Protect Your Brain, Extend Your Life: 7 Mistakes to Avoid for Better Cognitive Health with Dr Tommy Wood #681

36:00And he's absolutely right. That is sort of like fundamental to so much of this. Yeah. Can we say that social isolation is a form of stress? So yes, on multiple levels. We see in controlled studies that being socially isolated increases stress responses, which you can measure through things like heart rate variability and cortisol levels. And there are studies where they've done this, for instance, NASA and other space agencies around the world have wondered, how will people do if we send them to Mars, right? So there have been some Mars simulation projects where you put people either on their own or a very small group in a tight confined space for extended period of time.

36:47And even that for just weeks significantly increases stress responses. We know it's inherently stressful. even if there are other people there you're relatively isolated because there's only one or two other people and we also know that when you look at when you look sort of across a big population those who are more social isolated particularly those who feel lonely they have other markers of a heightened stress response so you can measure these stress responses in people who are isolated in a variety of different ways either experimentally or just as part of their you know unfortunately where they are in the world right now.

37:25On the other side, you can also see a response or changes in the brain with social isolation that look like the removal of stimulus and accelerated brain aging. So when you look at the areas of the brain, the human brain, that are most driven by the environment and are most driven by experience and sort of interaction with the world around you. They're also responsible for some of our most complex cognitive functions. Areas like the prefrontal cortex, the lateral parietal lobe, the lateral temporal lobe, so kind of like the front and sides of the brain, essentially, which are responsible for things like decision making, focus and attention, memory, language, vision, or visual processing, social cognition, things like that.

38:16These areas of the brain are essentially completely undeveloped at birth. Their development is driven by the environment and how you engage with it during childhood and then early adulthood. But these are also the areas of the brain that are most susceptible to the processes of aging, particularly the removal of stimuli. I mentioned earlier that part of the reason why I think our brains age is because we stop doing the things that help build these functions in the first place. interacting with other people, learning skills, focusing on stuff, you know, kind of doing complex activities. And those areas of the brain that I just mentioned, when you look at people who are socially isolated, those areas of the brain are the areas of the brain that tend to either get smaller or tend to lose function.

39:03And they've done studies where you look at, yeah, so people from those like, sort of simulated Mars trip studies, or people who were polar explorers, right, on their own off on some snowy glacier for months on end, or in prisoners who are placed in solitary confinement. Those same areas of the brain that I mentioned, tend to lose structure and function as a result of that loss of social input. So not only is social isolation and loneliness, not only are they inherently stressful, you're also removing a critical input that maintains these really important structures in our brains. Even if you're a polar explorer, right?

39:45And you're getting stimulated by all kinds of things in your environment and, you know, you have to be vigilant and all kinds of stuff, right? Even with that kind of stimulation, you're missing out on a very important part of stimulation or stimulation for the human brain. And it made me think, the brain needs stimulation. And this, I guess, fits in with the second mistake of focusing on solo health habits at the expense of social connection. Let's say you're an 80 year old and you live by yourself. Okay. And you've heard Tommy Wood or you've read your book and you go, yeah, I need to stimulate my brain.

40:20So you are learning new skills on your computer. You're competing at chess online with other people, but you're doing it all in isolation. So you're giving it a lot of stimulus, but it's individual stimulus as opposed to social stimulus. can we say then or can we hypothesize that even with all that stimulus you are still missing a significant primary stimulus that the brain needs which is social connection the way that i would answer it is that if that person feels lonely or feels that beyond what they're currently doing they lack some kind of purpose or meaning then yes i think there's more to be gained if that life is incredibly fulfilling to them which for some people it will be then no i couldn't say well you have to go out and make friends right so i think some of it is going to come down to like fundamentally how do you feel about the kind of setup and your current connection to other people because often when you talk about social connection and and rightly so some people will say this is directed extroverts who like to spend time with other people i was literally going to bring that up exactly um and you can be connected to a lot of people and still feel lonely um and some people only need a very small amount of of human connection to feel like that you know they're getting everything they need um my friend uh dr ben uh ryan who wrote wrote an excellent book called Why Brains Need Friends.

42:02You know, it talks about, you know, a flower in a pot. And like some people, the soil in the pot needs a lot of watering, right? It needs a lot of social connection for them to feel kind of fulfilled. But like some people are a succulent or a cactus, right? They only need a little bit and they feel just fine. And like wherever you are on that spectrum is absolutely fine. As long as you're getting what you need to feel like you're connected, to feel like you're supported, to not feel lonely, to feel like you have, you know, some kind of, you know, your life has some meaning, you know, outside of just yourself.

42:34So I want to make that very clear that it will come down to how you feel about the situation. Yeah, that's a really important point. And I think for those people who were pushing back when they had a social connection, I think that hopefully appeases people and helps clarify things. Okay, we've done two of these mistakes so far. Mindset and this solo health habit focus at the expense of social connection. I want to go to some areas that I think we haven't spoken about before. One is blood pressure. So I would say mistake number three that I think gets made a lot is ignoring high blood pressure.

43:10Do you agree with that statement, Dr. Wood? Yes.

43:16And I didn't necessarily realize it until I was doing the research for my book, but the evidence for blood pressure management and dementia risk is actually incredibly strong. It's one of the few interventions where we have multiple randomized controlled trials that have been put into meta-analyses to show that if you address this risk factor, you see a significant reduction in dementia. Most of the other things we talk about come from big population studies, observational studies. Yes, we're pretty sure that that connection is there. And if you modify this risk factor, you'll see benefit. But blood pressure actually has really high quality evidence.

43:56So when we talk about blood pressure normally, we're usually thinking about heart health, right? And heart disease risk. And it's obviously important there too. But if I've learned one thing over the past few years, is that even when people are taking cardiovascular disease risk fairly seriously, it's not as much of a motivator for behavior change as we might hope. whereas when we think about this in terms of our brains often that's the right somebody wouldn't maybe worry about their blood pressure oh it's a little bit high it's probably fine when you then realize that this is a critical risk factor for the majority of dementias both Alzheimer's disease and vascular dementia which have a lot of overlap and between them they make up 70-90 % of dementias often that's the key maybe for people to think about it but we don't really think about the brain when we think about blood pressure.

44:55But we know that once your blood pressure goes, you're much above sort of 120 over 80. And you really, once you get into the sort of the metabolic syndrome criteria level of blood pressure, which is usually over 130 over 85, you see a significant increase in the risk of dementia. And if you can reduce it, you see a significantly reduced risk of dementia. And the sort of the average benefit is if you can get your systolic blood pressure down by about 10 points, you see a significant benefit in terms of your dementia risk. So there are multiple ways to do that, right? We know we can do it through physical activity.

45:33We can do it through other lifestyle changes to improve metabolic health. But these studies are with blood pressure medications and you see significant benefit in terms of dementia risk. So if you need a blood pressure medication or your blood pressure is high and is not fully controlled, I think that is something that we really should take seriously. Yeah. I guess one of the problems with or potential problems with blood pressure is that people often don't feel anything wrong. They used to call it the silent killer, right? I think so in medical school, I'm pretty sure that's what we used to get taught that it's just going on in the background.

46:13I'm literally at the moment trialing the Hilo bands. I think it's the, to my knowledge, it's one of the only FDA approved continuous blood pressure monitors. The goal is that that is telling you more accurately whilst you're going about your everyday life, what actually is my blood pressure doing? But of course, you know, there are 24 hour monitors that you can get on the NHS. So there's all kinds of ways, but I guess the message you're sort of, I guess, trying to give people around brain health is get your blood pressure checked. Yeah. And we've now gotten to a point where you could go to Boots and a blood pressure monitor was it 20 or 30 quid?

46:54Yeah. Probably not that much. Probably not anymore. And if you do it two or three times a day at home or you could even get it you know your GP could prescribe it for you on the NHS right? So you might not even have to pay for it yourself. But just like you said having some idea what's in the morning what's in the afternoon take it two or three times a day that's going to give you a much better picture plus you get used to having your blood pressure taken so you have less of that kind of anxiety of that feels kind of weird and getting stressed about what it might be. And I think now it's gotten to a point where relatively regular blood pressure monitoring is something that's easy for all of us to do and we should be doing.

47:32Yeah. I think that's a good segue to get into the fourth mistake, which is not doing any form of blood testing until maybe until you get sick, right? Before we just jump there though, So I guess this is related to blood pressure. I mentioned earlier on in this conversation that over the last 12 months, I have taken up paddle. One thing I've noticed since I started playing, and you've got to bear in mind, it wasn't as if I was sedentary beforehand. I was already, I would say, pretty healthy before I started playing paddle. My resting heart rate has gone down by about four beats, right? That is significant.

48:15We've never covered resting heart rate before. There is a linkage here with blood pressure, of course, but as well as being a brain health expert, you're a performance coach for Formula One drivers and a lot of high-level athletes. What is the benefit of a resting heart rate going down in this context? Yeah, there are several metrics that you can sort of track physiologically that do seem to correlate with longevity, chronic disease risk, heart disease risk in particular and resting heart rate is one of them heart rate variability is another and I imagine if your resting heart rate has dropped your heart rate variability it has also gone up and then resting respiratory rate is another one that maybe we don't appreciate as much which is basically how many breaths you take a minute and that also seems to be a good predictor of stress burden and other things as well as being related to some aspects of long-term health.

49:15And when your resting heart rate is lower, your heart is essentially more efficient, right, to get blood around the body. And we know that those who have a lower resting heart rate tend to be fitter, they tend to live longer, they tend to, you know, have fewer chronic diseases, less heart disease. And that's probably a combination of, yeah, improved fitness, decreased stress responses, and, you know, all those kind of things are related to that. So having lower resting heart rate is absolutely like a measure of better sort of like overall health and fitness. Like you said, in this context, there are times when low resting heart rate can be a bad thing.

49:56You have later risk of things like heart disease, heart failure. And so by improving efficiency and improving heart function, you're decreasing the risk of that happening long term. Yeah. And almost certainly, had I been tracking my blood pressure, which I was not, I might also see that come down as a consequence, right? Because these things, of course, don't work in isolation. Let's get to that mistake number four, you know, this idea of not doing any form of blood testing until you get sick. And I guess underpinning this as a mistake is an idea that I don't think is widely known with the public.

50:37And, you know, I very much appreciate your take on this which is this idea that the bulk of our medical education and i would say certainly here in the uk the way that nhs is broadly speaking set up is to diagnose disease and treat it okay and i think it can do that exceptionally well the creation of health is a little bit different from the diagnosis and treatment of disease and one of my frustrations over the last couple of decades or so has been that we in medicine and maybe we could argue there's no resource for that within medicine but for whatever reason I feel that people are allowed to deteriorate somewhat not quite get into a disease category, but deteriorate and say everything's fine until actually something happens.

51:37Oh, no, you've got type 2 diabetes. Let's talk about metformin and insulin and sulfonylureas and all that kind of stuff, right? So this idea that HbA1c, for example, your average blood sugar marker, here in the UK, at 6.0 in old money, it becomes pre-diabetes. At 6.5, you're called a type 2 diabetic. But that does not mean that 5.7 and 5.8 and 5.9 is fine. And many people in the UK, if you go and get an HbA1c test from your doctor, you're told that's normal. Now, there's a resource issue within the NHS, I accept. At the same time, I think our approach to prevention is a little prehistoric. It's kind of a 20th century approach, even though we're now at 2026, we're in the 21st century.

52:38And so I believe it's much better if we were able to track certain metrics and start to see when things start to go wrong. so we can say, hey, listen, you're not pre-diabetic, but you're not where you were a year ago. You're on the way. Would you like some help in making some changes which will perhaps stop this process, right? So do you have any sort of thoughts on that initially, at least? I completely agree with you. This is relevant to pretty much any chronic disease. It's relevant to, we've talked about blood pressure. It's relevant to blood tests. I mentioned cognitive tests previously, or like just in passing earlier, because nowadays you can't get a cognitive test from a neurologist or an old age psychiatrist or whoever would be doing it until somebody suspects you have cognitive impairment.

53:32There had to be some trajectory of decline, but we had no idea where you started, no idea how long that took, no idea how long you've, or like how much function you've lost in order to get to the point where somebody diagnoses you with say mild cognitive impairment from a cognitive function test. because we don't track these things over time. A charity that I work with, Food for the Brain, that has an online cognitive function test that people can do for free if they're interested, but more importantly, they just got a big Invent UK grant to try and develop it so that it can be used in the NHS.

54:03Hopefully so that people will do it more regularly and then they can track their own function over time. But this relates to everything. Why I think it's so important, right, is because if you were doing an annual cognitive test, you may realize at 48, hey, listen, at 45, I was scoring here. At 48, I've just gone down a bit. Jesus, hey, doc, what can I do here? So it might motivate people to start these changes earlier. Yeah, absolutely. I think that's the case for many very basic blood tests, just like it is for blood pressure. we have to have diagnostic cutoffs like the ones you mentioned for pre-diabetes and type 2 diabetes when it comes to blood sugar you have to have some decision making point where you don't say right now it's time to treat with medication I completely understand why we have those that's very important but blood sugar is a good example so HbA1c because two people can have the same HbA1c but have very different blood glucose or blood sugar trajectories or experiences over the day.

55:13Because HbA1c is affected by many other things, including the life of your red blood cells, and there's some genetic components as well. So what they do is they say your HbA1c is this, your average blood glucose was this. But actually, there's a huge amount of error in that. Two people with the same HbA1c can have very different average glucose levels. And one may be problematic, but the other may not be. And so where HbA1c is most useful is tracking your own changes over time. But again, you can't do that unless you have a baseline. What was my HbA1c when I was young, healthy? Everything was good, right?

55:51Because for some people, that might be close, might be not that far from a pre-diabetic cutoff. For other people, it may be much lower. And then it's watching that change over time. And when it does start to change, realizing, oh, maybe now's the time or I should be doing something to intervene. Yeah. this is one of the reasons that I have created something called do health here in the UK initially and the truth is I I never had any aspirations to do something like this a health app a preventative health app to help people get on top of the health early but what I realized Tommy is that I've been talking about this stuff with the public now for maybe 12 or 13 years and people were saying, yeah, Dr.

56:34Chagy, I get all this, but I'm going to my doctor and I can't get this, right? And some of the tests that you talk about, like fasting insulin or homocysteine, I just can't get, I might be able to get an A1C, but I can't get it regularly. I can't track it. And I've been wanting the NHS to do this in the UK for years. I mean, my honest hope with Do Health is that within a few years, we'll have proved the case that the NHS take it and go, actually, we want to roll this out. Let's see what actually happens. But this idea that if you can empower people early, you can see certain things early, you can actually do something about it.

57:15And there's, you know, there's coaching built in and all this kind of stuff, which so it's not just do it. It's like, let's find out where your current state of health is. Let's help you make changes. And then let's recheck to see if those changes actually made a difference. I don't want to go through all the tests that we're doing, but two, I'd love your take on, and I really pushed hard for these two because you can't really get these easily on the NHS, is fasting insulin and homocysteine. Both are very important. Homocysteine, we'll start with. So homocysteine is a is a marker related to methylation in the body, particularly related to the status of B vitamins related to methylation.

58:00So B12, folate, B6, and riboflavin for most people, there may be a genetic component there as well. So the two most important are B12 and folate. and we know that having elevated homocysteine is associated with a higher risk of cardiovascular disease but also in particular dementia so it also influences the trajectory of cognitive decline so those who have elevated homocysteine have a more rapid rate of brain atrophy right their brain shrinks faster and they lose cognitive function faster or their cognitive decline their cognitive function declines more rapidly. The threshold based on the randomized control trials that have been done is probably somewhere around 10 or 11.

58:56So ideally, you'd get your homocysteine below 10. You definitely want it below 13 because that's considered elevated and you'd see a more rapid cognitive decline associated with that. And then the intervention that you would do is supplement with B vitamins or make sure that you get enough B vitamins in your diet. The proportion of people who have very high homocysteine has come down a bit in countries that have started to fortify white flour with folic acid. So in the big population studies done in the US where they started to fortify flour with folic acid in 1998, the proportion, the number of people who had elevated homocysteine did decrease after that.

59:41So just we know that getting more of this in the diet definitely brings homocysteine down. Randomized controlled trials have used folate and B12 and then plus or minus B6 as well. And we also know people, in particular people who have MTHFR polymorphisms, they have elevated homocysteine if they don't get enough riboflavin. But by enough, I just mean the recommended daily allowance. I know what you mean when you say that, but a lot of people will hear MTHFR polymorphism and go, come again? So could you just try and explain in layman's what that means?

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1:01:59Now as you've probably heard me say before, there are specific blood markers that can show you you're at elevated cardiovascular risk years before you ever feel a symptom. In fact, 46 % of DoHealth members had hidden cardiovascular risk they potentially had no idea about. Over 25 % of members had suboptimal homocysteine levels, which is linked to an increased risk of Alzheimer's. And this is exactly why I decided to build Do Health, to help people understand when things are starting to move in the wrong direction inside their bodies, instead of waiting until they get sick. Do Health takes everything I know about health, including my four pillars, and makes it personal to you.

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1:03:25Yeah, so unfortunately, you'll actually, you know, I imagine a lot of people who've listened to this podcast will have heard about MTHFR. It's a gene, methylene tetrahydrofolate reductase. There'll be a test later. That is involved in this sort of methylation pathway, which is essentially what methylation is. Maybe let's talk about that. Methylation is this process of moving carbons with some hydrogens attached. There's one carbon with three hydrogens as a methyl group, moving them around the body. And when you move methyl groups, you turn on genes, you activate proteins. It's like this really important signaling molecule that we use to kind of control biological processes.

1:04:16And the B vitamins are involved in kind of providing the methyl groups for our body to do that, just to kind of move these signals around, to turn things on and off. and so one of the the enzymes in that pathway mthfr it's very common most of us have a polymorphism which is just a slightly different genetic code that makes this enzyme that just changes how that enzyme functions a little bit and we're often you know if you go out into the world and you look up mthfr it's uh usually like sold as this disastrous thing like your body can't do these methylation processes and you need all these fancy supplements to overcome it none none of that is true and so if you go out and see a bunch of doom and gloom around mthfr i would ignore the vast majority of it because most of us actually the majority of people have you know one of these polymorphisms that changes activity a little bit but what these polymorphisms do and they absolutely have some kind of benefit right because you know most of them most of us have at least one is that changes how that enzyme binds to a cofactor, a cofactor being the thing that just allows that enzyme to run.

1:05:29And that cofactor is made from riboflavin, which is vitamin B2. And there are studies, there are randomized controlled trials that show that if you just get enough riboflavin, which you can find in whole grains and liver and things like that, then it's not an issue. So for most people, if you go out and you kind of see what's on the internet, you'll be told that things like homocysteine and methylation are driven by your genetics. They're not. They are largely determined by nutrient status, just getting enough B vitamins. So if you just get the recommended daily allowance, you've ticked that box.

1:06:09But if you do measure homocysteine and it's elevated, then the other B vitamins are a great place to start. There are some other things that you can think about as well. but those core B vitamins are really the main drivers. This just highlights something that has happened in the last 24 hours. So one of my really good mates has just done their Do Health blood tests and he texted me yesterday, said, mate, I've got my results and I'm loving it, loving the whole thing and the app and the explanations. And so, mate, if you're open to sharing, send me them and I can give you some advice if you want.

1:06:45Now, you know, he gets advice on the app anyway, but his homocysteine was 15. Okay. Now, why I'm so passionate about this, Tommy, is that you've already mentioned, and I don't know if we've covered before or not, but this idea that elevated homocysteine can increase your risk of cognitive decline as you get older. He has a family member who has got dementia. Now, it could well be for this individual that this elevated homocysteine is increasing his risk of cognitive decline like some family members of his. I'm being very careful, so it's not possible to identify who this person is I'm talking about, okay?

1:07:31Okay. And so what's really interesting is if you don't have your homocysteine checked, which is the norm at the moment, I would say in the NHS, then you don't know a critical piece of information that is actually quite easy to address. I said to him, listen, mate, you can try it with diet. If that doesn't work, it's quite easy with relatively simple supplementation of B vitamins and folate to bring that down. I said, at the same time, mate, you've got to understand that your omega-3 status is also important here. But the point is, is that that piece of information will directly impact his behavior.

1:08:14And when he rechecks the bloods in four months, we will know, has that made a difference? If it has, great. Have we brought it down under 13, but ideally under 11, under 10? And that is a meaningful piece of the picture in terms of his risk of getting dementia in the future. So when I think about prevention, one of the things that led to me doing all the work to try and create this is to go, well, there is another model out there for prevention that doesn't currently exist. But any comments at all on what I just said about homesteading and sort of my friend and how he can meaningfully reduce his risk of getting sick in the future?

1:08:52Yeah. So one of the reasons why homocysteine isn't routinely measured is because homocysteine had a moment 20 years ago in cardiovascular disease and neurological disease or neurodegenerative disease prevention. And then there were some trials where they gave people B vitamins and they didn't really see much of an effect. And so everybody, like, if you speak to neurologists now, most of them will say, oh, well, we looked at homocysteine and we tried it and the supplements don't work. Now, the critical part of that then is what you mentioned about omega-3s. And this has now been replicated in multiple clinical trials.

1:09:34And it actually makes perfect sense that if you take a person and they have insufficient levels of one B vitamin, or one vitamin, one nutrient, they're probably going to be insufficient in others, right? Not everybody. But in general, these things don't come one at a time. and when we've done clinical trials in the past, we haven't looked at a full picture of somebody's nutrient status and kind of addressed multiple things at the same time. We just like, we just, we've done the same thing with omega-3s actually. This person's at high risk of dementia, we give them omega-3s, does it decrease their dementia risk?

1:10:12Meh, it doesn't seem to have a big effect in most clinical trials because we didn't check whether this person needed more omega-3s in the first place or not. Plus, nutrients don't act one at a time. Yeah. Right? in order to like to send a signal in the brain, you need B vitamins, right? For mitochondrial functions, right? For your brain to make the energy to send the signal in the first place. And then you need to send that signal down along kind of arm of the neuron, we call an axon. And it's got this sort of wrapping of fat around it to kind of allow that signal to be transmitted faster called myelin.

1:10:50And it's like iron status is really critical for myelin. And then you get to the end and you're trying to send the signal and if it's like a serotonin neuron, then we need vitamin D in order to make that serotonin in the first place. And we need omega-3s to kind of sit at the end of that neuron at the synapse that sends the signal to the next neuron. We need like DHA, which is a long chain omega-3, kind of concentrates there because it's really important to kind of make the little sort of envelopes or vesicles of neurotransmitters to send them, right? So you need all of those things for that to happen at its kind of best.

1:11:30And so for this reason, when you look at sort of multi-component interventions, or you look at the status of multiple nutrients, you see that they interact. So the first time this was found, this was the VitaCog study run by David Smith at the University of Oxford. And this was the first study to show that if you have people with high homocysteine, and you give them B vitamins, you slow their rate of brain atrophy and cognitive decline. But only if they have adequate omega-3 status. That's now been replicated in multiple clinical trials. You can't just address one or the other. You need B vitamins and you need omega-3s.

1:12:08So this is one of, thinking about this as like a single variable nutrient problem is one of the reasons why it's hard to get a homocysteine test today because those previous trials didn't kind of address this full picture. but that's the kind of hangover of the kind of reductionist approach to health that we've taken right which is is obviously how we test pharmaceutical interventions you know you 100 people 50 get the drug 50 don't is there a difference yeah but of course as you're saying you know and i love the vice-contractor this idea that yeah lower the homocysteine and it will lower your risk of cognitive decline if you have sufficient omega-3 if you don't it won't yeah i think it's very very empowering which is why i told my buddy it said like listen omega-3 needs to be there as well right so of course testing omega-3 is a little bit harder yeah do you think people need that or if they're i guess if you if you're eating fatty fish two to three times a week do you really need an omega-3 test yeah maybe if you're vegan it's a good idea How do you think about this?

1:13:16Yeah, it's an important question because very quickly we can accumulate a large bill of tests, a large cost for all of these tests. But I will say that, so Food for the Brain, the charity that I mentioned, does have an at-home blood test called the Drift test that includes HbA1c, vitamin D, homocysteine, and omega-3 status. You have to pay for it. it's somewhere between one and 200 pounds. So it's not cheap. And I'm not saying that everybody needs to do that test. But if somebody wants to test omega-3s, right, that is an option. When you then think about testing omega-3 status, dementia risk, if you're regularly eating fatty fish, cold water fish, sardines, mackerel, salmon, two or three times a week, you probably don't need to test.

1:14:11equally if you're not doing those things and you'd rather just you know take a high quality fish oil or omega-3 supplement i think that's fine too and often um you know when i talk about this yes uh those who are vegetarian or vegan they certainly have questions i would recommend like an algal you know an algae-based omega-3 supplement so it's it's not um an animal-based supplement, but you can still get those fats in your diet. And then you take one to two grams of omega-3s a day. That's probably going to cover your bases. I think that's going to be enough for most people. Yeah. On DoHead, we don't actually test omega-3.

1:14:53Maybe it's something we'll bring in at some point. In fact, one thing I was very clear on is that over-testing is a massive problem. I know in America, there's loads of companies now who are doing, we're going to do 200 biomarkers, we're going to do 400, we're going to do 600, right? And I get that. One thing clinical practice has taught me is that too much data and too much information becomes very, very confusing. So our focus really is on what I call the 11 core biomarkers, which are, I think, 11 biomarkers which have a really good amount of evidence and science behind them, which are all to do essentially with metabolic health.

1:15:32and interestingly enough and I can't remember the exact statistic just on homocysteine Tommy I think so far the few thousand people have gone through I think over 25 might even be over 30 % of people have got elevated homocysteine which is quite interesting yeah there's been some recent discussion about where these blood tests fit in dementia prevention in particular so I think last time we talked about the Lancet Commission report on dementia prevention run by Professor Jill Livingston, they identified 14 modifiable risk factors for dementia, estimated that 45 % of dementias may be preventable.

1:16:10But diet wasn't in that, was it? And there's 14, I don't think. No, it wasn't. And so there were actually letters written to The Lancet where it was published. And then this was actually discussed in the sort of popular media as well, that B vitamins and omega-3 status weren't discussed, you know, even though we have some fairly good evidence for those. I absolutely don't want to put like words in people's mouths, but there was some discussion as to whether insufficiencies in B vitamins and omega threes were common enough that it was worth kind of, you know, building an evidence base around them.

1:16:44But like, I think you're right, particularly as people get older, 10 to 20 % of individuals at least may have elevated homocysteine. So that's like a significant chunk. Previous analyses done done by other groups suggested that potentially up to 20 % of cases of dementia were related to elevated homocysteine and low levels of omega-3s. So that's, you know, even if it's not 20%, it's still a meaningful contribution to future risk. So yeah, I think to kind of go to your original point about like, what's it worth testing? I also agree that just like more testing isn't isn't always the answer. And I do agree with this idea that if you're doing a test, you should be answering a specific question, like, why am I doing this test?

1:17:34So rather than just like doing a scattergun, test everything. And right in medicine, we have this idea of a pre-test probability, like how likely is it that you're going to find something that you and that you can address it? And I think that's really important. So we focus on metabolic health. we know that the vast majority of adults have at least one risk factor for metabolic disease right so it's very likely that you're going to find some kind of modifiable metabolic health risk factor that's why we focus on metabolic health and I had a criteria when choosing the 11 that there's got to be a good evidence base behind them and we've got to be able to do something with the results and I guess in answering some of the stuff around homocysteine and Amiga-3s, we've slipped into mistake number five, which is thinking all supplements are a waste of money.

1:18:28Okay, so again, the framing here is that Tommy's been on this show four times in the past, so this is appearance number five. If you haven't heard the first four, please go and listen to him. There are a wealth of information. The whole point of today is to go through common mistakes that people often make when it comes to brain health and longevity. We've done four so far. We've covered mindset, social connection, high blood pressure, and sort of testing. The fifth one, which I think relates to what we've just been talking about, is this idea about supplements. Thinking all of them are a waste of money, I think, is a common mistake.

1:19:04You've already mentioned the potential benefits of B vitamins and omega-3s. I want to go through some other supplements with you to get your take on them. But I wonder if it's worth talking about the COSMOS trial and what your take is on that trial, because I thought it was really quite illuminating. Yeah, so the COSMOS trial was a recent trial run in the United States. Thousands of people, it's a massive trial, older adults, randomized into four different groups. So they had a control group, and then they had a group that took a basic multivitamin. Centrum Silver was the multivitamin. and centrum silver essentially just has 100 % of your RDA of like the basic vitamins.

1:19:46Another group got a cocoflavanol supplement. So cocoflavanols are like the polyphenol, the antioxidant polyphenols that are in cocoa. You have similar compounds in coffee, tea, chocolate, berries, for example, like the things that make berries sort of purple and red. And then one group got both, right? So we call it like a two by two design. And what they found was that in the two groups that got the multivitamin, there was a significant reduction in estimations of brain age and cognitive function, such that on average, people's brains acted as if they were two years younger. So you kind of saw this slowing of brain aging by taking a multivitamin.

1:20:34And this is the most basic multivitamin. So like you go to Boots and you get an over 50s multivitamin. That's essentially what it is. And I'll also say this about the Vitacog study. Often when we're sold supplements and vitamins, we're like, you have to have this fancy version and this bioavailable version is going to cost X amount of money. The best evidence that we have for multivitamins, for B vitamins is the most basic version, the essentials version, some folic acid and cyanocobalamin. If everybody's like, there's a form of B12. It's like the cheap version of B12. That's what showed benefit in Vitacog.

1:21:11Just like the most basic, essentially low dose multivitamin showed benefit in Cosmos. And there may actually be a thing where your massive doses could potentially be detrimental. Whereas Cosmos just gave you, you hit 100 % of your RDA, you've got your bases covered, that's it. And that showed benefit. In the sort of the cocoflavanol supplement was a little bit more nuanced, where benefits were largely seen in groups that had low diet quality. So if you're getting few, like plant polyphenol antioxidants, because you don't eat many fruits and vegetables, or drink much coffee or tea, because actually, coffee is the most, for most people is their primary source of antioxidants in their diet.

1:22:00If you had a low quality diet, lots of processed foods, just like processed fats and carbohydrates and few nutrients, a nutrient poor diet. Then taking the cocoa flavonol supplement was beneficial. If you have a high quality nutrient dense varied diet, it didn't seem to have as much of an effect, which I think makes sense. Yeah. There's often been a negative view with doctors around supplements, possibly because the industry has been unregulated, which I get. but the truth is that I have seen so many patients over the years where the right supplement can be game-changing. But I think the Cosmos trial just showed us that actually across a broad population, there can be a benefit with the brain for a multivitamin and mineral.

1:22:46So I think it's a really good take-home. We've covered B vitamins and omega-3. The supplement of the moment is, of course, creatine. You take creatine every day. should the listener also take creatine every day?

1:23:08I recently heard this nice idea for how to think about supplements that I hadn't really heard before. This is from, I was actually on a panel with Jeff Bland, who many people call it, the father of functional medicine. And the first thing that he said we should think about, not is, could this work for me? Is, is it safe? because if it's safe, then you can try it with very little risk. If we don't have good safety data, then the will it work for me becomes much riskier. And so... So chemotherapy, right? It's like you want really good evidence that this is going to help you before you expose yourself to the downsides.

1:23:55Because there are a lot of downsides. and so I think that for most people a very basic level of B vitamin supplement we know it's going to be safe if you're not taking your massive massive doses you're just going to pee out any extra worth potentially trying especially if you've got some markers to kind of suggest that you could take it vitamin D trickier because again in very high doses of fat soluble vitamin you don't want to overdose on vitamin D there's some downsides there but we know in people who are vitamin D deficient, absolutely, well you said it's prescribed on the NHS for people who are deficient.

1:24:32We know it's important, brain health, bone health, etc. Then you come to things like creatine. One of the reasons why I think it's actually okay that creatine is the supplement at the moment is because we know it is incredibly safe. It's been tested in probably thousands of clinical trials at this point, randomized controlled trials for various people in various conditions. low doses, high doses, years at a time. Recent meta-analysis found essentially no side effects with creatine compared to placebo on average. And that's probably because it's something that we can get from the diet. Maybe not quite at the doses that some people might take, but close.

1:25:12So we know, assuming that you're getting a high quality source, it's not contaminated, that kind of stuff. So you want a reputable supplement maker, hopefully they've done something called third party testing, it's been tested for impurities, they can send you a certificate to show that they've done that, every good supplement, some company would be able to do that but we know that creatine is incredibly safe even in sort of like frail older populations so then we might say well is there a possibility that it might benefit me so creatine has been used for decades as a supplement in like sports performance particularly strength and power It helps you do an extra rep or two in the gym.

1:25:55And then if you do that over time, you can build more muscle, you can build more strength. The effect isn't huge, but it is statistically significant and meaningful, right? It's not magic, but it helps you do a little bit more work in the gym and that compounds over time. It's become of particular interest in the brain world recently because there have been some studies to show that, actually several different studies to show that it might help, particularly in what we could call or what I might call cognitively degraded states. So something has happened that's affected cognition or mood, and then creatine may be of some benefit there.

1:26:30So for the average person who thinks that their brain is working really well, there might not be that much of an effect. So when you look at meta-analyses, studies of many studies of creatine, it tends to benefit older people, and particularly is beneficial for memory. That's kind of where it's been shown to have some benefit. In other populations, there's some evidence, there's actually better evidence in like kids with concussions, but there's some evidence that taking creatine after like a traumatic brain injury may help with some elements of recovery. In the kind of the really flashy study that got a lot of press recently was in individuals who were sleep deprived, and they took a high dose of creatine.

1:27:13It was kind of the equivalent of sort of 20 to 30 grams of creatine when maybe a standard dose is like five to 10 grams. And they saw that people maintained brain energetics. You can do a brain scan, you can measure energy, sort of the production of certain energy metabolites in the brain. And that was, and cognitive function was retained better when sleep deprived when taking creatine. This was just like a single night of sleep deprivation. And there was an older study in rugby players actually that showed that when they were sleep deprived taking creatine actually a lower dose sort of five to ten grams helped to maintain rugby specific skills when they were sleep deprived similar to caffeine actually because they also didn't use caffeine in that study as a comparison um so in those kind of settings when sleep deprived maybe creatine can help to maintain some elements of cognitive function um and then there were a few randomized controlled trials now.

1:28:08Although some people have suggested that, you know, they were done in countries where maybe the quality of the science isn't as good as in the UK or the US. So some people have kind of questioned the quality of these trials. But it's been shown two or three times that in individuals with depression, adding creatine to, say, a medication regimen if they haven't had full, you know, remission of symptoms may improve symptoms of mood and well-being or depression symptoms. And again, sort of a five gram kind of dose. So lots of different pockets of things suggesting that creatine may be beneficial for the brain across a wide range of doses.

1:28:53A lot of people are now saying that you take a very high dose for it to benefit the brain, but I don't think we've seen that from the studies. I think we've seen benefit even at sort of a standard lower dose. Which is five to 10 grams. Which is five to 10 grams. and the reason why they say that is because when you look at studies of creatine like increasing creatine levels in the brain that takes longer and higher doses but you may actually see benefits of creatine before you're seeing increases of creatine levels in the brain if that makes sense you don't need to be saturating the brain with creatine to see benefit for the brain because it could be having other effects there was one study an individual with Alzheimer's disease where they gave them creatine and saw some improvements in cognitive function.

1:29:36However, there wasn't a control group. And we know that when you enroll people with, even with cognitive decline in a study, they tend to do better. They get better at the test. Even though some of their cognitive function may be impaired, they do better at the test the second time. They start to feel a bit better. feel a bit better. There's a placebo effect of being part of a trial, connecting with other people is kind of stimulating in its own way. So I tend to not include that trial when I say there may be some benefits for creatine for the brain, just because it was, you know, no control group.

1:30:13We know in cognitive, in studies that look at cognitive function, it's really hard to look at the effect of an intervention without having a control group because you get better at the test. There's significant placebo effects, things like that. So, but if you're somebody who identifies with any of those things that I mentioned, right, sleep deprivation, maybe some issues with memory when you're older, you know, maybe you're, you have been diagnosed with depression and you have had some benefit from a medication, but you might consider adding creatine on, which is what some of these studies have done, then I think it's worth trying.

1:30:53We know it's safe, it's cheap. It's not, again, it's not going to be a panacea it's not going to be magic but you know i think we're starting to see more and more evidence that it may have some benefits for the brain are you happy to share why you specifically choose to take it yeah i mainly take it from a performance standpoint so i train for and compete in strongman and so i i definitely can tell um that i just a little bit a little bit stronger you know a little bit faster uh in the gym when i'm taking it i find creatine to be mildly stimulating for me and that is the case for some people like um like i kind of mentioned that rugby players study right seeing similar benefits with creatine versus caffeine in the setting of sleep deprivation um and so i definitely noticed that i take it later at night i don't i don't sleep as well and so for the same reason i do feel like i get a bit of a cognitive boost from it when i take it in the morning but some of it might be placebo right i kind of maybe expect some of that but it could be that if you do get a mild stimulating effect from it whereas caffeine can can often like overstimulate people where so say if you if you had several espressos before you played paddle you might be sweaty anxious you like you don't you don't quite have the accuracy because right you're sort of overstimulated, creatine could give us a mild stimulating effect.

1:32:19And it doesn't happen to everybody, but those who experience it, if you're one of those people, maybe it's useful then. But in terms of sort of the strength and the power effects and the fact that paddle is more of a sort of aerobic cardio type sport, it's less likely to give you that kind of performance benefit. But there's a possibility that in some people, there may be some kind of cognitive effect. But then bringing it back to the start, if you bring up mindset, right? And so there's good science on creating, but if you also believe that taking it is helping you and making you sharper, it's hard not to make the case that that is going to do something as well, which is, I guess, the kind of hidden glue with all this stuff.

1:33:00If you believe something's helping you, it probably will. Yeah. Okay, we've got to five mistakes so far. We're not going to get to 11, but I think the two I would like to get to, because we haven't talked about them before, It's number one, neglecting oral health. And number two, ignoring the toxic load of the modern world. Okay, slightly inflammatory, but I'm talking about things like microplastics and should we filter our water and that kind of stuff. So perhaps we can sort of zoom through oral health. You know, point number six, what's the relationship between oral health and brain health and oral health and longevity?

1:33:37It's been known for maybe 10 or 20 years at this point that there is a connection between oral health and cardiovascular health. I think that was probably found first. In fact, there are some of the bacteria that you get when you have gum disease or what we would call... So gum disease has two stages. The first is gingivitis. And then if it starts to affect kind of the underlying bone, then it would be called periodontitis. But I think we can call it just gum disease more broadly. and some of the bacteria that tend to overgrow in the setting of gum disease things like Pseudomonas gingivalis and Streptococcus mutans you can find those bacteria in atherosclerotic plaques in the heart which we know sort of trigger heart disease and some of the thought is that because you sort of like have all this inflammation around the gum disease and you know bleeding and things like that that actually those bacteria can get from the mouth into the bloodstream and then can trigger systemic inflammation, might trigger the formation of some of these plaques in heart disease.

1:34:50And they've actually been found in amyloid plaques in the brain of certain individuals. And some people argue that one of the reasons why we accumulate amyloid is one of the parts of kind of the process of developing Alzheimer's disease is because it has antimicrobial effects. So it's accumulating around, say, bacteria that might have gotten into the brain. And one way that that happens, and does seem to happen, is through gum disease. This doesn't mean that if you have gum disease, you're definitely going to get dementia, right? We're all talking about what increases and decreases risk. So there are several studies that show that having gum disease is associated with increased risk of dementia in multiple sort of perspective, as in sort of like you follow people over time studies.

1:35:36and then in at least one study they also found that in people who have gum disease those who get treatment for that gum disease something like scaling and root planing which your dentist would do they then decrease their risk of dementia over the next several years compared to those who don't get treatment there have been other studies that show that the amount of antibodies you have circulating in your blood against those bacteria that tend to sort of accumulate because of gum disease, the more antibodies you have kind of suggesting that you've had a higher exposure, those people tend to have a higher risk of dementia as well.

1:36:14So like from multiple different directions, it seems that gum disease is associated with increased risk of dementia. And then there's also some evidence that if we treat that gum disease, that risk of dementia is decreased. Yeah. Basically, don't ignore going to the dentist. Don't ignore your oral health. And in terms of xylitol gum, are you a fan? So yes. and my favorite story about Xylitol is actually a colleague of mine, Greg Valentine, who I work with at the University of Washington. He's run several clinical trials. He's still running clinical trials looking at this. But his work is looking at ways to decrease preterm birth.

1:36:57So there's nothing to do with dementia, although people who are born preterm do actually have an increased risk of dementia. So it could sort of have this full kind of life lifespan effect. But we know that having gum disease is a risk factor for preterm birth because it creates this inflammatory effect and we know that chronic inflammation is a potential trigger for preterm birth. So baby's being born too soon. The more preterm you're born, the higher your risk of both death, but also neurodevelopmental impairment, multiple long-term health issues. Obviously not everybody born preterm experiences those, but it's just on average.

1:37:36So he's run multiple clinical trials. He's running them in the US right now, but the clinical trials he ran already are in Malawi, in Africa. Malawi has the highest rate of preterm birth in the world. And the majority of pregnant women in Malawi have gum disease. And so one trial they did was this large cluster randomized trial where they had different villages in Malawi and they sort of, they gave them, they gave them some of the villages xylitol gum to chew like three times a day throughout the last chunk of pregnancy. And they saw significant improvements in gum disease and a statistically significant reduction in preterm birth rates, which to me is just like mind boggling.

1:38:21Amazing. And right, the design of the trial wasn't perfect. They didn't have a placebo gum and that kind of stuff. those are the trials he's running right now. But like even that you would see that kind of effect is just incredible to me. And so we know that chewing xylitol gum or using xylitol mouthwashes can address the oral microbiome. And it's really the microbiome that kind of, and an imbalance in the microbiome that drives a lot of gum disease without having negative effects. So other types of mouthwashes, for example, like a alcohol-based or a chlorhexidine-based mouthwash, they can actually get rid of good bacteria that you want in your mouth whereas xylitol seems to particularly kind of decrease the ones that maybe we would like a little bit less of so if you do have gum disease i absolutely go to your dentist have it addressed whatever they suggest but you know xylitol xylitol gum is is one thing that you could try at the same time yeah okay Okay, very, very important message.

1:39:22Okay, final mistake for this conversation, right, is mistake number seven, ignoring the toxic load in the modern world. Now, I don't want to scare people, okay, because I think one of the problems with health these days is people get quite scared. And I think we've got to be careful not to do that. But I think a few things that people often talk about and worry about are microplastics. Should people be filtering their water or not, in your view? and air pollution inside and outside. So I wonder if we can just sort of talk about these themes and how they relate to people's lives. Yes, so the issue with all of these is that there's absolutely some important signal as it relates to these exposures and our health.

1:40:12but there's also a huge amount of kind of hyperbole and it's overblown and there's a ton of scaremongering but there is sort of like but but in the middle of those i think there is a way for us to navigate it fairly reasonably without sort of being overly stressed about uh what it might mean or you know overselling the effects of these things on our health so i think we can go through them one by one um microplastics i've certainly gotten a lot of press recently um and these are essentially the breakdown products of plastics that you know we use for packaging for food or um you know utensils or other things so our primary our primary exposure is from the food that we eat um you can get some from like skincare products and things like that um but there have been some recent studies that suggest that maybe our primary exposure is through food, food and drink.

1:41:13And a couple of years ago, there was this study that said, you know, the average human consumes a credit card's worth of plastic a week or something. And then everybody lost their minds. Then some more recent studies that got a lot less press went back and they redid the calculations and they were like, we estimate that this is out by like several orders of magnitude. It's like a fraction of 1 % of the amount that they said previously. So like - The decimal place went in the wrong spot. The decimal place was like miles out. Like several, like, I can't remember exactly how many. It was like six or seven places in the wrong place.

1:41:58Like it was huge, the difference. And so that's one part is, yes we do consume these things but the amount that we've been told we're consuming is probably a lot less than than than we've been told then the next part is there have been studies that have looked at microplastics in the body um in like tissues of people who've just who are deceased and like looked at them in um say artery plaques looked at them in the brain and and you know they've looked at them in like testicles and other organs and basically suggested that in those who have a higher disease burden, say higher heart disease burden or higher dementia burden, they have higher, so like people who have a higher dementia burden or people with dementia have more microplastics in their brain.

1:42:50This is certainly possible, but there's a few reasons why I'm not yet certain it's like the thing that we have to worry about. So the first is that we know that vascular disease, so issues with blood vessels, are present in most people with dementia. If you have issues with blood vessels in the brain, blood flow is going to be slower. You're more likely to accumulate microplastics that might be in your bloodstream. So the dementia is probably driven at least partly by the blood flow issue, the vascular disease. And then microplastics just kind of accumulate, they come along for the ride. We also have a big issue in terms of how microplastics are measured in these studies.

1:43:44so when you take tissues and then you try and measure the amount of microplastics in them the typical way you do that is through something called pyrolysis which is essentially just a fancy word for heating something up a lot and so what they do is they essentially vaporize the plastics and then measure it in something called a mass spectrometer the problem is that that doesn't work very well in tissues that have a high fat content, like the brain in particular. Because when you vaporize fat tissue, it looks like plastic. It breaks down into the same compounds as plastics do. So there have been some papers that say that particularly in tissues that have a high fat content like the brain, pyrolysis is not a valid way to measure microplastics.

1:44:39So it could be that when we're seeing high microplastics in some of these studies, it's actually just an error in the measurement, right, because of the method that's being used. So I think that some of that is overblown too. So some of the exposure is overblown. Maybe some of like what we're measuring in tissues is overblown. However, we do know that some of the compounds that come in plastic, some of the plasticizers, phthalates, bisphenols, right? people have heard of BPA, right? The lining of cans. And there are many other breakdown products of plastics, right? They are certainly linked to some changes in cognitive function, issues with neurodevelopment in kids, higher rates of heart disease.

1:45:23So these things aren't completely benign. And so I think we can end up down this middle road where we're like, yes, some of it's probably overblown, or at least we don't have the data to really say that it's this primary driver, but we also know that they're not benign and we should try and minimize our exposure where we can. There was a recent trial where they randomized individuals to multiple different groups where they changed different plastic exposures and then tracked their sort of levels, it was levels in the urine of different plastic breakdown compounds. And the biggest driver seemed to be the food.

1:46:01So they gave people that, So they stopped them using canned or reduced their canned foods, reduced storage of foods in plastic, reduced plastic utensil use. So, you know, if you're kind of like stirring a pot and you've got a plastic spoon, right, swapping it for a metal spoon or a wooden spoon, and then they reduced the number of foods that were just stored in plastic, right? So they actually controlled a lot of the food production process so that at no point were foods kind of stored in plastic for long periods of time. So you go to the supermarket and you're getting your veggies kind of loose and you're just throwing them in your basket rather than kind of packaging them up and stuff.

1:46:45Or, you know, getting things that you can buy loose rather than things that were sort of like pre-chops and stored in plastic, that kind of stuff. I would say that if you're going to avoid foods and then not replace them with other similar healthy foods that aren't stored in plastic, I would rather you eat those foods, right? So if the reason why you can eat vegetables is because you get them frozen and they come in a plastic bag but they're already pre-prepared and it's really easy to prepare them and you're going to throw them in a pot and then make dinner quickly do that, right? That has a much bigger signal in terms of benefit.

1:47:23But if you can, don't store your leftovers in plastic. Get a wooden spoon. Minimize the amount of foods that you get that are stored in plastic. Wherever that's possible, drink fewer drinks out of plastic bottles or cans. Then do that. So wherever you can start to move that needle a little bit, just decrease your exposure I think that's going to be beneficial but you know what if the reason you eat beans is because beans come in cans I would still eat those beans right because we know that they have a lot of health benefits so it's all about just reducing your exposure where you can rather than being really really concerned about all the different ways that you might be exposed yeah I think that's a reassuring message I guess importantly I guess we can probably make the case I think that a thousand years ago humans probably weren't being exposed to plastics in this way.

1:48:21So it's a new thing. So of course, we have to see how the research plays out. And if we're going to learn more things, remember when Dale Bredesen came on recently to talk about dementia risk and brain health. You know, he was, you know, at some point we spoke about microplastics. And I think to be fair to Dale, he said, look, we don't know the full story yet. I said to him, have you seen enough to make you at least reduce how many microplastics you're exposed to? He goes, yeah. So wherever possible, I try not to. And I guess that's the approach I've taken for a couple of years. I'm, you know, I try, you know, it's very rare for me to drink out of a plastic water bottle now unless I'm on a plane for eight hours and actually, you know, I'm thirsty, right?

1:49:07I personally no longer haven't done this for a while will get a takeout coffee in one of those containers because the heat and how that interacts with the gas again for me in my life that's not that difficult to do certainly at home we don't store in plastic anymore we store in glass containers when we overcook food and that kind of stuff so I think there's a lot of practical things people can do without necessarily worrying. But I guess time will tell with the science how much of an impact this is having on health. Okay, I'm sure we could talk for an hour on plastics, but let's leave it there on plastics.

1:49:50What's your take on filtering drinking water? Yeah, so I'd start by saying that, you know, luckily for, I imagine everybody listening to this podcast are like water supply is very safe, right? And so the... In many countries. Yeah, in the vast majority of countries, not all, but I would expect that wherever you're listening to this, your water supply is safe and it shouldn't be a primary concern. However, we do know that, for example, several pipes in the UK and the US still contain lead. And so there are several places where you drink the tap water and there's a significant amount of lead in it.

1:50:32we also know that there are other things ending up in the water that are very hard to remove like the PFAs and the forever chemicals and plastics and plastics so phthalates and things like that can end up in the water as well and we know that these have some potentially negative health effects so the way that I've approached this is that I do filter my water I have an in-fridge filter. You can get a jug filter, although the main thing with the jug filter is just remember to replace it because I know there are people who have a jug filter and then it's in there for a year and then it starts to grow stuff.

1:51:16You've probably undone the good work of filtering your water. You're probably adding your own contaminants. Yeah, exactly. And then you can scale that up to under... Some people have... You can get under-sync filters and stuff like that. But I think about it very similarly to how I think about microplastics. And actually, this is how I think about this whole topic in general, is that whatever you're able to do, do that, and you're almost certainly decreasing your exposure over time, right? So most jug filters will do a decent job of decreasing things like lead if there is lead in your water, or they'll do a decent job of decreasing phthalates and other things if they are in your water.

1:51:58and all of this stuff integrates over time right so if you just continuously do that you'll be decreasing your exposure over time and it's sort of like a other than you know remembering to change your filter it's kind of like a set it and forget it thing it's low low risk high potential for benefit not particularly cost intensive depending on which filtration system you go for so I that's that's generally how I approach it there's probably a level of water filter that each of us could do. I don't think you have to do it, but if we're trying to think about something that might give us benefit over long periods of time, it's low risk, relatively low cost, I think it's worth considering.

1:52:38Yeah, I think all these things, you know, it just depends. Some people get very triggered over water filtration, go, the tap water is completely safe. And it's like, yeah, compared to, you know, many countries around the world, it probably is, certainly here in the UK, you know, and I think that's fine. And if you are looking to just do a little bit extra, as I certainly am, you know, it's one of those things I didn't do till about three years ago, I don't think. You know, so I lived most of my life drinking tap water. Yeah. And I think I'm doing fine. And as I learn more, I think, hey, you know what?

1:53:15It's not that much of a heavy lift to have a water filter at home. So I've got something, I think it's called AquaTrue. It's a reverse osmosis filter. I bought it about two, three years ago. It reminds you when your filter needs changing. It's just we have a habit now in the house, so we fill it up and you pop it on. But yeah, you could call it a hassle if you want because it takes out lots of good stuff as well. It takes out the minerals. So we have to put some drops to remineralize it. Now, someone might call that a faff. it possibly was a faff three years ago when I first started doing it. Now it's just the new norm, which is what we do.

1:53:58And so I think that's one thing I always like about you telling me. It's a very practical, nuanced approach, which is really at its heart trying not to scare people and go, yes, things are changing in the world. It is harder to eat nutrient-dense food. We are being exposed to all kinds of new things now, which weren't in our evolutionary history at the same time going back to point number one about mindset worrying about this stuff ain't going to help you that much it's you know what can you feel that you have an element of control over what's your take on uh sauna use filtering out microplastics because i think there's quite a lot of noise emerging now that that could be a good way of removing it from our system yeah so you do definitely sweat out some of these uh compounds that you get um so exercise of course would do that as well.

1:54:47Yeah, so I think that sweating is important. It is a detoxification pathway in the most important sense, right? It's one of the ways, right? Just like with our liver and our kidneys, it's one of the ways that we excrete things that our body doesn't want inside. Urine, feces, skin, right? Yeah, exactly. So I do think sweating is probably beneficial. We know that some of these compounds can be excreted in sweat. exercise that causes you to sweat is free right so i i don't and actually many of the benefits of sauna particularly dry you know dry sauna sort of like a finnish hot hot sauna um many of the benefits of sauna actually overlap very significantly with aerobic exercise uh the pathways they get activated right the sweating um so yes i think sauna is is a possible intervention but i don't think everybody needs to sauna if you've got one and you enjoy it great but equally you you could go for a jog, go play paddle, and you're probably sweating out in a similar way.

1:55:54So yes, I would think about sweating, but however you achieve that sweating, I think matters a lot less. That's a great message. However you achieve your sweating, it's up to you. You choose the activity you want. Okay. And because I mentioned it, let's just touch on pollution in the air. Because when I think about how I think about controllables and uncontrollables, okay? So we know that air pollution from planes and cars and diesel and stuff can negatively impact human health and increase risk of dementia. But there's also the pollution inside our home. Again, I don't think we've covered this before, Tommy.

1:56:34So I think we have covered the big levers a lot. So yeah, external air pollution, I know there's a link to B vitamins and how we can attenuate our risk. So what's your sort of top level take on pollutants in the air? Yeah, so it's very similar to the others. Yeah, I guess we can touch upon that, the B vitamin study. This was done actually at the University of Washington where I work. And they looked at air pollution exposure. So it's particularly, people might have heard of PM 2.5. It's like two and a half micron, that's the size particles that are released from cars and roads and things like that.

1:57:14that seem to be, there were other aspects of air pollution as well that are linked to human health, but they're kind of the most frequently studied and associated with increased risk of heart attacks and dementia. So this study looked at dementia and they found that those who had good B vitamin status, if they were exposed to high levels of air pollution, they had that sort of mitigated the risk of dementia. Of course, this is not a randomized controlled trial, but it's thought that exposure to air pollution increases homocysteine, which we were talking about earlier. And so if you measure your homocysteine level and it's high, and then you supplement with B vitamins and it comes down, if it was the air pollution that's driving that, you've maybe offset a lot of the risk from the air pollution by supplementing with B vitamins.

1:58:00I think that makes sense. So it's just another reason to maybe consider getting enough B vitamins in your diet. Then a lot of the sort of inside air, well, it's obviously connected to the outside air, but because where you've got closed windows, things sort of like accumulate over time. And so often if you look at things like the Environmental Protection Agency in the US, they sort of have this big part on their website about how indoor air quality is often worse than outdoor air quality for that reason. And so I think that, again, if you, especially if you live somewhere, you live near a main road, or so I live in Washington state and Seattle in the summer, we have lots of wildfires, like often the air outside is filled with smoke, the house smells of smoke.

1:58:53And we know that's linked to poor health effects in the local population. Several studies have shown that. So I think in those kinds of settings, if you do have high exposure to air pollution, then I would consider getting an air purifier in the rooms that you spend a lot of time. And there was one recent study where they actually did a randomized controlled trial of air purifiers in people who have high exposure to air pollution and they they saw that having an air purifier on significantly reduced blood pressure so again a meaningful intervention that's kind of like a set it and forget it thing in people who have high exposure or high risk you know definitely something worth considering but again right we can't you know it's often very there aren't many people who can just move because they have a lot of air pollution right so um i think that if you can address that by just you know if you're spending if there are rooms you spend a lot of time in say the bedroom get an air purifier um again over time you're dramatically decreasing uh your your exposure with a relatively simple um intervention yeah and of course something we have covered before as a socioeconomic sort of input here in the sense that, you know, in many places in the world, your socioeconomic status hugely influences how polluted your environment is, right?

2:00:22So, you know, the middle classes and the wealthy people can live out in the suburbs and have less busy roads around them, etc, etc. So I think we always acknowledge that. I think it's always important to acknowledge that, that everyone has a different ability to make changes. Tommy, I love chatting to you. As you know, you're one of the doctors and the health commentators who I respect the most. I love your balanced, nuanced, but also open-minded approach to health. I think the book, The Stimulat I Mind is fantastic. And I really would encourage people to pick it up and take a look at it. I know we haven't covered some of the interventions we've covered before in today's show but I guess just to finish off for that person who has been listening to us talk and throughout the conversation has realized that they've neglected their brain health for a number of years maybe decades and is wondering well you know maybe it's too late maybe there's nothing I can do what would your final words for that individual be?

2:01:35I would say that it's never too late to start and we actually have really good evidence for that I mentioned the Lancet Commission report again the first time they published that report in 2020 they even said that on the front page of the Lancet like one of the world's premier medical journals it's never too late to start thinking about dementia prevention that's because they were focusing on dementia But then your brain health more broadly. Studies in individuals in their 60s, 70s, 80s, they start an exercise program, they start with some dietary change, they start to improve, they do some cognitive training, or like some kind of, you know, they start language or dance classes or musical instrument, or, you know, they start to improve their sleep, you start to see benefits you know even at the those later ages so know that start wherever you are and Even just starting with one thing can have significant benefits.

2:02:38Is it taking more steps a day or getting an extra 15 minutes of sleep or volunteering for something because you sort of connected to the stuff that we talked about in terms of social connection? Is it just like getting an air filter and a water filter and that's all you can do right now but you set it and forget it or you start a B vitamins supplement? these things we know have significant impact through very high quality trials regardless of the age that you're at and by starting one thing sort of like the whole system we talked about the 3S model that whole system shifts in your favor and yes maybe you have to you would ideally make multiple changes over time but these things just one thing is the place to start and then build from there yeah very very empowering message I just want to highlight your key message from the last couple of appearances on my show about learning a new thing.

2:03:34Give your brain a reason to grow and adapt. And I think since our last conversation, which was only a few months ago, Tommy, these are some of the comments that came in on the back of that. Artie has told us she started playing netball and paddle. Laura started figure skating. Lynn started reformer Pilates. Dorothy started tap dancing classes. Sosi started a heels dancing class Heather started playing pickleball Louise started ballet after a recent Parkinson's diagnosis and Daryl started playing table tennis and badminton and honestly that's all because of the information you shared on my show so I think you're doing wonderful work Tommy thank you for sharing your research so generously with us all and I look forward to number six at some point in the future Yeah.

2:04:25Thanks so much for sharing those with me. That's so, so cool. I'm so glad that people are just finding, like you said right at the beginning, you'll find something that you enjoy, right? You do it because it's fun, right? And then, oh yeah, just happens to have all these other sort of health benefits on the side. So like pick something that, any of those things are fantastic. I'm so happy people are doing it. I really appreciate your time as always. And thank you for having me on.

2:04:54Really hope you enjoyed that conversation. Do think about one thing that you can take away and apply into your own life. And also have a think about one thing from this conversation that you can teach to somebody else. Remember when you teach someone, it not only helps them, it also helps you learn and retain the information. Now before you go, just wanted to let you know about Friday Five. It's my free weekly email containing five simple ideas to improve your health and happiness. In that email, I share exclusive insights that I do not share anywhere else, including health advice, how to manage your time better, interesting articles or videos that I've been consuming, and quotes that have caused me to stop and reflect.

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2:07:00Making lifestyle change is always worth it. Because when you feel better, you live more. Thank you.