The Melanie Avalon Biohacking Podcast Episode - #367 - Dr. Tommy Wood

TRANSCRIPT

Dr. Tommy Wood
It's not like sleep only affects one pathway, or exercise only affects one pathway, or nutrition only affects one pathway. These things affect multiple pathways at the same time and sort of really synergize such that small changes can, can have big impacts.

Each of us is intelligent in a slightly different way, and each of us has the same capability to learn and engage with material that we're interested in. There's gonna be some influence of the environment and the other things around us that will determine whether we're able to express and engage those tendencies or not.

Melanie Avalon
Welcome to the Melonie Avalon Biohacking Podcast, where we meet the world's top experts to explore the secrets of health, mindset, longevity, and so much more. Are you ready to take charge of your existence and biohack your life? This show is for you. Please keep in mind we're not dispensing medical advice and are not responsible for any outcomes you may experience from implementing the tactics lying herein.

So, friends, are you ready to join me? Let's do this. Welcome back to the Melonie Avalon Biohacking Podcast. Oh my goodness, friends, my brain is on fire in a good way after today's episode. I absolutely adore Dr. Tommy Wood's book, The Stimulated Mind, and was so excited to talk to him, and this conversation blew me away. Tommy's book is one of the most thorough, comprehensive, and inspirational books I have ever read when it comes to everything supporting your brain and warding off cognitive decline. Tommy is so kind, and we dived into so many incredible topics in today's conversation. Things like: What is the one thing to prevent dementia? What does intelligence actually mean? How can you boost memory and enhance focus? Should you multitask? How does AI affect the brain, and how should you engage with it in the most healthy way possible? How do alcohol, caffeine, and nicotine affect the brain? And so much more. Today's conversation will likely give you a whole new perspective on all things your mind. The show notes for today's episode will be at melonieavalon.com/stimulatedmind. Those show notes will have a full transcript as well as links to everything that we talked about, so definitely check that out. I can't wait to hear what you guys think. Definitely let me know in my Facebook group, IF Biohackers: Intermittent Fasting + Real Foods + Life. Comment something you learned or something that resonated with you on the pinned post to enter to win something that I love, and then check out my Instagram, find the Friday announcement post, and again, comment there to enter to win something that I love. All right. I think that's all the things. Without further ado, please enjoy this fabulous conversation with Dr. Tommy Wood. Hi, friends. Welcome back to the show. I am so incredibly excited about the conversation I am about to have. So the backstory on today's conversation, a few months ago now, one of my dear friends who has also been on the show, Andrew McConnell, check out that episode, he offered to introduce me to the incredible Dr. Tommy Wood for his book, The Stimulated Mind: Future-Proof Your Brain from Dementia and Stay Sharp at Any Age. And I was an immediate yes, obviously from the endorsement, but also just in general. I'm a little bit obsessed with all things the brain, which is kind of evident having a podcast. It's really because I just love learning. Like, I could just learn all day, every day, and so anything about the what we do with our mind is an immediate, immediate yes for me. And then actually, Tommy, we booked you for the show, and then I think literally, like, maybe a week or so after you were on, your Joe Rogan episode came out as well, which was epic because I love that show.

Melanie Avalon
So then dove into the book and oh my goodness, friends, this is hands down... So I've, I've done a lot of episodes on different aspects of brain health on this show. I, I do think this is the most comprehen- okay, the probably the deepest dive, the most comprehensive.

I was just blown away with everything in this book. So it covers all things brain aging, you know, the current science on dementia and Alzheimer's and all of that, and then all of the factors that affect the brain, the role of diet, the role of exercise, the role of literally retirement and, and social networks, and you learn all about memory and how we focus, and there's a, a love of planning and scheduling, so I was, I was down with that. Um , but there's just so much in here. I am, my mind... Well, my, my mind is blown, appropriately enough. So, um, yeah, I've been looking forward to this for so long. I have, like, 50 pages of notes here, but don't think we'll get to all of it. Tommy, thank you so much for all that you do, and thank you for being here.

Dr. Tommy Wood
Thank you so much for having me. I'm really excited to be here.

Thank you so much for, for reading the book. I'm really glad you enjoyed it. I, I will say that, you know, you, you sent me a list of potential questions up front, and this is definitely the most well-researched list of questions I've ever been sent for a podcast. So I was super impressed with that.

I doubt we can get through all of it, but hopefully we can, we can tick off a good number of, a number of these topics.

Melanie Avalon
I love it so much, and spoiler, that was the, like, the toned down version. The, the original document was, like, three times as long.

I will say, so really quickly, there were a few different moments where we had things, like, weirdly and similar in common. You liked m- musical theater. I'm, like, a huge musical theater person. And then also, y- I, I love that you keep your... I keep my temperature at my bedroom at 62 degrees exactly. That is, like, the perfect temperature, and I actually get in trouble with my, my apartment complex because they come and tell me I can't do that. I'm like, "I'm paying for the air conditioner. I like, I think I can." In any case, and there's a reason for that with keeping the room cold for your brain, but re- or for your sleep.

Regardless, to start things off, your personal story, which you do talk about a lot in the book, so we'll let listeners, you know, read the book to get your full picture. But did you have an epiphany? No. There's so many, so many puns in this. Did you have an epiphany someday about your interest in brain health? What, like, what led you to actually doing all of this work today?

Dr. Tommy Wood
That's a, that's a great question, and in reality, there was no big epiphany. I, I sort of, I woke up one day a few years ago and I realized, oh, hey, I'm, I'm a neuroscientist and I'm an expert in the brain, and I just sort of like this, like, just happened o- over time. So I did most of my academic training in the UK, undergraduate degree, medical degree. Worked as a doctor for a couple of years before doing a PhD in physiology and neuroscience in Norway, actually, at the University of Oslo. And that PhD came about because of a lab I did some work in when I was an undergrad. It was a, a friend of my mom's, she was a professor who had a lab, and I spent a couple of summers working in that lab, and it was a neuroscience lab, and we were looking at ways to treat babies with brain injury. That's something that my lab at the University of Washington still does. I'm a, I'm an associate professor there. But I'd never really planned to get into neuroscience.

This was just kind of something to do a little bit of research, as you often do when you're, uh, as an undergrad. But sort of alongside my clinical work training as a doctor, my sort of formal academic work working in the lab, I also was very interested in athletic performance and working with athletes. So I was a rower in college. I was head coach of the Oxford Medical School Boat Club. I coached a lot of rowers. And then during my PhD, I started a... Or I helped build a startup company that worked with athletes of various levels, you know, from sort of weekend warriors through to world champions and Olympians in, in various sports, just trying to help all aspects of their health and performance. We did blood work, we did stool tests, we did urine tests. We looked at all aspects of training and lifestyle to try and see how we could help people's, uh, performance, and that sort of has continued over time. Right now, most, most of the work I do with athletes is in Formula 1. But sort of, I had these two parallel tracks. One was sort of like very formal, clinical, academic. The other one was sort of applied, you know, working with athletes. And sort of, I-- doing the work in these various fields, I sort of saw the same stuff again and again and again. And then a lot of the stuff I was doing working on, you know, physical performance, cognitive performance in athletes mapped very closely onto the stuff I was doing related to injury treatment or prevention, dementia prevention, and sort of all of it came together and made me realize that actually everything that I was doing in one way or another related to brain health. And so that was kind of, those things came together and now my lab and academic work and, you know, writing the book and podcasts and things like that sort of have brought all those different strands together, hopefully in ways so that I can translate some of the science of what we know about brain health to help people improve how their brain functions on a day-to-day basis, and then ideally long-term decrease the risk of dementia.

Dr. Tommy Wood
But it was really this sort of, I was just doing the things that I was interested in, and all of a sudden I just realized that, hey, I'm sort of become a- an expert in brain health almost by accident.

Melanie Avalon
I love it. And interestingly enough, so it's kind of like a metaphor in a way for the book because... So the idea that there are all these different things that aren't necessarily the one thing, but then they all related together and you realize you're a neuroscientist.

It's like the, the theme of the book, one of the themes of the book, which is that there are all these different factors that affect brain health and there's not one thing, but they all, you know, come together and, and, and affect each other and, you know, that that's more beneficial. Realizing like, I think you say something about like zooming out rather than zooming in, so like we tend to be really reductionist and... 'Cause you, you say in the book about how like with F1, that they always wanna know what's the one thing to do.

Do you... Is that like the question you still get a lot? Like, "What is the one thing to do for brain health?"

Dr. Tommy Wood
That is, uh, a question that I get a lot, and I, I do, I do quite l- like it as a, as a question because the, the alternative i- is what we often see, you know, in books, in podcasts, on social media, which is, "Here's a list of 20 things to do." And I think one of the reasons why Andrew and I, who, who you mentioned, one of the reasons why he and I got along so well is because, you know, the, the work that his company is doing realizes that if you tell people 20 things, they'll do zero things.

Whereas if you can find that one thing that you think is gonna move the needle, that they feel good about, they feel it's doable, then sort of like this whole system shifts in your favor because you're really, when you're doing one thing, you're actually doing many things. Because it's not like sleep only affects one pathway, or exercise only affects one pathway, or nutrition only affects one pathway. These things affect multiple pathways at the same time and sort of really synergize such that small changes can, can have big impacts. So yeah, you know, a lot of the work that I do, especially in that kind of environment where people are so time limited, which is actually very similar to the rest of us, right? We're all v- we're all very time limited, and we're all trying to figure out how we can feel better and perform better, but ideally without it being overwhelming or unsustainable. And so then it really comes down to thinking about where can we have some impact in something that, at least to start with, isn't gonna create a lot of friction, is very doable, somebody's gonna enjoy and/or is sustainable? Because we know from there it can have a really big knock-on effect. So that's, that's what I, I spend a lot of my time doing, is sort of refining down a, a massive, you know, possible list of things to do to just like one thing that, that somebody can start to move the needle on.

Melanie Avalon
It's so interesting, especially you have a section where you talk about kind of within, within different categories, you know, if you were to do one thing, so, you know, like in diet... And this, this is not the takeaway of the episode. The takeaway is not eat sardines.

Like, I promise. I promise.

Dr. Tommy Wood
I think that's a good ta- it is a good takeaway, but...

Melanie Avalon
I mean, it could be eat sardines. But you know, like a really practical, implementable thing that within these different categories that people could do.

You talk about, and I, and I'm not sure, like, when this comes up in the book, and it might come up multiple times, but you say something, and I'm paraphrasing, to the effect of, like, the importance of us, of our brain engaging in the world. Again, the book is called The Stimulated Mind, so there's this concept of the engagement of the brain and the brain being stimulated, and then the, like a, a sentence or like an explanation of it was that it, it gives the brain... Like, like as long as the brain has like a... is engaged and has a purpose, then it has a purpose to keep going. Does it really work that way? Like, does the brain really... I, and I get... When I was reading the book, I was getting so in my head, like thinking about thinking and everything. But do you think there is that, that purpose in the brain where just being engaged and stimulated is a reason that it would be anti-aging because it's gonna keep going and engaging?

Dr. Tommy Wood
Yes. I think you can boil it down that far or at least some, some version of that. And this is true actually of pretty much any tissue in the body. So the function of tissues, and we can be talking about bones, we can be talking about muscles, we can talk, talk about your heart, your liver, your immune system. Their function is driven by the demands that are placed on them or the stimuli that they're exposed to, right?

So we know that's the case for, right, if you wanna get bigger and stronger, you lift weights. If you want to improve, like, cardiac efficiency, you do some kind of cardiovascular training. If you want to improve the strength of bones, right, then axial loading, right? Again, weights, really important. The immune system responds to stimuli like infections or vaccines. The liver improves its ability to deal with toxins like alcohol if they're exposed to toxins like alcohol. That's not like a, a recommendation that you should drink more alcohol to make your liver function better, but, but you know what I mean. Like, the... Your, your body responds to these challenges by improving its function in that area, and, and the brain is essentially the same. Many of the biochemical pathways that you see in muscle tissue in response to exercise are actually very similar to the, uh, biochemical pathways activated in the brain when you stimulate brain networks. And a few years ago now, a friend of mine, a c- good friend and colleague, Josh Tuerkner, who's, who's neuro- a neurologist, we wrote a paper basically out- do- outlining this idea that one of the primary reasons why we lose cognitive function with age is because we stop using our brains in a way that challenges them, because it's that challenge that builds capacity. And we see this early in life, so education, educational attainment, probably the biggest predictors of early life gains in, in cognitive function. And then how we use our brains as we get older determines how or whether they decline. So people who do more cognitively stimulating work or engage in more cognitively stimulating hobbies and activities, they're more socially engaged or they feel like they have purpose. Their brains age less and decline less over time, and this is because you're continuing to stimulate them.

On the other side, if you remove stimulus, just like you stop training, right? If you, if you stop going to the gym, you'll lose muscle mass, you'll lose strength, and the brain essentially seems to be the same because we're no... if we're no longer stimulating the connections between neurons and all the other cells in the brain, then those connections become weaker. They start to be removed, just like muscle mass starts to be removed if we, if we don't use it, and then that can precipitate a decline in function. So really, this huge primary driver of how our brains function on a day-to-day basis is what we engage with, how we engage our brains, and how we challenge and stimulate them, which builds and main- then maintains function over time.

Melanie Avalon
It's so fascinating, and I guess the, the layer that I feel adds complexity, 'cause it's interesting comparing it, you're say- you know, to all the different tissues in the body. Presumably... I'm thinking about it, just confirming in my head.

Presumably all the other tissues that are not conscious don't really, like, have a... They just, they just respond, right? Like, they, they just do the thing when stimulated, and the brain though could choose not to, you know? Like, given the stimu- like the different stimulus, the stimuli that it faces. Like, we have to actually want to engage. So is it like the one tissue where it, it faces the things but it can decide just not to engage?

Dr. Tommy Wood
So that's absolutely true, and I, I think that the, you know, the primary reason for having a brain is to promote and ensure survival of the body and, you know, from there, you know, the, the sur- survival of your genetic line, be that either through reproduction or in post-reproductive years looking after your progeny and children and, and, and community. There's lots about human evolution that suggests that it's not just about reproduction.

It's also about supporting those who you're re- you're related to later in life. So if it's kind of a survival mechanism, you, you, you can see that early in life, children and adolescents or with a developing brain, it's constantly seeking input. Right? It's constantly seeking to learn from and be challenged by the environment, right? Kids are always testing the limits, be that physical or, you know, what, what they can get away with. And they're constantly trying to learn movement and social connection and language and trying and failing and learning from there. This, I, I think is this, you know, f- a fundamental driver of human engagement, is trying to gather information, especially social information, but trying to gather information from the environment in order to maximize the likelihood of survival. Part of the problem, though, is that at the same time we are in some way hardwired to minimize unnecessary energy or effort expenditure, right? Because evolutionarily, that wasn't really an option that we had available to us, where we had to do a lot of physical work to, to gather food, and we had to do a lot of physical work or cognitive work to, you know, keep our tribe alive and pass on the knowledge that we had, right? This is one of the... We are one of the uses of older adults in sort of the history of humanity. And so if we're trying to balance our efforts in the modern environment, we can now get away with not exercising. We can get away with not doing cognitively challenging stuff because really our environment doesn't demand it of us. And we've gotten to a point now where we have to actively seek it out because we're... Even, even though the brain is primed to try and get important information in order to adapt and survive, we've created an environment where that's not necessary to... That's not necessary for survival. So we're, we're kind of battling two drivers at the same time. And just like we've engineered movement out of the physical environment, so we've had to invent exercise, we've now also gotten to the point that we've engineered out cognitive challenges in ma- on many fronts so that we now have to go and seek those out as well. So I think that there's this fine balance between what our brains thrive on in order to build, uh, and maintain capacity and what the modern environment actually requires us to do for survival on a day-to-day basis, and those things may not necessarily be aligned. However, just like physical activity is sort of... The, the requirement of physical activity is, like, hard-coded into our physiology.

Dr. Tommy Wood
Like, our bodies require physical movement in order to function at their best, and, you know, we can measure that as being anti-aging. Physical activity is probably the one thing that either prevents or reverses all of the documented hallmarks of aging.

But... So it's, it's a basic requirement of our physiology. And now I, I think we, we've gotten to this point where cognitive inputs are becoming engineered out of the environment that we have to physically engage or, or, or, or seek them out because they're not, they're not as necessary as they were historically. But again, in order for the tissue to function at its best, your brain to function at its best, these are the core things that you really need in order to build and maintain first the structure and then the function that comes with it.

Melanie Avalon
Yeah, and especially with things like AI, which we can definitely circle back to. A quick question before that. I'm really curious how level of intelligence relates to that. So I've been... I'm really, really fascinated by intelligence.

And so when was this? Maybe, like, a decade ago there was a... 'Cause I mentioned, like, musical theater in the, in the beginning. So I went to film and theater school. So I saw a casting for a game show, and you had to be in Mensa for it. And so I went down a Mensa rabbit hole, and I, like, revisited the intelligence test, like, as an adult, and I, I started taking the test, and I was like, "Oh, this is, like, so..." It seemed like it was just a pattern. I was like, "I could easily figure out how to take this test." Like, I don't understand how this is measuring intelligence once you know how the test works. But my point is, I'm really, really intrigued by intelligence. I'm intrigued by, like, are you born at a, with a certain IQ? Does it change? Y- you talk about something called crystallized intelligence in the book. Bringing it back to what we were just talking about, I think there's this stereotype out there where people who are super intelligence, who's... People who are, you know, really high IQ, that they're always, like, thinking and learning and, and all the things. So do you know if intelligence correlates to the drive to be intelligent? Does it, like, self-sustain itself for some reason? Or can you be re- really intelligent and, like, not really though think a lot?

Dr. Tommy Wood
So the, the funny thing about all of this... Well, there, there are actually many there are many funny things about all of this. I th- I think one of the most interesting things you realize when you spend a lot of time looking at cognitive function, and I'm using that v- you know, very, very broadly on purpose, is that it's really hard to measure it. Like, what even is it? What is intelligence? And you, you could ask a dozen cognitive neuroscientists what intelligence is, and they'll give you a dozen different answers.

And so historically, we have thought that intelligence was synonymous with IQ, right? The intelligence quotient. But IQ is one very specific thing, and it's usually, like you mentioned, it's, it's essentially some version of non-verbal reasoning that involves a lot of pattern recognition. But maybe, you know, maybe some of the tests include arithmetic or, you know, basic math, some o- some other, some other things like that, and just the ability to do that quickly. But a, a lot of it is sort of like reasoning of some kind. Those tests were deve- developed initially, or, or one of the reasons those tests were applied was to show that men were smarter than women.

Melanie Avalon
Oh.

Dr. Tommy Wood
The history of, of the IQ test is both sexist and racist. I- IQ tests were essentially designed to show that white men were smarter than everybody else. And, and anybody's welcome to, to look this up. I realize that's a, a potentially inflammatory thing to say. But that's kind of the core of what these tests were.

And but the reason why, you know, you go a hundred years back in time or... The reason why white men were better at these tests is because they were the ones who got to go to school, and they were the ones who learned how to do these kinds of tests. So part of the reason that it's hard to measure intelligence is because first we have to decide what intelligence is, and I would argue that each of us are intelligent in very different ways. And intelligence shouldn't be just boiled down to the ability to do some kind of reasoning task, because it could be related to artistic talents or linguist- linguistic talents or social talents, which, or you are obviously very different, but all are all very important. And so when you look at these traditional tests, the people who do best are the people who get to go to school and spend more time in school because they get better at taking tests. That's, that's one of the reasons. That's one of the reasons for that. But when you sort of step back a little bit, you see that there are some core functions of the brain that all of us would hope to have. The ability to process information quickly, the ability to make decisions when we need to, the abi- the ability to kind of, you know, control our thoughts and emotions, uh, the ability to remember things on a day-to-day basis, whether that's sort of semantic knowledge or episodic memory, so remembering things that have happened to us. You do see that those people who spend more time engaged in cognitively stimulating activities do tend to do be- do tend to be better at those things. They tend to have faster processing speed. They tend to have... be better at certain am- aspects of memory or focus. And that's just because engaging in cognitively challenging things requires you to learn how to focus. There's this thing called learning to learn. You learn how to engage with material such that you, you know, retain it and it, it helps build capacity in the brain. So I think that inherently all of us have a desire to learn. It's just that we have not all always been given the same opportunity and environment in which to learn.

There's... It's not that I think that smart people or people with a higher IQ are just inherently driven to learn things more or better. I think it's probably largely to do with the environment that that person has been in in terms of the opportunities that they're given to learn, whether they're given the belief of being able to learn, whether they're, you know, kind of supported in those endeavors, and, you know, have all the other things that we know support the building of capacity. So high quality nutrition, sleep, psychological safety, incre- incredibly important. So you're actually investing time in, you know, future outcomes rather than just focusing purely on short-term survival.

Dr. Tommy Wood
And this is why socioeconomic status and other things play a, a big role in our, you know, various aspects of cognitive function and risk, and risk of dementia. So I, I like to think that each of us is intelligent in a slightly different way, and each of us has the same capability to learn and engage with material that we're interested in.

There's gonna be some influence of the environment and the other things around us that will determine whether we're able to express and engage those tendencies or not.

Melanie Avalon
I'm thinking about my grandfather who, um, he was completely brilliant. He ended up being a math professor. But he... I don't... He had some sort of learning disability. So they thought he was... Well, I guess it's politically incorrect to say now, but they literally thought he was retarded, and so they wouldn't send him to school. So he just taught himself to read, like himself, which is like mind-blowing. So I guess there it, it was him rather than being supported, it was him not being supported, so he had to, you know, do it himself.

The... It's interesting too what you're saying about the, the IQ test and the men and women because one of the things you, you talk about in the book is, you know, why do more women get Alzheimer's when the... You know, we don't... We live on average, I think four, six years longer. So you say that that doesn't, you know, that doesn't explain the, the gap there. And so did you say that one of the potential things could be like the historic role of women as homemakers and lack of like the, the jobs that they're exposed to and things like that?

Dr. Tommy Wood
Yeah, I, I think so. There, there are... Well, just to kind of put some numbers on this. About, about two-thirds of the burden of Alzheimer's disease is in women compared to a third in men. Alzheimer's disease makes up 60 to 80% of the cases of dementia, so the dementia burden overall is, is larger in women than it is in men. And there's a number of biological reasons why this may be the case. So there are your basic differences in how male and female cells respond to things like inflammation and oxidative stress. And that happens in a Petri dish ir- regardless of, you know, you... outside of the influence of hormones and things like that. This is, this is stuff that we've... that, you know, they've studied in many labs, including my lab. Just like there's some basic fundamental differences just based on the genes that, and proteins that are expressed on the X versus the Y chromosome. And that, you know, that's why men tend to age a little faster. Men tend to be a little bit more susceptible to oxidative stress, for example. And we also know that the burden of neurological diseases is different in women and men. Like men are more likely to get strokes. Women are more likely to get depression and migraines and Alzheimer's disease. Of course, you know, you can get any of those regardless of, of sex, but the, the, there is, there is a, a difference in burden. And part of that may be because there are certain genes related to brain structure and cells in the brain that are on the X chromosome, such as s- some related to white matter in the brain. And white matter is very susceptible to the processes of aging. White matter structure changes with age, and that sort of tracks quite closely with cognitive decline. So those gene-- the balance of those genes, the expression of those, those genes are slightly different in women compared to men. That may contribute to the, to, to the different burden of Alzheimer's in women.

Obviously, there's the hormonal differences. That certainly plays a role too. But beyond that, I do think, you know, the, the basic-- you know, the premise of my book is that how we use our brains and the environment that we engage with and/or are, you know, are exposed to is a significant contribute to our-- contributor to our cognitive function and cognitive decline. And we know that higher educational attainment is associated with a lower risk of dementia. You know, higher cognitive engagement and cognitive activity later in life is associated with a slower rate of cognitive decline and, again, a lower risk of dementia. And this we've known for several decades now. The, the-- there's a classic study that I, I talk about in the book called The Seattle Longitudinal Study, so it was done here at the University of Washington, where I work. And what they did for the first time, pretty much the first time at a, on a large scale, was look at the same people over several decades. So they would bring them back every seven years. They would measure their cog- cognitive function. They looked at things like their physical health. They looked at their home and work and social environment.

Dr. Tommy Wood
And this was back in-- starting in the '50s, you know. So this research back then was really quite gra- groundbreaking. And what they found was that the majority of the pe- the majority of people, so more than 50%, maintained cognitive function from their 50s into their 80s. And this is not what we expect. We just expect that people will lose function over that time.

And some people do lose function, but the majority of people, more than 50%, did maintain function. And those data were actually used to raise the retirement age in the US in the 1980s, just because they found out that, hey, when you reach 60, actually you're not gonna suddenly lose all your cognitive function, which is what was assumed before then. But in one of the studies from the Seattle Longitudinal Study, one, one of the main things they found was something that they called environmental complexity was one of the best predictors of whether you would maintain cognitive function, you know, over, over several decades. And environmental complexity was based on your education, your social environment, and your work environment primarily. And then they classified people into different groups based on their sort of, their level of environmental complexity. And what they found was that homemakers, as they called them, which traditionally has been women, tended to have the least level of social, educational, and cognitive or work-based engagement. They tended to be more isolated, and they tended to have a faster rate of cognitive decline. This is not a comment on people who are, like, stay-at-home parents, right? That can be very stimulating. It can be, it, it can be very important. It can be very fulfilling. But in this study back in the '50s, that was, that was what they found, that women who are primarily at home alone during the day tended to, to suffer more cognitive decline over time, and they felt that that was because they weren't getting the same level of cognitive engagement and stimulus that, say, their husbands were getting from, from the work, you know, going out and being part of the workforce. And when you think about the traditional role of women in society, they have, you know, maybe more likely to, you know, stay at home, so less likely to be part of the workforce, less likely to get access to education, and both of those things we know are protective against dementia. So the majority of pe- of, of women who have experienced dementia up to this point, who've contributed to the statistics I gave you previously, existed in a society where women got less education and they had less access to the workforce, and that really started to switch in the '70s. And, and now it's almost flipped, where now slightly more women get higher levels of education and, uh, participate in the workforce compared to men. But that only happened in the late 1980s. So I do think that a big part of our historical dementia burden in women may be driven by the lack of equitable access to the workforce and to education for women.

Dr. Tommy Wood
And I'm hopeful that with changes in society over the past, you know, four or five decades, that will actually improve and, or we-- and that would, that would tra-- you know, decrease the relative burden of dementia in women compared to men. The other things are gonna matter too, right?

Hormones, health, uh, uh, other things are gonna play a role. But I'm hopeful that an im- a more equitable society will allow some of those numbers to shift.

Melanie Avalon
Oh, wow. So I guess it would be my generation-- I was born in 1990, so right after the '80s.

It would be around my generation where we could start seeing if that's panning out, like when my generation becomes that age.

Dr. Tommy Wood
Absolutely. And, and I will say it's, it's hard to figure out the exact reasons why, and I think there are many reasons why. But when you look at the most recent statistics on dementia, yes, the, the, the overall burden of dementia is expected to increase over the coming decades. But right now, at any given age, let's say at like 65 years old or 70 years old, you are less likely to be diagnosed with dementia than pretty much any other time in recent history.

So if you're 70 now, you're less likely to be diagnosed with dementia it, than if you were 70 20 years ago. And so this is what we call age-specific incidence of dementia, and that has been decreasing over the past sort of 70 or 80 years or so. In multiple populations, they've looked at this, uh, in populations in the US, they've looked at it in populations in Europe, and I think one reason for that could be a change in societal sort of equity in, in those, in those countries. But other things have improved as well, right? Physical health has improved. Uh, we've gotten better at treating cardiovascular disease, and that's, that's certainly played a big role as well because, uh, cardiovascular disease directly affects dementia risk too. But we are seeing some positive shifts in age-specific instances of dementia, and it could be that those sort of societal shifts are, are driving parts of that.

Melanie Avalon
Awesome. Well, that is... That's promising, and then your work is continuing to help that as well.

One little quick comment because you were mentioning the, the white matter and everything. So I got actually really stressed out by this 'cause you mention early in the book about, you know, you question how applicable rodent studies are to, for human studies on, especially on, on this topic. And, and you mention at one point that, so a rodent's brain is only 10% white matter and a human's is 60%. Is that-

Dr. Tommy Wood
Yes. So rodents are less than 10%, humans are more, you know, at least 60% or more.

Melanie Avalon
That really stressed me out 'cause I was like, "Wait a minute. I don't know if I can trust any rodent study anymore if it's that different." Like, that's, that's a big deal. It's kind of like when we study the fasting, like fasting in rodents and you compare like a 24-hour fast in a rodent to, you know, a 24-hour fast in a human. I'm like, that's not, not the same thing to them.

Dr. Tommy Wood
So I say this as somebody who, I've done a lot of rodent studies in my life. We still do some in my lab occasionally, although less and less because rodent studies on the whole just have not translated to improved treatment, you know, particularly for no- neurological disease, uh, in humans. And I think a lot of that is fundamentally our brains are so much more complex and structured differently compared to rodent brains, and this is something I learned, you know, very early on during, during my PhD, like how little really the work that's done in rodents translates to useful interventions and treatments, uh, in, in, in humans.

And so as a, you know, as, as an example in an Alzheimer's disease, right? Mice don't get Alzheimer's disease, so we have to insert a bunch of genetic mutations that cause them to accumulate amyloid. You know, assuming that the amyloid cascade hypothesis is the... Or the amyloid cascade is the primary driver of Alzheimer's, which it's certainly part of it, but I, I think there's a lot more going on as well and, and most people would probably agree on that, uh, at this point. But what's interesting that they found in mice is that if you... So in, in humans, there was this thought that amyloid accumulates, that triggers the accumulation of hyperphosphorylated tau. So when, um, we're talking amyloid plaques, tau tangles, these are sort of the core neuropathological ha- hallmarks of Alzheimer's disease. If you fill a mou- a mouse's brain with amyloid, they don't generate any tau whatsoever. So, so again, there are just like these core processes that we see happening in humans that just do not happen in rodents.

We have to kind of force it to happen and then, uh, you know, the, even some of the downstream effects still don't happen. So that doesn't mean that like all mouse studies are en- entirely useless. I, I think some of them... I- if you really know what you're trying to model and you're confident that what is happening in the, in the rodent is, is truly what happens in humans, and there are some examples of that, then I think they can be useful. But whenever I see anything, anybody says anything relate, you know... It, it's in the, the newspaper, it's, it's on a, on a podcast. Somebody says, "This thing, you know, this thing happened in m- in a mouse study, therefore this may, you know, this may mean this for humans," I immediately ignore it because I know that 99.99% of stuff that happens in mice just won't happen in humans. That 0.01% can still be useful, but we just need to ackn- acknowledge that the vast majority of what happens in mouse studies in the lab is never gonna be relevant to us as humans, and that makes that work difficult and frustrating. It can still be important, but it just... I, I think we really have to put that in perspective, especially when we're then trying to translate that into what we should do, uh, you know, on a day-to-day basis.

Melanie Avalon
Yeah. I, I have a, one last animal comment, but before that, if listeners are interested in the amyloid hypothesis, I think if I... Okay, so your book, reading your book is the most... It, it's my example of like the most inspiring, like feel really great about the brain and the things that you can do. The correlate to that on the flip side, and not because it's a, a bad book, it's just, um, it'll make you feel a little bit... I interviewed Charles Piller, who is the one who, um, he's the science journalist who broke all of the... He found all of the fraud in Alzheimer's data research, and reading that book and interviewing him, I was... I just walked away being... I really recommend the book, but I just walked away being like, "Oh my goodness, I don't even..." I was so sad, like, like... For, if listeners would like to learn more about the Alzheimer's history, definitely check out that episode.

Okay. So rodents don't get dementia. I know you said in the book that apes don't either. Do any animals? Like, do pets? Do domesticated animals?

Dr. Tommy Wood
No. So ano- another really good... So you're, you're talking about, um, Doctored was his book, right?

Melanie Avalon
Yes, yes.

Dr. Tommy Wood
And there, there's another very good book and, and I, and I've, and I really recommend if you can find a podcast with, uh, a guy called Karl Herrup.

Melanie Avalon
What is it? What's his name?

Dr. Tommy Wood
Herrup, Karl, K-A-R-L, Herrup, H-E-R-R-U-P. And he wrote a book called How Not to Study, How Not to Study a Disease, and it's the hist- the history of Alzheimer's disease. I think we've seen this again and again and again where in the Alzheimer's field, we've become so hyper-focused on one particular mechanism that it's held us back in terms of being able to really understand the full disease process and, and where we can intervene. So what- You know, I, I talk about in my book is that, yes, there are many ways that, you know, amyloid probably play and tau play a role. There are many other things going on at the same time. All of the things that we can do, of which there is a ton of stuff that we can do to improve our cognitive function on a day-to-day basis, decrease our risk of dementia. They act through a variety of different pathways, and, you know, some of that is amyloid, but some of it is other things too. I, I think that the reason why I wanted to write a very positive book is because I think that, that there is a lot of hope, but we ha- we have to acknowledge that we've made some missteps that have, have made us sort of become first hyper-focused on one pathway and then, you know, uncovering some of the fraud in the history of the amyloid hypothesis, you know, made us feel, you know, very disheartened about what we might do.

But in reality, actually we don't need to know the mechanisms because we know what works, we know what decreases dementia risk. We can get into the mechanisms if we, if we find that interesting, but actually we don't, we don't even need to know them, and we may never fully learn them. But to actually answer your question, and the reason why I started with Carl Herrup is because he says this in his book. He says there are two things that you, that need to be in place for you to get Alzheimer's disease. First, you need to be old, and second, you need to be human. Because there are no, no other species, you know, have that sort of same process, you know, exactly the way that, that we do. There are some kind of parallel processes, so other... So non-human primates may accumulate some types of pathological changes. In dogs, you see some elements of brain changing, of, of some elements of brain change with aging, like some changes in white matter, but you don't see that kind of full comprehensive process in, in any other species.

Melanie Avalon
Oh my goodness. Do you think AI could get dementia?

Dr. Tommy Wood
So no, I don't think AI can, can get dementia, but I think it can, it could display cognitive elements of, or elements of cognitive decline. And there, there was this one, there was one recent study that, that actually did this.

What happened was they trained a large language model in multiple rounds, and every time what they did is they changed-- they, they trained the next generation of the algorithm with the outputs of the previous generation. And so over time, the, the, the quality of the cognitive function or the quality of the outputs, 'cause it's not truly cognitive function, but the quality of the outputs declined. 'Cause you basically ended up feeding AI its own slop, and it got like dumber over time.

Melanie Avalon
Yeah, I definitely have a lot of questions about AI. This is one of the... Okay, so when I'm, when I'm like taking all my notes, it's funny, I'll, I'll come up with like a qu- I'll have a question for you and I'll like put a big star, like, "If you ask one question, ask this question," but then like 30 minutes later, I'm like, "If you ask one question, ask this question." Basically, I have a lot of questions that have haunted me for a while.

And one of them, and it relates to the modern world and everything, 'cause you mentioned earlier how we're engaging now and that we have to create stimuli for our brain. I'm so perplexed, and I think I had this question going into your book. I've had it for a long time. You have a very long, in a good way, like a very thorough that's a better word. You have a very thorough section on the modern world and multitasking. I think after reading that, I kind of get it, but I would like to hear you articulate it, which is, when I think about the concept of multitasking, it seems like something that is very stimulating to the mind, and I've always wondered why, 'cause you always hear, "Don't multitask. It's not good. You're not as productive. It's not blah, blah, blah. It's bad for you." But I've always been like, "But why?" Like, it seems very stimulating to my mind. That's how I've casually thought about it. Why is multitasking both a high cognitive load and, or how does it relate to cognitive decline?

Dr. Tommy Wood
The most important place to start is by differentiating between busyness and true, like, cognitive challenge, right? Because in the modern world, we... And th- this is one reason why I quite like the title of my book. It's, uh, I think it's slightly provocative, and I, I wo- I won't take credit for it. It was actually my editor who came up with the, with the name for the book. We are simultaneously overstimulated and understimulated. We're overstimulated in terms of the multitasking, task switching, endless access to information, being contacted, being required to respond. And the, the same time, we're understimulated in terms of the true deep focused learning and challenge that what, that, that's what drives, you know, cognitive function and, and, you know, maintains brain structure. So we're doing a lot of stuff at the same time, but we're doing less of one hard thing at a time, and by one hard thing at a time is what really seems to build function because it requires all of our focused attention. It drives neuroplasticity, often through the processes of, of failure, which dri- you know, drives learning, that builds structure, that builds function. So we're not learning languages, learning musical instruments, learning complex skills, but we are doing a ton of emails and Slack and Zoom and Instagram all at the same time. And I think that those two types of challenge are fi- are fundamentally different. We feel busy with both, but they have slightly different physiological and cognitive effects.

So the first thing to realize is that in the grand scheme of things, human thought processes are actually very slow. We like to think that our brains are sort of these incredibly fast computational machines, and they are, but most of what your brain is doing is filtering out everything that you're exposed to so that you have just, like, one set of things that you can actually process and engage with at a time. So the-- I, I referenced this paper that came out a couple of years ago called The Unbearable Slowness of Being, which basically estimates that the speed of human thought is ten bits per second, a bit being a, a one or a zero in, like, computer code, right? So it's ten ones and zeros per second you, you can process and you- we-we're including like visual information, auditory information, all that kind of stuff. And they have, they have a number of different areas where they show that. So even people who are expressing like the most impressive human complex skills, they're still only processing information or enacting on that information at about ten bits per second. The rest of what your brain is doing is filtering out huge amounts of information so that you can process those ten bits, and they liken the difference between the speed of processing that the human brain is capable of, like truly engaging with, versus the amount of information that the brain is exposed to through, you know, our senses, our eyes, all these different things, as the amount of water that one person can drink relative to the water flowing through the Hoover Dam.

Dr. Tommy Wood
Like that's how much everything is compressed down so that you can just like process it a-a-and engage with it. So this then I think helps us to realize that our brains don't actually work that quickly. They in f- in fact, they even make a joke like, you know, we've been trying to do these human like brain comp-- these com-- brain computer interfaces and they're talking about fancier and fancier technology, you know, to kind of direct huge amounts of information to and, uh, away from the brain. But they kind of joke that actually if you connected to the right place, you could just use like an old telephone cable because that would be, that would be enough information for, for, for, for the-- It's like your, your brain is as fast as dial-up. It doesn't need to be broadband.

This then I, I think reframes things so that we can appreciate that actually there's only so much information that we can process at any given time. And so when you're multitasking, what you're doing, it has a very specific definition. Multitasking is doing two completely separate tasks, both of which or, you know, it could be more tasks, but like say it's two or more than one task where each task requires your focus and attention in order to perform it at its best. Because I've heard some people say, "Well, of course you can multitask because you can talk and walk at the same time." But like walking has become automated. It doesn't-- You, you don't have to like focus on where you put your feet in order for walking to happen, right? And so, you know, some people have said, "Oh, well, you can watch TV and eat at the same time." And yes, that's technically true, but there are lots of studies that show that if you watch TV while you eat, you overeat because you're not actually paying attention to the, to what you're eating, right? So you, you, you're kind of doing two things at the same time, but you, you do less well at each of them because you're focusing on something else at the same time, and that's what we call a multitasking cost.

So when you're doing multiple things at the same time, all of which that require your focused attention in order to perform them, you will do each of them less well than if you had done them one at a time. You then also lose the ability to be fully engaged with it such that you can lear- you can learn from it, you know, through the processes of like driving neuroplasticity and failure because you're not really focused on it, and, right, that requires focus to kind of open the gates of neuroplasticity. At the same time, you're doing them less well and that becomes inherently stressful. So there's lots of work by psychologist Gloria Mark. I talk about her a lot. She has a great book called Attention Span, and she's basically shown that in the work environment, if you're multitasking or task switching, which is often what we're doing, like going from Zoom to emails and back again, and, you know, if you, if you try that, you realize that you're not really paying attention to the conversation, uh, on the Zoom call, but then also y-you're, you're not really paying attention to the sentences you're writing in your email.

Dr. Tommy Wood
And like, as you bounce back and forth, every time you bounce back and forth, you sort of like lose a step as you try and re-engage with, with the other task. And so you do neither of those things well, and that is inherently stressful.

And they've sort of measured that with HRV and heart rates and things like that. So constantly bouncing back and forth between tasks or trying to do multiple tasks at the same time becomes inherently stressful, which then also can make you feel less productive because actually the work that you did was lower quality and you never had the chance to like truly engage your brain in something challenging, which is something that our brains actually enjoy. We enjoy being challenged. We enjoy overcoming challenges. It makes us feel inherently good, but we don't actually get a chance to do that if we're constantly sort of multitasking and bouncing back and forth between things. And then the final part of this is that we can get better at multitasking, and there are studies that, that kind of suggest that, that people who do a lot of multitasking get better or that there's less of a multitasking cost so they can maintain function in, in two tasks slightly better. They still do worse than if they were doing them one at a time, but they do-- they have less of a total cost. But people who, who multitask a lot seem to also be more distractible because your brain is no-- you've no longer trained your brain to focus on one task at a time. You've trained it to focus on lots of things at the same time. So then it becomes less good at filtering out distractions, and it becomes less good at actually being able to just focus on one thing at a time. So there are certainly situations Where you can multitask, you can get multiple things at the same time done at the same time. The multitasking cost doesn't cost anything because you can still do all your tasks more efficiently to the, to the, to a desired level of quality. There are certainly some combination of tasks where that's the case. But I would argue that for most times when we're either flip-flopping back and forth between tasks or task switching or multitasking, we're generally increasing stress, we're increasing error rate. That's also been shown if we multitask or we're interrupted during our tasks by notifications or somebody else demanding something from our time, uh, new emails coming in, then we have an increased risk of errors or we have increased errors. So we have more errors, more stress, and less productivity with, like, the quality of the work decreasing. So this isn't meant to be, like, all bad news. Like, there are... It, it's just to help people understand that some of the things that they're doing that they think is increasing efficiency 'cause they're doing multiple things at the same time may actually not be doing that. It may be decreasing their productivity and decreasing their efficiency, and they would just be better off doing things one after the other. And this, they use the same amount of time to do that work, but actually the work is a higher quality and is maybe even done faster.

Dr. Tommy Wood
So it's just kind of understanding that the brain isn't necessarily as, as capable sometimes as we expect it to be, and then just appreciating that sometimes we can do a better job if we just do one thing at a time.

Melanie Avalon
Yeah. After reading that whole section, I, I really started noticing in myself some of the things that you mentioned that happen when, when people are, quote, "multitasking." Like, you, you talk about the, is it cognitive residue? I feel like I can, like, feel it now when I switch. I'm like, "There's the cognitive residue from the prior task." And, like, the cognitive downtime or, or, like, the, you know, the amount of time it takes to actually restart the, the new thing. And, and I've become super aware because you've talked about the evolution of, of how, how soon, how quick we now want to, like, switch and focus on something else compared to how it used to be. And it's wild, like, when you're trying to focus. I don't... It's like, where does that thought even come from? Like, I'll be, like, focusing on something, and then I just get this urge, like, this crystal clear urge up to, like, switch to something else. And it's like where? And I have to ignore it. It's kind of like doing meditation. Yeah, it's fascinating, but I, I think that's really powerful, like, just being aware of what it's actually doing and then, you know, how you can best engage in it.

And something that I've found works really well for me for how I structure work because there is the... Is it Pomodoro? Is that how you say-

Dr. Tommy Wood
Pomodoro.

Melanie Avalon
Pomodoro method, which is, like, 20 minutes, I think, of uninterrupted work followed by a break. And I have a red light therapy device. So this is, this hits, like, multiple things at one time. I have a red light therapy device that I actually use a lot, not so much for the therapy, the, like, on my body, but for the light that it makes in the evening to, like, support my circadian rhythm, but it goes in 20 minutes. So I'll, like, set it for 20 minutes. I'll work, and then when it goes off, then I, then I get up and I, like, clean something in the apartment, and then I come back. And that's, like, the pattern that works for me.

And I know you talk about, like, finding what works for you for focus. So that's, that's my, my pattern. Do you have a, a, a work focus pattern?

Dr. Tommy Wood
I have used Pomodoro, uh, a lot, and I don't think there's anything, like, magic about the Pomodoro ratio. You do 20 or 25 minutes and then take a five-minute break. And you do that in multiple cycles. And then after you've done two hours, you take a longer break. The most important thing actually is that while you're doing the work thing, you're only doing work r- or whatever it is you're trying to focus on. So if it's a piece of writing or a piece of research, you know, reading something, writing a presentation, all you're doing is that, right? So ideally you don't have notifications, you don't have email open, uh, you have your phone turned over at least so you can't see stuff pop up on the screen. You get work done in that block.

And then when you take your break, you're truly taking a break, right? So going and cleaning something is a great example. Like, you can still do something, but you're, like, completely cognitively moving away from, from what you're trying to work on, and then you can go back and, and do another stint. And, you know, th- there's, like, like I said, there's, there's no magic amount of time, but, you know, that kind of, that kind of time seems to be a good chunk of what, you know, for what people, most people can focus for, like 20 to 30 minutes at a time before they need a, uh, a, a break. And there are other studies that, that have looked at different, different time balances, but, but something like that. Especially if you're gonna do... And then if you're gonna do an extended period of an hour or two, you know, breaking it up into three or four chunks with little breaks in between seems to be really good. And it's just like, you know, i- in the book I kind of relate it to sort of, uh, physical efforts you might do in the gym, right? If you're gonna lift weights or you're gonna do sprints, you can't do that forever. You need to kind of take a rest. The brain needs those rests as well. This is where then, you know, the work that you're doing is kind of integrated into other things, uh, into, into a, a bigger picture. The, the sort of everything resets, and then you can go back and, and go again. But I, I think that's really important, is building in these periods of time where all you're doing is just focusing on one thing and then you're taking a break, uh, afterwards. And yeah, if you have to do some multitasking, you have to do some emails and, uh, Zoom calls and all that other kind of stuff, also kind of schedule specific times for that so it doesn't kind of bleed into your full day, which is then again when sort of, like, stress and some of these other things can start to creep up.

Melanie Avalon
Okay. I'm realizing I might do a hybrid version then because sometimes I'll be playing TV during my 20 minutes of working, and then when I clean the apartment, I like to listen to the audiobooks, which brings it back to work a little bit, but I guess I can always improve on things.

Dr. Tommy Wood
Uh, I think you'll have, you'll have noticed that- My, like my whole kind of approach, like none of it is like saying like, "This thing is bad. You need to not do it," right? It's just about finding something that feels like it's sustainable, but then also that it's, you know, allowing you to be productive, but then also feel well rested and feel able to engage in the things that you need to engage in. So if like TV while you're working doesn't disrupt that, um, so like if I have TV on while I'm working, either I'm, I'm actually focusing properly and like the TV may as well be off because I'm not paying attention to it, or I pay attention to the TV and I don't get the work done, right? So I can't do that.

But if you can do that, like I'm not gonna say that's bad, right? Everybody sh- needs to find whatever pattern works for them. So I like to listen to drum and bass while I work. Other people would be climbing the walls with stress if they listen to, listen to my playlist. So like, this is just, it's just about finding what sort of allows you to focus, feel productive, feel good, feel rested, and, you know, able to continue.

Melanie Avalon
For me, it depends on like the type of work, and it's so true. So if it's like really focused work, I actually won't... The TV might be on, but I won't take any of it in. But if it's like more casual work that I can do with it on, then I take in, you know, different aspects of it.

I think actually there's probably two things in my life that really support that focus, like that uninterrupted focus, and one is podcasting. So, you know, I get to have these conversations where, I mean, I don't know how I c- how I would, how I could do something else and and have the conversation. The other one is one that I think used to be maybe seen and probably is still seen as, I don't know, maybe, maybe lazy, maybe like not a, um, positive thing for one's health. And now I actually think it's the opposite because it's one of the few things that people still do where they turn off their phones presumably for an extended period of time, and that's going to a movie theater to see a movie. I so appreciate going to a movie theater because it, it, you actually turn off your phones and like watch a movie.

Dr. Tommy Wood
You know, I, I genuinely think there's lots of good things about, you know, watching a movie and, and you can put it in a similar bucket. It's not quite the same, but you can put it in a similar book- a, a bucket to like reading a book, right? There's fiction, it's a novel environment, like new things. You have to like follow a, follow a story. Sometimes you're trying to figure out what's going on. Like there's... And right, you're doing just one thing, thing at a time, and it's very rare for us to do that nowadays.

So even if you put a movie on, on the TV at home, right? All of a sudden, like you're scrolling Instagram at the same time or you're like looking at emails. And I think going to a movie theater i, is a great thing to do, you know, once in a while. I, I think it, you know, gives you a good break. You're, you're doing one thing at a time. Movies are a very, you know, interesting and cognitively engaging thing. I don't think it's like a proper cognitive challenge necessarily, but that kind of stuff can be, you know, replenishing and, and beneficial.

Melanie Avalon
Yeah. And, and then speaking to the, we mentioned AI earlier. I am also super aware of... And you mentioned the book that you wr- you wrote your book the old school way.

Dr. Tommy Wood
No AIs were used in the writing of my book.

Melanie Avalon
I hope I'm not in denial. I feel like the way I engage with AI, I, I like to use it to outsource the tasks where I don't... It would've taken me so much longer in the past to do it. Yes, it would've been cognitively stimulating and required focus for me to do these things that I outsource to it, but by outsourcing that, and I don't like the word but, and by outsourcing that, I can then do something else more complex on top of it. So as long as I'm... At least for me, I feel like, I hope, as long as I'm using it to do things that yes, I could do, but by doing them, that now I can go on to the next more complex step that I will do, hopefully that, that's using it in a beneficial way.

Like what, what, what do you think is how AI is affecting people's brains?

Dr. Tommy Wood
Yeah. So I think that's one of two good universal approaches to, to the use of AI or any like technological tool, right? Like most of them are gonna be AI based, but certainly, you know, we could broaden this out to other types of technology. Plus this is kind of part of a framework going forwards because we, we don't know, like what's AI gonna look like in six months? Like literally, who knows? So we, we can't... But so we, so we, we have to think about frameworks rather than some like hard and fast rules because that stu- it's just gonna change so quickly.

So we've definitely seen so far that in studies where they've had, and a lot of it's in students doing things like writing essays or, you know, looking at how much they learn, what you see is that if you use some kind of large language model from the outset to say, write an essay for you rather than writing the essay yourself, and so there was one study that's gotten a lot of press. It was done at MIT. It was students writing essays. They were randomized to three different groups. One group just had to write the essay based on whatever they had in their head. Another group was allowed to use a search engine, and a third group was allowed to use a large language model. I think they used ChatGPT. What they found was that as you go up those levels of technological support, the, the brain networks associated with writing the essay were less activated. The students felt less ownership of their work. The work was more generic, and they remembered it less well. And this makes perfect sense. You haven't engaged your brain in the process, so why would your brain remember it or feel ownership of it? Like this is entirely as expected. So the way that I interpret that is, and this, this is very similar to, you know, thinking about detraining with physic- you know, physical activity and how that changes physical function. You know, it goes all the way to the stimulus idea we talked about at the beginning. If you want, if there's some set of skills that you want to maintain or build in the first place, do not use AI to do it for you because you will never learn that skill.

Or if you have that skill, you will de- you will de-skill because you're not actively engaged in that skill anymore. I think that makes perfect sense. I, I think that, that, that shouldn't be particularly controversial. What's interesting is that when you, uh, uh, there was a s- an- another group or like a, a s- like a follow-up part to this study where the students who had previously written the essay themselves then got access to ChatGPT and were asked to write the essay again, and those essays ended up being a higher, better quality. And so how I would use it, or one of the ways I would use it, is say, "I've got this piece of work. I'm gonna do it myself. I'm gonna write it, I'm gonna build it, I'm gonna code it," whatever it is. And then I would say to ChatGPT or Claude or whatever your favorite algorithm is, "Here's what I've done." Or you don't even need, you don't, you don't need to input it, but you can just say like, "I'm doing this," like, "This is what I've thought.

Dr. Tommy Wood
This is what I've, you know, included. What, what, what have I missed? What could I do differently? What could be better? What else should I be thinking about?" Something like that, right? So you use it almost as like a sort of like to give you feedback or it's, it's somewhere where you can like talk through your ideas or what you've done. Then it would give you, it would give you feedback, and you would incorporate that feedback. Again, you would do the incorporation yourself, right? So it's almost like you've sent it to a friend to read over it, and they've given you some ideas, but this can happen, you know, in much shorter feedback loops plus maybe with a, a, a bigger, you know, database of knowledge behind it. All of that requires you to build and maintain the actual skills to do the thing that you're trying to do, and the product ends up being better because you get additional input and additional thoughts and ideas. So that I think is the, is the best of both worlds. So that's one way to use it. And then the other way is, is kind of as you outlined, which is that sometimes we have to do tedious, repetitive tasks where if we can have AI do it for us and that frees up time so that we can actually do other things that maybe we enjoy more or are more cognitively stimulating, then as long as we do actually do that with that time, we can get additional benefit there. So to kind of finish this, there's an analogy that, that was developed by a, a friend of mine, Ken Ford. He's been an expert in the field of AI for at least 30 years at this point. And he talks about this idea of cognitive orthotics versus cognitive prosthetics. And an orthotic is something that you use to enhance your current function. So when I think of orthotics, you know, probably because of some of the research I do, I think about kids with cerebral palsy, that, you know, they have some issues with motor control, so maybe it, it makes it hard for them to walk. But if you give them a certain type of orthotic shoe, that changes the structure of the foot slightly or the, or the biomechanics slightly and it allows them to walk, right? So that orthotic is building their, is increasing their capacity. It's allowing them to walk. Whereas a prosthetic is something that you use if you don't have that function at all. So right, you have a prosthetic leg if you're missing part or all of your leg. So if we use AI as an orthotic, we use it that first way I described to kind of build on our capacity. We do whatever we're capable of to start with, and then we, we have AI help us build on that. But again, we're fully engaged in that process. Rather than using it as a prosthetic where it's like using AI as a brain as if we didn't have a brain. You know what I mean? And so that's how I would, how I would approach it. Just think about is my use of AI allowing me to augment or build my skills or is it allowing my skills to atrophy because I'm not actually challenging myself or using my brain at all? And then the third, the third kind of option is it's freeing up time so I can do more challenging, interesting things with my brain. So I think your approach is fine.

Dr. Tommy Wood
This is certainly nothing against people using AI. It's just thinking about how is it helping or hurting the skills that I want my brain to have, and then just leveraging it in the best possible way.

Melanie Avalon
One of the places I get concerned is I think people use it a lot. It's like when you're talking to somebody on text, you know, through emails or something, it's like, am I even talking to this person or is it just our avatar AIs talking to each other that got a stamp of approval from us to send?

Although I will say something that I feel very grateful for for AI is I used to be, I'm, I used to stress a lot about typos in emails from my end, but now I'm like, "Eh, if I put a typo, that just shows that it's a real person talking." I sometimes wonder if people like put in typos on, on purpose so that it is obvious that it's not AI. I might have done that on occasion.

Dr. Tommy Wood
That's interesting. I, I, I guess I'd never really thought about that, but I mean, that does make, that does make a lot of sense.

Like, obviously, if there's a typo, it, it was or at least there was some cortical input from a human. I will say that I don't ever use AI to write emails because I can tell. When somebody sends me an email, I can tell that they didn't write it, and I'm like, "What even was the point of, of this communication?" And I, and I think even though email is a relatively impersonal, impersonal form of communication and obviously, you know, voice and then video and then in person sort of in that order are more meaningful forms of communication, I, I still think that email is a very important form of communication. So if I'm gonna send you a message, I'm gonna write it myself. And yes, that's, it takes more time, but that's still important to me as like a skill of, of inter- interacting with other humans.

Melanie Avalon
Me too, and I'm, I'm major team emoji.

Dr. Tommy Wood
Oh yeah, me too. Yeah. That saves us time.

Do, do you know what? S- somebody, um- I was listening to somebody recently where, I, I think it was on a podcast where somebody was complaining about the use of emojis, and then the, the guest was like, "Well, actually, one thing that's missing from written communication is facial expressions." And so there's some evidence that emojis allow us to understand the meaning of the person slightly better and engage with it slightly more because we're bringing back some of that kind of non-verbal communication that we get, like, from face-to-face communication. So like that made me feel better about my emojis, 'cause I, I love a good emojis, a, a good emoji response.

Melanie Avalon
I could talk for like two hours my love of emojis. I think they are so important, like with, for that reason.

Because with text, like if it's just text, people read the text and the vibe that they're thinking, not ... They don't know the vibe, and I don't like the word vibe, it's very casual. But you know, they put onto the words the tone and intonation that they're thinking. And so the only way around that, in my opinion, is to splatter all the emojis all the time. Like ...

Dr. Tommy Wood
It, it's also why, um, I, I love exclamation points. Like literally my, my emails and texts are full of exclamation points. Because in general I'm a very expressive, positive person, and like that's how I can get that across in text.

And when I, when I was writing my, my book proposal my a- my agent was like, "You can't use ... You, you, you just can't use this many exclamation points." I think, I think my, my book proposal was 25,000 words long, and she let ... There was one, there was one exclamation point that, that she let me keep, and I think in the book there's maybe two or three. Because like, you know, in, in the formal, you know, the formal written book world it's frowned upon to have every sentence end in an exclamation point. But when I'm like communicating with other people I, um, I use them a lot.

Melanie Avalon
So two quick thoughts. One is I had an epiphany about exclamation points and I ... It's when I was thinking about the people reading things and the tone that they read it and I realized, oh, w- when I use exclamation points there must be an emoji. Because otherwise people might think I'm yelling at them, you know, without excitement. So whenever I'm like exclamation points, include the emoji.

Um, I think one of my other favorite ... So one of my favorite words is aposiopesis. Do you, have you heard this word?

Dr. Tommy Wood
I have not.

Melanie Avalon
Oh my goodness. Okay.

So it is the concept of the dot dot dot. So it's when you talk and then you ... That would be aposiopesis, what I just did. So it's like I love when there's like a word that describes a concept that you didn't even know was a concept and there's a word for it.

Dr. Tommy Wood
That, that is very cool. So that, that, that makes me think a, a, a little bit of o- one of the things that my wife and I bonded over when we first met was, um, various uses of grammar and punctuation.

So like I'm a, I'm a massive proponent of the Oxford comma. Very important to me.

Melanie Avalon
Me too. Team Oxford comma.

Dr. Tommy Wood
Both of our favorite piece of punctuation is the interrobang, which also just has an amazing, amazing name. So that's the, uh, question mark, exclamation point together.

It's formally called an interrobang.

Melanie Avalon
I didn't know there was a word for that.

Dr. Tommy Wood
Yeah. See? There's another cool word that you didn't realize ... Yeah.

Melanie Avalon
Yes, the interrobang. I'm gonna start integrating that into my vernacular. Okay. This has been amazing.

We don't have to do a deep dive. Just one really last quick question, and I don't even know if it's a question. Maybe I'll just, I'll just state it and then you can let me know your, your thoughts. But, um, on the, the nicotine and alcohol side of things. So the daughter of the woman who led the MIND diet trial, they, th- they came out with a book, like The Official MIND Diet, I think, a few years, like, like a year or two ago. Um, so I had them on the show and of course my ... I'm a big wine fan so I've always loved that the MIND diet includes wine as ... You get, you get positive points for it for cognitive health. I appreciated, not because I'm biased, but I appreciated your take on alcohol in the book. I feel like people are often ... And you, I think you started off by saying this, which I thought was so, so brilliant. You said something to the effect of people when they ask about alcohol it's either because they wanna justify, you know, not drinking at all or they wanna justify drinking a lot. I was like, that actually, that tracks pretty ... Yeah. Alcohol and the brain. Can I have my nightly glass of wine?

Dr. Tommy Wood
I would say ... Yeah, so, so, so I, I agree that we've gotten to this point where sort of the, the kind of the, the focus on alcohol and health has shifted from, oh yeah, this n- you know, the nightly gr- glass of red wine is really good for, for us. Now it's shifted over to any alcohol is bad and it's like this super puritanical approach. And in reality neither of those are true. And so if I were scoring the MIND diet I wouldn't include alcohol in it.

I don't think there's a net benefit to s- to regular alcohol consumption, but equally if it's infrequent or small amounts there isn't a net negative, right? It's essentially neutral. So everything that we see from ... So from an overall health perspective if you're drinking, you know, less than one drink a day on average, and you kind of have to calibrate based on the country the, the research was, was done in. Because one US standard drink is 14 grams of ethanol. One UK unit, which is ... So and a lot of the recent studies have come out of the UK Biobank. One UK unit is eight grams of ethanol. So a, a unit in the UK is about half a US standard drink. But if ... So if you're consuming less than a unit of, a, a UK unit of alcohol a day, so that's an alcohol ... you know, an, uh, a US standard drink every other day on average, there's essentially no net effect on the brain, positive or negative, right? No increase in dementia risk, no change in brain volume, brain structure. Above that- Brain volume does start to decline. Dementia risk does start to increase. When you look at other health outcomes at that kind of level, cardiovascular disease risk decreases a little bit, but that's balanced out by a, a, you know, a slight increase in stroke and maybe some cancers. So again, like no net effect. So if you're, you know, drink, you know, a small glass of wine a night on average, you know, that's, that, that, that's probably fine. I think that's within those parameters but, you know, we're talking like, you know, just a, like three or four ounces or something, right? Like genuinely a small glass. Like that's certainly within those parameters and then, you know, there's, there's other things that could come from that, right? Maybe it's in a social setting. Maybe it does truly help you to relax and switch off. I would argue that you don't, you don't need alcohol to do that, but you, you can. So there's some ... And there is some ... There could be some potential benefit there, but equally we also know that, you know, alcohol impairs certain aspects of sleep partly by affecting REM sleep, partly by affecting thermoregulation at night. Maybe that's why, uh, you have your bedroom at 62 degrees. So in reality, like what I say is like one or two drinks once or twice a week is absolutely fine, and I think the evidence really shows that quite clearly. I don't think that it should, should have been included in the MIND diet. Like if I was doing the MIND diet, I wouldn't have included alcohol.

Dr. Tommy Wood
But what I will say is there have been some very nice studies that have looked at all the components of Mediterranean style diets, and it wasn't the, the MIND diet specifically, but it was other scores of the Mediterranean diet which included red wine, and they looked at dementia risk and what they found was that no individual component of the diet was responsible for the, the benefit of a Mediterranean style eating pattern and dementia risk. So if you remove red wine, you, you still see benefit. If you add red wine, it doesn't negate the benefit, if that makes sense.

Melanie Avalon
Yeah.

Dr. Tommy Wood
'Cause it's really the overall pattern that's, that's important. Higher quality, less calorie dense, more nutrient dense foods, more fiber, more protein, more nutrients, et cetera.

So your nightly glass of wine is almost certainly fine. I, I think that there's probably no net effect one way or the other.

Melanie Avalon
I'm also neurotic about like low alcohol, organic, high polyphenol. One of the things in all the alcohol literature in general that I think is important that nobody talks about is that it's often just like alcohol is a group or it's like wine or beer, but it doesn't take into account the actual ... like the actual drink.

So like the ... Is it, you know, does it have other toxins in it? What is the alcohol content itself? 'Cause it can range so much.

Dr. Tommy Wood
Yeah. That's why, that's why I always talk in units and drinks because then you, you're sort of standardizing the amount of alcohol and that's also how the ... 'Cause that, that's an important part. Plus there are ... You can certainly have your much higher polyphenol wines. Whether that's enough polyphenols to have an, you know, a, a large biological effect is, I, I think potentially debatable.

Um, although there are, there are ... So there's, there's probably better studies on, say, wild blueberries or cherries or strawberries. You have a couple, two of those, you're getting enough polyphenols to have a measurable benefit on terms of cognitive function both acutely and, and long term. So we know that these polyphenols that you're getting from berries are, are, are having benefits for the brain. I w- I would prefer them as a bowl of blueberries, but equally I also enjoy a Manhattan when I go out for my ... like for date night with my wife. So I, I certainly stick to those same alcohol parameters that I just mentioned.

Melanie Avalon
Awesome. Yeah.

And I also ... I wear a fourth of a nicotine patch every day 'cause I like the way it ... I've never smoked or anything, but I like the way it makes my brain feel, but it's a very low dose. Yeah. Do you have thoughts on nicotine?

Dr. Tommy Wood
Nicotine is interesting because it's become this ... It's, it, it's become sort of like this new nootrope or people call it a nootropic even though it's not a nootropic. For, for a nootropic to be a nootropic it has to improve brain function with no downsides or negative side effects and also not rel- result in tolerance where you need a higher dose to get the same effect or dependence where you get withdrawal if you don't, if you don't take it and like nicotine doesn't hit any of those.

Same for caffeine, right? Caffeine is not a nootropic either. So ... And I, I am a ... You know, I, I, I, I very much enjoy my coffee in the morning. So there are studies that show that in both people who do and don't smoke, giving them nicotine does improve some aspects of cognitive function, right? Particularly related to focus and attention, um, and maybe some aspects of working memory because acetylcholine, you know, particularly in sort of like the areas of the, you know, the prefrontal or frontal areas of the brain is re- is really important for signaling attention and focus. So you do get some improvements with nicotine. The only reason why I have concerns about chronic nicotine use is for those other reasons that I mentioned, right? You get withdrawal or dependence. The, the kind of ... The doses that you're describing I think are, are probably absolutely fine, but we have people now who are taking potentially hundreds of milligrams of nicotine a day 'cause it's so easy to get it through pouches and vapes and things like that. So I ... And, and, and vapes themselves have some potential health issues. They're, they're probably ... Yeah, they're certainly better than smoking tobacco but, you know, they, they do have some, some potential health, health effects as well. So yes, there's very interesting data on the acute effects of nicotine administration but usually it's like a one-off dose in one study. They haven't sort of looked at chronic low level administration in healthy people in the kind of way that you're describing, so it's just ... It's mainly an unknown. That's, that's one of the reasons why I, I sort of, I, I don't recommend it routinely. But as long as you're not escalating the dose, not getting withdrawal symptoms, there's probably minim- minimal downsides at sort of very low ve- you know, very low doses.

Melanie Avalon
Yeah, I think mine is the equivalent, 'cause I cut it in four and it's 12 milligrams, so it's like three milligrams and it's slow release, so like three milligrams over the entire day. Wow, okay.

Well, I think we got to like 15%. No. No, we got, we got a ton done. Um, and listeners, honestly, we only barely scratched the surface of everything in this book. So go get The Stimulated Mind now. I will say, if you wanna remember, there's a whole section on memory in the book that we didn't talk about that. But if you wanna remember anything from today's show, I think there were so many studies that you talked about, but my, I think my favorite study that was the most mind-blowing to me was the one where they had the, they had the two groups of students and they were studying material and they let one group read the material and then like reread it. I don't know how many times they reread it. But then the other group re- only read it once and then they just tried to remember what they had read and then that group, they remembered it better later. Is that, was that what happened?

Dr. Tommy Wood
Yeah. That, that, that's right.

So, uh, this is a, a, a, a classic, classic study in, in memory where, yeah, so students could either, or they were randomized to either ... I think they, they read the material up to ... Th- they read it and then read it up to a three additional times or they just read it once and all they did was try to remember it.

Melanie Avalon
And they weren't even told if they were correct or not, right?

Dr. Tommy Wood
No, that's right.

Melanie Avalon
That's the mind-blowing part. I was like, "Whoa, exclamations."

Dr. Tommy Wood
You know, there's, there's been a ton of additional studies for, for why this might happen and a very good book if you're particularly interested in memory is Why We Remember by Charan Ranganath and he's done a little bit of work where basically by trying to remember it, you're sort of engaging all the machinery to, to sort of re- it, it's really the reactivation of those same synapses involved in the formation of the memory that creates, you know, that, that strengthens them. Whereas if you're just rereading the material, particularly if you've recently read it, you're like, "Oh yeah, I j- I just read this," you're not really engaging that machinery whereas you, you really engage it when you try to remember something.

And there's some other really fascinating studies where, um, which I, I, I didn't talk about in the book, but the one study where people are trying to remember pairs of words. What you would learn is you would learn kind of a trigger word and from the trim- trigger word you had to re- you had to remember the, the paired word and what they did initially ... You know, and what they did in, in one group was just, you know, have them, you know, just memorize the, the, the, the word pairs but in another group they had them come up with the b- the, with the, the paired word they were supposed to remember first without knowing what it was. So like if the pair is like apple, shoe and I give you the trigger word apple and you're like, "Oh, the paired word is gonna be tree," and then you learn it's shoe, you actually remember shoe better even though initially you created this idea of tree and that's because you've, you've created an infrastructure that you can then correct and say, "Oh no, it's actually shoe," and you combine those things together. And there are, there, uh, yet another study where they had people answering general knowledge questions and they then had them estimate how right they were or how confident they were in their answer and people who were more ... who were wrong but were more confident in their wrongness, when they then learned the actual answer, they remembered it better. So making a bigger mistake that you're more confident in then actually created a better anchor for you to sort of add the right answer to. So just like lots of these really cool studies about how it's just, it's truly doing things to engage that process of memory and creating a structure to, that memories can be bound to, whether that's being wrong about something or just thinking about trying to remember what it was you learned actually allows you to remember better.

Melanie Avalon
That makes sense, especially 'cause yeah, when you're so sure about something and then you find out you're wrong, you never ... I mean, I feel like I never forget it.

Dr. Tommy Wood
Yeah. Exactly.

Melanie Avalon
So yeah, so listeners, just try to remember what you learned in today's conversation. Don't even have to re-listen to it.

No. But this has been absolutely amazing, so thank you so much for your time, Tommy, and everything that you're doing. How can people get the book, follow your work? I know you gu- I know you work on a, you're like you're working on a lot of stuff in your lab that you've, that you've talked about so what all would you like to put out there for listeners?

Dr. Tommy Wood
Thanks so much for having me. This, um, uh, we covered a lot of ground that I actually don't frequently cover in podcasts so that wa- that was really cool to, to, to do.

So yeah, the book is The Stimulated Mind. It's available wherever you buy books. You can go to thestimulatedmind.com for more details. That actually links to a part of my website which is drtommywood.com and then my Instagram is where I post, uh, most of my podcasts and studies and papers and things that come out so that's, uh, @drtommywood on, drtommywood on Instagram and I also have a Substack and a podcast called Better Brain Fitness. You can go to betterbrain.fitness and you can sign up for the free version. All the content is, is the same regardless of whether it's the free or paid version and yeah, th- I share that with my colleague Josh Turknett who I mentioned, uh, um, earlier and, uh, the, the podcast is like a Q&A style so any questions you have, submit them there and, uh, we slowly work through them across our episodes.

Melanie Avalon
Oh perfect, especially 'cause I, I did have like a dozen listener questions for you but did not get to any of those so listeners submit them directly to Tommy on his podcast and we will put links to all that in the show notes and, um, thank you again so much.

The, the last question that I ask every single guest on this show, super easy, it's just because I am very much obsessed with gratitude and mindset, so what is something that you're grateful for?

Dr. Tommy Wood
I am really grateful for the, the people who supported me th- to allow me to do ... to, to write the book and then sort of get it out into the world so that's the, the people who work in my lab. I have several research staff and students who do all the hard work in the lab so that I can be traveling around the world speaking to Joe Rogan and, and, and writing the book so I'm, uh, really grateful for them and then also my wife who took on a ton of additional house care and other duties so that I could be out there first writing the book and then promoting it so I'm incredibly grateful to, to all of them.

Melanie Avalon
Amazing. Well, thank you so much. I will be eagerly looking forward to all of your future work and, um, yeah, thank you so much. I really, really enjoyed this.

My brain feels stimulated so goal accomplished. Thank you. Bye.

Dr. Tommy Wood
Bye.

Melanie Avalon
Thank you so much for listening to the Melonie Avalon Biohacking Podcast. For more information and resources, you can check out my book, What, When, Wine, as well as my supplement line, Avalon X.

Please visit melonieavalon.com to learn more about today's guest and always feel free to contact me at contact@melonieavalon.com and always remember you got this.