Neuroscientist’s 3 Proven Steps to Improve Brain Health & Prevent Cognitive Decline | Dr Tommy Wood

28:29Do you want to know what I'm really worried about after hearing this?

28:35AI. Yeah. Yeah. It is a valid concern. It is, because in one way, AI is amazing, because there's so many things that can help enhance your work with. I mean, I use it through so many of my core operations now. It's integral. I kind of forgot what life was like without it, which is worrying. But if you're not in that camp, you're behind, right? And so I then, you know, I wanted to look into this like very briefly, but I don't know if you've seen the MIT study. that came out and showed that after four months of chat GPT use, 83 % of users couldn't recall sentences they'd just written, with a 47 % decrease in brain connectivity.

29:20And I remember reading that and then asking chat GPT more information about it. But it's this weird world where you were just saying, you know, we peak cognitively as we leave school but are kids now just going to be using AI to get through school like there's so many interesting conversations that kind of coming out of what you're just saying talk talking about you know the autonomy to use your mind to test it to to push it to learn new things to stimulate it as much as possible but now we've got this technological world that's coming out that is kind of taking away any of that creativity and just giving you the answer in seconds like what do you think that's going to do to our brains?

30:03This isn't to sound also very unhopeful. It's just, that sounded like a really horrible question where I was like leading you in for complete dismay, but... It's so funny because I think that there have been, obviously we haven't been a part of them, but there have been these discussions every time there's been a major technological revolution, right? So I think some of these concerns are valid and some of them will probably turn out to sort of be a bit overhyped. But it really does depend on how we engage in these processes. So if you think about this MIT study, or at least there have been a couple of MIT studies, but the most referenced one is this one where they had individuals write essays.

30:44And there were several groups. And I will say, I still don't think this paper has been, you know, at the time that we record this, the paper hasn't been formally published yet. It was just released as a preprint, which is sort of you put it out there before it goes through peer review and all this kind of stuff. I'm sure it will be at some point soon. I also guarantee that most people talking about this study have not read this study because the full paper is somewhere over 200 pages long. It's a very long paper. So like most people who chat to be seated, they'd like run it through. Do you know what?

31:17Actually in the paper, there's an Easter egg, which only LLMs can read and it gives instructions to an LLM for summarizing the paper. It's quite funny because they know that most people are only just going to run it through ChatGPT. Anyway, so they had students write essays, and there were some who just had to write essays based on the knowledge that they have. Some were allowed to use Google, and then some were allowed to use ChatGPT. And what they showed was that as you sort of increase the amount of assistance that you could get from technology, so Google through to ChatGPT, the less students remembered of their work and the less they felt like the work was their own.

32:00None of this is surprising, right? If you didn't engage your brain in the process, you're not going to remember it as well and you're not going to feel as much ownership of it. However, they did later on sort of switch groups around. So sometimes groups went from one to the other. And so some groups that previously wrote by hand then wrote using ChatGPT afterwards. And they actually found that if they tried to write the essay first, and then they wrote the essay again with the help of ChatGPT afterwards, they developed a better overall answer because they already had a framework that they developed and then they were just using ChatGPT to sort of improve it.

32:38So what this kind of says is that the amount that you engage your brain in the process will then determine how your brain is functioning or determine what your final outcome and how much that has actually made any difference to you personally. This is not a surprise. So I don't know why everybody was wringing their hands out of it. If you ask something else to write you an essay, you won't feel like that essay was your work and you won't remember it. That's not surprising at all. But it does kind of give you this hint that you can use some of these tools to augment your skills and thinking processes, as long as you actually engage your thinking processes in the first place.

33:17So I think, you know, right now with technology, um, sort of accelerating at a pace that we can't predict. And this is why you sort of mentioned future-proofing. Like, I don't know what the landscape is going to look like in one year, let alone 10 years or 20 years. But if we think about as technology comes forward, you can just think about this. I have a simple heuristic, which is, is this thing augmenting skills that I want to have and I need to have, or is it causing them to atrophy? As in, I am just like giving the jobs to the LLM and my brain isn't engaged in it at all. And that's okay if there are just some things that you don't need to maintain as skills, and they take up a lot of your time and, you know, a chatbot can do it better.

34:07Fine. But I would argue that there are some skills that we're giving up that we would probably like to maintain. Like, I get emails from my colleagues that are very clearly written by ChatGPT. And I refuse to do that. Even though it takes me more time, I want to still be able to craft a nice, personalized, you know, truly from me email to my colleagues. I think that's incredibly important, right? Especially because that's a communication tool we use all the time. And when I know that I'm being sent chat GPT emails, right, that makes me think slightly less of, you know, just automatically makes me think slightly differently of the person who sent it.

34:49And then equally, you get into the scientific fields. And I also have colleagues who are using chat GPT to analyze their data and write their papers. And at this point, you're no longer a scientist, right? You are not developing or maintaining your scientific skills. You're just letting AI do it for you. So if you're a scientist, these are incredibly critical skills. If you start to give them up, then you're no longer going to be able to have those necessary skills to do high-quality research. So the alternative is you can use AI to help you do some things faster, but still require you to engage your own brain in that process.

35:32So I use ChatGPT to write statistical code for me. So I do a lot of data analysis from the work in my lab. All the work in my lab is done by real humans, hands-on stuff. It can't be automated. You can't have ChatGPT do it for you. I have my students design their own experiments, analyze their own data. But if you're trying to write complex machine learning code in R or Python, it might take you several hours to, you know, you want the output, right? You're thinking about the input, you're generating the data, you know what you want to get out of it. That can shorten a step by several hours. I think that's fine, because you're still engaged in the full scientific thinking processes that are required to do that work.

36:13So it really just comes down to thinking about are you able to improve or are you giving up skills that you actually really want to maintain and that's then going to apply to whatever technology we have ahead of us so you can still you know dramatically upskill but it just requires you to make sure that you're still engaging in these processes and not giving up these things to the llm or whatever it is that comes next it's true it's like you know the word that i was looking for when i was trying to describe that was critical thinking. And there is a member of my team who is a nutrition student, she's in her last year, and we had a neuroscientist on here called TJ Power who was speaking to us about dopamine and like phone and stimulation.

36:57And she said to me that when she's in her university lecture, like 90 % of kids are on just chat to PT. Just the whole day. I am just really interested to see I mean, I think it's not that far till we have chips in our brain. And I'm like, what does that mean about our kind of future for cognitive decline or cognitive enhancement? Like, we just don't quite know. But I don't think we're that, I don't feel like we're that far away from this happening. So there are a few things again that come up. So one that we didn't cover yet was you worried about kids in schools. And there's huge pushback now in several countries and, you know, counties across the US, or at least, you know, at least individual schools.

37:40And now it started to gather momentum where, you know, there's just no phones in the school whatsoever, right? Some schools are even going back to like pen and paper tests. They're getting rid of tablets. I don't know what this will look like on a global scale, but people are starting to appreciate that at least during these critical periods of learning, you know, there's something magic about actually writing it down by hand. and there's something magic about engaging with the teacher and with your fellow pupils. So I think people are starting to understand that and we're starting to wind some of that back.

38:12So I'm a little bit less fatalistic around that because there's been such a big push and I think some of that will change and we'll just use the technology maybe in a slightly more targeted way. When you then think about your bigger technological advancements, I think that what's interesting to me is that some of the most promising technologies when it comes to at least treating neurodegenerative disorders, maybe recoveries after strokes, recoveries, recovering senses after we've lost them, actually just involve directly stimulating the brain. And that can be with electrical signals, with magnetic fields, with light.

38:55There's still a huge amount to be done there. But I think really some of the most powerful upcoming technologies come just from directly stimulating the neural tissue. And what you're doing is you're doing exactly the same thing. You're just like pushing energy through the system. By doing that, you're activating the mitochondria. By doing that, you're stimulating all these maintenance and repair processes. So, even though they're external, you're still leveraging that basic principle of stimulus being the thing that's really critical to brain function. So, I don't necessarily mind how we get there.

39:29I would prefer if it was you going to the gym and doing some bicep curls and then going to a language class or a dance class. But if the net effect is that we see less cognitive decline, we see more recovery from from strokes, then, you know, I'm good with it. You mentioned something there. We're still on, I know you have three models, well, the 3S model, and we're still on stimulation, but there's so much in stimulation to get through, but I'm staying on it. Yeah. Because you mentioned something there that was really interesting, senses. And I loved finding out about the importance of hearing and smell.

40:07And I think, you know, we're so acute to understanding about touch, but there's a lot of people that are very connected to, you know smell and that I remember taking rosemary into all of my exams and using that how much kind of research I mean it's kind of very nuanced but that was really and it also calms me like when I have sensory smell I find very I'm very connected to that you know I always think about losing your sight or your hearing and how much effect that's going to have on you and there's quite a lot of research here there isn't there so like how important is it to keep up maintenance with our hearing and our eyesight, because I don't know when the last time I had a hearing test or an eyesight test, but I probably should do after reading your book.

40:51So, like, why is this so important? There's a few different reasons why this might be important. And it also, it goes back to what you mentioned earlier, which is, you know, that kind of, that experience of getting older. and some of the ways that we either do, either we sort of lean into it, maybe in not a good way, and some of the ways that we resist it, and again, not necessarily in a good way. So, you'll often have people who, as they start to lose their hearing, right, you get this age-related loss of hearing called presbyacusis. They might be like, well, I'm just going to like muddle through it, right?

41:31Because once I have a hearing aid, then I'm definitely old. and also by the way i don't just think it's people getting older my old producer he is in his 30s and he's losing his hearing because he's worked with audio so much so i know quite a few people in their 30s who are saying to me in like the next couple of years i need a hearing aid yeah and it may there's there's also some interesting data just started to come out on like constantly using noise cancelling headphones because you're no longer processing sound in the normal way and And I don't yet want to sort of ring the alarm on that because we don't necessarily know.

42:06But there's certainly some doctors who are kind of worried about that, particularly with kids who just never learn how to process or filter out sounds. So then when they're out in the world without noise cancellation, it's very overwhelming because there's just like so much noise that they never really learned sort of how to filter out. So there's so much that comes into the brain through our eyes and through our ears. you know a huge part of what the brain does is actually filter that stuff out so you need to learn how to train the brain to do that but then once you start to lose those senses a few things happen so one could be that and so we know that people who have hearing loss or who have eyesight loss for instance with cataracts they have an increased risk of later dementia and sort of observational studies, you know, where you sort of look at people who did and didn't get cataract surgeries, those who do get cataract surgeries seem to then, that risk seems to be reversed.

43:05If they, so if you have cataracts, you have an increased risk of dementia, if you get cataract surgery, that risk is completely mitigated. Because you're bringing back in the stimulus. Because you're bringing the stimulus back in. Wow. They haven't done randomized control trials of that, but they have done it for hearing aids. And for those who are at a high risk of dementia because of cardiovascular disease or other physical health issues, if you have hearing loss and you get hearing aids, those hearing aids, getting the hearing aids significantly decreases your risk of dementia, which would otherwise be increased because of your loss of hearing.

43:35So rather than resisting. Rather than resisting. Right, which people can do also with glasses and being like, oh, I don't want to because I don't even know if this is true, but I've heard so many people say, well, if I get glasses, my sight's going to decline even more. So they kind of resist getting glasses. and I'm sure it's very similar to hearing aids. I'll just put up with it. Yeah, so there's two different parts to it. So one is actually there is some evidence suggested, particularly as your eyesight changes, if you try to, some of those changes are due to the eye ages, so the shape changes slightly, it gets a little bit stiffer, but then part of it is muscular as well.

44:19And if you're not using full ranges of your vision, then the vision that you have will kind of constrict in terms of the full range possible. So you can potentially retrain some of that by sort of trying to look at the kind of the edges of your current limits of focus. It's not magic. You can't prevent that entirely. But some of it is neuromuscular, and that means that you can train it. So some vision changes with age, we can probably slow down just by how we use our eyes, i.e. just like not staring at a screen in front of us the whole day, you know, spending some time looking further afield, occasionally at more complex things.

45:01and so that's part of it but then so as you start to lose sight and hearing one thought is that those losing senses increases the risk of dementia because you're just no longer getting those direct inputs in and the brain's like well i'm not getting any information to this part of the brain so i'm just not going to maintain that area of the brain so that's part of it but then probably a bigger part is that as you lose those senses you stop doing certain things right so if you can't hear as well, you're less likely to go out into busy social places because it's harder for you to carry on a conversation.

45:35Or if you start to lose your eyesight, you're less likely to go out at night, or you're less likely to go out and do certain things, drive a car. And so you stop, you get fewer of those inputs that we know are critical for maintaining brain function. So it's probably the combination of those two things that's really important. It's very similar with physical function. As you get weaker, you're more frail, you feel less physically capable, you go out of the house less, you don't carry your shopping anymore. And again, it's by stopping doing those activities, then the decrease in function accelerates.

46:14I'm interrupting for one moment to ask one small favor, please subscribe to the show. This helps it grow more than you know. and I'm so bad at asking this from you. I'm so bad at thinking about this. But you know my goal is 100 ,000 to get to on YouTube. And I really want to bring you more content and better guests and bigger episodes. And we can only do that with your help together. So please do hit subscribe. Thank you. I'm obviously feel fine with my eyes in it, but I'm still now like, I really should go and get an eye test just to check. Does it change do people get like laser eye treatment and things?

46:51Because that's been such a big thing in the last 10 years. I actually haven't seen any evidence of that. It may be because people tend to have that earlier in life. And I think the what's important is that. So like you say, I haven't had an eye test yet. If you haven't noticed that your eyesight has changed such that it's changing what you're doing, then you're probably fine. Just like if you never had a sense in the first place. Like if you were born congenitally deaf, that doesn't automatically increase your risk of dementia because you have other ways of interacting with the world that will allow you to get those those normal stimuli.

47:31So it's the loss of a sense and then the change in behavior that comes with that. Smell? Is that a thing? So smell. Because of Covid. Yeah. And there were there were some people that think that part of the reason you get the sort of post-Covid change in cognitive function and brain fog is because you no longer have that sense of smell that lots of people lost. Most people got it back, but some people had persistent changes in smell. And that was maybe part of the picture of like the long COVID. There is one study that actually used smell and has significantly improved cognitive function in a group of older adults.

48:09They had an essential oil diffuser that they had by their bed while they slept. They had seven different smells that they rotated through, like one a night. So one a night every week, and they rotated for six months. And they saw significant improvements in cognitive function compared to a control group. And they also did brain imaging and saw significant changes, I think it relates to areas of the hippocampus, which is really important for cognitive, particularly with memory, as we get older. So just novel smell as a stimulus seem to improve cognitive function. Again, this is in older adults.

48:50So exposing yourself to a wide range of new smells may be another way to continue to stimulate the brain. I know what I'm getting my parents for Christmas. So, the group that the academics who ran the trial, they now have a device that you can buy that does this. But it's quite expensive. How much? I think it's like$800. Whereas a$20 essential oil diffuser that you could just put by your bed would work just as well. So, you can get the fancy version, but I think just a regular essential oil diffuser will do the job in exactly the same way. So, before I move on to the next part, which is really important, I have to ask you about owls.

49:37Oh, yeah. People are like, where's she going with this? But you know why I'm asking you about owls. Tell me, why do you love owls? Not owls. Owls. Owls so much. So my entire book is written based on human studies in humans. You know, as much as possible of it is randomized controlled trials. Like, you know, obviously that's not possible with everything, like some of the things we've already talked about. But generally, like hierarchy of everything. So like, as much as possible, every study that I cite in the book, of which there are nearly 2 ,000, is from humans. But the preface of the book talks about owls, which kind of sets everything up and I think shows exactly the same things that I then sort of expand upon in the book.

50:28But there were essentially a series of studies done by a group at Stanford, Eric Knudsen and his colleagues, with barn owls back in the sort of 80s and 90s. And what they did is they took owls and then onto their heads, they kind of glued these little prism glasses. And what the glasses do, so like anybody who's familiar with the prism, it shifts light, right? So you have these prism glasses on. And so when you're looking straight ahead, what you might see and what you think is straight ahead is actually shifted slightly to the left or right. And they did a series of experiments. First, they showed that if you were a young owl and you put on these prism glasses, you would adjust really easily, right?

51:20You'd figure everything out and then you would just go about your daily business, no problem whatsoever. And then - As an owl does. As an owl does. And then, you know, catching mice and things, which is an important part of the study, actually, is the catching of mice. But then they put the glasses on older owls and they couldn't adapt, right? And so this sort of lends us to this traditional thought, was that, you know, the old brain can't change, can't learn, right? These are sort of like the old dogs who can't learn new tricks. But what really transpired was that the old brain just needs a reason to change, right?

52:00So as you've spent decades developing in your environment, your brain has become optimally adapted for you to perform well in the environment that you have. So you don't want it to just change on a whim, right? It's really important that your brain be good at the things that you need it to be good at. So when you're an owl sitting by yourself in a cage and your food is kind of just, you know, you dead mice are put in the bottom of your cage and you've got your prism glasses on, your brain doesn't really need to change because you're just like hop over, you'll smell the mouse, you'll eat, so you don't really need to do anything, right?

52:37So why does the brain need to change? You're like, it just continues. The world looks a bit weird through the glasses, but why does anything actually need to change? So then they showed that if you house the owls together, so you weren't just alone, but they were in a social group, then actually older owls could start to adapt because they're now having to sort of engage and understand the world around them. And then the final step was rather than have them just feed them dead mice, they fed them live mice, so they had to hunt. And then again, they found that their adult brain could adapt very quickly, but because it needed to out of necessity.

53:20You had to be able to figure out where the mouse was to be able to hunt it. And then the brain started to shift to re-represent the world now in this slightly shifted manner. And what this really just kind of tells us is that it's this continuous continuous engagement with the world that allows our brains to change regardless of how old we are. And it was like really nicely shown in these AL experiments. And then, you know, there's actually even older examples in humans where they give them these prism glasses. And so I have this excerpt from one of these studies where an individual was given glasses that completely flipped the world upside down.

53:59So this is an adult. And for like five days, they're like tripping over everything. you know, they're trying to like walk on the ceiling and they can't really do anything. But then by like engaging with the world, like they had them riding tricycles and drawing and fencing and doing all these things that sort of requires them to engage with the world, their vision flipped up upside down within a few days. So like within a few days, even though their glasses are telling them that the world is the wrong way around, it just adapted so that everything looked the right way around. But again, that required them to like continuously engage with the environment.

54:33So all of this tells us that our brains can actually change a huge amount, even as adults, but it requires us to give our brains a reason to change and to continue to engage in the world in some way. I guess this boils down to making sure that we try to keep, it's hard because I feel like our environments are so complex, like we live in a very stimulated world. So is there a difference of living in a hyper-stimulated world that ultimately a lot of people say like we're killing our brain cells because we're overstimulated but creating stimulated environments that aren't overstimulating us yeah i think that's a it's a really important question because and it's one of the reasons why i quite like the fact that the the the book is called the stimulated mind and it wasn't my title it was my my editor came up with the title because most people would be like boy aren't we like overstimulated like why is that isn't that isn't that a bad thing?

55:28And I think it comes down to what these stimuli really are, and then the changes, sort of the downstream changes that they create. So what we're doing less of is engaging with the real world in real life, learning complex skills with real people, doing difficult things where we fail and make mistakes and learn. And like, that's what really drives these sort of big changes in the brain. And what we're doing more of is just continuous, low-level task switching, distraction, low-level stress, constant meetings, never actually taking time to switch off. And so the stimuli that we have are much less complex, but they also never stop.

56:21And so one really critical part of stimulating your brain from a beneficial standpoint is that you need then time to recover and adapt afterwards. So it's exactly like, you know, going to the gym and lifting weights or running, sprinting. Everybody knows you don't get stronger and fitter in the gym, you get stronger and fitter when you recover afterwards, right? And that's why professional athletes spend so much time investing in recovery, because that's really where you sort of make the physical adaptations and the physical gains. And so this is why, you know, when you asked me earlier, is sleep the most underrated tool for brain health?

56:55I sort of ummed and ahmed because sleep is so critical. It's this time when your brain does adapt and recover from all the complex stimuli that we give it. But I think that the right type of cognitive stimulus is probably the most underrated sort of tool for maintaining or building brain health. but it doesn't work unless you sleep and take time to rest and recover afterwards because that's when the adaptation happens because that's your second part of the three s's and i think the thing with sleep i mean i've just been in like two weeks of england la mexico la new york and i'm talking now about sleep ironic but i think it's about the quality right the quality of the sleep is the important part because you can have eight hours sleep but you might not be getting good quality sleep and you might be using sleeping aids and all of that type of stuff to get you to sleep um so i guess like is it really important about the quality of the sleep or the duration of the sleep so there are several sort of fundamental parts of of sleep that that are important and And that's both those things that you talked about just then, but then also like the actual mechanics of the different stages of sleep and how they sort of interact.

58:16And all of this is important. And you're right that we do need to attend to them. But hopefully we'll come back to the fact that, you know, that thing that you just mentioned doesn't have to be this thing that we then get really concerned and worried about. because what has kind of happened in a lot of spheres is that we've become so hyper-focused on sleep and so hyper-focused on data and wearables that we spend all our time worrying about our sleep. And then I think that can have a negative effect. There's now research to show that actually the one time that wearable actually isn't that helpful is when you obsess over sleep.

58:51Exactly. Yeah. Orthorexia. They've had to create a term for it. So my UX. No, orthorexia is for food. Orthosomnia is for sleep. But So there are technically four sort of parts of sleep that we can think about. Quality, quantity, regularity, and timing. I don't talk about timing that much because timing isn't something that most of us necessarily have a huge amount of control over. And so the timing part is, when do you sleep relative to your chronotype? And everybody has slightly different chronotypes. Some of that is influenced by the environment. Some of that is influenced by genetics. but you have a job that happens at a certain time and you have kids and responsibilities and things.

59:33So it's like, it's not always possible for most people to actually sleep in perfect time with their chronotype. I don't think so. So I don't focus on that as much, but I think we can get most of the benefit, if not all of it, by focusing on the other three. So quantity is the amount that you sleep. And the risk for dementia really starts to increase when you consistently sleep for fewer or less than six hours a night. So it's actually, you have to be quite sleep restricted for long periods of time to see really significant increases in dementia risk. You know, seven to nine hours is probably the average target.

1:00:11I know some people say eight to nine, but I think the data probably say seven to nine. But in reality, it's so different from person to person and even within a person, your sleep need changes, right? I need to sleep more if I'm training harder or if I'm sick, right? So women on a menstrual cycle, I need to sleep more in my bleed stage than in my like little phase. Exactly. So like me telling you that you have to sleep eight hours every night is not very helpful, right? Because that's not necessarily going to align with your, with your own needs. So I think like seven to nine and then it'll be like the outer bounds sort of like six to 10 hours, like somewhere in there is going to be your perfect amount of sleep.

1:00:47And so if you're not regularly getting enough sleep opportunity to hit that, that's a big lever that people can pull. So then quality is the next one. So you mentioned, right, you can be in bed for 10 hours, but if you're constantly tossing and turning, you have a high sleep onset latency, or it takes you a long time to fall asleep, or you're waking up in the middle of the night, then that's a big problem. And equally, like you mentioned, one way that we measure quality and how we know that poor sleep quality is associated with an increased risk of dementia is the other things that we do in order to try and help us sleep, like alcohol, antihistamines, certain other tranquilizers, most of which impair the individual stages of sleep.

1:01:33So like alcohol and Ambien cause a REM sleep deficit, a relative REM sleep deficit, which then can cause issues down the line. So quantity is important, quality is important, And then regularity is increasingly appreciated as being important as well, which is sort of a line, you know, how regular is your sleep time relative to sort of your circadian rhythm. And we know that in general, deep sleep happens earlier in the night, REM sleep happens later in the night. And that's true both in terms of your sleep period, but also in terms of the clock time. so you tend to get more sleep more deep sleep slightly earlier in the night and then more REM sleep later in the night so when you sort of have more regular sleep right you're going to bed at a similar time you're waking up at a similar time that seems to be associated with the best sort of long-term health outcomes there are some studies they haven't looked at dementia but they've looked at things like cardiovascular risk and they suggested that regularity was more important than quantity and quality but it's probably a little bit of everything I think but So those are the main parameters that we should try and address as much as possible.

1:02:45And I think that's, for a lot of people, they may have very complex cognitively stimulating jobs, they may be learning lots of skills, they may be very socially active, maybe they've got the stimulus part covered. Then I think the next important thing that's really critical is, well, are they giving themselves enough time to sleep? Is that regular enough? Are they giving themselves the opportunities to recover and adapt from all those stimuli that they're getting. The mental offloading. Yeah. That's such a big one. So many people, even recently, I was on a trip, press trip, and, you know, one was like, I've had struggles with my sleep for so long, and I wake up at 3am, and Dr.

1:03:23Andy Gelpin came on, who you know very well, and he was saying, we did a whole episode on sleep, and he was saying it's such a common problem, and it's the mental, it's the overstimulation, which is like what we've just been talking about, of actually, like, putting things down on paper and trying to create, a system where your brain knows it's ready to sleep. Because I know when I'm traveling, I find it really hard to sleep because my brain is constantly on and there's no routine. Because my brain and body is like, what time zone am I on? I'd be really interested to know if people that are like pilots have an increased risk of dementia or not, because they're constantly flying between time zones?

1:04:05I'm not sure I've ever seen a study on pilots and dementia risk. But you would, you know, there's a number of reasons why that, why that job could be associated with a higher risk. It's equally, it's probably quite, you know, particularly in the learning phases, it's probably quite a cognitively stimulating job. So maybe some of that offsets it. But, you know, there's a circadian rhythm issues. And we know that shift workers certainly have an increased risk of dimension. This is essentially constant shift work. Plus, as a pilot, you know, most of the day you're sedentary, right? You're sat down, there isn't a huge amount of space to move.

1:04:43So it's certainly possible that you could see potential increased risk. But I don't know if I've seen that study. If somebody has that study and send it to me, I'd love to see it. Yeah, please, I want to know as well. I'm sorry if you're a pilot listening to this at the same time so the last one i have to just touch on very briefly we spoke about this in our last two podcasts so i feel like we don't need to definitely go and listen to the other two because we are basically all on nutrition last time but i can't like not finish this podcast without talking about nutrition my world house yeah we've been talking about this a lot um and obviously it's a third s the nutrient supply yeah and it's interesting because we align exactly like word by word from what I've written and what you've written.

1:05:27It's like we've crossed notes, which makes me very happy when I read The Stimulated Mind. But you mentioned key nutrients. I think we have a very similar view that it's food first. The quality of your food is really important. But obviously there are key supplements that can also help, especially if you're plant-based, you won't be getting your long-chain omega fatty acids. So you talk about long-chain omega fatty acids, vitamin D, magnesium, your favorite, creatine. And I'm also going to put hydration in there because I'm really glad that you put that in because we know that 2 % dehydration already starts affecting our cognitive functioning.

1:06:08So when we're looking at like those supplements, how much of a role does this play in dementia as a whole? Is it just good for like cognitive performance or is it actually key to reducing like dementia risk? I think I'll start because you've mentioned the individual components, but I guess I'll start by just mentioning the model and what it looks like, because this is kind of what the book builds up to, right? I have a chapter on each of these different areas that we talked about, nutrition, exercise, stress, sleep, all these different things, and sort of like tools to kind of improve those and how they're related to cognitive function and cognitive decline.

1:06:44But then I'd sort of bring them together in what we call the 3S model. So the 3S is stimulus, supply, and support. So stimulus are all the things that we've talked about. And we can think about this very similar to how we would think about, say, lifting weights to build muscle. So if you want to build bigger muscles, you have to lift weights, right? The stimulus is the most critical thing. You can improve how much strength and muscle you get from a specific workout regimen by having better nutrition and by sleeping more, right? Because you get more rest and recovery. But you can't just take naps and chug protein shakes.

1:07:26You have to lift weights, right? And so stimulus is the core feature of what drives the whole system. But then once you've stimulated the brain, in order for the brain, the networks that you're using to do the thing that you want them to do, they need to bring in more blood supply, they need to bring in oxygen, they need to bring in some kind of energetic substrate, so that could be glucose or ketones or lactate, and then they need to bring in the nutrients that kind of build the synapses and run the mitochondria and all those things in those areas. So that's the kind of the supply bucket. And so it's supply of nutrients, but it's also having a good cardiovascular health, so good blood vessels.

1:08:04We talked about vascular dementia and how that overlaps, intersects a lot with Alzheimer's disease. So that's why what's good for the heart is good for the brain. We know that's really important. So that's kind of the supply bucket. And then the support bucket, we touched on sleep is one critical area, but then also avoiding chronic stress. So chronic stress sort of creates this hypermetabolic state in the brain where we can't fully recover, right? So that's like you kind of talked about the mental offloading and those things that kind of prevent us being able to rest and recover and sleep. and then avoiding things that sort of kind of impair that adaptation process like alcohol, smoking, air pollution.

1:08:40There was sort of a lot of things that kind of fit into that sort of support bucket, kind of making sure that we can adapt to the stimulus that we get. But if we come back to supply, the way I kind of think about it is I kind of give this journey through signal being sent in the brain, right? So you need energy in mitochondria. So you need, right, that's where a lot of B vitamins play a big role. And then you need the things that sort of make the neurotransmitters. So if that's acetylcholine, you're going to need choline. And choline is actually also critical to help build the actual membranes of the cells and the synapses.

1:09:19And choline is also sort of interconnected or converted into either serine, like, so phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine. I mean, these are kind of like the core phospholipid head groups that hold your omega-3 fatty acids in, hold them together. And choline, for no one that people don't know, it's like eggs and it's in meat and it's in all of these type of food sources. And then you need some minerals that are important for neuromodulation, so like magnesium and zinc are critical. Vitamin D is really important for actually synthesizing certain neurotransmitters like serotonin.

1:09:53So just by looking at that very simplified process, you've covered some of these core nutrients that I think pop up again and again. And it's not just these are important for sort of day-to-day cognitive function. We know that those who have poor B vitamin status, poor omega-3 status, lower vitamin D, if they're anemic or they have low iron, all of those are associated with a significantly increased risk of dementia, and they also compound. So there are actually now several studies that show that having multiple nutrient deficiencies or insufficiencies, so low vitamin D, high homocysteine as like a marker of B vitamin requirement, low omega-3s, these kind of interact to sort of like synergistically increase risk.

1:10:41And that's probably because they also synergize in the brain in terms of being able to play all their roles in terms of just the function that the brain requires on a day-to-day basis. I have a really key question here because I saw a clip quite viral on a podcast recently, and I'm not going to name what the podcast was, but it was hammering home the ketogenic diet. The ketogenic diet is the best diet for the brain. Having a nutritional background, I know the ketogenic diet is amazing for children that have epilepsy, and that's kind of where it started. And I think there's kind of a for and against argument for this, but what's your thoughts on the ketogenic diet for brain health?

1:11:21I think as a starting point, one of the reasons why I talk about nutrients for the brain rather than diets or foods is because I just want your brain to get the nutrients. I don't care where you get them from, if I'm honest, right? As long as you have enough of those things to run the machinery, you can do that across any number of different dietary patterns. Of course, that's easier if you have a whole foods, nutrient-dense, varied diet, because you're going to get most of those nutrients that you require. We haven't talked about antioxidant polyphenols and things like that, which can be really critical as well.

1:11:58And that's some fiber, which is not very high in ketogenic diet. Yeah. And the other part then, so if we're thinking about these different aspects of my supply bucket, right, so there's the nutrient part, and you can certainly get all the nutrients that you need that I mentioned from a diet that is either ketogenic or not. And I think one thing we should clarify is that any diet can be ketogenic if you're not eating enough of it or if you eat it in a certain way, right? So you can eat plenty of carbohydrates, but if you intermittent fast or you have a short time-restricted eating window or you have a low energy availability, you're not eating enough food, right?

1:12:37You will generate ketones. So I think very specifically what we're talking about here is a diet that's very low in net carbohydrates. And very high in fat. Very high and generally very high in fat. And you can get all those nutrients that I talked about in that kind of diet if you're sort of, you again get foods from a variety of sources and you sort of like tick all those boxes. but it's not necessary for brain health. But for some people, it can help you to overcome other issues that have already come up. So we know that low carbohydrate and ketogenic diets can be very beneficial in those who have insulin resistance or metabolic syndrome.

1:13:18And in that case, your supply of glucose substrate to the brain may have become impaired, which we do see in some cases of Alzheimer's disease. And so then ketones may be able to overcome some of that. So there are settings where if your supply is impaired, a ketogenic diet could be one way to overcome that. However, we also know that if you significantly improve your metabolic health through physical activity, improving your body composition, maybe improving other aspects of nutrient status, right? That ketogenic diet doesn't have to be the way that you do that. There are multiple different ways to skin that cat.

1:13:56So I am very pro ketogenic diets when they sort of help you achieve all those different things, but they're not something that's necessary for most people. And so there are some very interesting studies where they use MCT oil in individuals who already have some cognitive decline. You start to see improved brain energetics. You start to see improvements in cognitive function. These are still sort of relatively small studies. We haven't seen these big, large, randomized controlled trials yet. But if you have impaired ability of energy substrate to get into the brain, then ketones may be an alternative that get in more easily and you can sort of overcome some of those issues.

1:14:35So I'm not against them, but I don't think that they're magic because we know that there's millions of people around the world who don't get dementia and don't eat ketogenic diets. So then we haven't touched upon how they seem to be powerful in some studies with like bipolar disorder and some other mental health conditions. So I think there's a number of groups where ketogenic diets could be beneficial. I'm all for them, but I don't think that they're something that we need to prescribe to everybody. And sort of even beyond the diet itself, people have been talking about ketones for a whole range of neurological conditions for long periods of time, including myself but it's sort of this there's this promise of these diets and ketogenic supplements we just haven't seen really good studies yet like i want you know i've wanted this to be a you know really big breakthrough and we i think we're we're still waiting for that science to come in well i think this is the whole kind of end to the answer it's so nuanced right it's a nuanced topic but i do think that when it's just when one person dials a message so hard that's convincing that that's the only answer.

1:15:43And a lot of them people lose hope when they don't get the answer. Or they feel that everything they've been doing is wrong, which actually potentially not. There might be some really helpful things in there. And as you said, like it's so, we've had Dr. Chris Palmer on here, who I love and I think he's amazing. You know, and he'll talk about it for exactly what you were speaking about, like specific mental health conditions. But then you look at Felice Jacker, who did the SMILES trial, who also has looked at the modified Mediterranean diet, which is the opposite of a ketogenic diet. And that's also helped patients overcome chronic depression.

1:16:14So it's like there's so many different types of conversations. It really is so individual. But I think when people hear one message, they think that's, you know, well, I think we all do, because it's so convincing. And I think that's like the nuance of it. It's like, we just kind of don't really know. So even across all those people that you've mentioned, I think the sort of the core feature of all those diets is still compared to, say, a standard Western American diet that most people are eating. You've dramatically improved diet quality. You've dramatically improved nutrient density. Usually, even on most ketogenic diets that people who I trust would recommend, very nutrient-dense, include sources of fiber and polyphenol antioxidants and all these other things, where you're still including berries and plants and these kinds of things.

1:17:11Then again, I also know people who do very well eating nothing but beef, and I can't argue with that. If you're eating a diet and it allows you to do all the things that you want to do and you're in great health, I would never argue with that. But I think the main component, and so I actually, I mentioned the SMILES trial as an example in my book of like, here are some diet parameters that you can start to move towards because actually they're very easy to achieve and they will all significantly improve nutrient density, decrease calorie density, and improve diet quality overall. And so the common component of all those diets, be it ketogenic, plant-based, Mediterranean, I don't think any of them is individually magic.

1:17:56Everybody talks about the mind diet, the Mediterranean diet for brain health. But in reality, when they've done studies looking at individual components of those sort of like broader dietary patterns, there's no one food that explains the magic of the Mediterranean diet, right? It's the fact that it's nutrient-dense, much less calorie-dense than, say, a standard American diet, much less ultra-processed foods, much less hyperpalatable, much harder to overeat. All these things are important. And so I think, actually, there's a lot more commonality across these diets, as long as you don't argue about carbs versus fats too much, which I don't think.

1:18:37I think humans actually are adapted to both ends of that spectrum just fine, as long as you're hitting those other things. Yeah, I mean, it is the most polarizing topic online. Everyone's got something to say. But I don't know, I want to say we can all equally agree that reducing ultra-processed foods is probably the best step forward, but somebody will comment and say, no, it's not. So I'm like, that kind of. I can understand that too, because protein powder is an ultra-processed food, right? But if that's helping somebody achieve a certain goal, getting enough protein is certainly important ultra processing might involve adding in a bunch of bunch of vitamins right and fortifying it and then actually it's even better for you so I can understand why people yeah it's so hard because I can understand why people kind of get kind of get into it I guess my brain is like processed and then you have ultra process and it's hard because I guess the overarching is like you cut out crisps and cake yeah and fizzy drinks basically as things that just don't have any nutritional value in.

1:19:34But it's always going to be a polarizing, topical conversation. Everyone's got something to say in this space, and I always want to hear it. So I guess the big takeaway for me from reading the book, from talking to you today, is that although, well, first of all, dementia is actually declining, not rising. The age-specific incidence of dementia is declining. The overall burden of dementia is increasing. Yeah, okay. But there was one piece of hope in that first opening sentence, which I think is great. You know, that we need to be cognitive stimulated, but not over stimulated in the wrong way of doom scrolling, but like pushing ourselves out of our comfort zone, actually.

1:20:14And you said, I didn't pick up on it, but you said the word failure. Yeah. And actually I've come to learn that's been one of my greatest lessons. For me, like, you know, going through this podcast, I failed so many times in so many different domains, but actually it's made me feel way more resilient and stronger. and so like pushing that and I did speak to my parents before this conversation I felt like I was being a little bit preachy but you know you do have that fear with your parents that once they retire they slow down so really like understanding what that is and like how you can push yourself to stimulate your brain in so many different ways and also you know social interaction and things like that sleep and recovery as you were saying how important that is really have to think about my sleep routine at the moment, but also like nutrient supply and, you know, making sure, I mean, this podcast talks a lot about nutrition.

1:21:04So I feel like hopefully our listeners are like, you know, all kind of connected to that side of things, but it's, it's just, there's, there's hope that actually sometimes dementia, the overarching conversation of dementia or neurodegeneration feels like a life sentence to so many people and to their family. And actually now having the conversations that there's so much hope that you can work on prevention. Doesn't mean you can prevent every single one, but there are such big lifestyle factors and levers that you can push and pull to try in so many different domains. Gives it so much more hope than maybe we had before.

1:21:43I think that's like actually what's really exciting about this. The most important takeaway is knowing that we actually have a lot more control over this than than we might traditionally think. And you're right that we have to think in probabilities rather than certainties. And so any time I say exercise decreases dementia risk, or stopping smoking decreases dementia risk, then somebody will say, well, my granddad exercised a bunch and he's still got dementia. And that's very sad, and I'm not trying to minimize that. But we know that at a population level, these things are really important. So we can dramatically decrease our individual risk.

1:22:22But if we all change these things, we could have a massive impact on overall dementia cases, dementia burden. And we also need to remember that even though some of these studies are now just ongoing, by doing these same things, even if we do experience some cognitive decline, even if we do end up experiencing dementia, we can have fewer symptoms or improved symptoms by continuing to engage in these things. So even if you're unfortunate enough for a family member to get dementia, despite doing some of these things, it may have happened later, they may have had less severe symptoms, you know, it may have been, you know, less of a significant decline than it would have been otherwise.

1:23:02So I think there's a huge amount that we can do. And I'm very, very hopeful that actually it doesn't require a huge amount, doesn't require a huge amount of supplements or anything else, that, you know, sleep, physical activity, you know, all those things related to cognitive stimulus that we talked about can have a massive impact. Yeah. But equally, there's probably a lot that we have to do at a societal level as well, because if we really wanted to reduce the impact of dementia as much as possible, we would need to make education accessible to everybody, and we would need to make sure that everybody got access to the best possible health care and access to as sort of a stimulating environment as we possibly can.

1:23:45And we know that socioeconomic status plays a huge role here. So we just have to acknowledge that. And so hopefully there'll be some societal shifts at the same time. I think there will be. And I guess like without this being like another full answer, just so they know of our time, a lot of people are just saying dementia will be cured in like 10 years. Do you agree with that? There's going to be like a pill or medication? No, no, I would love to be proved wrong. Don't don't get me wrong. But the the current therapies that we have and the current targets that we have have just, you know, they only have very incremental benefit.

1:24:22And, you know, maybe it's, you know, some people argue that we're starting too late. You know, if you're starting to treat Alzheimer's once you already have Alzheimer's, maybe you should have been treating it 20 or 30 years earlier. These things were all possible. But I think because, you know, we talked about reductionism right at the beginning of the podcast, because we've taken such a reductionist view of dementia, largely focusing on amyloid and tau burden in the brain, which are a part of it, but they're not everything, I think we're kind of holding ourselves back because we've become so focused on just one small set of targets.

1:24:53Whereas all the things that we talked about today have a huge number of targets and a huge number of effects across the brain and the body. And that's probably why they're so impactful. So that's helpful because actually that's lifestyle and that's not drugs. So that's also another added benefit because you don't really get side effects. But equally, I would say that, so imagine a scenario, you know, we haven't talked a lot about amyloid and tau, right? These are the proteins that sort of accumulate in the brain and are misfolded, you know, in individuals with Alzheimer's disease and certain other dementias and actually certain other neurological conditions.

1:25:27And by removing those things, because they can have a direct negative impact, they can be neurotoxic, right? This sort of like can kill neurons and other cells in the brain, cause chronic neuroinflammation. If you had a drug that removed those things, and we actually do have drugs that remove those things, you would still need stimulus and these other things in order to promote repair and function, right? So even if we have drugs that have a huge impact on dementia, which I hope that we do someday, right? I would like, I would love dementia to be eradicated as a disease. I still think that these things are going to be important because if you remove some major disease-causing process, if you want to then create function again, that's basically going to have to come through stimulus and nutrition and all these other things that we've talked about.

1:26:21Sleep is going to remain critical regardless of the therapies that we have. So even as therapies improve, I think all the things we talked about today are going to remain really relevant. They're going to be really good. Well, it's similar to SSRIs, right? We can also treat depression, but it's also really important to make sure that somebody's still feeling nourished and gets exercise and gets sunlight. Like, that's still really important factors for mental health, even if a drug is really helping. So I haven't looked back on our last episodes to know what the answer was, but I always leave with the same question, which is, Tommy, what does live well, be well mean to you?

1:26:58I can't remember what I said before either, so I might say the same or something. That's also interesting, whether you change it. Or something completely different, so people can go back and compare. But because we've focused so much on the brain, I think what it means to me really is maintaining brain health. And what I mean by that is having a brain that does the things that we wanted to do when we wanted to do it. And that gives us so much scope to personalize that, right? Because what I want my brain to do is different from what you want your brain to do. And what I'm good at is different from what you're good at.

1:27:40And that's what's so amazing about human brains. And that's, I think, something that we should embrace, right? That's a big part of this whole process. So that's what it means to me. And it gives us so much scope to do things differently, be our own people, engage in the processes and the things that we want to be good at. And I think that process of engagement is really what drives that whole process. With the neurodivergent brain here, I agree. You don't want to be in my brain. Thank you so much for coming on. Wait, that was that negative self-talk right at the end there? It was. Well, no, I mean, I use it now as a joke.

1:28:14okay because now i'm very it's a very abused term but i use it as a superpower all right um but as in it's just chaotic in there there's a lot going on it gives me great ideas but it's just chaotic um in the best possible way you should have my friend chantelle pratt on your podcast okay wrote an excellent book called the neuroscience of you and she's writing a new book all about individual differences in learning but basically a whole of ex whole area of expertise is individual differences in brains and why that's so important and so cool it's so important and i honestly think i should get around because the linear system of school i can believe can take us out of that individualism of understanding our brains it did for me and then this show's brought it back which has been amazing well i'm very excited for your book to come out simulated my when's it out when people can go and buy it it's out uh march 24th in the u.s march 26th in the UK.

1:29:07It's available now from anywhere that you might like to buy your books. I always love it if people are willing and interested to pre-order it because that can definitely help sort of the publisher and people think that, you know, there's interest in the book. But yet next March, it will be on all shelves near you, hopefully. Amazing. Well, we'll be putting a link in the show notes that you will send us. and thank you so much for coming I'm so glad we could do this in person in New York this was so great it was amazing