Neuroscientist: “The Silent Symptoms of Dementia - Watch Out for These Warning Signs” | Tommy Wood

Dr. Rangan Chatterjee 0:00 It's no wonder when we currently study populations, like, there's a linear decline in, in our brain function.

Dr. Tommy Wood 0:05 Yeah.

Dr. Rangan Chatterjee 0:06 So with all the good news, let's go more.

Dr. Tommy Wood 0:08 [laughs]

Dr. Rangan Chatterjee 0:08 Let's go to number three.

Dr. Tommy Wood 0:09 It's lack of, it's lack of stimulus, right? So we've already talked about that-

Dr. Rangan Chatterjee 0:12 We've talked

Dr. Tommy Wood 0:12 ... in m- in multiple ways. But if you, um ... The way that we would do that in animal models, um, is we either socially isolate an animal, which is incredibly stressful, and you have to get, um ... What, what's interesting, and it's im- it's import- I mean, it's incredibly important for doing high quality animal work that's ethical and that actually helps us move human health forward, which is ultimately the goal. If it's not doing that, I don't think it's worth doing. Um, that, you know, in order to do ethical animal work, you have to, you know, look after those animals as best as

Dr. Tommy Wood 0:42 you possibly can. And one of the ways that that's ensured is, you know, there are committees at every university that make sure that every experiment that's proposed is, is sort of as, as, um, ethically sound as possible. But unless you have a really good reason to, there are two things you're not allowed to do. You're not allowed to socially isolate the animal, and you're not allowed to remove any stimulus from the environment, what we call environmental enrichment, and that can be in terms of, uh, like a running wheel for mice, or it could just be, like, toys or something in the cages. Um, and if you think about humans, socially isolated, lack of cognitive stimulus, like, we're doing this to vast proportions of our population, particularly as they get older and we've taken away social connection, we've taken away stimulus. Um, you're not allowed to do that to a rat in a lab unless you have a very good reason for doing it. But you can do it to a human no problem.

Dr. Rangan Chatterjee 1:34 That is ... Just to look at it through that lens is completely nuts, isn't it?

Dr. Tommy Wood 1:38 Yeah.

Dr. Rangan Chatterjee 1:39 Wow.

Dr. Tommy Wood 1:40 So that's, that's the third part. And then the fourth part, uh, we kind of talked about a little bit as well, which is that, right, you need the stimulus, you need the things that require nutrients to respond to the stimulus, you need the absence of toxins, and then you need some kind of period of rest and recovery. So that's why sleep is critical. But then also, um, absence of chronic stress is probably something you could put into that bucket as well. And, um, you can do this, uh, with social stresses, say, um, in, in ... if you're gonna do this in, in an animal model. Um, so we, we talked about social isolation. That's, that's, that's a chronic stressor. But you can also do it with, um, aggressors. So you might have a- an aggressive, um, mouse that you introduce into the cage, and then that continuous aggression, which, uh, could be, uh, discrimination based on your physical ability, based on your race, based on your socioeconomic status. You know, these things that people are exposed to again and again and again, and we might model it in that way. And then that's ... You know, there's a whole host of, um, physiological, immunological, you know, things that we can measure that result from that. But, you know, cognitive decline and chronic health conditions can be one of the things that come from that.

Dr. Rangan Chatterjee 2:49 Yeah. I'm thinking of that aggressive boss, that aggressive family member.

Dr. Tommy Wood 2:54 Yeah.

Dr. Rangan Chatterjee 2:54 The, the sort of thing we can all think about in our own lives, whether currently or previously, and what an impact that can have. And it also speaks to what you said early on in the conversation, and it's something we have to be super conscious of when we're talking about making changes to improve the quality of our lives. You know, I'm all like you for empowering people with helpful information, but I think we do need to acknowledge maybe in this wellness community more than often does get acknowledged, that there are huge psychosocial stresses-

Dr. Tommy Wood 3:24 Yeah

Dr. Rangan Chatterjee 3:24 ... cultural stresses for different communities, financial stresses, racial stresses. These things hugely impacts our biology and our physiology.

Dr. Tommy Wood 3:33 Yeah.

Dr. Rangan Chatterjee 3:33 And for some of us, it's easier to make those changes than for others, isn't it?

Dr. Tommy Wood 3:39 Yeah. And I, I think it's a ... It's been something that's sort of aimed at, uh, whether you call, you know, the lifestyle medicine or, uh, functional medicine or integrative medicine, uh, ancestral health communities, you know, those people who focus on these lifestyle factors that we've talked about. And it's a worthy critism- criticism to say not everybody can do that, right?

Dr. Rangan Chatterjee 4:00 Mm.

Dr. Tommy Wood 4:00 Not everybody has the financial ability to remove themselves from the environment that they're in, if it's, you know, um, they have to live close to a road or they have to live close to a refinery, right? So in, in, in the, in the United States, um, you know, near, you know, large petrochemical plants, that's where you've had redlined housing areas where people from low socioeconomic status, usually more likely to be Black, have been put around-

Dr. Rangan Chatterjee 4:22 Mm

Dr. Tommy Wood 4:22 ... these areas. And then it's, you know, it's baked into the environment and you can't afford to move out. Um, and or it may be, you know, we talked about food, but, you know, what food to- do you have access to? Um, do you even have a kitchen? You know, do you have-

Dr. Rangan Chatterjee 4:36 Yeah

Dr. Tommy Wood 4:36 ... are you working two jobs and do you, do you have time to cook? Um, you know, we need to be very mindful that the social determinants of health play a big role here.

Dr. Rangan Chatterjee 4:44 Yeah. I, I mean, I totally agree with that. I, I think it's ... I think there's a lot of nuance to that because sometimes that criticism gets leveled and say we shouldn't be giving any information out because it's not relevant to that community.

Dr. Tommy Wood 4:56 Yeah.

Dr. Rangan Chatterjee 4:57 I don't agree with that.

Dr. Tommy Wood 4:57 No.

Dr. Rangan Chatterjee 4:57 It's like we should definitely be giving out information, but we also need to be aware that that information may not be relevant or as relevant, and so we shouldn't look down when people can't take that advice, for example.

Dr. Tommy Wood 5:11 Yeah.

Dr. Rangan Chatterjee 5:12 You know, and I've always fought for that, uh, wellness, for want of a better term, is for everyone. I think every single human being has the right to good quality health information that they can try and apply in their own life, and my bias comes from my clinical practice. So, um, I, I've worked in lots of different practice throughout my career, but there was a particular period of time where I worked in a practice in Oldham in North Manchester, and it was a very low socioeconomic status area, lots of immigrants, lots of people on benefits, people working two jobs, lots of single parents. A lot of, in adverts commas, "struggle" for day-to-day life compared to other areas I've worked where it's, um, you know, more affluent.

Dr. Tommy Wood 5:58 Yeah.

Dr. Rangan Chatterjee 5:58 Um, there's struggle there as well in a different way.And you know what I learned, Tommy, in that? Is that because I think it's easy, and I see this in the media a lot, we ... It's either we can empower people with their lifestyle choices, or we say that there's huge social determinants of health. It's kinda like, well, why does it have to be that black or white? I think all these things are nuanced, and I'm-

Dr. Tommy Wood 6:20 Yeah

Dr. Rangan Chatterjee 6:20 ... I, I do passionately believe that this information is relevant for everyone, and we should be giving it to everyone, but with the acknowledgement that for some people it's harder.

Dr. Tommy Wood 6:29 Yeah, and, and I completely agree. And I, in that line, I think it's very both patronizing and disempowering to say-

Dr. Rangan Chatterjee 6:38 Yeah

Dr. Tommy Wood 6:38 ... that, "Oh, you shouldn't be talking about lifestyle or diet because it's ... You know, these people m- you know, may, may or may not have an ability to change that."

Dr. Rangan Chatterjee 6:44 It's very condescending.

Dr. Tommy Wood 6:45 It's incredibly condescending. So but we just need to acknowledge that all of these things are important. Um, but again, there have been the ... There was a, a recently published study came out in, in Lancet Public Health a few years ago that looked at using UK Biobank data, looked at, like, uh, mortality risk. Um, and they stratified individuals by some lifestyle factors, so based on quality of diet, whether they smoke, you know, physical activity, and then also stratified them by social deprivation. And you see that, yes, as your, um, like, socioeconomic status decreases, overall risk increases.

Dr. Rangan Chatterjee 7:19 Mm.

Dr. Tommy Wood 7:19 But when you s- look at the effects of lifestyle, movement, diet, there's still great benefit there.

Dr. Rangan Chatterjee 7:26 [laughs]

Dr. Tommy Wood 7:26 So, so, yes, the overall risk is greater, but you can ... Like, those ... There are individuals there, you know, reducing it through those, through those activities. So to say that we, we shouldn't be talking about it, I think, is in-

Dr. Rangan Chatterjee 7:36 And

Dr. Tommy Wood 7:36 ... incredibly condescending.

Dr. Rangan Chatterjee 7:37 A- and also, you know, what I found, Tommy, is that if I change the advice I give them because I make that assumption, I'm depriving them of good quality advice. And what I learned there is actually sometimes in the poorest communities, they would actually literally follow my advice to the letter more-

Dr. Tommy Wood 7:56 [laughs]

Dr. Rangan Chatterjee 7:56 ... than in more middle-class affluent communities. Like, I remember I thought that, you know, there wasn't much money in the family, and, you know, at the time, I don't think we were allowed to give vitamin D. This lady had really bad pains, and I was convinced it was related. And, um, you know, she went and bought from the local health food shop supplements for her and her family and got huge improvement. And, like, it's unfair to, to think that we know what they will prioritize-

Dr. Tommy Wood 8:25 Yeah

Dr. Rangan Chatterjee 8:25 ... with their money. It's not up to us. Yeah, I think this is, this is complex, but I think it's important that we talk about it, actually.

Dr. Tommy Wood 8:30 Yeah. A- a- absolutely. Um, uh, all of the, all of these pieces are ... You know, different parts are, are important for different people in, in, in different amounts. And, um, there's ... You know, part of it is just getting information out there, and, and so, uh, again, empowering people to n- to know what may or may not be important, uh, for them, for ... And it could be whether they're worried about their risk of dementia or heart disease or, you know, they just wanna be able to play with their grandkids. Uh, you know, you know, often people's goals are, uh, much more practical than a doctor might think. You know, you're, you're worried about some diagnosis or something, but people, you know, wanna be able to just interact with their family or something like that. And different things are gonna be a different relative importance for different people, but they should be allowed to, to make those decisions.

Dr. Rangan Chatterjee 9:11 Yeah.

Dr. Tommy Wood 9:11 And, you know, yes, we sh- I, I think that, um, we need greater support for behavior change for individuals who want it. Um, we don't necessarily-

Dr. Rangan Chatterjee 9:22 Sure

Dr. Tommy Wood 9:22 ... do a good job of that.

Dr. Rangan Chatterjee 9:23 And doing something new that's stimulating and challenging, there are a lot of low-cost ways to do that-

Dr. Tommy Wood 9:29 Oh, completely free

Dr. Rangan Chatterjee 9:29 ... if not free ways to do that.

Dr. Tommy Wood 9:30 Absolutely. Yeah, absolutely.

Dr. Rangan Chatterjee 9:32 You know? Balancing, hopping around your ... You know, I don't know. We could make up all kinds of things that would actually provide a stimulus.

Dr. Tommy Wood 9:37 Yeah, absolutely.

Dr. Rangan Chatterjee 9:38 And, and so I think that's a great piece of practical advice. Okay, so that was in the first bucket. The second bucket was about important nutrients not getting to the brain, whether that be because we're not taking them in, or because we're taking them in, or we might be taking them in, but they're not able to get to where they need to get because, let's say our, our blood vessels are in poor health for whatever reason. So you've been on a bit of a journey, Tommy, since I've known you and from what I've seen in public. Um, as we have this conversation in 2022-

Dr. Tommy Wood 10:12 [laughs]

Dr. Rangan Chatterjee 10:13 ... uh, what is your current viewpoint on nutrition for human health? Uh, I guess specifically we're talking around brain health-

Dr. Tommy Wood 10:24 Yeah

Dr. Rangan Chatterjee 10:24 ... preventing cognitive decline as we get older, which I think everyone wants. What kind of advice would you give to people regarding foods?

Dr. Tommy Wood 10:32 I think the f- the starting point is that you should eat something that is accessible to you, that you enjoy, and is sustainable. Like, that has to be a, a starting point, because I could give you a whole bunch of recommendations, but if it's none of those things, then you're not gonna do it or not gonna stick to it. And one thing that constantly fascinates me about the human body is how adaptable it is.

Dr. Rangan Chatterjee 10:57 Mm.

Dr. Tommy Wood 10:57 Um, and the wide variety of diets that people, um, evolved while eating or, you know, a- ancestrally, you know, the, the different diets that ... You know, my ancestors ate a very different diet to your ancestors just because of where they are on the planet, and they both thrived, and I find that fascinating. And so it, the ... It's the same thing now. Like, what somebody enjoys and is sustainable to them is very different from the person next to them, and they may sustain their health in, in an identical manner with, you

Dr. Tommy Wood 11:27 know, objective, objective measures that you could take. So I don't have any particular one way that I would recommend that people eat, but it should support your health, and we can certainly talk about things that you might measure, uh, and want to, to track, um, over time. Specifically t- for the brain, uh, because we have interventional studies that, that show it's the case, um, B vitamins are incredibly important, so we're talking, um, B12, which generally you can only get from meat and animal foods. Um, if you are vegetarian or plant-basedI think the best people who, uh, promote or work with individuals with those diets would recommend you take a B12 supplement. Um, then, uh, folate, uh, uh, B2, which is riboflavin, and, uh, B- B6. Those are probably the most important, uh, nutrients for, for, for, for brain health. And again, you know, any diet that has a, a reasonable number of whole foods, plants, vegetables, eggs, meat, fish, will have enough of those probably. Um, then the other important thing specifically, uh, for the brain is, uh, uh, the omega-3s, long-chain omega-3s. And in this, in these studies that I mentioned earlier, uh, by David Smith, they showed that the greatest benefit from the B vitamin supplement came from those who had what they called adequate omega-3 status. And again, so these are long-chain, um, omega-3 fatty acids like EPA and DHA, which in the diet are generally only available from seafood. Uh, but there is a g- there is a slight genetic component based on people who can take shorter ones that you might get in chia seeds or walnuts and then convert them to, to longer chain ones. Um, but, uh, so again, there's, there's, there's a slight genetic component there, but some seafood is probably important as well.

Dr. Rangan Chatterjee 13:16 Yeah. Okay. This, this is super interesting. So you first mentioned B12, and as you say, if people are eating animal products in their diet, they're likely to be at least taking in enough B12. What I've found when I used to measure this quite a lot, is that even people who were taking in reasonable amounts of B12 had suboptimal B12 levels on their bloods.

Dr. Tommy Wood 13:43 Yeah.

Dr. Rangan Chatterjee 13:43 There's a whole variety of reasons why that might be. Uh, in my view, I, I feel, I certainly feel stress is a huge part of it because to be able to actually absorb that B12, what needs to happen can be impaired, I think, by too much stress. Because I was thinking, why is it that they're eating enough B12 from what I can tell, yet that's not being shown up? And, and there's all kinds of reasons for it. That's just one of my views. I mean, what, what's your perspective on that? Is that something you've seen, and do you have any opinions as to the reasons why that might be?

Dr. Tommy Wood 14:16 Yeah. Um, uh, absolutely. And I, I remember even, um, you know, 10 years ago, uh, it's now 10 years since I worked as a doctor, pretty much, uh, as a junior, junior doctor at St Thomas' in London. I was working on the elderly care ward, and when people got a, a first diagnosis of dementia, even then one of the first things we did was, uh, something called a dementia screen, which we looked at iron status, uh, vitamin D, and some, uh, B vitamins, B12 and folate at least. And then if f- um, B12 was low, there was a second test they called methylmalonic acid, which is produced, uh, when you're B12 deficient. And so even then we were doing it in an NHS hospital 10 years ago.

Dr. Rangan Chatterjee 14:55 Yeah.

Dr. Tommy Wood 14:56 Right? Just these basic nutrient sta- status checks. And I think, uh, stress, you know, stress, um, certainly may affect, um, acid production, which is really important for B12 and also iron absorption. Um, but then some medications can do it. So metformin can, can affect B12 absorption. Uh, proton pump inhibitors, which people might take for, um, you know, reflux, that can affect, uh, B12 absorption, and these are very common drugs-

Dr. Rangan Chatterjee 15:21 Yeah

Dr. Tommy Wood 15:21 ... uh, to prescribe. So, uh, you know, there's probably some, some lifestyle factors, but then, you know, it, it may also be a result of some- something else that somebody's taking.

Dr. Rangan Chatterjee 15:29 Yeah, I remember Professor Bredesen when I spoke to him about this a few, a few years ago. He, he will work with his patients to do all the tests, the homocysteine, the, the MMA that you mentioned, and the serum B12. And at the time, I remember thinking, "I, I can't get this stuff for my NHS patients" back then. And he said he likes to see for cognitive function, a serum B12, right? So that's your regular cheap, uh, B12 test. Um, and you know, I'm gonna say it depends on your lab, but, you know, the normal value that will be reported would typically be something like 200, 250 to 700, 800, maybe 900-

Dr. Tommy Wood 16:11 Yeah

Dr. Rangan Chatterjee 16:11 ... depending on the lab.

Dr. Tommy Wood 16:12 Yeah.

Dr. Rangan Chatterjee 16:13 Right? So huge, huge range of normal.

Dr. Tommy Wood 16:15 Yeah.

Dr. Rangan Chatterjee 16:16 And he said in his experience, if it's under 600, he would treat it.

Dr. Tommy Wood 16:20 Mm-hmm.

Dr. Rangan Chatterjee 16:21 And I remember I came back 'cause I, it w- I was chatting to him in America, and I, I tried that with a few patients actually. And again, this is just anecdotal. It's not a scientific study. But people would come back and say, yeah, they feel sharper, their cognitive function has got better when I'd treat their serum B12 from, let's say, a normal level of 250. What do you think to that?

Dr. Tommy Wood 16:42 I think that's, um... I mean, I'm, I'm not necessarily surprised. Uh, again, it depe- probably depends. What's interesting about, um, the difference between the US and the UK is that in the US you can't get an active B12 test, what we would call holotranscobalamin. It's very common to do in the UK. You can't do it in the US. So you, in, on the US test, you probably need to be at the high, at the upper end of normal because, um, there are lots of other things that can cross-react with the test, and they look like B12, but they don't have the function-

Dr. Rangan Chatterjee 17:17 Hmm

Dr. Tommy Wood 17:17 ... of, of B12, and that's the case with some, like, plant-based B12 analogs. Uh, so that, so for him, I, I imagine that's probably one reason why that may be the case. But equally, more broadly, I spent a lot of time, uh, looking at, looking at and thinking about blood tests, and if we think back to what we said right at the beginning, which is that the average popula- the, the average adult has at least one chronic condition, takes at least one, um, medication, has at least one, if not two, of the components of metabolic syndrome, of which there are five. If that's the average person and the normal range is just... The way you define the normal range is you test a whole bunch of people, and you take the middle 95%-

Dr. Rangan Chatterjee 18:01 Mm-hmm

Dr. Tommy Wood 18:02 ... and whatever the bottom, the lowest person of that middle 95% or whatever the top person is, that's the normal range. And if the average person-... is sick to some degree, then what's normal is not necessarily normal. Um, and I think that's part ... And y- you see this again and again, um, that they've changed the ranges over time. That's been, uh, that's been the case for certain sex hormones, you know, like ... And people have talked about this a lot. You know, they, they're decreasing the normal range for testosterone in men because they think that testosterone is de- decreasing, um, on a, at a population level. Whether it's actually true or not is up for debate, but it's something that's happened. That's, you know, they've changed the ranges if they see that, you know, the overall the population level changes. I saw something similar when they were trying to develop normal ranges for grip strength. Um, and what they saw over, you know, generations, you know, from, you know, like, uh, Generation X, uh, Generation Y, Millennials, like, uh, coming through to what w- in America we call Gen Z. Um, grip strength was declining, particularly in males. So there was a publication that said that and said, "We need to change the normal range for grip strength," rather than saying, "We're getting weaker. Why aren't we working on that?" And so, you know, it's, it's like, um, the, the frog that sits in water from when it's cold, and then if, if you bo- if you boil it, it will slowly heat up. It'll never jump out, right? 'Cause it never realizes-

Dr. Rangan Chatterjee 19:28 Yeah

Dr. Tommy Wood 19:28 ... 'cause it's so incremental and slow. And so that's, that's one of the problems, is that we're look ... You know, some normal ranges are constructed around a population that's sick, so then normal isn't necessarily, isn't necessarily normal, and that's p- that may be playing a part in the role there, too.

Dr. Rangan Chatterjee 19:40 Yeah. It, it, it's super interesting, and hopefully we'll get time to go into some blood tests that people can do. You mentioned seafood. Why do you think seafood is so important for our brain health?

Dr. Tommy Wood 19:51 Mm-hmm.

Dr. Rangan Chatterjee 19:53 And then for people who are vegan or, you know, choosing not to have animal products, can they still have good brain health and get those nutrients that you would get from seafood in other ways?

Dr. Tommy Wood 20:10 So there are a few strands, um, the m- the m- the l- of information that lead me to think that, that seafood... Or I say seafood because it's the m- the most common dietary, um, component that gives us long chain omega-3s. What I'm really interested in is long chain omega-3s, particularly DHA in the brain. And again, if I go back to what does it take to build a healthy brain in the first place, DHA is preferentially sucked up into the brain while you're making it, as much that the mother will sacrifice her own DHA status so that the baby gets enough. Because it's one of the most critical fats that makes up the brain, for a number of reasons. Um, it... And it goes, it goes directly into the, the cell membrane. So people may or may not know that most of your brain, which is in water, is fat. Almost all of it, right? So, 'cause fat makes up all the, uh, insulation around the nerves. It makes up all the, the membranes around the cells. And DHA is incredibly important both for the function of the synapses, how they talk to each other, because of its, because of the, because of its structure. It has this, you know, very important, um, role in terms of, like, how the synapses work, how neurons talk to each other. But then it's also, uh, accumulated into the mitochondria, which people might know as the powerhouse of the cell. It sits inside the cell, generates most of the energy. And some of it is really cool physics, that basically how electrons travel through DHA is really interesting. Um, but equally, you know, as sort of like a more basic way, you can see that the more DHA that's in a mitochondria, the greater energetic capacity it has, the more energy it can produce. Um, and that's the reason why... And, and there are some evolutionary theories that say that, you know, maybe the human brain as it currently exists developed in a se- i- in, like, a group of hominids that had either di- direct access to lots of seafood or to the brains of other animals, uh, because brains are an incredibly rich source of DHA because your, your body preferentially shuttles it, uh, to the brain during development. So it has this really important functional role. Um, and when you, um, don't have it, that's associated with neurodevelopmental disorders or developmental delay, um, risk of other neurod- uh, like, neurodevelopmental issues. Um, and then you can also see things like, um, there have been some interesting studies done in the UK and in the Seychelles where, uh, you look at the, the amount of seafood that a mother or her ba- uh, her children eat, and then you look at long-term neurodevelopment. And you, you asked about heavy metals earlier. Particularly mercury is important for seafood, but it seems that even if you have a higher mercury burden because you eat a lot of seafood, you get a, you get greater benefit-

Dr. Rangan Chatterjee 22:55 Yeah

Dr. Tommy Wood 22:55 ... uh, because of the omega-3s in the diet. Um, so that kind of, you know, that sort of first principles approach says, well, what does a brain really want when it's developing? And it really wants DHA. It's, you know, it's, it, it's essentially that's where all your DHA goes is, is your brain. And, and again, one of the things that, um, is interesting about humans is that we're the only mammal that has fat babies. No other animal has fat babies. And one of the reasons why, um, uh, human babies are fat is because they have adipose tissue as a store of DHA for the brain as it grows.

Dr. Rangan Chatterjee 23:34 When, when you say fat, you don't mean unhealthily fat.

Dr. Tommy Wood 23:37 No, I m- You know me, like-

Dr. Rangan Chatterjee 23:38 Healthy, sort of-

Dr. Tommy Wood 23:39 ... healthy, chubby, plump little babies, right? So if you look at any other mammal, um, when they're born, they're very lean. Even other primates. They don't have large adipose stores. And one ... You know, it's, it's an en- So it's an energetic store, right? We know that adipose tissue, fat tissue is a, is a store for energy, but what ... But it also stores fats that are then particularly used for the brain, and D- DHA is one of them.

Dr. Rangan Chatterjee 24:02 So a developing brain needs it.

Dr. Tommy Wood 24:04 Yes.

Dr. Rangan Chatterjee 24:04 Can we therefore say that a developed brain also needs it?

Dr. Tommy Wood 24:11 So-This is an exceptionally nuanced topic

Dr. Rangan Chatterjee 24:16 Yes

Dr. Tommy Wood 24:16 ... even more so than any of the other topics that, that we've talked about. A colleague of mine, Dr. Rory Heath, and I wrote a paper recently about DHA and Alzheimer's disease, and some people have said that the DHA in, in patients with Alzheimer's disease, uh, in their brain is low. Others haven't quite found the s- the, the same thing. Uh, part of it is probably that, again, your adipose tissue is, is essentially a very nice buffer of DHA that you can use across your lifetime. So it's, it's, it's quite... If somebody is... Unless somebody has never eaten seafood or has never eaten really any long-chain omega-3s, it's very unlikely that you're gonna be deficient, um, in, f- for the brain, for cardiovascular function, um, and, and other things that, that, that may not necessarily be the case. Um, and that's why the omega-3 index or, you know, how, you know, your omega-3s in your blood is a increasingly used, um, risk predictor of cardiovascular disease and things like that.

Dr. Rangan Chatterjee 25:06 Mm.

Dr. Tommy Wood 25:07 Um, so it's, so it, it's very nuanced. Um, but if you're going to be maintaining cell membranes and cell function, you're definitely gonna need some. And then the much better line of evidence comes from systemic measures of omega-3. It's impossible for me to measure how much DHA is in your brain, right? But I can measure how much is in your blood.

Dr. Rangan Chatterjee 25:26 Right.

Dr. Tommy Wood 25:26 And when these studies were done at Oxford, they showed that you needed both adequate B vitamins and enough omega-3s in order for you to get this slowing in, in brain atrophy and cognitive decline. So if you measure omega-3 levels in people and they're low, they have a, a faster rate of cognitive decline, which tells me that that's important.

Dr. Rangan Chatterjee 25:49 Yeah.

Dr. Tommy Wood 25:49 Because if you fix it, then you can, you can change that.

Dr. Rangan Chatterjee 25:51 [upbeat music] If you enjoyed that short clip, I think you are really going to enjoy the full conversation, which you can check out here. [upbeat music]