line up like that. And I think that's lucky, right? Because then we don't need to focus on different things. We can just appreciate that they're also maybe doing some benefit for our brains. Or making some kind of a pure choice between physical health and brain health. Exactly. The way I think about it is very similar to a stimulus recovery adaptation model that you might see in physical exercise. So if you're trying to improve physical performance, we know that the primary driver of improved cardiovascular fitness or improved muscle size or strength is the stimulus that you apply to it, right? So the training that you do for your marathon or the lifting you do in the gym if you're trying to build muscle strength, you can improve how you adapt to those stimuli by attending to your nutrition and attending to your recovery. But the stimulus is the most important thing, right? I like to lift weights and unfortunately, like no matter how many naps and protein shakes I have, I won't get bigger biceps on my side. Do some bicep curls. And the brain, I think, is essentially the same. So the thesis in the book is that how we use our brains is the primary determinant of how they will function. And that means that we need stimulus. And I know that this is slightly controversial in the current world where I believe that we're chronically overstimulated while being understimulated at the same time. We're sort of constantly bombarded with multitasking and multimedia and social media and these things that don't truly drive improvements in brain function and feeling overwhelmed because of it whilst not being able to attend to the real focused deep learning and skill development, which is what really drives brain function. And so the stimuli that we can think about, the sort of drive this whole system include education and learning, any kind of skill development, be that music, languages, complex motor skills, and then also social interactions, which we know is a primary driver of both human brain evolution and then human brain development and maintenance. So we need to think about how we're using our brains. But then once you've stimulated a region of the brain by engaging in some task, you need a supply of the things that allow that to happen. So now we're kind of getting into what I call the 3S model. The first S is stimulus. The second S is supply. And so if you activate part of the brain, the local cells, the neurons, the astrocytes, they stimulate the blood vessels to dilate, to widen, to bring in more blood flow. So that's where we need good cardiovascular health, right? You need that to be able to respond to changes in activity in the brain. And then you also need a supply of energy. So that's where we need good energy regulation, good metabolic health because glucose is going to be our primary source of energy, but ketones, lactate, those can play a role too. And then we need a supply of nutrients to kind of run that system. So things that become critical, particularly in terms of dementia risk are B vitamins associated with methylation, omega 3 fatty acids, vitamin D, iron, and then some others like magnesium, zinc, antioxidant vitamins like vitamin C, vitamin E, and then the antioxidant polyphenols that you can get from colorful foods do a bunch of cool stuff for the brain. Then maybe some other precursors like choline or ethanolamine that you can get from eggs or whole grains like those kind of provide a structural component. And we can get into all of these different sections. But so we've stimulated the brain, we've brought in a supply of things that we need to kind of allow it to do its job. And then just like with our physical performance, you don't get stronger when you're training, you get stronger when you rest and recover afterwards. So this is my third S, which is support. So sleep is a critical part of that. That's when all the synapses that you've generated during the day by through your skill learning are cemented and refined to kind of build part of or like build new aspects of structure and function in the brain. And we can see that with skill learning, we can see the brain change on MRI scans as these sort of processes are driven, even in older adults in their 60s and 70s. Then we can support those processes with what we call trophic factors, the things that like support the growth of synapses and function of neurons in the brain. So one that's produced during exercise is brain derived neurotrophic factor. Hormones play a role here too. I mean, you had an excellent episode with Lisa Mosconi, that's really her area of expertise, but hormones sort of support brain function as well. And then we want to avoid things that kind of inhibit the adaptation process. So this is where things like alcohol, smoking, chronic stress, air pollution come into play. And so all of these things interact. And the reason why I talk about it in this way is because it's not this massive list of 20 things you need to attend to. Because stimulus drives the processes of adaptation and stimulus drives the processes of supply and supply drives support, they interact. And what you see quite clearly is that when you change one thing, you change lots of things at the same time. So you can, so if you start by stopping smoking, right, you've removed one risk factor, you also see improvements in inflammation and improvements in blood pressure. And you're more likely to make other healthy diet choices. For example, we know that that happens. Or if you start to sleep better, again, blood pressure improves. And the next day, you feel more social and you're more likely to engage in cognitive estimating tasks. So I think about it this way, so that there's an in for everybody. And that in could just be one thing. And then the whole sort of network starts to shift in your favor. There's so much in there. Don't worry, we're going to tease out all of these things individually. But I really like this paradigm, this 3S model of brain health, stimulus, supply and support. And within that, you canvassed exercise, nutrition, challenging your brain, stimulating it in various ways, supplementation, etc. Within the hierarchy of those respective pillars, what is to your mind like the most important? Or is that too reductive? You have a whole kind of thing in your book about the problems with the reduction in nature of science. And yet, you get asked these questions that are compelling you to kind of reduce these things down. So this is actually another part of the question that you asked earlier, which is, why haven't we started to think about dementia prevention in this way until very recently? And I think part of it is because we've been chasing down one reductionist pathway, which is the amyloid cascade. And then that's kind of, I think it's distracted us a bit, not that that's not important, right? That should remain a part of the whole picture. But it's kind of, it drew resources and attention away from these other things that we can talk about. The answer is that it's going to differ from person to person, of course. And I think that these things shift across the life course. So in younger individuals, maybe in their 30s and 40s, I think in general, they're probably receiving a good amount of stimulation, unless they're just like at home, scrolling on Instagram all day, which is going to be some portion of the population. But if you think about knowledge workers in their 30s and 40s, they're probably going to be doing some kind of complex, cognitive stimulating work. But what they need is more on the sort of like the support and recovery side. Are they ever giving their brains a break? Are they spending all their days task switching and multitasking, which we know are inherently stressful? Are they giving themselves the time to kind of sleep, to be able to recover and adapt, which we know is critical for the brain? Then as sort of people get older, we might start to see declines in physical activity or metabolic health. So maybe that becomes a really critical component in midlife. And then later in life, particularly as people retire, I think that's when they're at the biggest risk of a decline in cognitive function. And we see that from the research as well. And so then I think that's where stimulus really comes to the fore, is making sure that you're maintaining these either complex skills or learnings or social interaction that you got from work previously or that you got from education previously, but then become harder to come by once you've retired. And I think that's one of the reasons why cognitive decline tends to accelerate retirement is because we lose those stimuli. So I think that as we go through a sort of a standard life course, the things that are most important are probably going to shift in that kind of manner. The stimulus aspect of this is very interesting. The idea that we're overstimulated in all the wrong ways and understimulated in the right ways, like just scrolling on Instagram or offloading the synthesis of information or the processing of information to AI, like all of these things are basically harmful to our long-term brain health. We think that we're engaged in these tasks, but we're just basically short circuiting our ability to problem solve and to do the deeper thinking. And we're just so increasingly distracted now that there's great opportunity for somebody who can carve out, you can make your way in the world better than ever right now, because the competition is all distracted. Yet, when you think of that from a population level, what is that doing to millions if not billions of people? Fast forward 30, 40 years from now, and what are our brains going to look like? Because we haven't really had to do the kind of problem solving that historically we always have. Yeah, like an important place to start is that these technologies aren't inherently bad. It all comes down to how we engage with them. So there's even some evidence suggests that something like five minutes of scrolling on Instagram, as long as it's not making you mad because of some emotional political information, or as long as it's not only exposing you to people who are richer, better looking, more successful than you are, which makes you inherently feel worse about yourself, that has triggered triggers effects in our physiology that can negatively affect our health. If it's just like you spend five minutes looking at dogs doing funny things, which is a lot of my Instagram feed, that can actually be a real mental break that will allow you to go back and do hard work. But the problem is that's not how we're using it. We're constantly, we're using it for extended periods of time, plus using it while we do something else. So you're scrolling on Instagram while you've got Netflix on or while you're doing emails or while you're in a Zoom meeting. And what you see, there's some really interesting studies where they look at how much people multitask across different multimedia in that way. And what you see is that just as you'd expect, if the stimulus is the primary driver of how our brains function, our brains do actually adapt to that. So people who do that kind of thing are better at multitasking. And the way you would test that in a study is you have one cognitive task, and then you have them do have to do another like another cognitive task at the same time. And everybody who multitasks does worse on both tasks, right? Because the human brain actually isn't, it cannot multitask properly. You can't give full focused attention to two different things at the same time. But people who do a lot of like Instagram plus Netflix plus Zoom meetings, etc., they are better. They have less of a multitasking cost when they multitask. The problem is that other studies show they're also more distractible because their brains have learned to stop filtering out information from the periphery because they're trying to attend to multiple things at the same time. And then the result is that we're distracted, right? Right. It impairs the ability to actually do the deep work. Exactly. Because you're not acclimated to it. Yeah. But this is, again, it's just the brain responding to the stimulus, right? It's you're training it to do this and it gets better at this, but there's a trade-off. Right. Just if you want to be an elite level marathon runner, you're not going to be a super heavyweight power lifter at the same time, right? And this is the brain, right? You're training it to multitask, so therefore it's less good at deep focused, like attention driving work. So then it comes down to how are we using these tools? How are we using technology? And right, the other example that is going to come up, just like you kind of mentioned is AI, right? Anything we say about AI is probably going to be completely obsolete in two months time. But I think, again, there's like a framework that we can use. And this was, some of this stuff is proposed more than a decade ago by a colleague of mine called Ken Ford, who's an expert in AI. And like, back when AI wasn't even a thing, he talks about this idea of cognitive prosthetics versus cognitive orthotics. And orthotic is something that you use to enhance or support your current levels of ability, right? So when I think about orthotics, I think about shoes for individuals with cerebral palsy, right? If because of issues with motor control, they're unable to walk, but you give them the right orthotic, they can walk. You've enhanced their capacity. Whereas you use a prosthetic to replace something that you don't have. You have a prosthetic leg because you're missing part or whole of your leg. We are at risk of using AI as a prosthetic instead of our brain as if we didn't have one. And we know that when we don't continue to engage those skills or things that we're using AI to do for us, we will lose those functions or we'll never develop them in the first place. But we could use these tools as an orthotic. We could say we do the work ourselves, right? And there are some initial studies on this with students writing essays. This is one study that sort of blew up the internet was an essay writing study at MIT. So the students who ended up doing the best were the students who wrote the essay first themselves. And then afterwards, they got access to an AI tool. And then you're saying, how can I improve this? What can I do better? What have I thought about? What have I missed? And then you take that information and you integrate it back in yourself. All of that requires you to do the work. It requires you to be engaged. But you could use these tools to help you learn and expand your capabilities. But it's all going to come down to how we choose to engage with them. Yeah. Are you using them for the purposes of offloading or synthesize it? If you're using as a tool and then you're doing the synthesis yourself, the heart, the heavy lifting of like, how do these pieces fit together? That would be brain health promoting because it's a stimulus. Exactly. It seems like in the context of dementia and Alzheimer's, stimulus, speaking of reductionism, sort of been reduced to this, well, you do crossword puzzles and this is like, no, this is not... The idea kind of writ large is, how engaged with life are you? Are you actively spending time with friends? Are you engaging with other people? Are you trying to learn a new skill? On this idea of our brains maintaining a degree of neuroplasticity throughout the entirety of our lives is somewhat novel. I grew up in a time where it's like, oh, yeah, well, if you're going to learn a language or a musical instrument, you got to do it when you're young and then it becomes hard. And so we all have that experience of not being as neuroplastic as we once were. And I think we just sort of assume, well, we're just... It just becomes harder and harder to learn new things. But essentially what you're saying is not only can we do that, it's urgent that we are always kind of engaged in that process. Absolutely. I think that sort of whole idea has been embedded in society for more than 100 years, if not well before that, that as we get older, we essentially become useless. And we're unable to learn new things. We need to be put out to pasture. That was how retirement was framed when it was first popularized back in the beginning of the 20th century was. By the time you're 60, you're essentially... You have no use to society, so we just have to find a corner to stick you in. And we've embodied that as a society. And therefore, this is something that we expect. This is this idea of stereotype embodiment theory, which is that if we expect aging to be associated with a significant loss of physical and cognitive function, we will know... We stop engaging with the things that maintain physical and cognitive function. Oh, I'm too old to learn that. I'm too old to lift that. A vicious cycle. Yeah, and it becomes a vicious cycle, exactly. So what you see is that even in people in their 60s, 70s, 80s, when you do a randomized controlled trial of language learning or music learning or physical activity, you can see structural changes in the brain. You can measure improvements in cognitive function. The brain is still plastic at those ages. It's true that learning is potentially slightly harder and takes a little longer than when you're very young. But that's not because the adult brain isn't capable of change. It's because you have shaped your brain to allow you to best function in the environment that you've put it in. So you don't want it to be really, really malleable, because it's already become the person that you are. And that's what you want. So it's capable of change. You just have to engage in the processes that drive change, show your brain that it matters, and the way to do that is by truly focusing on something. And then that change will happen, and we can measure changes in both the structure and the function of the brain in regions that are susceptible to the process of aging that become dysfunctional or lose volume in the processes of dementia. So we can see even later in life, we can change that trajectory if we engage in these different, true cognitive stimuli. Hydration is one of those things that is far too easy to forget, just like element forgot to add vowels into its product name. Oh, I jest. 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Get a free eight-count sample pack of Element's most popular drink mix flavors with any purchase at drinkelement.com slash richroll. You know, we develop these neural pathways and preferences over time and, you know, kind of like groove these ruts in our brain. And we know what we like, we know what we don't like. And, you know, the older we get, we're more kind of calcified around like doing anything different or new or more resistant, right? As an athlete, like I want to do the things that I'm good at, that I know how to do. Like I want to go trail running and I want to go swimming. And, you know, but what I probably should be doing is taking a jujitsu class or an archery class or, you know, trying to develop a new skill where, you know, in something that I'm not good at. Yeah. There's this interesting thing that you see in adults, which we've all experienced, right, compared to kids. And I think this is one of the reasons why kids learn much faster than adults do, is that the primary driver of neuroplasticity is errors and making mistakes. So when you are experiencing the world, you're not truly experiencing the world, right? You're experiencing a prediction that your brain has of the world as it happens around you, because everything happens on a slight delay. So because of that, the brain is constantly looking for errors, mismatches between expectation and reality. And you can measure these mismatches with like an EEG, electroencephalography, you can measure electrical activity in the brain, you can see when the brain notices something that it didn't expect, it's largely driven by like a drop in dopamine and a few other things. But then that's what drives change, because the brain's like, oh, hang on a second, I didn't get that right. I need to create new connections. I need to shape something differently in order to improve my prediction in the future. And we see this from learning research as well, like what helps people learn faster. And one of the most important things is making mistakes, is making errors, because it drives those processes. That's why, a lot of neuroplasticity is driven by neurotransmitters like noradrenaline and dopamine. And these are catecholamines, these are stress hormones, right? So it feels slightly uncomfortable. And that's part of the point. This is your brain attending to something important and diverting resources to change in response. So what that means for us is that we have to do things that put us in a position to make mistakes or to fail. Occasionally, right? You don't want to fail all the time because it becomes very demotivating. But some way you can see progression, but occasionally you're sort of like pushing at the edges of your current capability, because that's what drives neuroplasticity. But adults hate that, right? Anytime you think about doing something, you go to a jujitsu class and you're like the bottom rung of the ladder and like, people are going to kick your ass and throw you over their shoulders and like, you're worried about injury and all these other things, all you're worried about looking stupid. But it's putting ourselves in those situations where we have the capacity to try, fail, learn, go back again. That's what's really driving those changes in the brain. So we need to kind of lean into that discomfort. This is not the retirement that I was envisioning for myself. The idea that like the work is never done, the principles that drive growth and evolution for mental health, physical health, etc., like apply to the brain and there is no destination or endpoint to this. And if you want to protect your brain, you have to get out of your comfort zone and do things that you're not good at and fail, etc. So if you are somebody who is hamstrung by this notion of failure or being in a vulnerable situation, perhaps a mantra is to think of it like differently as a brain-promoting, a brain health-promoting kind of exercise that you're supposed to fail. If you're failing, then you're succeeding because this is enlivening your circuitry and activating your neuroplasticity. Absolutely. And I think this is where the right social context can make a big difference as well. We know that social connections are an incredibly important part of this. So having other people who are willing to do this with you, you join a class where everybody's a beginner and you learn together or you and a friend go to jujitsu together and you can laugh at each other as you fall over and try and figure stuff out, that's going to help people feel a little bit more comfortable doing it. Of course, some people will just go and try it and they'll lean into it and do great. But giving yourself a social context to do this and feel supported and feel supported and learn together, I think that's going to add another layer that might make this a little bit more palatable to people who could already feel uncomfortable thinking about it. Which overlaps with the Blue Zones idea. Of course. Like a big thing that drives HealthSpan extension is your engagement with your friend group, your community, whatever that looks like and being accountable to them and doing this as a collective. Yeah. Let's talk about exercise. How important is movement to brain health? Why is it so important and how should we think about this? It's incredibly important. And the most fundamental reason for that, I think, is that historically as a species, we've moved a lot. And it's kind of like there's a quote from Minigo Sumilan who says that movement is evolutionary baked into our genes. It's like a requirement of our biology. If you want your brain and your body to function well, it needs to move frequently. If you think about even just our recent ancestors were maybe walking 15,000 to 20,000 steps a day, they were moving six to eight hours a day. And it's essentially required just to keep maintenance and other cellular processes going in the body. And that includes in the brain. And so because we no longer have that, just like we've sort of engineered the food environment in a way that means we have to invent diets, we've engineered the built environment such that we now have to invent exercise. And now I think we're getting to the point where we've engineered the cognitive environment such that we now have to invent new stimuli, right? That's kind of like the next frontier. But we know that different types of movement actually have different effects on the brain. So even just breaking up periods of being sedentary, what we might call exercise snacks can immediately boost mood, it changes blood flow to the brain can immediately change cognitive function. So just starting with regular low-level periods of movement during the day, we already see an impact. And we know that the sort of like number of steps that you have in a day, and it could be right, if you don't walk and some people can't walk, it could be like propelling a wheelchair around or however you get about the world, right? As that increases up to sort of the equivalent of 8 to 12,000 steps a day, you see a linear reduction in risk of dementia and a linear increase in cognitive function. From there, we know that it wrote sort of a aerobic type movement. So now if we're getting into brisk walking, jogging, cycling, this seems to be particularly good for memory function and the structure of the gray matter. So like if you think about the brain, it's this big wrinkly sort of fatty ball, and the outer part is the cortex, is the gray matter, and there's more gray matter inside. Part of that is the hippocampus, which we know is really important for memory and is particularly susceptible in the later stages of Alzheimer's disease. And so we know that people who regularly do something like brisk walking, they can significantly improve the structure and function of the hippocampus. There was a more recent study that kind of told us that intensity is also important. So some of the things that get released during exercise, I mentioned brain-derived neurotrophic factor earlier, there are dozens of myokines or exokines that get released, many of which can impact the brain, but they're released in an intensity-dependent manner. So there was another recent study in individuals in their 60s and 70s. They randomized them into three groups. They had like a control group. They had a sort of like a zone two, low zone three-ish sort of jogging kind of group, and then they had a high intensity interval training group. And for six months, three times a week, they did 40 to 45 minutes of their chosen exercise. The HIT group did the Norwegian four-by-four protocol. So for those who aren't familiar, it's four minutes of running at 85 to 95% maximum heart rate. In this study, they had a three-minute rest in between. Some studies have four minutes, some studies have five minutes. I don't think it matters that much. And then they do that four times over, and they did that three times a week for six months. And interestingly, what they found was that both the sort of the jogging group and the HIT group improved cardiovascular fitness by the same amount, but the HIT group had much greater improvements in the structure and function of the hippocampus. And so they did much better on a learning task, and that benefit was retained for five years. They went back five years later. And they still had maintained improvement, even though they'd gone back to their previous levels of exercise. They hadn't said, oh, I love sprint training, so I'm just going to do more of it. They'd gone back to being relatively sedentary, and they still had benefits five years later. So that's kind of on that spectrum of aerobic exercise up to sort of sprint training. You see across the entire spectrum, you see benefits. But that type of exercise seems to particularly benefit the gray matter and memory function largely by improving the hippocampus or supporting the hippocampus. Then you might think about resistance training. And what we see with resistance training is that it seems to particularly benefit the structure and function of the white matter. So the white matter sits underneath the gray matter, and it's where all the myelin is, like all the sort of fat in the brain, and it's responsible for the really fast connections. It's really important for our complex cognitive functions, like decision making, executive function, that kind of stuff, which we know is lost even early on in the dementia process. And resistance training, something like the studies they've done two times a week, exercises like on machines in the gym that cover the entire body, five or six different exercises, three sets of eight to 12 reps, a very basic resistance training program, twice a week for six months, significantly improves the structure and function of the white matter. So improved executive function and other things. And you can see the changes on an MRI scan. And then the final piece when it comes to exercises is like these complex movements that we might call co-ordinative exercise or open skill exercises, often what they call it in the literature. So like a closed skill exercise is something like running or cycling, like unimodal, unidirectional, whereas an open skill exercise is something like badminton or a martial art that requires you to kind of learn complex motor patterns, respond to the environment, respond to other people, maybe strategize, you're trying to manipulate your opponent around a tennis court and process information much more quickly, which is particularly important as we get older as processing speed tends to drop off, but it is trainable if we're doing things that require us to rapidly process information. And this seems to be the best way to support sort of overall cognitive function, depending on which kind of meta analysis of the studies that you look at. And so that stuff, like I said, ball sports, team sports, board sports, martial arts, dancing, dancing is often like wins out across, you know, compared to almost any other activity in terms of supporting both mental health and cognitive function. So to then kind of like fit all that stuff together, we can think about just like just moving regularly throughout the day doesn't have to be particularly intense, just to kind of break up extended periods of sitting. If we can make our sort of aerobic type training something that has a co-ordinative component, right, so it's a, and especially if it has a social part, right, so rather than just going jogging, maybe you play soccer or you play badminton or even like table tennis, then I think you can get some additional benefits there. Plus maybe once or twice a week, you do some kind of resistance training. Once or twice a week, you do some kind of sprint training where essentially you're just the goal really is to generate lactate. Lactate goes into the brain, switches on production of brain-derived neurotrophic factor. And so it doesn't really matter what you do. It's just something that, you know, gets the heart rate up, you feel the burn a bit. And that could be even part of, that could be part of your coordinate exercise, right? You get a lot of stopping and starting and sprinting in some things like badminton or tennis, but something like that. So regular movement, some aerobic sessions being that kind of complex, coordinated movement, and then once or twice a week, you do some kind of more intense sprinting a few times and some kind of basic resistance training program. That kind of hits all of those things based on what we know even late in life can significantly improve and maintain brain function. Essentially what you're saying is it's a yes and approach. It's a buffet. It's not about, you know, the Norwegian protocol necessarily. That's one piece in a larger whole that encompasses every, you know, kind of form of exercise that's, you know, driving you effectively forward. So aerobic exercise, resistance training, dynamic movements, and high intensity work, right? And finding a balance and then the very kind of like low output walking, you know, type of activity. All of these things are important for different reasons that impact the brain in different ways. And if you want to be as comprehensively brain healthy as possible, you have to, you know, attune yourself to all of these different forms of activity. Yeah. There's a couple of important takeaways there. One, first, it's worth mentioning that as much as possible, we want to avoid this kind of like medical, what Daniel Liebman calls the medicalization of exercise, right? And this happens when I cite a specific study and you're like, oh, well, then I have to do Norwegian four by four to benefit my brain. But like, that's not the case at all. There's a lot of confusion around Norwegian four by four. And it all tracks back to our, you know, our deep-seated need to, you know, reduce these things down to like a little nugget that I can remember. I mean, you're a rower, right? So as a swimmer, any, as any track and field athlete or rower or swimmer can tell you, you do all kinds of interval work. You're always varying, you know, that program. And I think the Norwegian four by four is a, is an effective like, you know, interval modality. But there's many more that, and once you acclimate to that, then you need to change it up, right? Or you're not actually stimulating your physical body in the way that you could be if you're changing the structure of those interval workouts. Yeah, exactly. And so I think if we just think about the physiological response to that kind of thing, heart rate goes up, you release lactate is kind of like, you're at that high level of intensity, you have rest periods in between. So you work hard for a short period of time, you rest in between. That's essentially it, you're going to be driving those those physiological responses. If people need like specific protocols, like I provide several in the book that have evidence behind them, but in reality, it's just move really, really quickly, rest a bit. That's going to be your driving those functions. Then the other thing to kind of take away is that there is sort of these core principles across all these different types of activity, but how you choose to do that is entirely up to you. Because you'll get similar benefits from dancing or badminton or even your martial arts jiu-jitsu, right? Because it is doing all those same things in terms of like the pathways is activating. So you can pick one that you enjoy and you want to get better at. And so like you said, it is a smorgasbord and you get to pick and choose. But don't enjoy it too much. You're going to get stuck there, right? Like, that's the thing with me. Like, do I really want to play pickleball? No, I want to go do the thing that I know how to do. You know what I mean? I don't want to be bad. Yeah. So then of course, we go back to the previous thing, which is try and find something maybe where you've got something to learn. You're going to sort of lean into that little bit of discomfort, especially in the complex, co-ordinative stuff. Because I think that's going to give you extra bang for your buck. On the resistance training aspect of this, there's a lot of discourse now around longevity extension and the importance of maintaining your muscle mass. So when you think about resistance training, what's more important, muscle mass or is it functional strength? How do you parse those two ideas? In general, your strength is proportional to your muscle mass. So when you're building one, you tend to build the other. As we get older, often you train strength more than you train muscle mass. But in reality, what you want is to survive the sort of like the immediate benefits, like just like moving your having having muscle and moving it, where we release things that go and support the brain. It's important for blood sugar regulation. Our muscles are our biggest, like blood sugar sink. For most people, I think that any kind of resistance training is going to get you both at the same time. When there are some interesting like population studies where they look at strength and they look at muscle mass and they look at the relationship to dementia or heart disease risk or mortality risk. And what you see is that at high levels of muscle mass, you almost start to see risk increase again. So like there are some there have been some studies out there that say that at very high levels of muscle mass, you have a higher risk of cardiovascular disease, a higher risk of all cause mortality. The problem is that those studies don't determine how you gain that muscle mass in the first place. So if you gain that muscle mass through resistance training and exercise, your muscle mass increases in line with your strength. And we know that strength at high levels of strength, you don't have an increased risk of disease. Like the higher your strength, the better, essentially. So what you're seeing at the population level is that some people would just gain more muscle mass because they've gained more total mass. But that's not functional muscle in the same way as if that muscle was gained through resistance training, if that makes sense. So I think the real kind of takeaway is building strength that's functional and provides relative strength for you. You just need to be strong enough for yourself, relative to your own body size, whatever that body size is. And so if you're larger or smaller, you would expect to on average be stronger. If you're larger, you would expect to be stronger. If you're getting to the point where you've gained a lot of muscle mass, but it's not through exercise, that muscle may not be functional in the same way. So the easiest way to measure this to kind of like give a takeaway is that strength is probably more important than muscle mass. And when you work to improve your strength, you will also improve muscle mass at the same time. So like a final important part, particularly if we think about as we are getting older, is we can measure multiple things. We can measure muscle mass, muscle strength, so like how much like the maximum you will lift, but then also things like power. So like how fast can you contract and move your muscles? And things like power are lost the fastest. And that's important because when you lose the muscle fibers that are associated with greater strength and power, that's where you stop being able to like stop yourself from tripping over or grabbing onto a handrail if you're about to fall down. And we know then the knock on effects is hip fractures and spending a long time bed bound, where you then lose even more physical and cognitive function. It's really hard to come back from that. So in addition to just like any kind of weightlifting, I think, which is going to improve strength, there's really interesting studies on like jumping in older adults, just like a minute of jumping a day significantly improves like bone mass and muscle strength and power. So in addition to just like the kind of like say using weights in the gym, just finding something that requires you to jump, you know, you could be skipping ropes. It could just be like jumping on the spot, jumping on one leg. We know those have additional benefits because you're maintaining some of those some of those elements of function that we know are going to be important. Yeah, interesting. Yeah, if you are weightlifting like a bodybuilder, but you're not thinking about speed acceleration or compound movements, like don't we sort of want to be like Edo Portall or, you know, take Kelly Starrett's advice and make sure that we're supple and able to, you know, bend in all the right ways and move quickly, laterally, forward, backwards, and all these sorts of things that just a, you know, straightforward weightlifting, you know, and the tradition of bodybuilding is really not going to do the trick. So luckily, I don't think those things are mutually exclusive. Actually, you know, doing even traditional style bodybuilding work can help to maintain mobility and stability. So if people are just getting into resistance training for the first time, the safest and easiest and best way to do it is to train like a bodybuilder. And that could be a combination of compound or machine or, you know, dumbbell, bands, anything like that. You're going to significantly improve strength. You're going to maintain muscle mass or improve muscle mass. You're going to improve types of muscle fibers. These are the ones we know are important for, you know, strength and power. And the injury risk is super, super low. Of course, you're then hopefully doing all these other things that we mentioned that require you to, you know, have some element of, you know, flexibility, stability, cutting, jumping, running, if you're doing some kind of ball sport or team sport, you're doing a martial art, because those things are important as well. But even, especially if people are new to it, even bodybuilding style training is going to give you a number of those benefits. So I don't think that we want to avoid it entirely because the evidence that we have from randomized controlled trials for like what type of resistance training significantly improves brain structure and function in older adults is that like super, super basic bodybuilding style training. Interesting. I've been sleeping on my birch for many years now. And what I have realized over time is how much my day actually starts the night before. When my sleep is solid, shocker, everything feels steadier, my energy, my focus, my mood, you all know what I'm talking about. So your mattress matters. And with birch, I sleep cooler, I sleep deeper. And with a kind of quiet ease that I don't think I really had before, I don't love the idea of spending a third of my life surrounded by synthetic foams or off gassing materials. 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All right. Let's turn to nutrition. Danger zone. No matter what you say, you're going to get shit from people. But I like the fact that you've done a great job of not being reductionist here. You're not talking about any particular diet being the best. And you have a principled approach to how you think about the way we should be thinking about what we put in our mouths. So how do you want to kind of introduce how you think about food? So I think about food in terms of sort of three again kind of interacting features of a diet say. And those are the nutrients, the energy and then the pattern of the way that you eat that allows you to maintain good intake of the nutrients that you need as well as adequate energy intake. In the kind of the modernized westernized world, I think energy availability is probably the right now seems to be the most important lever that we need to consider when it comes to long-term brain health. Mainly because of all the things that we talked about earlier, where we know that there's an increasing rate of prediabetes, metabolic syndrome, these come with high blood sugar, high blood pressure, these are significant risk factors for dementia. We know that people who have metabolic disease have an increased risk of multiple types of dementia. And this is something that really we're at risk at a population level because of the food environment. You do see, and this is relevant to athletes and longevity sort of focus people as well, you see this like bell-shaped curve between the amount of energy that we have in our bodies, amount of energy availability we have in our bodies and the sort of the structure of our brains, something we call brain reserve, which is essentially a fancy way of saying how much brain do you have in your skull and the more the better usually. So at the high end, we know we have lower brain reserve, higher risk of long-term cognitive decline in dementia. We see that based on blood sugar or blood pressure or central adiposity, like a high waist to hip or high waist to height ratio. But we also see the same thing at the low end. And this has come from sort of big population studies across multiple populations around the world, including some hunter-gatherer populations where they don't have access to the kinds of calories that we do. But this is very relevant to sort of like athletes and the longevity groups because you see that if you have low energy availability and you're probably of it maybe you've experienced this yourself or you've experienced it with other athletes you've worked with, we know that low energy availability or relative energy deficiency in sport, Reds or Red S is associated with significant changes in cognitive function, mood, sleep, and it's sort of like the population level, those who have, you know, low energy availability tend to have smaller brains because they just don't have the energy required to maintain that much structure of the brain. So this is relevant for those who are doing very high volumes of exercise, I think, but it's also relevant to those who think that chronic caloric restriction is like some font of longevity. And I think that we have evidence to say that's probably not the case. You need to get enough energy in that you remain weight stable whilst maintaining strength and, you know, strength performance, fitness, all these other things that we know require some amount of energy. So like chronic restriction is potentially going to be bad there in addition to chronic access. It was sort of like attending to our energy needs, then the next important thing, or, you know, which we know is equally important, at least sort of on a global scale, is nutrients that are essential for brain function. So these are all the things I mentioned earlier are the ones that we have the best evidence for. So iron status, vitamin D status, omega three, the B vitamins associated with methylation. So the ones that affect our home assisting level and home assisting goes up as our need for these B vitamins goes up. So if we have inadequate levels, home assisting tends to go up. And so that's B12 folate, B6 and riboflavin, which is B2. And then on top of that, you know, we know there's important things related to antioxidant polyphenols. So the things that make berries purple, like the anthocyanins, or we see similar compounds in coffee and tea, which are associated with a lower risk of dementia, sort of moderate consumption, chocolate, the roasted skins of nuts and seeds have like similar compounds in them. Then there's things like lutein and zeaxanthin that make your peppers and carrots, or make your peppers that are red and yellow. The carotenoids include like beta carotene in carrots. And then things like astaxanthin, which makes salmon and shrimp pink. All of these have sort of like similar benefits. Or in terms of they affect gut function, affect vascular function, and they can improve brain function. There's some of the best evidences for blueberries or like dark berries. Dozens of studies showing both acute and chronic benefits in terms of cognitive function with berry intake. And then some of the antioxidant things like vitamin C, vitamin E, magnesium and zinc crop up frequently as well. All of this to say that I call nutrients the great leveler. Like these nutrients are important. I want you to have enough of them. I don't mind where you get them from. And I don't think I think that matters much less. To your point of not caring where you get them from. Do you care if they come from the whole food versus supplementation? I would prefer if they came from the whole food. And I think the best example of that is seafood. So when we look at omega-3 status and dementia risk, in general, it seems that the epidemiological studies, those who regularly consume seafood have a greater reduction in their dementia risk than those who take omega-3 supplements. That's probably because there's a whole bunch of other stuff in there that's important. So selenium, maybe if you're eating salmon or shrimp, you're getting acids and thin as an antioxidant. And in general, our diets are relatively poor in many of these antioxidants I mentioned. Protein, if you're not getting enough protein in your diet. And there's a whole bunch of other stuff. So there's this nice phrase, which is nutritional dark matter, where it basically acknowledges that 90% of what's in your whole foods, we don't know what it is. And we don't know what it does. There's interesting compounds like ergothionine that you get from mushrooms. That's like the new longevity supplement because it does a bunch of cool things. But we're only just learning about them. So when you get it from the whole food, you're kind of stacking the deck in terms of there's some other stuff in here that may be beneficial too. However, there are studies where if you supplement with omega-3s and you're omega-3 deficient, you see significant improvements in cognitive function and the rate of cognitive decline. There are omega-3s in particular interact with B-vitamin status. So there are multiple studies that show that if you supplement with the mega-3s, but you have poor B-vitamin status, then you don't benefit from the mega-3s and vice versa. If you supplement with B-vitamins, but you have poor omega-3 status, you don't benefit from the B-vitamins. And I think this is where reductionism has gotten us in trouble in supplementation studies, which is that we give thousands of people one supplement and we're like, oh, hey, it doesn't reduce dementia risk. Therefore, it doesn't work. You didn't measure whether they needed it, and you didn't measure the other things that supplement is dependent on. So one of the reasons why I think it's safer to get things from whole foods is because you're getting these other nutrients at the same time. But with that said, if you're somebody who doesn't consume seafood or any other source of long chain omega-3s, I know that there's benefit from you supplementing from it. So that's kind of the approach that I would use. Yeah, yeah, yeah, yeah, that makes sense. I'm going to have more questions about these pillars, but let's get through them. So we talked about energy, we talked about nutrients, and then the other pillar here is pattern. Yeah, pass and is just finding a way that you can achieve adequate energy intake and good nutrient intake in a sustainable way for you, right? That's either what you can afford, what you have access to, what makes sense for you culturally or locally, financially. And I think that there are innumerable ways to skin those cats. It's just making sure that you're kind of hitting those targets in a way that's sustainable for you. So that's why like pattern is that last part because, right, when we take a supplement, we probably usually take it for a month and then we forget to rebuy it, we never take it again. But this is something that's going to be important long term. So finding a way to make this sustainable, enjoyable, nourishing, like that's where pattern really becomes important. Setting aside this diet versus that diet and returning now to this notion of energy, you mentioned that there is a certain cohort of people in the longevity community who are under the impression that chronic underfueling is some secret to unlocking health span extension. But the vast majority of people are overindulging. We're in this world of overabundance. Everybody's eating too much. Everybody is a little overweight, if not a lot overweight. So we can set aside those longevity people and focus on the average person. And one of the things that I thought was really interesting that you said, which is overeating shrinks the brain. So explain that because we're all overeating. Yeah, there's definitely like a step in between. But we know that even in short term overfeeding studies, right, and this is usually done with some version of a Western diet, they add candy bars to the diet, or they make you eat an extra like serving of French toast or waffles every day for like even a week, you can start to see changes in both mood and say, like hippocampal function memory function, this is in humans. This then, you know, long term translates into what we see in the large population studies, which is people who have higher markers of what I call excess energy availability. And so that's essentially the markers of metabolic syndrome. Those are the ones who have the best evidence for so a high waist circumference, low HDL cholesterol, high triglycerides, high blood sugar or high blood pressure. These are all significant risk factors for dementia. And they are direct, measurable effects of chronic excess calorie consumption. They are like the outputs of excess energy. And this is this is what hundreds of millions of people are, you know, if they had their blood worked on, it would reflect those very things. Yes. Depending on which estimate and which data set you have something like 10% of US adults don't have any of any of the components of metabolic syndrome, you need three to five to technically have metabolic syndrome, but probably less than 10% don't have any of them. High blood pressure, elevated LDL, elevated triglycerides, LDL actually isn't in the LDL is one of the modifiable risk factors in the dementia prevention reports about so LDL and cholesterol, apo B are important, but they're not in the metabolic syndrome criteria. Okay, so given the fact that we're overindulging on food and a lot of these foods are we're not overindulging on whole foods, we're overindulging on ultra process foods and just, you know, a bunch of crap. And I know just as somebody who's always trying to make the right choice when I'm not at home where I've control over my food, I'm traveling or, you know, I'm at a restaurant or whatever, like it's very difficult to really eat well because even if you order the salad, there's too much dressing on it or they load it with all kinds of other stuff to because they think that's what people want in order for it to taste good. Like even the healthy choice is compromised. So you're really going against the grain to try to, you know, do the right thing unless you're in your, you know, kind of personal controlled environment. I think that's absolutely right. And the way that I would think about this and think about, you know, everything that we have talked about and we'll talk about today is that as much as possible, you know, control this environment at home, right? So if you, you know, however it is that you eat at home or that you would like to eat, figuring out how you can access those foods, cook them, make them a part of your diet in a sustainable, enjoyable way, right? Or, and it's the same with exercise, right? You have your routine, you play your pickleball, you go and you lift your weights. So that when you do go out into the world and these choices are harder, it matters much less because this stuff integrates over a really long period of time, right? So one meal out doesn't make that much of a difference. And we get to the point where like, I have friends where you, you know, historically you go, you, you know, when you're in this health kind of world, you know, everybody goes out to dinner after a conference and right, everybody's stressed about what they can or should order at the restaurant, right? And I think we want to avoid that because it's a net negative, right? Just like, enjoy the moment with the people and like what you eat that one time makes much less. This is the flip side of, you know, these kinds of conversations because we're basically, you know, pushing people towards this optimization mindset where it's impossible to live up to the standards that are being articulated and that leads to guilt and shame and stress and all these other things that are obviously, you know, across purposes with the aim. Yeah, no. And I think that, you know, a lot of what I write about in the book is the psychology of how we approach this kind of health information because that's exactly what I want to avoid. I don't want people to feel like they're not doing enough. I bring up and we know that people need to do the work, right? We know that you need to find a way to kind of have this sustainable but nourishing diet that gives you the nutrients and that you're not overeating. We know that you need to create some kind of cognitive stimulus so you need to lean into the discomfort. Right? We know that you have to do those things. But if you get to the point where you're constantly feeling like you're not doing enough, you're not doing well enough, you need to do more, that's an inherent stress in its own way that then negatively impacts your health and we have studied to support that as well. So I think it's all about doing what you can and like moving things forward and like improving things over time. But then once you've built a foundation, the occasional thing matters much, much less. And the goal would be to avoid getting really stressed about that. I've spent most of the last three months on the road. I can't eat, I can't work out the way that I would, that I normally would. But I know I can't sleep the way that I normally would. But I know that I've created a good foundation by having, you know, my base at home to do, you know, when I can do these things. And the rest of the time, like the thing when I can't control it, I try not to worry about it because I know that there's not going to affect that worry as well. On the nutrients side of things, you talked about the importance of omega three, B vitamins, antioxidants in the berries, etc. What are some other foods that are brain health promoting that people can just like, oh, I can remember that. And I'll make sure I incorporate that into, you know, tomorrow's dinner. Yeah, my two favorite sort of brain health foods are sardines and blueberries. Don't have to be eating together though it's an option. So like, luckily, if you if you eat a varied, like whole food based diet. So there's a lot of, I talked about interesting structural compounds like choline and ethanolamine, you can get those from eggs, but you can also get them from oats and quinoa and other whole grains similar with like phosphatidol ciri and you can get from and phosphatidol cologne as well, you can get from from soy products. Any of this sort of like colored vegetables are going to give you some smorgasbord of those different antioxidants. We also know that the fiber is really critical right it's going to support gut health. And then sort of fermented foods in that category as well. So sauerkraut, kimchi, fermented dairy, those will sort of like fit into that picture as well. And then like whatever your preferred protein choices are, I think most people probably overeat on the like refined carbohydrate side, like we don't need tons of rice, we don't need tons of pasta. I would focus on the things that sort of those other because they're not particularly both calorie dense and relatively nutrient poor. So focusing on those other areas, I think is going to give is going to make you more satiated as well as giving you sort of more sort of nutrient bank for your buck. As somebody who's been plant based for a very long time, other than the sort of obvious things that I need to be aware of making sure that I'm supplementing with an omega three, what else should I be focused on or thinking about and the B vitamins obviously. Yeah, so those are the two that I'd and you can just measure right. So measure a homocysteine level. The goal is to be at least below 13 ideally below 10. You can measure your omega three status so omega three index at least above six ideally above eight. The other thing where it's just it's common particularly as people get older to not consume enough of it, just make sure you get enough high quality protein, especially as people get older, they get more frail or they experience some metabolic disease that's associated with a faster loss of like muscle mass and strength. And there are randomized controlled trials that show in that that show that increasing the amount of protein you eat to sort of actually what is now the target level in the updated dietary guidelines that's actually in the in the trials is associated with better maintenance of muscle mass in in sort of older in older adults. So that's the only other thing that I would those yeah, so B vitamins omega threes protein are the ones that are maybe easiest to to miss out on the protein recommendations just seem to continue to go up. I can't I've never been eating protein at that threshold level. I think I've always been eating less protein. I still I really don't have trouble putting on muscle mass like I've now recovered enough from a spinal fusion surgery. I have this past spring where I'm in the gym and I'm noticing gains pretty regularly. And I'm not really that focused on protein despite hearing from people like you all the time who are like, you need to be, you know, one gram per body weight, like, I'm way below that. But then I'm, I'm like, is it is it does it matter? I mean, I'm hearing this, obviously, there's evidence to support that I should be thinking about this differently. But I haven't been so there's, well, there's a few, there's a few different parts that get that go into that. So the first is that in the context of a calorie dense nutrient poor diet, we know that protein is a lever for satiety. So people will continue, you know, this is some of Kevin Hall's work, right, people will continue to eat until they they some of it will be some some protein threshold. So one reason to focus on protein is that it's maybe going to help you overeat less, right? That's less of that's not that's not an issue for you, but a population level that can be important. It's also particularly important as people start to age and experience frailty or sarcopenia, right? That's the context that I was talking about earlier. Again, that's not as relevant to you. But I'm at that age where it is harder, you know, and you're just like, well, this is taking a little bit longer, you know, like, so maybe I should be, you know, focused on my protein. You do see that in older adults and now people in their 60s, if they consume again, at that sort of level of protein, so like 50 to 100% above what was like the previous dietary guidelines. So that was 0.8 grams per kilo of body weight. Now we kind of think targeting 1.2 to 1.6 grams per kilo of body weight. At that level, you also have higher like antioxidant status, which we know is important in terms of dementia risk factors is important for recovering from exercise as well. And then you write as you get older, like, even if you're doing everything right, you're more likely to experience anabolic resistance where you just need a greater protein signal or more of a training signal to kind of benefit from that exercise. So it's probably worth, you know, considering increasing intake up to somewhere in that kind of range. The, but the final thing I was going to say is that when it comes to muscle mass and strength, the most important thing is still stimulus, right? So yes, eating more protein will prevent you losing muscle mass. If you're not, if you're not regularly doing some kind of resistance training, but resistance training is still going to be the most important thing. But, you know, as you get older, I think that requirements are going to, are going to increase a bit. On the topic of Omega threes, I've had, I couldn't even count how many conversations with people like yourself sitting across the table, you know, discussing the finer points of, you know, how to supplement properly. And to this day, I will admit that I still don't quite under, like there's DHEA and there's DHA and there's EPA. And like, I still don't understand, like when I'm looking at a supplement, like what are the levels I'm supposed to be looking for? How do these things interact? And as a plant-based person, what maybe should I be thinking about that an omnivore isn't in terms of the effectiveness of the supplement? Interestingly, I would say that the majority of omnivores probably aren't eating enough Omega threes either, right? Because they're just like people just aren't eating that much seafood. So I think this is relevant to most people, regardless. I will say that we, and by we, I mean, like well-meaning, health-focused scientists like me, I think we've overcomplicated it a little bit, right? So the two main Omega threes that we might think about are DHEA and EPA. There's also things like DPA, which occurs in sort of smaller quantities. Here we go. Oh yeah, right. So like, but, but what I'll say is that, like all of these are important, most Omega threes supplements are going to contain DHEA and EPA at a minimum, right? And that's where we have some evidence from like giving people these supplements. If you're not regularly consuming seafood, any kind of supplement, you know, and assuming like high quality, you get it from a good quality manufacturer, right? Because these things can be poorly processed and they become rancid and oxidized and things like that. You know, assuming it's a reasonable quality supplement from a respected manufacturer. Something that gives you one to four grams of total DHEA and EPA a day is probably good enough. Format is much less like people have talked about triglyceride form versus phospholipid form and you get one in seafood and you get another in like sort of krill and things like that. Or this is high in this, but it doesn't convert like there's this conversion thing. Yes. Oh yeah. So the conversion part is the is the shorter chain of Omega three fatty acids like ALA, alpha linolenic acid, which is what you get in like chia seeds and walnuts and things like that. Most people and actually the conversion is worse in men on average than it is in women. Most people, if you only get Omega threes in that form, most people won't convert enough into the long chain form. So that's why you need to supplement. But I think in general, if you're getting a couple of grams of long chain Omega threes from a high quality supplement on average a day, right? That's it. I wouldn't worry so much about the ratios. I wouldn't worry so much about the total amounts because you're then going to be ticking the boxes that you're close enough and you're also well beyond what most people are consuming. Then the easiest thing that you can do is measure something like an Omega three index, which just measures the amount of those in your blood and say, am I close enough to a level that we know is associated with lower dementia risk, which would be sort of six to eight percent or like above six percent, maybe ideally above eight percent. So maybe that simplified it a little bit. I think that we know that DHA and EPA are both important. You're going to get both from any supplement. The real problem is people consuming none. Like once you get to the threshold of consuming some like more than a gram a day on average, right? You're already like in a much better bucket than most other people. We're tiptoeing towards a longer discussion around supplements and what's effective and what isn't, what's nonsense. But before we do that, while we're still on food, let's talk a little bit about the worst defenders. Obviously, we know ultra process foods aren't good for us. But what are some maybe less intuitively bad things that we should avoid? You'll notice that I work really hard to not demonize anything in particular because it makes things tricky cognitively for people and like nothing is black and white. So I'll give one broad example, which is that the levels of home assisting in the U.S. in general, particularly high home assisting, which is a sort of above 13, which is associated with increased risk of dementia, that significantly improved since we started to fortify flour with photocacid in 1998. Heavily processed foods can almost be beneficial in one way because it allows us to add back nutrients that the population is missing. But in general, I think anything that's full of refined fat or refined carbohydrate that's so calorie dense and nutrient poor. So that's kind of all of the baked goods, snack goods, things that are very easy to overeat and are designed for that to be the case. It's not that you can't include these and it's not like I avoid those things completely. But you have to think about them in that goal of overall energy balance and nutrient intake. So like you're eating more of those things, you're sort of like pulling away from your nutrient goals and you're also kind of heading towards the risk of overeating. So that kind of, yeah, the heavily processed carbohydrates and fats are usually where things get trickiest. So fried foods, baked goods, sweet sodas, sugar sweet and sodas, that kind of stuff. Then a big trap that's now easy to fall into is when something's hey, eat these protein, they're like Doritos or eat this protein candy bar. It's still a candy bar. They've added a little bit more protein, but it's not getting to the point where it's actually going to meaningfully move the needle and you're very likely to overeat it. Same for, hey, these brownies are keto or these brownies are plant-based or vegan, right? They're still brownies, right? Yeah, and they still have 900 calories or something like that. Setting aside the keto thing, like sugar. I mean, you can kind of, I know you don't want to vilify any one thing, but is there really a place for refined sugar in any kind of healthy diet? In the context of all those other things, like occasionally consuming sugar is fine, right? But you have to maintain those other components. And it's likely that if you're consuming sugar at the level that's going to be associated with overeating and these other like metabolic health conditions, you're very unlikely attending to those two things. So it is possible to occasionally consume sugar, being a good energy state and overall have a very nutrient-dense diet. It's just that the more you shift in that direction, the harder those things become. So I will occasionally eat dessert. I'm not that physically sweet too, so I don't eat a ton of it, right? But because I know I've got those other things handled, I'm less concerned about it. So what you often see is that, particularly as you get to like processed or packaged foods, something will be sold as like low sugar, but it's still energy dense, it's still nutrient-poor. So like, it becomes a thing where we think, oh, there's no sugar in this, but actually, it doesn't make it any healthier. So that's why, again, we've become kind of over reductionist. So not something that I think that you have to completely avoid, but the more you're consuming on it, the less you're likely to kind of hit those other things that we know are critically important. Sure. One of the things that you see in the longevity community online is this notion like, oh, if you've been really good and then suddenly you have a dessert, it's like, oh, I feel awful and I couldn't sleep tonight. And it's like, how resilient are you actually if you're so dysregulated by this one kind of like indulgence? I think that's a really important point. And my guess is that, so yeah, we know that you've got microbiome will kind of adapt to the foods that you regularly give it. So like, I had family members who were vegetarian for a long period of time and then it's sort of harder for them to eat meat later because their body just hasn't adapted to it. Right. And we know that there's some shifts that can happen in the gut to kind of support that. And so the same might be for large boluses of sugar. But I think a lot of where that comes from is because, and we've made this worse with the advent of like continuous glucose monitors and stuff like that, is you're like, I know this is bad and I expect it to be bad and therefore I feel bad because of it. Whereas if instead we thought, I'm just going to very occasionally, I'm going to enjoy this, I'm just going to enjoy it. I think you would experience a very different physiological effects from it. Which gets into mindset and the role that mindset plays in all of this, which you talk about in the book as well. Yeah, the so one example that we'll have that you can use here is a study by Ellen Langer, which looked at diabetics and brought them into the lab. And because they're diabetic, they're obviously very cognizant of their sugar and carbohydrate intake. They brought individuals into the lab and they gave them a milkshake and they like, look at the nutrients on this milkshake. There was a high sugar milkshake and a low sugar milkshake. And then they measured their blood sugar. And the blood sugar was much higher after the high sugar milkshake than the low sugar milkshake. Like, of course, as you'd expect, the problem is this is the same milkshake. So the stress of anticipating a blood sugar spike, which they know is going to affect their health, right, drove their blood sugar up even higher. And so this is, you know, every time we approach anything like this, and we think about, this is going to be, this is going to be bad for me. This is going to be, you know, you might get some benefit, it's going to be good for you. But in general, we see that if we think something's going to be good for us, it has like a neutral effect. If we think something's going to be bad for us, it has like a negative effect. This then translates to all the other ways that we can think about health information. So I mentioned earlier that thinking that you're constantly not doing enough can negatively impact your health. And there are some studies that suggest that when you ask people how much exercise they're doing compared to people like them, and you look at those who think they're doing less than, less exercise than people like them as much exercise as people like them or more exercise than people like them. People who think they're doing more exercise than people like them tend to live longer and they have better cognitive function. However, this is after you adjust for how much exercise these people are actually doing, and they have like, they use like activity monitors, right? So is this, and the people who think they're doing less end up having like worse health effects. So if you're just a narcissistic sociopath who thinks you're better than everybody, there's something screwed up about that. That's true. It's like your mind is creating your reality. And if you're like, I'm doing great, then you are creating, you know, your own version of greatness. Yeah, to an extent. So there is some benefit of this sort of like ignorance is bliss almost, right? So like, this is the, and you've already said this, like, this is the risk that we run by sort of overanalyzing health and lifestyle. Because everybody's walking around, let's face it, everybody's walking around thinking they're not doing enough and they're falling short. If you have a social media account and any kind of fitness or nutrition stuff happens to come up, we're all judging ourselves against some imaginary standard that we're not even close to living up to. So every choice that we make is a choice of falling short of what we feel like we should or could be doing. And so when you aggregate that over time, what is that doing to our mindset? We're always in a place of lack. When you look at things like self-compassion, which you can break down into multiple components of self-kindness, mindfulness and common humanity, you see that, and this is relevant again to like athletes and to like the health of the general population, athletes who are more self-compassionate tend to be more resilient and tend to perform better over long periods of time because they understand the nature of setbacks. They understand that we're just humans and they treat themselves like they would treat other people. And then that allows them to learn, do better, come back and perform again. People who are self-compassionate in the chronic disease setting tend to have better health outcomes for the same reason, right? They understand that, oh, you know, I didn't necessarily eat the way I would normally do, or that I didn't sleep or exercise the way I normally would. But do you know what? I'm human, I'm going to come back and I'm going to do it better next time. And like overall, they tend to see, you know, when they do interventions that improve self-compassion, they tend to see better health outcomes, so like better blood sugar and blood pressure in diabetics who are kind of taught about self-compassion. So what we're kind of told, which is that we always need to do better, we always need to be telling ourselves we're not doing enough, we always need to be pushing through, right? It's actually the exact opposite of what creates a sustainable and well-being supporting mindset, which is that, yes, I know I can improve, yes, I know there are these things that I can do, and I'm going to celebrate the wit, like my wins, I'm going to celebrate, I'm going to enjoy that feeling of discomfort, I'm going to enjoy the fact that these things are improving, but acknowledge that you can't make everything perfect, you can't optimize everything. And, you know, we'll slowly get better over time. And then not only are you engaging with the things that you know will improve your health, but you're also maximizing the likelihood that you'll benefit from them because you're not spending the rest of your time beating yourself up, that you're not doing even more. I feel like you just said the quiet part out loud, and perhaps the most under-appreciated aspect of all of this, not just for brain health, but overall health. In this epidemic of loneliness and isolation and disconnection and, you know, kind of a decline in our overall, you know, mental health on a population level, a lot of it stems towards this sense that we're not enough, you know, that we're not good enough. And, you know, we have to go out and, you know, earn belonging and acceptance. And perhaps the greatest lever for longevity and brain health is adopting a loving kindness meditation practice. Like, yeah, we could talk about omega-3s, but if you hate yourself and you think you're, you know, nothing's ever going to work out and so-and-so is always going to have more, whatever, you know, whatever negative frame that you perceive the world, you can supplement with as much DHA and EPA as you want. But ultimately, you're kind of driving yourself towards the grave as much as it is a counter-intuitive concept that, like, the most successful athlete is the most self-compassionate athlete. Because you do think, like, well, it's the person who's like, I'm, you know, I'm never satisfied and, like, I'm just hard driving. And that's all coming from that place of lack and not feeling enough, right? Like this compulsion to compete from that negative frame as opposed to, like, this is awesome and I'm doing it from a place of joy and self-honoring, you know? So it's a mental health issue as much as it's a physiological issue. Yeah, this is why, you know, so much of the book focused on the psychological aspects, because I think that, like you said, the things that are important, we already have some intuition about, right? Maybe reframing cognitive stimulus is really important, but, like, we know exercise is important, we know that diet is important, right? We know it's not an information problem. Yeah, it's not an information problem. It's how we approach that information, how we speak into ourselves, how we engage with that information and applying it to ourselves. Because, you know, we've been told that, you know, if only we weren't so, if only we weren't so lazy, we could look a certain way or perform a certain way. But it's really, it's really not about that. It's all about how we're treating ourselves that even allows us to start to engage with that information in a way that will benefit us, but also that makes it sustainable and supports well-being and, you know, hopefully belonging and purpose and meaning and all these other things as well. Because I guarantee that the best way to minimize your risk of dementia is not sit at home by yourself chugging supplements, despite what some people are trying to sell to us. It's going to be much more about how you're treating yourself and how you're interacting with others that then allows you to do some of these things almost naturally. It is the western frame of mind, though, that the solution is in a pill or a capsule, this sort of shirking of taking personal responsibility. Like, if I just eat this or I take this stack, right, then it will take care of it for me, as opposed to what you're advising and what your book is all about, which is shouldering personal responsibility for a lifetime commitment towards the principles and the pillars, like the foundational aspects of what drive health. Even beyond that, I think that we can almost think about shouldering as societal responsibility for that as well. Because the people who have the time and the resources and the ability to think about taking the supplements to hack their way into better brain health, they might not realize it, but they're already at such a privileged and advantaged position when it comes to their long-term dementia risk. Because we know that socioeconomic status and deprivation and not having access to education and healthcare, these are some of the biggest drivers of long-term dementia risk. So not only is it, how do we treat ourselves and how do we engage with this and shoulder some personal responsibility? But I think that we could even expand it beyond that to how are we engaging with society in a way that minimizes or improves this risk for other people who maybe don't have the same kind of access and availability and time to do some of these things. Let's do a little truth-telling around supplementation. Responsible supplementation has its place. What can you tell us about what's effective versus the perception of what's effective? Well, the first thing you could say is that if you think it's going to help you, it might. That's an Ellen Langer. It's all about Ellen Langer. There was a point when my editor told me that I referenced too many Ellen Langer studies in my book, so I had to take a couple of them out. But why not? I say more Ellen Langer. She's amazing. Yeah, incredible. I'm absolutely one of my all-time favorite scientists. But where I think we have solid evidence is essentially the stuff that we've already talked about is attending to nutrient status for nutrients that we know are critical for brain health that are either deficient or insufficient in the diet. And we know that the majority of adults around the world are deficient in at least one nutrient. So finding some way to attend to that. So it's supplement to a vitamin D if you need. So if somebody is to go and get a blood panel done, what are the markers that you would like them to pay attention to? Again, the ones that we have the best evidence for. So vitamin D, you definitely don't want to be deficient, which is less than 20 nanograms per mil. But ideally, or at least above 30, probably above 40 is best, 40 to 60 is probably a good target range. I was below and I started sort of megalozing on vitamin D. And then my levels were way too high. And I was struggling to sleep. And then I realized, oh, excess vitamin D can impair sleep. And so yeah, this is, and I say this just because more is not always better. And you have to really gauge how you're managing your supplementation, even if you're trying to make up for a shortage or a low level. Yeah, absolutely. So and vitamin D is one of the ones where it's because it's fat soluble, it's easy to take too much, especially if you're taking several thousand daily for long periods of time. So yeah, definitely get above 20, maybe target 40 to 60. Home assisting for B vitamins. Like I said, definitely less than 30, ideally less than 10. And if home assisting is elevated, then those B vitamins I mentioned earlier, the ones that they usually give in clinical trials is B12 and folate. But you might also add B6 and riboflavin. Other things that can bring down home assisting might include creatine, betaine or trimethylglycine, potentially choline too. Then you might think about that, you know, are you, do you have a diet that includes those things, right? Betaine is high in beets and choline is high in eggs and creatine is high in meat and fish. Right. So that might help help you sort of like target any supplementation if you need it. Iron status is really critical. So you would normally just measure hemoglobin level, but then there are a whole bunch of iron metrics that you take along the side to kind of help you interpret it. So like ferritin, transferrin saturation, iron binding capacity. But ideally sort of women want their hemoglobin to be at least above 12.5 men, 13.5. But not too high. So if you're if you're in like men, a hemoglobin above 17 or in women, a hemoglobin above 16, makes it much more likely that you have something like, especially if you're older or you have some elements of metabolic syndrome, makes it likely that you have something like obstructive sleep apnea. When you stop breathing during the night, your oxygen levels drop and your body makes more hemoglobin in response. So because we know obstructive sleep apnea and other sleep disordered breathing is a risk factor for dementia. Another reason to check your hemoglobin is because of the high end and that's something that you need to address as well. Yeah, we already talked about omega three status. So omega three index, if you can get it, doctors will do most of the other things that I mentioned. You can just get like an at home test for omega three index, if you can't get it through your physician. So at least above six, ideally above 8%. And then other things that they're important, it can be harder to test. So like it's really hard to test magnesium status, for example, but magnesium tends to be something that people don't get much of or get enough of. And we know that people who sweat a lot or who are athletes tend to need more magnesium. So a safe recommendation is often to think about magnesium supplement, especially if you're an athlete. So particularly for people who struggle with sleep, there's increasing evidence that taking magnesium at night can help to improve sleep. Other things, especially as we sort of get into some element of ageing or cognitive decline, there's some evidence for choline, which I've already previously mentioned, that may be beneficial. But even even then, that's sort of like well apart from those others, I think that the kind of the core vitamins are where we have the nutrients, where we have have the best evidence. Then beyond that, it might become very context dependent. And there's very few things that I would give a blanket recommendation for. If you're getting those blood tests, you're addressing those nutrient requirements. And then you're also testing your blood pressure, testing your blood sugar, testing your cardiovascular risk through your lipids. That's the big bulk of risk right there. Anything else is going to be like you said, sort of like cherry on the top. Creatine has been in the news lately. It went from being this thing that only bodybuilders use to sort of mainstream adoption, but in limited amounts, five grams a day, maybe 10 grams a day. Now we're seeing this science emerge around the relationship between creatine intake and brain health. And every time I open up my social media feed, the daily recommended intake increases. It was 10, then it was 20. I've seen people saying you should be taking 30 grams of this a day. What say you, sir? So creatine is the only supplement outside of those vitamins and minerals that I mentioned that I actually mentioned in my book. Not because I don't think it's magic, but there is an increasing burden of evidence that it does interesting things for the brain. There's some studies after concussion where it may improve recovery. There's studies in the setting of particularly in older adults or those who started to experience cognitive decline, creatine supplementation may improve memory in particular. It seems to help improve cognitive function in the setting of sleep deprivation. And now there are several trials where they've added creatine to antidepressants in the setting of treating depression and it seems to provide additional benefit. So I think it does lots of interesting things for the brain. It's also the best studied supplement. And because 5 to 10 grams of creatine, which is a fairly standard dose, even 5 grams of long-term standard dose, you could achieve that through diet. You'd have to eat a fair amount of steak and salmon, but it's certainly possible. So we know that it's very safe and we know that it has very few side effects. So if you're thinking about supplements, I often think of this idea of positive asymmetry. So where is their potential for benefit with very low downside other than the cost to your wallet? So in terms of dose, actually some of the first study that looked at creatine in the setting of sleep deprivation was in rugby players. And they looked at rugby specific skills after in the setting of sleep deprivation, they compared caffeine and creatine. And a standard dose of creatine, 5 to 10 grams, depending on body weight, right? So a smaller person would take 5 grams, a larger person would take 10 grams, or somewhere in between, was enough to see to see benefit. In some of the depression trials, again, they're using 5 to 10 grams. Some of them using 5 grams and seeing benefit. In the like the one most recent sleep deprivation trial, which is the one that got a lot of press where people were sort of kept awake for a night and then they were given, they were given creatine and it showed that it helped maintain their cognitive function in the setting of sleep deprivation. I think they were using 0.3 grams for kilo. So that's where something like me would take 30 grams. But you know, something like you might take 20 grams. So that's where like this dose escalation is happening. In if you look at studies where you're looking at creatine levels in the brain, you start seeing significant increases in brain creatine at sort of like loading type doses. So that's that kind of like 0.3 grams per kilo per day for, you know, a week or more. So that's like, you know, 20 to 30 grams a day. However, some of the evidence of benefit in things that are related to brain function seem to happen at much lower levels. So I'm not convinced that everybody needs to take 30 grams of creatine a day because I have evidence from other studies that actually maybe even at 5 grams, people are starting to see benefit. So the way I kind of approach it right now is the general, I would generally recommend 0.1 grams per kilo. So I take 10 grams every day. And then yes, if you're very stressed or sleep deprived, maybe you could try increasing the dose. So for me, as it is for some people, not everybody, creatine is quite alerting, like it feels like a very, very mild stimulant without making me jittery, like I've had a bunch of coffee. So I can't take creatine late in the day because I don't sleep as well. But like if I haven't slept well, I might double my dose for the day. But that's not like a long term thing. So I think the standard dose is actually where people will start to see some benefit. And then maybe in edge cases, and I expect much more research in Alzheimer's disease and other things to come, then maybe, you know, higher doses will end up being better. I can't let you go without talking about sleep. On some level, we all know this already. It's like, we need to be getting eight hours of sleep. We need to be practicing good sleep hygiene. Clearly, sleep is just absolutely foundational to brain health. And I've had plenty of guests share, you know, the sort of detoxing process, the clearing out that occurs overnight. What can you add to this or stress about the importance of sleep with respect to ensuring your brain's health? So that we don't like rehash old ground in terms of mechanisms, like I think the main takeaway is that sleep is when all the information, all the skills, all the things you've learned, the new synapse you've generated, which your brain is constantly generating, the ones that are important, they are cemented and refined during sleep. That's kind of there. There's a synergistic effect between REM sleep and deep sleep that allows the synapses to be kind of perfected for one of a better word based on the previous day's input and integrated into everything we've experienced already. There's also sleep is also really important for emotional processing and other things like REM sleep in particular. And then, right, you're washing out amyloid and other things that accumulate during the day, during deep sleep, but also just sleep in general through the lymphatic system. So we know that people who don't sleep enough long term have a higher risk of dementia. The risk really seems to tick up in people who are chronically sleeping less than six hours a night, which is probably lower than most people might expect. In general, I think people say eight hours, but in reality, depending on person to person, and it changes over time, the window is more like seven to nine, maybe even six to 10 hours, based on how much sleep people need. So you're waking up the next day, you're feeling refreshed, you feel good, you're probably getting enough sleep regardless of what it was. Things to consider, how we think about our sleep is also really important. So people know all about the sleep routine, why sleep is important. In addition to the sleep time, sleep quality is critical. So usually when we think about poor sleep quality, we know it's associated with increased risk of dementia. The way that we measure that is usually by asking people, do you take something to help you sleep? And those who take things to help them sleep tend to have a higher risk of dementia. That's probably because of a downstream effect of the things that they're taking. So are you drinking alcohol to get to sleep? Are you taking anti-estimines like Benadryl to get to sleep? Are you taking these like Ambien to get to sleep? There is probably a combination of issues that are causing insomnia in the first place that haven't been dealt with, plus the effect of those medications themselves, if we consider alcohol self-medication, that negatively impact our sleep. And that's probably why contributing to long-term increased dementia risk. So alcohol creates a REM sleep deficiency in general. If you're using alcohol to counteract all the caffeine that you drank during the day because you didn't sleep well the night before, which is a very common sort of vicious cycle, then caffeine can also impair deep sleep in particular. So if you're still drinking caffeine in the afternoon, then having a glass of wine to help you fall asleep, right? There's sort of like a double whammy effect there. Ambien seems to negatively affect various aspects of neuroplasticity, which you can see, this is mainly from animal studies, but then the anti-estimines, because they're anti-cholinergic and astylcholine, which they sort of influence the function of, is really important part of long-term cognitive function. Those anti-estimines that make you drowsy, we know if you take those regularly, that's associated with increased risk of dementia. So thinking about, are you using those things to go to sleep? If you require those things to go to sleep, first of all, you're not necessarily asleep. You might just be unconscious. That's not the same thing. It's a facsimile of sleep. Yeah, exactly. It's resembling sleep. Any kind of like pharma intervention to produce sleep isn't actually producing sleep. And if it feels like sleep, it's still, the sleep is not doing the job that sleep is supposed to be doing. There are some new drugs that are maybe changing that. But equally, people who have insomnia, the required architecture to get good quality sleep is still there. It's just that the environment and the cognitive processes around sleep, like they either don't feel safe or they're unable to wind down such that you can produce sleep. So that's where things like cognitive behavioral therapy for insomnia, CBTI, can become important. That's where the sleep environment can become important again, we can become dependent on those medications. So you might need expert help to overcome that, but your sleep isn't broken. You just need to like retrain yourself up. The final thing that I think is worth mentioning is that for many people, we've kind of swung too far in the other direction when it comes to sleep. And the sort of like the hyper focus on wearable data and this idea of orthosomnia, where we become so focused on wearable and like our sleep metrics become the target. Whereas the target should be that you get a restful night of sleep because it allows you to do all these other amazing things. It's the new garment. Like, oh, if it's not tracked, I didn't actually sleep last night or I wake up and I don't know what to do with myself. I mean, I have a whoop, I love it. I definitely check it every morning, but I try to have an arms length relationship with how I let that data impact me. I still have to live my day. And if it's all in the red, what is that doing to my mind in terms of how I'm problem solving and approaching those problems and making sure that I maintain a positive mindset? Would I be better off had I not known that I was in the red? From an Ellen Langer perspective, if I like, I feel great, you know, and I think I have a healthy relationship with that, but I can see how that becomes problematic for people and it becomes a, you know, like a neurosis. You know, there's one classic Ellen Langer study. She wasn't the senior author. The senior author was Steven Lockley, because he's a circadian biologist at Harvard, but they collaborated on a study where they had people come into the lab and they were randomized to sleep either for five hours or eight hours. But in classic Ellen Langer style, they manipulated clock time, right? So they changed how long people thought they'd slept relative to how they actually slept. And what they found was that how long you thought you slept was a better predictor of how you felt the next and perform the next day than how you actually slept. So the example being people who slept for five hours, but thought they had slept for eight hours, didn't experience any impact on their function the next day. And there are other studies that have used wearable data to manipulate this, like, hey, you slept terribly last night, even if they slept fine, how fatigued they feel the next day is based on how well they think they slept. This is important because wearables aren't great at actually detecting the quality of your sleep. They can tell you how long you're asleep for pretty well, but telling you whether you were in like deep sleep versus REM sleep, they're really not that good at that. And this is like published data that are out there. So when they use those sleep stages to tell you something about your recovery score, your sleep score the next morning, you're using quite low quality data to tell you how you should feel that day. So the way that I've used this with professional athletes, and they're lucky because I work with their coaches who can sort of oversee this stuff on a day to day basis, I would usually have the athlete, the athlete doesn't see the data, but the coach sees the data, and they use that to look at trends over time, which are probably more accurate than like individual pieces of data. So then we can integrate it and kind of change things if we need to. If you can create, I think you create like a cognitive distance from the data, but like, I think you can also create a temporal distance from the data because you don't need to know how you slept last night in order to be able to perform today, because you have to perform today regardless, or you have to go about your day regardless. Review, like a week later, go back and review the past week. Yeah, especially if you can then say, oh yeah, I didn't sleep that well that night, but that was the night where I went to bed late, or that was the night where I had an extra beer before bed, or that was the night where I had a coffee in the afternoon, right? So you can still use those data to inform important things, but you're not allowing it to influence how you then, you know, perform on a daily basis. Speaking of the relationship between the rest itself and your kind of mental relationship with the rest, this is something that is kind of an important issue in the world of Formula One, and you've, you know, played a role in working with some of those athletes because they're just literally going across the world every week. I mean, the time zone shifts are insane. So what have you learned about working with those athletes and how have you counseled them? Some things that I've learned, and which were surprising to me at the time, but maybe shouldn't have been, is that the basics, particularly when it comes to rest and recovery, the basics still matter. So I've had athletes come to me and say, oh yeah, I'm looking at my wearable data, I'm worried I'm not getting enough REM sleep as an example. And I look through the data and it's very clear why they're spending five hours in bed. If you spend five hours in bed, we know that most of your REM sleep happens at the end of the night, you're going to get less REM sleep. First of all, is that REM sleep number that accurate? Hard to tell. But second of all, like the most important thing for getting a good quality night of sleep is getting enough sleep opportunity, which just means spending enough time in bed ready to sleep. And you see this again and again, like when there's issues with sleep, it's the athletes aren't giving themselves the time and opportunity to get high quality rest. Of course, some of that comes from a travel schedule and things like that. So you kind of have to take that into account. But when they are able to build those routines or maintain those routines or maintain the things that help support sleep at home, whilst they're traveling, they can maintain a much better quality of sleep. Something that we do, so I do all my Formula One work through a company called Hints of Performance. And they, you know, so we work with the coaches as well. And the coaches sort of like inserted into the life of the driver, they're doing the training program, they're doing the nutrition, they're like traveling with them the whole time, they hold the helmet, hold the umbrella, like they're there the whole time. We'll often do things like jet lag plans. So can we start to have them shift their circadian rhythm before they travel? So it's starting to manipulate caffeine and light and sleep time and food timing a day or two before they travel, you know, so that they're closer to the target time when they get there. And there are a number of apps that kind of allow you to do that. Now there's one called Phase that was developed by one of these F1 coaches, because he was so used to having to do this on a daily basis. He's now kind of created something that people can use themselves. But then sort of like the bigger overarching thing is that again, like the rest of us, they struggle to just, right, they're getting plenty of stimulation, right? They have very complex jobs, like driving the car, they're getting lots of inputs doing that, but then they also have media commitments, they have meetings with engineers, they're constantly giving feedback on how the car drives, right? This is all very cognitively stimulating stuff. So for them, it's finding ways, like I was saying earlier, sort of like in that kind of age where they are made 20s, 30s, 40s, where you're doing a lot of stuff with your brain, it's how can you find time to kind of relax and down regularly? So for them, it's all about how can we give them space, how can we give them time to improve and recover? And that's the message that I hear from them most frequently is like, how can I recover better? How can I switch off? How can I just get some downtime because the demands on them are so high? So then there's all this stuff around sleep schedules, but then it's just finding things that allow them to truly switch off in a sort of a sustainable, regular way. And for some of them, it's meditation or breathwork practices, although most of the times when you say to a 20-year-old, hey, you should meditate more, like you just get a funny look. And similarly... The receptive athlete is the athlete in the sunset of their career who's looking to extend another year or two. They're all about it. The young ones, they're like, no, no. And young athletes in general can do a lot, quote unquote, wrong and still put your skill at home well. I will say that the young generation of athletes is miles ahead of what the young athletes were like 20, 30 years ago. They're very into finding that extra edge with these very types of things. Absolutely. And this is so because we have a... Well, it hints as this whole driver development pathway. So some of it is about instilling some of these things early on so that it's much easier to make those habits and sustain them once you're in the F1 kind of world. All right. So I want you to imagine the... I don't know, 35 to 55-year-old person who is listening to this or watching this. And they're thinking, I've been eating the standard American diet for 30, 40 years. Yeah, my aunt or my... What parent is experiencing dementia? I don't want that to happen to me. But I've kind of like cast my vote already. When is it too late? Is it too late? Give that person a reason to take what you're offering urgently. The short answer is it's never too late. And actually, this was one of the things I was going to say about sleep. There was an interesting study done by Matthew Walker where they looked at sleep trajectories in people across their lifetime and then looked at the burn of amyloid and tau proteins in their brain, sort of like part of that, the process of dementia. And they found that people who'd improved their sleep later in life, so even if it was in their 50s or 60s or 70s, if your sleep improved, that was associated with the lower burn of later amyloid in the brain. All of that saying, because people ask, well, I spent all this time, I was young, I had kids, I was busy, I didn't sleep that well. Did I already do this damages are undoable? And on a sleep perspective, at least from that study, it kind of suggests, no, it's not. And we see that then across all of these different areas. So there are now multiple studies where the best evidence probably comes from multi-intervention approaches. So the most famous one is FINGER was run in Finland. It was just repeated here in the US. That study was called Poynter. Lots of other studies around the world have done something essentially similar. But what they do is they address cardiovascular risk, they have people start a new exercise training program with some resistance and aerobic exercise, they have them improve their diet quality. And then there's some other pieces. Sometimes there's like a stress reduction component. But just starting to attend to some of these basics, and this is either in people who are at high risk of dementia or starting to experience some decline already. And actually, you see bigger benefits, who tend to see bigger benefits in people who may be starting to see some decline, not that they've gotten a diagnosis of dementia, but maybe they're already below the average in terms of cognitive function. And you can see this within sort of like six to 12 months of just starting to attend some of these basics once you're already in your 60s and 70s. So if you start even earlier, right, you start in your 30s, 40s, 50s, you potentially have 20 years to change this trajectory. Another example might be when you look at cognitive changes that happen during perimenopause, the menopausal transition in women, which is in that kind of towards the mid to latter part of that time window that you mentioned, we see that a greater cognitive changes tend to be experienced in those who have some element of say metabolic disease. So the swan study in the US showed that. So again, we know that changing your diet, changing your physical activity, addressing cardiovascular risk factors, then affect your the severity of metabolic syndrome related components that you can you can improve blood pressure, you can improve blood sugar. And, you know, doing that at that time period could potentially like completely change that trajectory. So all of that to say, like wherever you are in that window, even if you're beyond that 55 years old, there's still scope to change that trajectory. That is incredibly empowering and and speaks to the unbelievable resilience of the human being. Yeah, like it is kind of amazing. But reflecting on how we kind of opened this podcast with this notion that 45 and you say up to 70% of dementia cases are preventable. And here we are talking about, you know, people who are kind of tiptoeing into that, and there's still the opportunity to halt it, reverse some of the symptomology or like stave off, you know, this, this, this, you know, kind of terrible future. Why isn't this something that everyone is shouting from the mountaintops? Like so many people are suffering from this just absolute horrible affliction that is devastating to families. Like, I feel like this is a message that needs to get out there and should be being repeated constantly, you know, you can avoid this. Here's the way to do this. Why is this the conversation that we're not having all the time? I'll, I'll, like, before I get into that, I'll quickly say that that 70% number wasn't something that I made up. That was another analysis that was done by Professor Junta, you are using UK Biobank data. So a big data set more than half a million people in the UK, they estimated the upper end of dementia that may be preventable is over 70%. So again, just like a similar way, you do a big statistical analysis, and that's the kind of number that comes out. So like, regardless of where the truth is in that, in that range, whatever it ends up being, right, that's still a huge number of dementias that are potentially preventable. Of course, we're talking at the population level, right, we can't, and we're talking about statistics and probabilities. I'm not saying that you could definitely prevent any individual person from, from getting dementia, but we know we can dramatically decrease our risk. So I'm, I'm really hopeful that the conversation is changing. Like, over the last two or three years in particular, like, especially a lot of people struggled with their brains after COVID, either due to, you know, long COVID or the effects of lockdown and everything, how that changed, you know, the, the sort of like our lifestyle and our environment. And since, you know, the, since the last sort of two or three years, people have been talking about brain health more and more and more. And so I see it out there, you know, they're mentioning Jill Livingston's work and they're mentioning some of these analyses and they're saying that, you know, it's not too late, you know, things like the point of trial that was just published last year. So I agree that we're not saying it enough. And I agree that we should be hopeful if we're able to engage at this on a personal level, and then ideally make changes at a societal level as well. But I think that tide is changing. So I hope that, you know, you and I speak in a year or two and you'd be like, oh, yeah, you're right. You know, people are talking about this more and more and people are realizing they have so much more agency here. And so I hope it's going that direction. And it certainly seems like people are starting to go that way. That's very exciting. Yeah. So maybe to conclude the conversation, it would be good if you could, you know, even like look right to camera is like, what do you want people to know? Like, somebody's listening to this, I've never heard anything like this before. Oh, my goodness, you know, I now am going to take greater agency over these decisions that I'm going to make. I certainly don't want to have this kind of thing happen to me. How do I begin? And how can you kind of leave them with an empowering message about how to embark upon this journey? Sure. So the thing that I want everybody to know is that we each have a huge amount of control over our long term cognitive trajectory. And we can dramatically decrease our risk of dementia, even if we have a family history of dementia, or, you know, know people with dementia. And the best way to start to do this is just to find one thing that you know you can start to move the needle on that feels doable to you. And so it could be slight changes to your diet. It could be adding a new aspect to your exercise routine. It could be going to your doctor and getting your blood pressure checked and treating it if you need to think about the risk factors for other people that you know, or in your family who had dementia that you might share with them. That's always a great place to start to know that because all the different factors that affect brain health interact with one another, when you start to change one thing, the whole network will start to shift to your favor. Amen. I love it. To the audience, I want to say we covered a lot of ground today. And it may feel like, hey, we didn't drill down enough on this, that or the other thing. Well, the good news is you can find all the particulars in Tommy's new book, The Stimulated Mind, out now. Again, I'll say what I said at the outset, like this is a real public service and your work is vital. Brain health obviously impacts all of us. Very few people are untouched by the diseases of cognitive decline. And so I urgently impress upon everybody who's watching and listening to pick up the book and take your brain health more seriously. So thank you for your time today. Thanks so much for having me. And I hope everybody found this useful.