#339 7 Habits a Neuroscientist Swears By to Keep Your Mind Sharp at Any Age | Dr Tommy Wood| Dr Tommy Wood

Dr Rupy: According to the Lancet, 45% of dementias are preventable. For someone hearing that for the first time, how should they unpack that?

Dr Tommy Wood: This is a really important thing to think about because when people hear this for the first time, it often brings up a mixture of feelings, especially if they have a history of dementia or they know somebody who's experienced dementia. People may think that when we say that, we're assigning blame to people who had dementia previously, right, they did something, they did something wrong, which is absolutely not the case. This is not, having dementia is not anybody's fault. But what it means essentially is that when you look at all the risk factors for dementia that may be modifiable at either the individual or the population level, you can do some statistical analyses to estimate if one particular risk factor was completely eliminated from the population, what proportion of dementias would no longer happen. And when you look at all the individual percentages, they add up to 45% in the in the Lancet Commission report. So it's like 7% based on education, and then two or 3% based on individual things like obesity, high blood pressure, hearing loss, brain trauma, smoking, alcohol. And it is a slightly artificial way of thinking about it because each individual risk factor, if you only have one, you're probably unlikely to get dementia. They they really do interact and stack up on top of each other. We see that from from several studies that the more healthy lifestyle factors you have, the lower your risk of dementia. But it's a way of sort of framing and understanding at a population level how these different risk factors affect dementia risk. So then, really the goal is first for people to understand they can dramatically reduce their dementia risk. Probably about half of those modifiable factors we think are truly modifiable at the individual level, or you know, about half of that 45%. And some would require societal change, particularly say education status. So we know that education is protective against dementia, but not everybody gets the same access to to certain types of or certain levels of education.

Dr Rupy: If if I'm a listener, right, particularly to a listener listener to this podcast, I'm probably thinking, well, touch wood I don't have high blood pressure. I definitely don't smoke. I don't drink that much alcohol at all. My diet's pretty clean. Am I at the top end of what's possible in terms of reducing my risk? Or are there things in addition to some of those risk factors that have been isolated by the Lancet Commission and the UK Biobank data studies that can give me extra protection?

Dr Tommy Wood: Some of the ones that you've mentioned are obviously like the heavy hitters, right? So we know that high blood pressure and high blood sugar are two of the most important risk factors for future dementia. We know that diet quality and nutrient density and hitting intake of of certain critical nutrients is really is really important. And physical activity is critical too. And the biggest impact happens when you go from being sedentary to doing any kind of movement. But there are a number of other risk factors that people could consider. So things like periodontal disease is increasingly being seen as a risk factor. Air pollution is one, so you can think about air quality, water quality, which we may have more or less control over. Then there's things like as we get older, and this is really what I've started to focus on more and more is thinking about how we use our brains. And the the way that we use our brains is the primary driver of how our brains function. It's just like our physical bodies, how we use our bodies determines how our bodies function. And we can support those processes through nutrition and sleep and all these other factors that that are important. But thinking about how we use our brains, how we engage with the world, challenge our brains to improve and maintain function, which in sort of modern society, we tend to as we get older, do less and less with our brains. We offload things to other people. We specialise and we no longer sort of put ourselves out there in terms of failing and learning like we do when we're at school. And that's why education is is so beneficial for the brain. So that's probably a big area that that people might start to start to think about.

Dr Rupy: As you were talking about failing, I was just thinking about my son, who's 15 months old, and there is no stopping him after he's failed. So like, you know, he's just learned to walk and he's jumping on the sofa and he's falling off and, you know, he'll hurt himself, he'll start crying, but like five minutes later, he'll be trying to do the same thing. So it's that it's that mindset of like constantly going for it even when you fail. Like we at a sort of like beaten out of us on a on a grander level as we get older, right? But there is this myth that we were talking about before that, you know, when you hit a certain age, you deteriorate and it's almost like a given that you are going to deteriorate. But what you're saying and particularly in your book as well is that you can navigate that and you can mitigate against this idea that that we just get old and crumbly and we use our faculties.

Dr Tommy Wood: So I think this is the one of the most important takeaways from the idea that dementia is is preventable, right? Is that if we can modify that trajectory, then we must be having some major impact on how our brain is functioning when we're older. And one of the reasons why I think that the 45% estimate may be conservative in terms of dimensions that may be preventable is that there were some risk factors, particularly late life cognitive stimulation, which we have good evidence for changing the trajectory of of cognitive decline and improving cognitive function, and sleep, those those were not and and poor sleep, those were not included as modifiable risk factors when I think we have enough evidence to say that they are. So when you look at how society thinks about the aging brain, a lot of it is tied to the the reasons why we instituted retirement as sort of like a a thing that everybody does, right? They get to a certain age and they retire. And this was largely popularised by Sir William Osler in the early 20th century. He's famous for making an address at John's Hopkins where he says that at 60 years old, the adults are essentially useless, that's his word, and they should be put out to pasture, right? We need to get them out of the workforce. To be fair, at that time, and this is in, right, this is in America, he's a Canadian physician, then became professor of medicine at Oxford. At the time, life expectancy, average life expectancy in the US was about sort of late 50s. So the average 60 year old was was probably not in great health. And of course, that was balanced by, you know, higher infant mortality and all those other things that drag the average, um, you know, average life expectancy down. But we've kind of internalised this idea as a society over the last 120 years that as you get older, you will inevitably lose function. You will essentially at some point you'll become useless and you have to sort of be put to the side. Whereas in traditional modern societies, that wasn't the case, right? We always, you know, there was you had a role regardless of how old you were. And the problem with that idea, and I I'm I'm not saying that nobody should be allowed to retire. Like if you've had a you've had a long career and you know, you can you you deserve the the fruits of that of that career. But you have to make sure that you remain cognitively engaged and cognitively stimulated because you see in multiple population studies that retirement is the time at which cognitive decline accelerates most rapidly, especially in those who retire early, just because of the important like social and cognitive stimulation we get we get from work. But when we think that we're going to lose function as we get older, we start to do things that will accelerate that. So there's this idea of stereotype embodiment theory, which basically means that there's a stereotype of what aging is, which is a loss of, you know, physical and cognitive function. And if we expect that to happen, we stop engaging in the things that will prevent that from happening, and therefore it becomes a self-fulfilling prophecy. So it's it's kind of at least partly driven by what we expect and we expect less of ourselves as we get older. But there are dozens of studies using a wide range of interventions from physical activity to cognitive training to dietary changes that show that cognitive function can improve even in people in their 60s and 70s as long as they start to engage in those processes. So we have actually a lot of agency and power over the ability to change the adult brain and even the older adult brain has significant capacity for neuroplasticity and learning and improving function. We just have to engage in the processes that drive that.

Dr Rupy: Yeah, I love that. I want to dive into some of these strategies. But before we go too deep in the weeds, I just want to bring people up to speed with this idea of dementia and exactly what we mean because we're going to be, I certainly am going to be using this word interchangeably quite a bit today, cognitive decline, dementia. So when we say dementia, what are we largely referring to?

Dr Tommy Wood: So dementia is a clinical diagnosis for a significant loss of cognitive function where it gets to the point where you're unable to look after yourself on a day-to-day basis. That's sort of a simple definition. There are multiple different causes of dementia, although I will say that the field is increasingly realising that they're they're probably less distinct than we than we first thought. But people will probably be familiar with Alzheimer's disease. That makes up 60 to 80% of dementias. Vascular dementia, which is where you have diseased blood vessels in the brain that affects, you know, blood flow and inflammation in the brain. That makes up something like 10 to 20%. So between Alzheimer's disease and vascular disease, we're talking 70 to 90% of dementia. And when we're talking about preventable cases of dementia, they largely fall into those into that into that bucket. Other less common causes of dementia include frontotemporal dementia, dementia with Lewy bodies or Lewy body dementia, dementia that's associated with Parkinson's disease. They may they're sort of within the bucket that's right now is potentially less, or we we understand them less well, certainly so and some of the risk factors, although many of the risk factors for those dementias do seem to overlap a little bit with with the other risk factors. But really when we're talking about the the preventable dementias, it largely falls into that sort of bigger grouping of Alzheimer's and vascular dementia.

Dr Rupy: Got you. So with that broader picture, let's go down into the promise of this episode because I don't want it to just be about prevention of dementia because that's like, you know, we're all attracted to something immediate. And you know, this premise is something like pushing something further down the line, it's not as attractive, even though it's super, super important as we'd both agree. But people also want to stay sharp today, right? And and I know you've talked about this before where the benefits of what we're about to talk about can be felt almost immediately, you know, within within weeks. So with that in mind, let let's go through some strategies and talk about the fundamentals of of brain protection. What would you start with?

Dr Tommy Wood: You're absolutely right that humans are very bad at working towards some unknown future goal, especially when we're talking about preventing something. So like, you do all this hard work and the the benefit is in something not happening, right? And and so it's it's hard for us to wrap our heads around that, especially when we're talking about probabilities, right? I'm just trying to decrease the probability of something that might happen in 40 years time. What's cool then for me is that the things that we can do to improve cognitive function and, you know, reduce brain fog or fatigue right now, those same things are the things that that decrease the risk of dementia long term. So you can see immediate benefit, which then means you're more likely to stick with it. When I think about how to approach that, I have a a model for the the various components of lifestyle and the environment that are the biggest contributors to to cognitive function. And this is this this comes from a wide range of different types of work that I do. So I study how to treat the injured newborn brain and, you know, improve brain development. I study how to treat or prevent traumatic brain injuries and concussions, how to improve or you know, work to try and improve cognitive function and performance in elite athletes in in Formula 1 in particular. And then increasingly also looking at how that affects long-term cognitive function and cognitive decline. And you basically see these same things popping up again and again and again. So kind of telling us that there's these critical foundations to brain health and cognitive function that that we can lean on wherever we are in that trajectory. And so this is what I call the 3S model. The 3S's are stimulus or supply and support. So stimulus really is the the bucket of how you like like I said earlier, how you use your brain determines how it functions. And so then this is related to learning, complex skill development, social interaction, doing these things that we as humans have done for for centuries, millennia, complex skills that require multiple sensory inputs, that require complex social interaction, music, language, different types of movement that require us to strategize and interact with others and respond to the environment, like ball sports and team sports. And these are the things that that really seem to even though they they sound they can they can sound quite different, right? I compare music to to languages to actually there was even evidence for video games having some of these same benefits and like visual arts like painting. They all seem to have these very similar benefits in terms of the networks in the brain that are susceptible to aging, like the frontal parietal network, which is important for like attention and memory. So we if we do these complex skills and we, you know, we learn them, engage with them, we take the opportunity for failure because failure and mistakes are actually what drive neuroplasticity, which like you kind of alluded to is is is a bit of an issue because we we like beat out of people the the the willingness to to engage with something new and fail. Like adults, we hate failing, especially if somebody else is going to see us like fail. But like that's really what that's really what drives learning, that's what drives neuroplasticity is that discomfort. There's a the the gap between what you're trying to do and what you're currently capable of. That's what that's what drives these sort of processes in the brain that are important important for building and maintaining function. So I I relate that to and the process is very similar to you know, physical strength or or physical fitness. So if you want to get bigger and stronger, then you have to lift weights in the gym or you know, something equivalent. You can improve the your ability to to get the most out of your workout with a, you know, good diet and sleep and all these other things, you know, focusing on recovery. But unfortunately, you can't just drink a bunch of protein shakes and nap and then have bigger biceps, right? You have to go and do do some work. And and the brain is essentially the same, right? So so using our brain is what drives these processes. So that's the the stimulus bucket. When you activate certain regions of the brain or networks in the brain with some kind of cognitive task, those areas of the brain ask for more blood flow, right? There's this thing called neurovascular coupling. The the astrocytes and the neurons in that area get those blood vessels to widen, bring in more blood flow because you need more oxygen. And this is where vascular health, cardiovascular health is really critical, healthy blood vessels are really important. And heart disease risk factors and dementia risk factors have huge amounts of overlap. And actually, even though we talk about Alzheimer's disease and vascular dementia, the majority of individuals who have Alzheimer's disease do have evidence of vascular disease or blood vessel disease in their in their brains. So there's there's quite a lot of overlap. There's a lot of there's a lot of overlap, yeah. So that's where, you know, heart health is really important. Then, uh, sort of physical metabolic health, blood sugar regulation is important because you need to be able to deliver energy for those areas of the of the of the brain to run. And then you need critical nutrients, vitamin D, omega-3s, B vitamins that sort of allow the brain to do what it does. So that's kind of the supply bucket. And then when you stimulate an area of the brain, it brings in all the required resources, you adapt and improve function during rest and recovery. Again, very similar to to physical training, right? You don't get stronger in the gym, you get stronger when you recover afterwards. And so the majority of this happens during sleep. But um, also requires you to take enough breaks, maybe even during the day to just like give yourself a minute to reset, especially if you're going to do focused hard cognitive work. And then, um, so this is now we're in the support bucket. So sleep is a big part. Um, there are other aspects that are important for supporting the brain. So, um, hormone status can be important. Um, there are a whole bunch of factors that are are released by the rest of the body that we call trophic factors that can kind of support the the growth of of new connections in the brain. Um, so things like brain derived neurotrophic factor, which is released during exercise. And then the final part of the support bucket is avoiding things that sort of inhibit that adaptation process. So that's um, smoking, alcohol, we talked about air pollution, um, other causes of sort of chronic inflammation. So that's where gum disease can become an issue. Um, as well as um, chronic stress that impairs the ability to sort of like really switch off and and um, and and recover. And you see a very interesting kind of, you know, if we if we stick with the sort of the physical training comparison, you see like an overtraining picture in the brain when you're chronically stressed because you never get the ability to sort of like switch off and and recover. So those are the those are the three main buckets. And then in reality, they all kind of they all interact. So the reason why I think of it as this sort of um, network of three areas that have kind of common mechanisms is because they affect one another. So that means that you might be able to identify one or two areas that feel like they're the areas where you can make you you have you know, the most to gain. You know, it's most worth your time and investment. Um, because if I gave you a list of 50 things to do, you will do zero things, right? We we we know that. So, what's also very cool though is that when you change one thing and you think about this as this sort of like network of factors, the whole network shifts. So a a great example is sleep. When you sleep better, especially if you're not sleeping enough for long periods of time, we know your blood sugar improves, your blood pressure improves, you feel more social the next day, you know, social interaction is important. You are you're more likely to engage in cognitively challenging tasks because we avoid them when we're when we're fatigued. Um, similarly, if you do, um, if you start to exercise, then then you sleep better and you improve blood pressure and blood sugar and so like so it only really takes one change to start to see a big shift and you can kind of appreciate that when you think about it as these sort of like network of factors. But then that allows each of us to think, oh yeah, that's well that that one thing that he said that kind of resonates with me. And that's one area where, you know, investing a few extra minutes in a day, you know, could have a big impact.

Dr Rupy: Absolutely. So I love how you set that up with the 3S's, stimulate, supply, support. And it's almost like you've given us a smorgasbord of, you know, things to choose. Have I said that word right? Because I know you're Yeah, smorgasbord, yeah. You're Icelandic, right? That's your background. Yeah, yeah. I don't want to get that wrong. I think smorgasbord is Swedish, but yeah. It's Swedish. Yeah, yeah, yeah, yeah. Sorry, I just lump you all together up there. All those Nordic. Yeah, yeah. So you've given us a selection of all these different things that we could try. If you if you were using the 80/20 model, right? Because you're right, if we had 50 things, we're going to get paralysis by by by choice and and overwhelm. What do you think is like a non-negotiable? If you if the listener is going to do one thing and one do one thing really well, obviously you want them to do as many as possible, what would that be?

Dr Tommy Wood: I would pick some kind of new sport or physical activity that includes a social component, that includes complex motor skills and includes strategy and planning on like you know, rapid rapid responses. Because as we get older, we lose all of those things. And one of the things that we lose as we as we age is processing speed, which is rapidly processing information because like how often do we really have to like take something in in a few hundred milliseconds and respond to it? You only really see that in the setting of something like um, sports or you know, computer games. Um, and both both can can do the job there. Or now there are like formal brain training programs that that do have some evidence behind them that that can do the same thing. But if you do that, you if you pick one of those kinds of activities, you tick multiple boxes at the same time. You're improving cardiovascular health. Um, many of them include like varying levels of intensity. We know that intensity can be important for physical activity. Like any physical activity is great, but adding some intensity can be important. Um, and then right, you're you you create a cognitive stimulus on top of like the physical stimulus. And there are several studies that show that when you match activities for the level of physical intensity, if you have one that has an additional cognitive component, so you compare like jogging or cycling to badminton or table tennis, the badminton and table tennis have a slightly bigger impact on cognitive function because it requires some of these additional skills. So then it could be anything, right? So dancing has a huge amount of evidence to support it improving cognitive function, um, associated with a lower risk of dementia, improving mood, right? A big effect size in uh, randomized control trials for depression. But um, yeah, all the all the ball sports, um, so you play football, table tennis, um, badminton, paddle in the in the US, pickleball is is really um, uh, is really popular. And actually pickleball has a very complicated scoring system. Does it? Um, so like that's that's another it's like another layer on top. Yeah, yeah, exactly. Um, or, you know, martial arts, you know, ideally not getting like punched in the head a bunch, but you know, you know, any sort of but that's the same thing, right? You're you're kind of having to you know, it's it's very physically strenuous, but you're having to like strategize and respond to to to the other individual. But probably like board sports as well, skiing, snowboarding, surfing, skating, um, anything that requires you to sort of really rapidly respond to the environment and learn complex skills, ideally if done in um, in a social setting, I think that's going to have additional benefit. Um, and then I think one reason why dancing is is uh, so impactful is because it has like music laid on top of that. So you have to kind of like process and attend to the music, which has, you know, um, you know, activates other areas of the brain. But any of those, I think if I was going to pick one thing, it's those tick so many boxes that I think that's a really sort of high impact way to start.

Dr Rupy: I'm definitely getting the the vibe that it's uh, it's the communal aspect. So let's say someone is a jogger or like they like to go for a run and they're like, look, I don't really do paddle, like, you know, last time I did paddle, I smashed something and this actually happened to me. I've hurt my arm and I couldn't do any of my strength training for a while. So it kind of put me off paddle. But maybe a jogger could join a run group or something. So you have that you have that added layer of social connection.

Dr Tommy Wood: Yeah, so, um, there are and there are ways that you could expand beyond that. So I'm thinking about when I lived in London, I did there was this, I don't know if it exists anymore, this thing called like rat race where you'd like you'd you'd go and you'd run around the city and then like as a group and then at different points you do some like other kinds of exercises, like you'd walk up and you like lunge up and down stairs or like do push-ups and burpees and like different. And so I think that kind of thing could could layer on some of those additional benefits. You have the social component, it's a bit more varied. Um, and that maybe that's a that's a way to build out. But even just starting with a running club, great, because you're sort of, you know, meeting other people and and um, and getting some of those some of those uh, benefits. But equally, maybe maybe you've decided that you're training, you know, you train alone, um, doing some of these sort of unimodal type exercises, running, weightlifting. And you're like, that's good for me. I don't you know, I don't want to add more there. So then I might think about, well, can you learn a language? What about a musical instrument? You know, there are um, any kind of new complex skill that you can learn, um, will give you some of those benefits. So you don't have to completely overhaul your training program if you don't want to. There are so many ways that you can that you can skin this cat.

Dr Rupy: And also, for those of you listening to this, I'm I'm across the table from Dr Tommy Wood and he does not look like he just does running. He's got massive biceps. So I'm assuming there's some element of like strength and weight training that is also important for the brain as well that you would you would suggest.

Dr Tommy Wood: Yes, so yes, I would. I I will say that I have often come up against people who say, well, you know, I don't want to have to look like you or like, right? And which is fine. I completely understand, right? I do way more strength training than would be required to to support brain health. And I acknowledge that, right? And so my sport is strongman, which I compete in. There's a great local community in Seattle where I live. Strongman, what's strongman? Yeah, so have you ever watched world's strongest man? Like pulling trucks, lifting rocks, boulders, logs. It's basically that but for for less large people. I was going to say you don't like so so we so we compete we compete in weight classes and now and now because I'm over 40, I complete compete in like the old guy category. Um, but and which which you you have to do or else I would just get completely get completely crushed. Um, but it's a it's like a really nice community. Some of the strongest people in America actually live in Seattle, reigning America's strongest man is there, you know, a number of other like national champions. Um, and so, so yeah, uh, it's pulling trucks, lifting logs, lifting rocks, that that kind of stuff. It's a lot it's a lot of fun. And I like it because it's um, it is very varied and I have to learn new skills while I do it. And it's it's not as complex as learning how to dance of course. Um, but it um, it sort of gives me a little bit of that. Um, but yes, so some resistance training or weight training of some kind, I think is really important because not only are muscle mass and strength really critical to maintain long-term overall function. And we know that um, falls and you know, loss of function that sort of leaves you um, housebound or you know, less likely to go out. All of these significantly increase the risk of dementia because you're unable to to get those stimuli from from other people. So you need to maintain some high level of function and you will lose some as you get older. So the the more you can build earlier in life and the harder you can work to maintain it, you know, the better. But beyond that, there seem to be specific benefits uh for the brain from from resistance training that are different from aerobic type exercise. And when you look at aerobic exercise, it seems to be particularly beneficial for the gray matter of the brain. So like that's like the wrinkly outside and includes um, parts inside like the hippocampus, which is really critical for for memory and it's a high risk in in dementia. Um, and so all the like randomized control trials where they have people do some kind of aerobic exercise and it could be brisk walking if they've been sedentary previously. If they're more physically active, they've done like higher intensity, like high intensity interval training is shown been shown to have significant benefits for the hippocampus. But it's particularly benefits the gray matter and benefits memory. Resistance training, um, because I think you know, different types of exercise release different things. I mentioned these trophic factors, myokines or exokines that are released during exercise that can have effects in the brain. What are those? Um, yeah, they're basically, uh, what we've realised, you know, as a, you know, scientific community over the last 10 or 20 years is that your muscles are an organ. They're not just like structural tissue that are, you know, there to fill a t-shirt. Um, they release these factors. So if they're if they're released from muscle, they're called myokines um, during exercise. Myokines are part of a like part of a bigger group of um, compounds or molecules called exokines that are released by, you know, other organs in the body during exercise. So the liver releases some some exokines, bone releases some some exokines like osteocalcin when you load it. So like you're doing some kind of um, resistance training, right, with some weight, you're adding additional load to the bone, the bone releases factors that can then go and have um, benefits in the brain. Got you. And so one of those with resistance training is IGF-1, insulin-like growth factor one, which is really critical for the development and function of white matter. So white matter makes up about 60% of the human brain. And it kind of sits underneath the wrinkly outer cortex, um, and it's responsible for all our fast connections, right, between different parts of the brain and between the brain and the body. It's what allows us to have, you know, complex language, complex decision making, some something we, you know, we might in neuroscience call executive function. Um, and where you in all these different areas I mentioned earlier that I work in, IGF-1 is seems to be really critical. So in particular, um, babies who are born pre-term, they are at a high risk of white matter injury and their white matter not developing properly. And the main reason for that is because they lose the IGF-1 that's provided by the placenta while they're, you know, in utero, in like in the womb. Um, and if you can find ways to replenish that, and there were some studies that people are doing that, they think that's going to improve that that white matter development because they're at risk of things like cerebral palsy, which is a an injury to the white matter. So as we get older, loss of function and structure of white matter is one of the best predictors of cognitive decline. Um, actually maybe even better than some of the other more traditional uh predictors of Alzheimer's disease and dementia. It sort of tracks um, more closely. And so when you do resistance training, you release IGF-1 and there are randomized control trials that show that resistance training improves the structure and function of white matter even in older adults and and what comes with that is improved executive function and rapid decision making. So all of that kind of lines up. Um, the minimum effective dose seems to be one to two sessions per week, can be done in like 30 to 45 minutes. We're talking the most basic training like type of training program, you know, anybody could do in any kind of any kind of gym, six to eight exercises that cover the whole body, three sets of eight to 12 repetitions. That's that's it. That's enough to have a significant effect on brain structure, brain function. Um, you could do it at home with whatever you've got lying around, you could do it with bands, um, you could get some adjustable dumbbells. Um, you can pick up your kids, your wife, your dogs, like I I did that during COVID. I was squatting with my wife and my dogs because, you know, we couldn't get to a gym. Um, so any of any of that, it's it's a relatively accessible and easily doable minimum effective dose that it's worth adding on to any kind of running or other kind of program that you might have.

Dr Rupy: That's amazing. And in your and and sorry, before I ask my next question, just quickly, when people start doing that very basic exercise, how quickly can they feel the benefits on on white matter and executive function?

Dr Tommy Wood: So the the trials that that show significant benefit that sustained, they they usually last several months. So probably at least probably at least, you know, we we wrote a paper kind of summarizing the evidence of this a couple of years ago and we kind of said, twice a week for six months is probably where we're confident you start to see some some benefits. But we do know actually with any kind of um exercise, you can get an immediate cognitive boost um, as long as it's not exhausting exercise, as long as you don't like completely like destroy yourself. So you can get some benefit from it straight away. Plus resistance training is particularly good for things like blood sugar control. Uh if you're doing, it can also help with blood pressure. Um, so you'll probably get some smaller like immediate benefits, but in order to like really change the brain, then it's probably going to take a few months.

Dr Rupy: Got you. Okay. But but the I think the important point to underline there for people who want that immediacy is you can feel the benefits as long as you're not like going really pushing and overtraining, you can feel these benefits in in the short term.

Dr Tommy Wood: Yeah, yeah. The same with same with most exercise. Um, as as long as it's not exhausting, like resistance training and aerobic training, you usually get a cognitive boost for like the the hour or two afterwards. And then there are some studies that show that if you exercise the day before and then especially if you sleep, you know, reasonably well that evening, you get an additional cognitive benefit the next day.

Dr Rupy: Amazing. And in your book, you have a lovely beginner's guide of exercises that people can try um, initially if they're not used to doing it, um, that will give them that full body. What what are some of those exercises that you added?

Dr Tommy Wood: Yeah, so, um, basically like five or six exercises that you can do. Um, one is uh, some kind of some kind of squat, um, or it could be a lunge. Um, and if if people pre-order my book, actually there's a video where I go through all of these things and I show like different different options of it. Um, and so you can just do this with whatever you have at home. I I like I get a backpack, I fill it with books, right? That's a decent, that's a decent weight that you can use for a squat or a lunge or something like that. Um, and then some kind of pushing motion. Um, so, you know, this would usually be some kind of push-up. Could be against a wall if you're starting and then sort of like the lower your hands get to the floor, right, the harder it gets. Um, if you're stronger than that, you might put your feet up on something, right? That that adds a level of challenge. You can do it on your knees. Again, just to sort of hit that kind of eight to 12 rep rep range. Then some kind of pulling motion. Um, this can be trickier at home, but you can like again, grab a bag full of books, you can grab, you know, a big water bottle or, you know, we sort of like in the US we have these big like gallon gallon milk jugs that you can fill you can fill with water like so you can use something like that. Um, but then another nice option that that I really like is to get some um, resistance bands that cost 20 or 30 quid. Yeah. Get something with with a door anchor. So if you look up like resistance bands with with handles and a door anchor, um, then that allows you to kind of anchor the weight against the door so you can do like a a pulling motion downwards or a rowing motion, which is which is which is really nice. Make makes that really accessible. And then you can use that for uh, shoulder presses and which would be the next exercise. And again, any kind of weight you can use there. Um, and then so I so I do a a squat, some kind of pressing, yeah, some kind of like horizontal press, some kind of vertical press, so like a chest press, shoulder press, some kind of rowing or pulling motion. And then I then some kind of carry. Um, so like pick something up and carry it. You can carry it in front of you, you can carry it at your sides, could be shopping bags, could be a box. You know, so like I think in my video I get a plastic box, I have a like a a sandbag because we have we were doing some some work in the garden. So I I threw the sandbag in the box and I carried that, right? And that that's actually really hard. Um, and you just like carry it for like 20 or 30 seconds. But so like any kind of weight that you can carry for for that kind of time. And and because of picking up the box, you're doing a kind of a hinging motion that's really important. You know, being able to pick stuff up. And when you think across like all those different um, exercises, you're working all the muscles that you need to have some strength in for just like day-to-day activities. That's that's kind of that's kind of the goal. Um, so those five things I would usually if you're doing it at home, do it in some kind of circuit back to back, do that three times through, might take 20 minutes.

Dr Rupy: Yeah, sounds great. Um, just on the I just want to get nerdy for a little bit. Uh, and then we'll get we'll go back to 30,000 foot view. Uh, with the exokines that you mentioned, so you got myokines, you got osteocalcin. BDNF gets a lot of like attention right now. Are these things having an impact on brain derived neurotrophic factor? Is that how it works or is there something else going on in the brain when you exercise?

Dr Tommy Wood: Yeah, so BDNF, brain derived neurotrophic factor is separate from some of those other things. Um, although osteocalcin may increase BDNF production in the brain. Um, BDNF is really interesting. It's also slightly complicated. So, um, when you do any kind of exercise, BDNF is increased. You can measure it in the blood. Lots of studies do this. And then people say, well, you know, you've increased BDNF in the blood, this is good for the brain, right? You're supporting and what BDNF does is it supports the function of neurons that have been recently activated. So if you're, you know, learning, challenging yourself, like the networks of the brain that you're using, like BDNF preferentially kind of supports those. But the issue is that the BDNF that is produced in the body during exercise that you measure in the blood doesn't really get into the brain. So it's doing things like it improves muscle function, it's it's great for a whole bunch of stuff, but it's not directly working in the brain. Okay. Um, the there is a there is a critical messenger between the body during exercise and the brain for BDNF, which is lactate. So everybody like thinks like lactate is a bad thing during exercise, right? It it causes acid and the burn and all that kind of stuff. And actually none of that is none of that is true. Like yes, you are building up acid in the muscles. Yes, they do burn, but and lactate and lactate does accumulate at the same time, but it's actually part of a buffer system and it's and it's a really important messenger. So this is when remember earlier I said that intensity was important and this seems to be this seems to be why. There was a one of the best exercise studies that I think has ever been done in terms of when it comes to to brain function was published in 2024 by an Australian group. And they randomized older adults again sort of like in their 60s on average to three different groups. They had a control group that was sort of didn't really do any additional activity. They had like a jogging group. So 40 to 45 minutes of jogging three times a week. And then they had a high intensity interval training group, um, who did something called the Norwegian 4x4 protocol. Oh gosh. Um, if never attempted those. Yeah, so what it is and you're you're realize why just said oh gosh. Um is uh, so it's four minutes at 85 to 95% of maximum heart rate on a treadmill. Then so in this study, normally it's a so it's like a three to five minute break depending on the study. In this study they had a three-minute break. And they did that four times over. So 4x4, four minutes times four. They did this three times a week for six months. For six months. Which is incredible that anybody so like anytime you talk to somebody who's familiar with this protocol, they're like, I can't believe they did this for for for six months.

Dr Rupy: I jump on the bike and I'll go and I'll try and do one and a half minutes with a I give myself two minutes as a break and then I repeat. And I can do about three or four of those, but I'm but I'll do that once a week.

Dr Tommy Wood: So so what I will say is that I think that is great too. So you probably need only need to do this kind of work once a week. Anything that like gets you working really hard. Sure. Right? And so that the harder you work, the longer your rest periods need to be, right? Because like the goal really is to just generate lactate. And so like the kind of protocol that you just described will generate plenty of lactate. You'll you'll you'll get you'll get the effect. So like the the problem when I talk about one specific protocol and one specific study, we're like, oh, that's the protocol we have to do. But you really don't. Like anything that you do that kind of gives you that burn, like you know you're kind of like that's great. You're you're you're doing the the right kind of thing. Um, but in this study, when they looked at the two exercise groups, the the jogging group and the the high intensity interval training group, they both improved fitness by about the same amount. Oh. Um, which is surprising, right? Because you might think that the hit group would get would get a bigger benefit. But when they then looked at the structure and function of the hippocampus, right, MRI scans, cognitive function tests, uh, yes, there was some benefit to the jogging, but there was a much bigger benefit to the high intensity interval training group. Um, and it wasn't just related to improvements in fitness. And the best explanation that I think we have is is the things that get released during very intense exercise, which lactate is the one that we understand best. There are other things as well. But we know that lactate, the more lactate you have in your blood, the more lactate gets into the brain. There are there are transporters, the monocarboxylate transporters for anybody who's who's, you know, wants to get nerdy. They basically allow free flow of lactate into the brain. Okay. And when lactate is in the brain, it switches on the production of BDNF. Right. So lactate is then this critical messenger between higher intensity exercise and BDNF production in the brain that has, you know, so in this study, right, so significant improvements in structure and function of the hippocampus after six months, and that benefit was maintained for five years. They came back five years later. Five years. And those individuals still had benefit and they they went back to their previous. They weren't doing like They weren't like nobody does six months of the Norwegian 4x4 and is like, oh yeah, I want to do more of that. So they went they went back to the the previous levels of physical activity and still had benefits five years later. Um, so, so and I think lactate is is providing a lot of that benefit.

Dr Rupy: That's super impressive. Wow. And I think that's a a really important reframing for lactate because yeah, we we tend to see it as a waste molecule, is that it's not, but it's a signaling molecule and it's super, super important. Are there any benefits of actually measuring one's lactate um, you know, outside of an acute setting?

Dr Tommy Wood: Yeah, I my my guess is probably not. I think if you're, you know, there are there are a whole bunch of different hit and sprint protocols that are associated with improvements like acutely in terms of cognitive function and then um, you know, some have been looked at uh, longer term. But like you if you do a an all-out six-second sprint, you immediately see cognitive benefits, right? And there are studies where they do 30 seconds of all-out sprints with four and a half minutes rest in between, they do that six times. Again, you see an immediate benefit in terms of cognitive function. Some of it is probably just because you're like a little bit more aroused, right? And arousal is really important for like focus and attention. Um, but some of the studies that have looked at that sort of correlated the amount of lactate that was produced with with like an immediate boost in cognitive function. So I I think if you're kind of doing something that makes you work hard and you do that a few times and you feel sort of like a little bit, you know, you're pretty out of breath, um, if not just like but not like completely destroyed, you're pro like you're probably fine. Most of these studies, you're ending up in sort of like the low double digits of lactate. So if you are measuring it, you're like 10 to 12 or 14 millimolar of lactate. But I think most people just don't need to don't need to measure it. Like just go out and work hard for a bit, enjoy the burn and know that it's kind of it's it's having some of those additional benefits.

Dr Rupy: Yeah, I mean if you've ever done any of those exercises, you'll know. You'll know you're you're generating a lot of lactate. Um, okay, great. Uh, I want to move us away from exercise and stimulation because I we could definitely talk a lot more about this and language learning and and all the rest of it. Uh, let's talk about supply. Um, so obviously our bias is food and supplying nutrients to the brain. Um, you mentioned a couple already like vitamin D. Um, in terms of like again, the selection of nutrients that we should be considering and the holistic picture of our diet being blood sugar balancing, what are some of the key nutrients that you would call out for folks and and where we would get that from from food as well as supplements if you like?

Dr Tommy Wood: So, when it comes to looking at risk of cognitive decline, brain atrophy, dementia, um, based on nutrient status and some of these then have been slowed or potentially reversed with with interventions, you know, generally supplements based on a requirement. Then the the big ones are vitamin D, omega-3s, um, the B vitamins that affect methylation, um, and the way that this is generally determined is uh, an increase in homocysteine levels in the blood. So homocysteine, high homocysteine says that there's something in the methylation system that requires an additional, you know, an additional nutrient and it's usually um, folate or B12, but it can also be riboflavin and um, B6. So those B vitamins. Then iron status is critical. Um, so being anemic is associated with an increased risk of dementia. Um, and iron status is particularly critical for women in that sort of perimenopausal, menopausal transition. Um, and often the cognitive symptoms that they experience is related to low iron status. Um, so measuring, you know, measuring and addressing that if needed. Um, those are like the big ones. Then additional things that become important because of, you know, the effect neurotransmitters or the, you know, production of um, you know, other sort of important compounds in the brain, you know, magnesium and zinc. Um, then additional things just because of what the brain needs to do and and be able to to recover recover from. So like the antioxidant polyphenols are critical. So both those like the anthocyanins that you find in berries and so many very cool randomized control trials of berry interventions showing significant improvements both acutely and long-term in cognitive function. Um, and then, you know, similar compounds that you would get from tea, you know, tea and coffee and actually the roasted skins of nuts and seeds, they generate actually very very similar, very similar compounds. Um, plus then, you know, the the sort of like the oranges and reds, lutein, astaxanthin, zeaxanthin. Um, so, you know, peppers and carrots and then the the pink color of of salmon and shrimp is where that's astaxanthin. They they seem to they seem to be beneficial for the brain as well. And across all those different polyphenol antioxidants, there are studies that look at the brains of people who have dementia versus not, um, and they tend those who experience dementia tend to have lower levels of those antioxidants in the brain. Um, other studies have looked at brain age, so like how old does your brain look on an MRI scan? They tend to have, you know, if you have a lower levels of those antioxidants or lower intake of those antioxidants, you tend to have an older looking brain. Another one that isn't in the antioxidant category, but is has been associated with an older looking um, brain is a low intake of choline, which is an important structural compound in the brain. And then, um, the some of some of the other like antioxidant vitamins like vitamin C and vitamin E, uh, crop up uh, very frequently as well. So those are the ones that I think we have some of the best evidence for.

Dr Rupy: Got you. So if someone's listening to this, they're like typing out their shopping list, going to get magnesium, zinc and iron and all the rest of it. So when you when you think about a diet, uh, you know, I'm just thinking of okay, rainbow diet, making sure you're getting good amount of protein from whole sources as much as possible, whole grains, seeds and nuts, etc. How do you communicate that to an individual? Like how do you how do they make sure that they're covering all the bases? Or maybe a better question actually is where do you think there are deficiencies, most deficiencies that we see in people's diets on a population basis?

Dr Tommy Wood: So I think most of the things that I mentioned, we do we have high levels of insufficiency at a population level. The majority of people in and this sort of like there's there's a big um, Lancet paper looking at nutrient status across the entire world. And in sort of westernized, modernized societies, it's very, very common for people to be deficient in B12, magnesium, zinc, the antioxidant uh, vitamins. They didn't look at polyphenols, but you know, if you're not regularly eating um, berries and other fruits or seafood, then um, you you're probably not having a high intake of those. Choline, if you're not regularly eating eggs or liver, um, you may not be getting enough of that. You can get related compounds from whole grains like um, oats and quinoa. So that's like ethanolamine, which can be converted to choline and it also has that kind of a similar structural role. So some whole grains can can give you some of those um, things as well. As soy is another one um, that that gives you some of those like choline type phospholipid compounds. Um, so it's actually surprisingly common for people to be deficient in in these in these uh nutrients. And my my focus is is always a as much as possible a whole foods based, varied, nutrient dense diet. Um, and so then it it's some combination of a of a nutrient dense protein. Um, fish and meat, you tick off omega-3s, choline, like some of these other things. Um, and then from the the fruits and vegetables, obviously fiber becomes critically important plus, you know, a lot of a lot of the polyphenols and antioxidant um, um vitamins. So like that's that's really where I'd where I'd focus. You know, sardines and blueberries, you've ticked most you've ticked most of those boxes in in one go. And you can eat them separately if you want. Sure, yeah, yeah. I mean, to be honest, I have them all the same. We we have a thing in in the Doctor's Kitchen where we talk about BBGs every single day, which is beans, berries, greens, seeds and nuts every day. You've got to tick like at least a handful of those every single day. And you know, if you can add some oily fish to that, you're looking at a really brain healthy diet, you know. Um, I think uh, a lot of people may struggle with choline and they might be hearing this and be like, well, yeah, I get this is good for my brain, but then what about my heart? And you you ticked off a whole bunch of things that I don't tend to have in my diet, like eggs, for example. Like how do you balance all these things? I mean, how do you ensure that we're looking after our brain but also like making sure that we're not consuming too much in the way of saturated fats that can raise our risk of cardiovascular disease that can also affect the the brain obviously.

Dr Tommy Wood: Yeah, I mean it's it's a great question. So in general, um, and this is the way I eat, I would focus on leaner cuts of leaner cuts of meat. Um, but can absolutely include red meat. It can can be an important source of B12, zinc, um, and you know, iron, uh, which um, which can can be important for for for some people. And there was actually a recent randomized control trial where they added um, you know, lean red meat, lean pork in this study to a a plant forward diet and actually saw some some some benefits. And I think most of the issues that in terms of we see that we see in terms of the nutritional epidemiology is the um, sort of like meat is is part of this bigger low quality calorie dense diet. But when you're using um, yeah, especially leaner meats that can be that can be very nutrient dense in the context of all these other things that we're eating that we just mentioned, you know, beans, whole grains, uh, veggies, berries, nuts and seeds, then I think they it can be an sort of they can be an important source of protein. You're not taking in much saturated fat. Um, and there are randomized control trials of red meat, so beef, um, up to, you know, 100 or 200 grams per day, no effect on blood sugar, no effect on inflammation, very minimal effect on cardiovascular disease risk um, you know, risk factors like lipids. But again, most critical in the context of all these other all these other things. And it's the it's the same for cancer risk, it's the same for heart disease risk. So I think they absolutely can be part of the diet, but you know, the bigger context is important too. Um, and so that that like I said, that's that's how I tend to eat leaner cuts of meat, um, fish. And then, um, particularly, uh, eggs aren't going to be a huge source of saturated fat in the diet. It might be a few grams, but you can absolutely stay under. So like if if a population health target is less than 10 grams per day, you can easily eat two or three eggs and stay well under that, you know, and include some other lean meats as well. Um, so these things aren't mutually exclusive. Um, you you can absolutely hit those targets and get those nutrients and and sort of have that overall uh, good picture of health.

Dr Rupy: Yeah, yeah, I completely agree. I think um, you know, there are ways uh, in which you get all of these nutrients on a plant forward diet, an exclusively plant-based diet and an omnivorous diet that I personally ascribe to. Um, I want to dive a little bit deeper onto into choline if possible. Um, because liver, eggs, I mean, with the exception of eggs maybe, but some of those off cuts less popular these days. I personally quite like liver. I haven't really got on board with like, you know, brain and some other things, but um, why is choline so important from the perspective of brain health? What is it doing?

Dr Tommy Wood: Yeah. So, I think that to to think about this, it's worth actually stepping back even further and thinking about some of these other nutrients that I that I mentioned, uh, particularly B vitamins and omega-3s. So when you look at um, risk factors for dementia and then randomized control trials that um, have improved that, you know, slow brain atrophy, improve improve cognitive function, um, in those supplemented with omega-3s or B vitamins. So if they have high homocysteine, what you see is that both are required in order to benefit. So there's the the Vitacog study, uh, was run out of the University of Oxford by Professor David Smith, used to be a department chair of pharmacology there. They looked at individuals with a high level of homocysteine, um, and they gave them B vitamins to bring that homocysteine down. Um, and it was they used um, folic acid, cyanocobalamin, so folate and and B12 or a version of B12 and uh B6. And they saw significant reductions in homocysteine, but in terms of the benefit on, you know, the brain, that benefit was only realized in people who had adequate omega-3 status. So you need both. And multiple studies have now shown this. So the B proof trial did the same thing, reduced homocysteine with B vitamins, but they saw benefit only in people who had good omega-3 status. And the omega AD trial did the opposite. They gave people omega-3s, but they only saw benefit if they had low enough homocysteine, right? So they had good enough B vitamins. Okay. And this is important because people may have heard of a large number of trials where they give omega-3s and they're like, well, it doesn't have any effect. Yeah. Because they're not looking at these other things, right? They interact. So, and the reason why this is important is because if you want your omega-3s to be in the membrane of your neurons in the in the synapse. So like the synapse is where the neurons communicate. That's where DHA, the long chain omega-3 ends up. Um, that's where it's really important. If you want it to be in the membrane there, first of all, it needs to get into the get into the brain and and some of that is regulated by metabolic health. So like if you have insulin resistance or something, that that might impair some of that uptake. And then it needs to be attached to a head group to create a phospholipid that sits in the membrane, right? So right. So this DHA doesn't just like float around, it has to be in the membrane. And so the head group is often derived from choline. Got you. Um, it's often, um, so it's phosphatidylcholine. In the brain, it's it's it's it's more likely to be phosphatidyl ethanolamine, that's what I mentioned earlier, or phosphatidylserine. These are all interchangeable. You can interconvert them, but that requires methylation. As does the process of attaching the DHA to the head group also requires methylation. So that's where the B vitamins come into play. So choline and related compounds and omega-3s and B vitamins all kind of work together to then have this downstream effect. And which is why I think eating, uh, you know, a varied nutrient dense diet is is really important because you need all of these things. You can't just like isolate one compound. We know that if you take just one thing, if that's not the the sort of like the rate limiting step for you, you'll have you'll have no you'll have no overall benefit. And you're more much more likely to hit all of those things if you are eating that sort of like varied nutrient dense diet. Um, so that's why choline is important is because it's part of the structure that fats are then important fats are attached to in the brain.

Dr Rupy: Got you. That makes total sense. So and and it sort of adds a lot more clarity as to why some of these omega-3 trials have not been as successful as you would have imagined given what we know about those long chain omega-3 fatty acids, DHA and EPA. Um, in terms of like looking at omega-3 status, do you think those blood tests where they look at omega-3 index are useful and and if so, like where we should we be aiming for that that blood level?

Dr Tommy Wood: So, if people are not regularly consuming long chain omega-3 fatty acids. So if you're not regularly consuming seafood and you're not then supplementing, so so if you are on a an exclusively plant-based diet or very a plant forward diet, um, and you're not consuming long chain omega-3s, you you might consider testing if you can or or supplementing, you can take an algal like an algae based uh long chain omega-3. Um, the it can be important to test. One reason why I wouldn't necessarily recommend it for everybody is because it's expensive. You have to pay for it out of pocket, right? These things, most of the other tests, things that I mentioned, you know, blood sugar, blood pressure, lipids, right? Your doctor, you know, they'll do that in the NHS. Um, vitamin D, iron, right, they're part of typical screens for risk factors for dementia, right? So these are things that are accessible to most people. Omega-3 status isn't yet. Yeah. Um, so if you're not regularly consuming omega-3s, it it might be worth considering testing or, you know, you could just take a high quality supplement if if if needed. Um, and there's a there's a charity that I work with here in the UK called Food for the Brain. Um, and I help I run their research arm. So I'm not like involved in the charity itself, but they have a big database. They have a large um, a database of cognitive function test results. So they have a free online cognitive function test that's been done by about half a million people now, as well as a questionnaire related to lifestyle and risk factors for dementia. Um, and so I sort of like help oversee research that's done with that database. But they've just developed a an at-home test, they call the drift test. You have you have to pay for it out of pocket, but you do a sort of like a finger prick and you do like dry blood spots. And that includes omega-3s, HBA1C, uh vitamin D, and homocysteine can all be measured. So like can all be can all be measured at home. So if people are considering this, that's one way that they could that they could do that, even though I have to acknowledge you have to you have to pay for it. Um, then the you ideally, if you're looking at your omega-3 index, um, you ideally want to be above 6%, um, at least above 6%. The lowest risk is probably above 8%, which is a measure of the percentage of long chain omega-3 fatty acids in the membranes of your red blood cells. That's what the percentage is.

Dr Rupy: Got you. And vitamin D, what should we be aiming for? Because there is a bit of discrepancy between what the NHS would recommend as sufficient versus what might be optimal from a brain health perspective.

Dr Tommy Wood: Yeah, so the the greatest risk is is in people who are definitely deficient. So below 50. Um, 50 in uh, you know, SI units over here. In the US, it would be below 20. Yeah. Um, and then, but I I think from you know, a good target for most people is to be at least above 75. Um, then because I think that's where the risk is is lowest if you sort of look at it as like a continuous measure. Um, when working with athletes, we try and get them over 100, probably between 100 and 150. Um, because that's where there may be some additional benefit from like an athletic performance stance. So definitely get above 50. Um, then there may be some additional benefit, you know, maybe even getting above 100, but the that's then we have less good evidence you need to get that high for like dementia risk, but it might be benefit beneficial for some other areas like athletic performance.

Dr Rupy: Got you. Do you suggest people supplement with vitamin K2 if they don't get that from their diet as well?

Dr Tommy Wood: Yeah, um, I think that we then think about the bigger picture of heart health and bone health. All those other fat soluble vitamins are going to be important. So, um, and and then, you know, thinking about bone health, magnesium is going to be important, um, K, yeah, K2, vitamin A is is can be important as well. Um, so there is some evidence that uh, yeah, K2 from especially, you know, epidemiological evidence, a higher K2 in the diet is associated with lower lower heart disease, better bone health. There are some some randomized control trials of of um K2 supplementation. I think most of them show benefit. There's some question about the quality of of some of those studies. Um, but yeah, if you're not uh regularly consuming fermented foods that tend to be higher in K2, then you might consider a a supplement. In general, I think now there's actually fairly good evidence that people could just take a high quality multivitamin that's going to hit a bunch of those uh, you know, tick a bunch of those boxes. So there was a recent trial done in the US, the Cosmos trial. Oh yeah. Right, where they randomized, I mean thousands of individuals to either a multivitamin and or a cocoa flavanol supplement. So like cocoa flavanols being some of those polyphenols that I mentioned earlier. Um, and the cocoa flavanols were beneficial in those people who had a low quality diet, so low antioxidant intake overall. Um, and then the multivitamin was just like beneficial across across the board. Um, and it it was just like it was like a like a spectrum like standard multi. It wasn't even like a fancy multi. It wasn't even a high dose one. I think it just like hit hitting RDAs and stuff. Yeah, yeah. Um, so, so yeah, I I I would think that if if people are sort of concerned about individual nutrients, you may just consider taking a reasonable quality multivitamin just to sort of like cover some of those bases.

Dr Rupy: My perspective on multivitamins has really evolved. We had a few researchers on talking to me about higher dose multivitamins actually and the potential benefits for those with mental health issues. It could just be covering deficiencies that haven't been picked up from a dietary assessment and maybe you can get it all from diet, but um, I certainly see the potential benefit of multivitamins a bit more now than I than I previously was. Um, and I love chocolate. I tend to have raw cacao uh, and I mix that with a bit of raw honey and some other bits and bobs and I just have that as my afternoon drink because I drink my coffee in the morning so it doesn't impact my sleep. Yeah. Um, because as as we're going to get into now with the support side of things, uh, sleep is something I need to protect vigorously. Yeah, especially with a 15 month old.

Dr Tommy Wood: But dark chocolate, another thing that could that's been found to acutely improve some aspects of cognitive function. So like similar similar to to berries. And that's probably right, some of it may be the theobromine, right, having a similar similar effect to caffeine, they're related compounds. Um, but some of it also uh, because it's it's been found mainly with dark chocolate, 85% and above. Um, uh, probably related to some of the the polyphenol compounds in there.

Dr Rupy: What's your percentage, my guy?

Dr Tommy Wood: Um, so I actually prefer milk chocolate. I knew you were going to say something. I don't I don't I don't eat it, I don't eat it frequently, but like Cadbury's fruit and nut I love. Not going to you're stocking up whilst you're over here. Yeah, yeah. So like like when I'm in when I'm in uh duty free in Heathrow, I'm buying like this big one. It will take me a long time to get through it. Um, but my wife is a proper dark chocolate connoisseur. She's she's like 85 and above. Right. Okay, yeah, yeah, yeah. So she definitely that's where she gets her her brain health from.

Dr Rupy: That's brilliant. That's so funny. My I got another friend of mine who lives in Illinois and he stocks up on Galaxy whilst he's over here because the chocolate in America just isn't the same. I don't know what you guys do to it over there, but it's just it doesn't taste right.

Dr Tommy Wood: You're right, it's it isn't the same.

Dr Rupy: There's something off. Um, let's talk a bit more about support. And actually, I do want to start off with stress. Um, you know, I don't think it gets as well, it's definitely getting more attention now. I mean, have you seen, I mean, you don't spend that much time on social media, but cortisol is having a moment right now in the same way blood sugar had a moment maybe like four or five years ago, but everyone is talking about cortisol all of a sudden as a means to sort of like uh, it's like a marker of stress. Um, it's definitely having an impact and something that is impacted by our um, our state of mind. Um, but how do you unpack stress and and and how do you parlay that with this conversation around cortisol?

Dr Tommy Wood: So, it's really interesting to see people talk about cortisol because most people don't understand it at all. Um, especially when you're like saying cortisol is bad, which is nonsense. Like and it's we're thinking about it just in that in that reductionist way. Um, and like anybody who's ever like worked with or treated an individual with like Addison's disease, right? You don't have cortisol, you don't have blood pressure, you don't have blood sugar, like it's incompatible with life. Cortisol is very important. Um, now obviously beyond that, cortisol is a stress hormone, it's released during stress. In in my book, I actually go through quite a lot about how you think about stress because we've got to this point where we think stress is bad, uniformly. And when we talk about stress, we think about one particular thing, we think about psychological stress. When actually, like the origins of the research into stress responses, you know, started with Hans Selye and what he called the general adaptation syndrome. Um, and so this is that anytime your body detects something that it needs to respond to, it initiates the stress response. So stress is there to divert research like resources so that you can so that you can respond. And that includes improving like fitness and strength, right? So when you do exercise, you release cortisol. One of the things they measured in that study, that that hit protocol study, those like after after the Norwegian 4x4, you are stuffed full of cortisol, right? Um, and it's it's part of the body diverting resources to respond and adapt and improve. Um, and what's interesting is that when you stress people and you change how they think about stress, you also change their physiological responses to it. So there's a whole uh, a whole bunch of fascinating research primarily done by Alia Crum at Stanford. Um, she trained with Ellen Langer, who's my favorite psychologist of of all time and her her work is amazing. Um, and what they do is they take individuals and they they reframe their stress before they go into a stressful situation. So half like half the group are told about, you know, stress is bad for you, right? It damages your health. Um, and the other the other half of are told, you know, stress is enhancing, it's there to help you do the job, it's there to help you respond, it's there, you know, to help you grow and improve because because it is, that's like it's it's driving growth and adaptation, at least initially. And when you then stress those people, they both groups release the same amount of cortisol. But the stress is enhancing group also release other sort of more growth and adaptation um, uh, driving hormones like DHEA. And people who release more DHEA under stress make better decisions under stress. So how you think about your stress actually changes how you respond to stress, which then changes the impact of that stress has on you. So when people are then out in the world telling you that stress is bad, they're actually having a bunch of downstream negative effects because you're then worrying about your stress. And there's a there was a very interesting study that looked at mortality risk in people based on their levels of stress. And they found that your risk of death, and this is like epidemiology, right? It's not a randomized control trial. But the risk of death was only increased in stressed people who thought that stress was bad for their health. Wow. But people who are like, who didn't think stress was bad for their health, even though they were stressed, didn't seem to have a negative impact. So, yes, like stress is very important, but we need to know what stress is for. Stress is there to help us attend to something important, right? It helps us improve our focus, improve our attention, be that for exercise, be that for, you know, some performance, like giving a talk, um, be it um, to heal a wound, be it to like run away from a bear that you come up against, right? Like that's stress really critical in those situations. Now you can you can get to a point where stress becomes chronic. And then yes, it does have have a negative effect. So then sort of like building on that original research, we have this idea of allostatic load developed by Bruce McEwen, which is basically the sum total of all your stresses and they can be psychological, physical, um, etc. They they have an impact if you're unable to recover from them. Um, and you can think of stress as chronic, I think, quite simply, if that stressor is preventing you from sleeping because sleep, you know, poor sleep dramatically decreases your ability to then handle handle the stress. And you can then see signatures of high allostatic load in overall health that then increase are associated with increased risk of dementia. So people who have a high allostatic load tend to have higher blood sugar, higher blood pressure, higher waist circumference, they're more likely to smoke and drink. And some of this is like cause and consequence, right? They're more likely to have low vitamin D. Again, could be cause and consequence. Um, but if you're starting to pick up some of these like metabolic health and other nutrient risk factors associated with a high burden of chronic stress, then those two things are probably connected. And some of the then later risk of something like dementia is probably through, you know, mediated by those other health effects that sort of like down downstream of it. So it's not that like chronic stress, like chronic stress is is is a big issue that we should should consider. But we have to get away from this idea that stress and cortisol is bad because it's not. Actually, in the moment, it can be a very good, it could be a very good thing. Um, and we just want to be able to leverage that stress response to allow us to grow and improve our function and do the things that we need to do because that's what stress is for. But then make sure that we're finding ways to, you know, down regulate, sleep, adapt afterwards because, right, any kind of stimulus which drives some version of that stress response, then requires sleep and recovery in order to adapt afterwards.

Dr Rupy: Yeah, that that really speaks to me. It's empowering to know that my perception of stress and overwhelm is in some way mitigating against the stressor in of itself. And what if I'm understanding correctly what you're saying is stress is bad, but the framing of stress can also direct whether there are going to be positive adaptations or not. Exactly. And you know, when when I think about like all the different hats I wear and all the rest of it, I I I have to just constantly remind myself of like why this is a good thing. Case in point, my my wearable. I've used many wearables before and that can derail my day. If my wearable tells me that, you know, your heart rate was slightly more elevated last night or you haven't slept as much as your your trend for deep sleep, you know, I need to be able to look at that and just be like, okay, that's fine, but I'm going to rise above it and I'm going to, you know, like I'm going to focus on rest perhaps at the weekend or tomorrow or do better or just like put my laptop down or what did I do the night before that I can it's just the perception. Like that's I that's what I'm gathering is is super important.

Dr Tommy Wood: Yeah, and so they've done this with wearable data and with like manipulating how people interpret their sleep. And so like for people who use wearables, my number one piece of advice is don't look at it in the morning. Oh, right. That's exactly. Just don't look at those data. Don't don't look at it. And I'm I'm going to I'm going to tell you why. So two two main studies um, that that kind of show why I wouldn't look at my wearable data in the morning. Actually, before that, I'd say that the majority of wearables aren't actually that good in terms of detecting um, sleep stages in particular. They they they're pretty good at knowing like how long you're asleep for. So, um, sleep opportunity, sleep timing, sleep regularity, like when you're in bed, when you're asleep, that kind of stuff. Great. Knowing whether you're in deep sleep or not, it's basically a coin toss. Not much better than a coin toss. And this is like the the these are published data from the you know, the latest uh versions of these wearables. Just not great. So first of all, I wouldn't put much stock in those data to begin with. But second of all, there are studies that have manipulated how people think about their sleep. And it's how they think they slept that affects their performance the next day rather than how they actually slept. So one of the the first studies, I mentioned Ellen Langer previously, she collaborated with um, a circadian uh biologist called Steve Lockley. They're both at Harvard. And they did a study where they took people into the lab and had them sleep. And one of Ellen Langer's favorite things to do is manipulate clock time. So in this study, they had um, people sleep either for five hours or eight hours, but then they changed how quick the clock moved. So they then thought they either slept for five or eight hours and they randomized them. So it was like a a two by two, right? People who slept five hours knew they slept five hours. People who slept eight hours knew they slept eight hours. But then people who slept five hours and thought they slept eight, and people who slept for eight hours but thought they slept for five. The next day, reaction time and fatigue were more closely tied to how how long people thought they slept than how long they actually slept. Wow. Um, then there was another study run by a group at at Oxford where people slept with a wearable. And then the day after, they were randomized to be told that they slept well or poorly, regardless of how well they actually slept. And again, how they felt the next day was driven by how well they were told they slept by the wearable rather than how well they'd actually slept. Okay. So if you're relying on poor quality data first thing in the morning to tell you how to feel during the day, right, that's why I wouldn't listen to my wearable first thing. Like so they can be useful for trends because even though there's error in the data, those errors are probably fairly consistent for you. Yeah. Right? So, yeah, you could look at them to see how's my sleep changing over time, you know, or look back during the week and be like, oh yeah, where didn't I sleep well? Like what did I do that night? Fine. But don't let it tell you how how you're feel during the day because it's a it's a self-fulfilling prophecy.

Dr Rupy: Yeah, yeah. I'm definitely going to change the way I interact with my wearable. I still like looking at the trends. I'm like, you know, data driven and I like looking at the heart rate um, average as well. Um, but maybe not first thing in the morning. That's definitely one thing to change for sure. Uh, okay, on this on this support um, uh, pillar, um, we talked about uh, stress, uh, the importance of sleep. I think we are touching on. In terms of like optimization because I I'm I'm going through very, very poor sleep right now and I wish I could put more energy into it when I'm trying the best I can. But in terms of like the basics, um, why is sleep so important from a brain protective point of view? And how do you, I mean, how do you personally optimize it given everything you know about the field?

Dr Tommy Wood: There are two or three like really critical things that happen during sleep. And the easiest way to think about it is that um, you have this synergy between non-REM or deep um, it's particularly deep sleep. So right, there are multiple stages of non-REM sleep, but slow wave sleep or deep sleep and REM sleep. They basically synergize to um, reactivate networks that were activated during the day to sort of like cement those new connections that were made, to they to process um, information and you know, this is where we and sort of like link things you you experienced during the day to like a bigger picture of of the things that have happened to you. Um, so there are lots of and this is particularly happens in REM sleep. There are some very interesting studies that show that um, when there's you know, people are learning something and there's some kind of underlying um, rule or pattern and you allow them to nap afterwards, they're more likely to to realize the pattern based on how much REM sleep they got during during the nap. Um, and then REM sleep is also, so like deep sleep, you see reactivation of memories that were activated, particularly in like um, learning. And most of this um, some you know, some of this has to come from mouse studies, but you know, you see similar things in humans. And then, um, REM sleep sort of refines those connections and then sort of like puts that information into the bigger picture and also is really important for like emotional processing. Um, so between them, what they do is they kind of cement what you learned the day before, put it into the bigger picture, um, process any sort of emotional experiences and and sort of like reset everything so you can go back and learn more and and put more in the the next day. Um, and then during that time, particularly during deep sleep, but just in general during sleep, you you essentially you you like the the the street sweepers come in, right? You have activation, expansion of the glymphatic system, which is this uh, system of fluid around the cells in the brain that sort of like just like washes out all the junk that accumulates. Um, and so that can be proteins like amyloid that we know is is is is is part of the the picture of uh dementia and Alzheimer's disease. But just like there's there's a whole number of uh, proteins and things that accumulate during during the brain and compounds and metabolites. Um, some things have specific clearance mechanisms. So adenosine is something that um, uh accumulates during the day is because so like when you when you release neurotransmitters, um, sometimes they're released with ATP, so like the energy currency of the cell. Um, that ATP is broken down to adenosine and adenosine helps to like builds up and starts to drive sleep pressure. It's part of what like makes us sleepy at the end of the day. And so the enzyme that then um, sort of turns that adenosine back into something to be made back into ATP, that gets upregulated during sleep. So some things are kind of like bulk washed away, some things are sort of um, uh, you know, metabolized back back to their their you know, to another form. Um, and there are other things that accumulate. So, um, glutamate is the major um, the the major neurotransmitter in the brain. During a day of hard cognitive tasks, like glutamate accumulates, that helps to, you know, drive and and some other, you know, related uh compounds, excitatory, uh like amino acids. Um, and they accumulate and they sort of again, kind of drive fatigue and some other things that sort of help to drive sleep. And so like they're turned over and and and removed. So all of these things kind of essentially wipes the slate clean, takes what was important for the previous day, stores it for one of a better word and then allows you to go back and and do it again the next day. And so one of the reasons why we think that people don't remember things as well, say after they haven't slept well, is because you haven't fully processed all the things that you that you learned or saw or had to remember from the previous day. And a loss of the ability to process emotions during sleep, um, particularly a loss of REM sleep might be one of the reasons why people experience PTSD because if you experience a traumatic event and then you don't get the opportunity to sleep properly afterwards, which is would is very normal, right, because of this event, um, it's a a lack of REM sleep seems to be associated with some of that. And some of the therapies, um, for PTSD nowadays, uh, like medical therapies actually, um, so prazosin is a is a drug that they use for some people use for PTSD and it helps to like reinitiate REM sleep that people have been missing out on with PTSD. And that's not all of PTSD, of course, but like it's thought to be like part of the picture. So all of these things are kind of happening during sleep and they sort of like synergize and and and come together to sort of wipe the slate clean and allow you to go back the next day. Um, so then when you're thinking about sleep, um, not like the mechanisms of sleep, but actually trying to get some sleep. Um, there are several things that are important. Um, like quality, quantity, uh, regularity and timing. Um, that framework, the QRT framework comes from Matthew Walker, who's one of the the you know, the world renowned sleep scientist. He's the person who's made us all worried about our sleep. I think he even acknowledges, right, it's very, very important, but even he acknowledges maybe maybe he was a little bit too bullish about it because now everybody's stressed about their wearable data. Um, but I tend so like uh, right, quantity is how long you sleep, quality is how well you sleep, regularity is are you getting the sleep at the same roughly the same time every day and then timing is are you sleeping in time with your circadian rhythm and like or your chronotype. Um, that last one, I I personally focus on less because I think people have less ability to to manipulate that, right? Uh, because you probably have a job and kids and other things that that you have to attend to. So like massively shifting when you sleep in the day is just not reasonable for most of us to worry about. Um, but there's other things I think we can we can attend to. So, um, quantity, right, how much do you sleep? The you know, most people need seven to nine hours of sleep at night. The you know, it's hard to give a fixed number though because like even with in ourselves, we need to sleep different amounts, right? You need to sleep more when you're sick. Um, you you might sleep more or better when you're very physically active or you're doing a lot of cognitively challenging work. So this stuff changes and shifts all the time. Um, the full range that of like people and their the amount of sleep they need is probably more like six to 10 hours. Like it's actually quite a big window. Oh wow. And the risk for dementia significantly increases like in people who are regularly sleeping less than or fewer than six hours a night. Okay. So it actually needs to be quite sleep restricted to to to see a big effect on dementia. Um, but that that risk absolutely is there for those people who are sleeping five hours a night for long periods of time. Um, when you say long, do you mean like a year? Yeah. So and you're asking for a friend, right? Um, what's particularly interesting to me and so like this is a tangent. We'll come back to sleep, but Yeah. Um, when you think about parenthood, Yeah. you would think parenthood has to be a disaster for your brain, right? This is initially what my thought process is right now. And so like sleep deprivation, stress, like all this other stuff that you have to like you have to juggle. So there was a really interesting recent study that came out of the UK Biobank that found that parents, the more kids they had, the lower their risk of dementia. What? And this this was the same for both men and women. Uh-huh. Um, and so I think that, yes, we could and we do this all the time, right? It's it's the same as when we focus on like um contaminants in food or or something like that. Like we focus on the negative when actually the vast like the the vast benefit always almost always outweighs any any negative side. And so like parenthood seems to be the same because what else does it come with? It comes with cognitive stimulation, it comes with prosocial behavior, it comes with a whole bunch of things that you you wouldn't necessarily get otherwise. Um, and so the net effect of parenthood despite the sleep loss and despite the stress, right, is actually seems to be a net benefit for your brain. So now you can go in thinking, do you know do you know what? I didn't sleep well, but like there's a there's a net there's a net benefit here. It's sort of the analogy of exercise. If you were to, you know, dive in to someone's muscle fibers and look at the cells and you'd conclude that exercise is a pretty bad activity for your health, but actually the net effect is improvements in pretty much every domain. Yeah. Exactly. The the analogy I use is that if you look at heart surgery halfway through, it looks like murder. Um, so that's exactly what right this this acute effect but long-term there's long-term there's a benefit. So, um, and maybe we can come back to why I I wouldn't be that worried about individual um, like lost nights of sleep. Um, so, um, yeah, like if like, you know, years of of short and sleep certainly associated with with an increased risk of dementia. But if you're regularly waking up, you feel pretty refreshed, you're able to go about your day without like falling asleep and feeling so fatigued that you can't do your work, you're you're you're probably okay. If that's not the case, the the most common reason people don't sleep enough is that they don't get enough sleep opportunity, which is a fancy way of saying they don't spend enough time in bed. Yeah. Um, and so the the way that I approach that is and I think this works for most people is I know when I'm going to get up, right? Most of us know when we're going to wake up. For me, my dogs want breakfast at 6:00 a.m. So I'm going to get up at 6:00 regardless. Yeah. So then if I want to sleep for eight hours, that's approximately what what I do best on, I need to be in bed for nine hours, right? Because we you don't sleep the entire time that you're in bed. Yeah. Right? So I need enough sleep opportunity. So I go to bed at 9:00. Um, and that kind of, you know, sets me up then for the next day. Um, there will be then a period of like wind down before that, right? Sort of like dim the lights, um, you know, my wife has a my wife has a cup of herbal tea, you could have a hot bath or, you know, a hot shower, right? That can help to sort of like trigger some of those changes in temperature that can trigger sleep. Just just some kind of routine that helps you sort of relax. Like I know that if I work after dinner, it's going to be running through my head when I'm trying to sleep. Totally. So there's other things like um, mental offloading that you know, some studies, like really nice studies show that they work. It's basically you you write down the things you're stressed about, things you're worried about, your to-do list, something like that, right? So that you know it's there, you can stop worrying about it again in the morning, right? And actually that that helps to that helps people sleep. Yeah. Um, other studies in insomnia, you know, people do some kind of slow-paced breathing, right? That helps to down regulate. They they fall asleep faster. Just so just something to allow you to kind of uh wind down properly. So so like that's that's how I would structure it. Um, but then the the next thing we might think about is um, right, quality. So one of the reasons we know that sleep quality is important is because of how people respond to poor sleep quality, which is usually by self-medicating. So people who regularly use alcohol or antihistamines or other sleep uh or other drugs to kind of help them sleep, um, Ambien, etc. Um, that you know, chronic use of those is associated with uh an increased risk of dementia. Um, and that's probably because they're impairing certain aspects of sleep. So alcohol in particular gives you a relative deficiency in REM sleep. Um, so like anybody who's like, you know, drunk a bunch and then gone to bed and then they they like wake up like having crazy dreams. That's like your brain trying to catch up on all its REM sleep that didn't get during the night. Um, but even then you end up with a deficit. And um, like caffeine tends to impair deep sleep. Um, so, uh, you know, all these different compounds can kind of affect sleep quality. So even if you're taking something that makes you unconscious, it's not necessarily supporting sleep quality. Um, so then, right, there's a whole bunch of things you can consider, but equally, that sort of wind down, no significant intake of caffeine after, you know, midday or you know, sort of like at least eight to nine hours before bed. Um, right, that's what the studies kind of suggest. Um, that will help there. Uh, but then some people might need some, you know, intervention, you know, so CBT-I, CBT for insomnia, um, can be really helpful. You can even get that through an app now as a starting point. And for most people who who have insomnia, right, their sleep mechanisms aren't broken, they just need to create new new habits and environment that kind of supports supports sleep. So like the underlying things are usually still still working. It's just recreating an environment that allows you to feel safe and, you know, able to and and rest, you know, able to feel like you can rest. Um, and then the the final part is regularity. So like are you going to bed and waking up at a similar time every night? And this is particularly interesting because there are some studies that suggest um, sleep regularity might even be more important than sleep quantity. Ah. Um, they've they've looked at this mainly at mortality, not not at dementia risk or cognitive function. But one of the reasons for that could well it could be that, right, all the other things that you might be doing that are like negatively affecting your sleep regularity could be having an effect, right? Because it could be alcohol or caffeine or shift work or something like that that we know can can have other effects. But we also know that, right, different you have a different balance of the different sleep stages depending on the the time of the night, right? More deep sleep early in the night, more REM sleep later in the night. And there seems to be an alignment of um, sort of like the underlying processes based on the circadian clock. So it may be that, right, deep sleep is slightly more is slightly better at what deep sleep does when it happens at this particular time of the night and REM sleep is a little bit better when it happens at this time, you know, early in the morning. So that's why regularity may be important. And it's sort of like if you're like plus plus or minus 30 minutes on average, like most of the time, fine. Yeah. Um, it's like the people where it's a big issue is if it's very, very erratic. Yeah. Um, but there's probably some benefit to sort of like trying to sleep at a similar time every night, again, if you can. Um, so like those are the things that I would kind of kind of think about.

Dr Rupy: Yeah, yeah. I so what I'm hearing and this is something I'm going to be actively putting into practice myself, regularity. There's just something I probably struggle with the most because if I want to go out for dinner on a Friday or Saturday night, I can almost guarantee that with the travel and all the rest of it, I'm going to go to sleep later. And I have the same sort of pressure of waking up early because my son has decided to start waking up at 5:45. And I I thought I was all smug waking up at 5:00. So I go get myself a good window of time to do work and work out and all the rest of it, but now he's eating into that, but aside. Uh that regularity, I think is super important. And the wind down routine. My wife does this really well. She's like the lavender spray and like the sleep mask and all that kind of stuff. She's way more wellness than me. And I've recently started doing a a little journal. It's called um, one sentence a day. It's like a five-year journal. So you literally do one sentence a day and it's just like the thing that you reflected on during that day. And honestly, I fall asleep like that straight afterwards. It's amazing. I love it.

Dr Tommy Wood: Some some of it is literally it's literally just right building in that routine, right? So like I I like I have like blue light blocking glasses. Um, and at this point it's just Pavlovian. Like the glasses go on and my brain's like, it's bedtime. Right? So like regardless of what it's doing for light, you know, if it's having much of a benefit there, it's just like that's the thing that just triggers my brain. Oh yeah, you know, it's it's it's time to go to sleep. Um, the what's I think again, what what might be interesting to to know is that if if you have this fixed wake up time, even if you go to bed late, that's actually might help you maintain regularity, right? So you're getting some benefit from regularity even though you didn't sleep quite as much as you wanted. Because then the next night, it's much easier to get back to sleep because you haven't slept in, you've like affected your sleep pressure. So, yeah, right, this is going this is going to be different from person to person. Like sometimes what you need is more sleep whenever you can get it, right? Um, but when it's sort of part of a a bigger picture, it might just be like, yeah, you had a late night, but it was for a good reason, right? You're out with friends, right? You're doing all these other great things. And then you'll be back to a normal night of sleep the next night.

Dr Rupy: Um, dude, this has been awesome. I I'd love to do some hot takes on a few things. I know this is going to be really hard as a neuroscientist researcher who runs your own lab and all the rest of it. Uh, and the first one I want to I'm going to start with is keto. All right. Uh, so what are your what is your perspective on ketogenic diets uh, as a means to prevent, but potentially also in a therapeutic uh, scenario for someone with, let's say cognitive decline.

Dr Tommy Wood: Yeah. So, I think um, ketogenic diets, exogenous ketones have a lot of promise in neurodegenerative conditions, in acute brain injuries. Um, there's a lot of research actively being done right now in this arena. Um, there are a couple of studies using they use um MCT oil, right, to the the that increases blood ketones in individuals with some element of cognitive impairment. There's a study that's run by Stephen Cunnane. And they saw some improvements in um, like energy supply to the brain, which can be impaired in Alzheimer's disease and saw some improvements in cognitive function. So in like certain, I would call them cognitively degraded states, they may they may be, you know, may be some benefit. Um, and in certain psychiatric conditions, there've been some randomized control trials of ketogenic diets in like bipolar disorder, for example, and they've seen some some some significant improvements. And like there's a lot of research that's being done at the University of Edinburgh right now showing some significant benefit in in certain psychiatric conditions. So I think as and then obviously for some people very very powerful for controlling seizures in epilepsy, right? That's that's where it's used basically in pediatric epilepsy. Um, so I think a number of very interesting therapeutic benefits. There's probably a lot more that we could learn. Like I think ketones could be really beneficial in traumatic brain injury, but we just don't yet have those have really high quality studies. Um, I don't think though that we need to be in a ketogenic diet to prevent um, dementia because I think the most important thing is, you know, regulating overall metabolic health. Are like do we have good blood sugar control? Do we have good blood pressure? Um, are we maintaining a healthy body composition? None of that requires a ketogenic diet. Um, it might require some attending to diet quality and all those kinds of things. Um, but I don't think like ketosis is required there. Um, where I've seen, you know, people benefit from ketogenic diets most is when there's some other neurological condition going on. Um, so I, you know, I know some guys who have a a history of traumatic brain injury from the military, they feel like their brain works better when they're on a ketogenic diet. But I I don't think it's something that all of us, uh, you know, if if if everything otherwise looks good and we're maintaining good metabolic and physical and cardiovascular health, then I think, you know, it's it's not something that we need to to be concerned about.

Dr Rupy: Creatine. Uh, what are your thoughts on creatine? Do you think people should be taking that from from a brain health perspective actually, rather than just an exercise perspective?

Dr Tommy Wood: Yeah, so I think similarly, um, actually similar to to ketogenic diets probably, creatine may have seems to have a more of a benefit under significant cognitive stress or like after some loss of cognitive function. Um, and you know, the the studies look at acute sleep deprivation, creatine seems to um, overcome some of the some of the cognitive deficits you see with sleep deprivation. Actually some of these studies go back more than 10 years. They did a a trial in rugby players and they sleep deprived them and then they either gave them caffeine or creatine and then looked at their like rugby specific skills and saw that both caffeine and creatine helped to um, offset like the negative effects of sleep deprivation on on skill performance. Um, and then there was a more recent study that had people sleep deprived and then they gave them a a bolus of creatine and saw, you know, on brain scans that it offset some of the like um, metabolic effects of sleep deprivation. Like I talked about adenosine earlier, it kind of suppresses brain metabolism. Um, and that's one of the reasons why you feel kind of foggy when you're sleep deprived. Um, but creatine helped to offset some of that. Then there are trials, um, what was the bolus, do you remember like the Yeah, so it was it was 0.3 grams per kilo. Okay. So for if you're 100 kilos, it would be 30 grams. If you're 70 kilos, it'd be 20 grams. Yeah. Which is a fairly typical sort of like loading type dose. Um, in the in the rugby players, both a a lower dose, like 0.05 grams per kilo, so like even five five to 10 grams was enough to to have an effect. Um, then when you look at uh, creatine supplementation across a wide range of uh people, it seems to have more of an effect in individuals who are older, um, and particularly for memory. Like that's the cognitive function that seems to have the the best effect on. Um, and there was a recent, there was a recent trial in individuals with Alzheimer's disease where they gave where they gave creatine and saw some improvement in in cognitive function. And um, but the the problem was there wasn't a control group. So we know that even when people are experiencing cognitive decline, if you give them the same test multiple times, they just get better at the test, right? There's there's there's a learning effect. So it's hard to tell whether creatine was was the the main driver there. Um, but yeah, when you look across all the randomized control trials, it seems that it's like maybe more beneficial in the setting of some kind of cognitive stress, like sleep deprivation. It's been used uh in multiple trials in depression, like in in like treatment resistant depression where you've already started, you've started some kind of antidepressant, you see an incomplete an incomplete benefit, adding creatine on top seems to give um additional antidepressant effects. And this is at a standard dose like five grams a day. So, and you know, in certain types of cognitive stress or, you know, if you're experiencing some cognitive decline, creatine may be beneficial. Um, I find it quite uh stimulating. So like I can't take creatine at night or in the afternoon because then I don't sleep as well. Oh right. Um, but so so I like so I so I take it in the morning. Um, and that's mainly from an athletic perspective. Um, but equally, I think that it can, you know, it can maybe help to buffer some of those times when you don't sleep as well or you know, you've got some other things kind of going on. So creatine really works by helping you do the work, right? So creatine helps you like build muscle and strength because it like gives you maybe an additional rep in the gym, right? Over time you do more reps, you can build more more strength or muscle mass. It's probably going to be similar in the brain, right? Just like taking creatine on its own isn't going to do that much. You're going to get more benefit if you're actually like using your brain to do the thing. So, so it it's not like it's not magic. I think I may have previously said that creatine is magic, but like maybe maybe I'll disagree with my former self. But like there is certainly some evidence of benefit in in those in those different scenarios. Um, and you can actually get a good amount from the diet. So a tin of sardines has a few grams of creatine, like three grams or something. So, um, the one reason why I'm fairly bullish on creatine is because you could get the doses I'm recommending from diet if you really wanted to, right? Two tins of sardines and you've like you've hit those doses. Yeah, yeah. Um, so we know that it's very low risk. Maybe there's some potential for benefit, especially if you're thinking about physical and cognitive, uh, probably more of a benefit for cognitive if that you're already experiencing some cognitive decline. Um, but yeah, we know we know it's very, very safe. Very few side effects, if any. Um, actually a big meta-analysis just showed of all the placebo control trials, like no difference in side effects compared to placebo. So, you know, it's cheap, it's safe. So like I don't think everybody needs to take it, but you know, of the supplements that are out there and being recommended, it's certainly one of the ones that I'm, you know, most comfortable with.

Dr Rupy: Yeah, I I completely agree. I uh, I started taking 15 grams actually because of the potential brain protective effects during my sleep deprivation era at the moment. Um, and for folks who find maybe some GI side effects, even though it's very interesting to know that there was no difference in side effects with placebo, you could split it out, you could, you know, titrate up the dose if you want. Uh, I personally take a high dose, but I don't think it's relevant for for everyone, but you know, five to 10 grams seems seems reasonable.

Dr Tommy Wood: There there's some, there's some evidence that maybe once you get closer to 10 grams, you might sort of saturate creatine uptake in the gut. So like that may be causing some of the the gut side effects. And then but then the other thing to to consider, which is very critical for for creatine but also all supplements is that lower quality creatine has a bunch of other stuff in there and they may be driving the the GI side effects. So make sure you get Creapure creatine monohydrate. It's made by a company in Germany. Every uh, like every sports supplement company then just buys it from the same place and white labels it. But if it's not Creapure, it's like who knows what it is and where it's from. Um, and it could be actually contaminants in low quality creatine that's causing some of the side effects.

Dr Rupy: Absolutely. Um, nicotine. Uh, nicotine gum and nicotine patches and you know, it just sort of came out of nowhere for me, but any brain potential benefits there?

Dr Tommy Wood: Yeah, so, um, obviously mitigating against the addictive properties. Yeah, so so so I I find this really interesting because um, as soon as you think nicotine, you think like vaping and smoking and like those definitely have like negative health effects that that we would want to try and try and avoid, right? Smoking is linearly correlated with dementia risk, right? The more you smoke, the higher your risk. But in like neuroscience studies in the lab, if you give people a small dose of nicotine, like one to four milligrams, you see significant improvements in cognitive function, right? So we know that nicotine um improves cognitive function. The reason for that is it right, it activates acetylcholine receptors. Acetylcholine is really important for focus and attention. Um, it's one of the reasons why acetylcholine esterase inhibitors are given early on in Alzheimer's disease to help manage symptoms because you have more acetylcholine in the synapse, you're better able to like create and retain memories. And acetylcholine is really important for that. Um, so, yes, some people may experience cognitive benefits. We we like we we see those in the studies. Um, but the problem is that it is um, it is addictive and it does create tolerance. So you end up needing bigger doses to get the same effect. So anybody who says like nicotine is a nootropic is is lying because it's not. So a nootropic is something that improves cognitive function with essentially no downsides is and doesn't create um tolerance, right? So you don't need higher doses to get the same effects. So, um, things like caffeine and nicotine don't fit into that don't actually fit into that bucket. So I'm perfectly okay with people using targeted nicotine for like specific tasks if it feels like it helps them achieve that. But I would generally recommend against it. Um, because I can think of a whole bunch of other things that can help you boost your focus and attention uh both in the short term and long term that don't require um, don't require supplementation. Um, or, you know, you know, taking anything exogenous like that. So, um, yeah, it's it's not something I use, it's not something I recommend, but I know that if you can take it in the absence of like some of these delivery vehicles that are bad for us, you can see a boost in cognitive function. Like we we know that. I just worry about the addictive properties and the and the tolerance.

Dr Rupy: Yeah, totally. Um, on the subject of nootropics, are there any that you think are potentially beneficial from your experience working with athletes?

Dr Tommy Wood: Um, in in general, there's there's nothing that that I that I recommend. Um, I'm not sure there are there are many nootropics that are that are widely available that are high quality that actually truly fit the definition of of a nootropic. Um, there are other interesting compounds like um, the racetams that have been around for a long time, but like they have evidence in cognitive decline, you know, very little in sort of normal healthy people. Most of the time when you're boost when you're using a pharmacological like a pharmacological compound to to drive one type of cognitive function, you're usually creating a trade-off, right? You'll get better at this one thing, but you'll get worse at this other thing. If that benefits the individual and they feel like they're genuinely performing better and it works for them, fine. But know that there's know that there's probably a trade-off. Um, and so I'll give you some I'll give you some examples that and these aren't technically nootropics because actually there are very few things that that really fit that mold. Um, but when we give people caffeine, they feel great. They think they're performing well, but in complex tasks, they often perform worse. When you do like formal cognitive function testing. Okay. And it's probably because, right, they're a little bit more anxious, they sort of they react too quickly, right? They're they're they're they're a little bit more on edge. Um, you see the same thing in um, healthy people when you give them um, stimulants that you might use to treat ADHD, like methylphenidate or something like that. You see the same thing, right? They feel great and they they think they're performing well, but actually they're performing worse, particularly on complex cognitive tasks. Uh-huh. Um, there are similar things that you see in um, creative work. So like people who who who use cannabis or THC and think that it improves creativity. Yeah. Again, they think they're more creative, but if you objectively measure their creativity or look at the things that they're doing that are creative while they're, you know, under the influence, they're actually less creative. Right. And so I think that a lot of what we experience when we take these things is we feel better and we think we're performing better, but we we either there's no effect on our performance or we're performing worse. So the issue with a lot of these compounds is you it disconnects the subjective and the objective. Whereas normally, and this is particularly relevant to athletes, how they feel and how they think they will perform is actually a very good predictor of how they will actually perform and how they do perform. But when you start bringing these other things into the mix, those those become uncoupled. So I would question a lot of people who say, well, I I think I'm performing better when I take this thing. Are you actually performing better or, you know, can you objectively check whether that's true? Yeah. Um, I think it's just interesting. And again, no judgment. I've tried a whole bunch of different things, um, because, right, they're out there and I think it's my job to understand how they work, whether they work. Um, but I think, you know, for a lot of us, I think we're we're maybe kidding ourselves. Placebo has a big effect. Um, so nothing that I would regularly recommend.

Dr Rupy: Got you. Okay. That's really good to know because it saves us a ton of money as well. You know, there's so much you can spend in in a lot of these like health stores and stuff. And I think, you know, if there's anything I've learned from this conversation, it's just majoring in the basics and spending a lot more time thinking about those three S's that you went through and and optimizing your environment. And you know, I think perception is something that's huge. You know, if there's one thing uh, I want to dive more into, it's that perception. Ellen Langer, that was the yeah, she's a psychologist, yeah. Incredible. Like it's just incredible about how much impact the mind can have on the literal outcomes of these tests that can't be faked. You can't fake your blood sugar, you can't fake your hunger hormones. I know that was another milkshake study that they did. Yeah. Which is incredible. Um, I could ask you a ton more hot takes, but I'm not. I'm going to call it there. None of them were actually hot takes. No, no, it's all good. But everything's covered in your book, the stimulated mind. It's an incredible read. I can't wait to dive deeper into it. And uh, your work's uh, incredible. I I just can't wait for the the next stuff that you come out with and, you know, uh, what what's next for you, but appreciate your time, Tommy, coming over here. It's been brilliant. Really interesting to talk to you.

Dr Tommy Wood: Yeah, this is so much fun. I really, really appreciate it as well.