ZOE Science & Nutrition - How to maximize health in your later years

Episode Date: February 16, 2023

Why do some people remain fit and healthy in their later years while others become increasingly frail?   Researchers from Kings College London have been following thousands of twins for 30 years in ...an effort to understand how each of us ages differently. And some of their findings will surprise you! In today’s episode, Jonathan speaks to Claire Steves to better understand what all this means, shedding light on how aging works and what we can do about it: Dr. Claire Steves is a senior lecturer at King's College London, a medical doctor, and the clinical director at TwinsUK Download our FREE guide — Top 10 Tips to Live Healthier: https://zoe.com/freeguide Timecodes: 00:00 - Introduction 00:10 - Topic introduction 01:39 - Quickfire questions 03:16 - Claire’s work during the pandemic 05:17 - What happens in our bodies when we age? 08:26 - Genes and aging 09:33 - What factors affect aging? 11:39 - Effects of physical activity 12:23 - Microbiome effects on aging 13:33 - Claire’s research 19:11 - What evidence is there that we can slow the effects of aging? 21:44 - What are some modifiable factors that can help reduce aging effects? 23:06 - Alzheimer's and dementia 28:21 - Stimulating your brain 29:45 - The importance of social interaction for the brain 31:02 - Diet. health and aging 35:27 - Menopause 37:30 - Actionable advice about maximizing health while aging 39:14 - The biggest myth about aging 42:20 - Summary 43:41 - Goodbyes 43:50 - Outro Episode transcripts are available here Find Claire’s publications here The UK’s largest adult twin registry - Twins UK Follow ZOE on Instagram: https://www.instagram.com/zoe/ Have an idea for a podcast? Contact Fascinate Productions to bring it to life.

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Starting point is 00:00:00 Welcome to ZOE Science and Nutrition, where world-leading scientists explain how their research can improve your health. Why do some people remain fit and healthy in their later years, while others become increasingly frail? Science has been searching for answers. Researchers from King's College London have been following thousands of twins for 30 years in an effort to understand how each of us ages differently. Some of their findings may not come as a surprise. Obesity, activity levels and lifestyle choices play a huge part.
Starting point is 00:00:43 Other discoveries are startling. Their tests demonstrated inflammation levels rising steadily with age, so-called inflammaging. More radically, they looked at the gut bacteria of these twins to see if there was a link between their microbiome and their inflammation. There was. So what does this mean? What are the foods to eat or avoid?
Starting point is 00:01:08 And at what age is it too late to make changes that can prolong your life? Today's guest is here to help us understand. Claire Steves is a senior lecturer at King's College London, medical doctor, and the clinical director at Twins UK. Claire's research focuses on better understanding how aging works and what we can do about it. Claire, thank you for joining me today. It's a real pleasure to have you on the podcast. Why don't we start like we almost always do with a quick fire round of questions from our listeners.
Starting point is 00:01:45 And we have some very simple rules. You can say yes, you can say no, or if you have to, you can give us a one sentence answer, but you're not allowed more than one sentence. And we know that all scientists find this really hard. So do your best. Are you ready to go? Yeah, go for it. So Claire, are most of us doomed to many years of poor quality of life before we die?
Starting point is 00:02:09 No. Well, that's a very reassuring start. Once we are in our 60s or older, is there anything we can do that can really improve our long-term health? Yes. All right. See, it's going to be positive all the way today. Is it possible to reverse age-related poor health?
Starting point is 00:02:27 Oh, interesting. Sometimes. Am I allowed that? Absolutely. You are, of course. In fact, that's where a lot of people go. All right. Another great question here. Can the microbiome influence age-related conditions such as dementia and Alzheimer's? Yes, probably, though we haven't got all the evidence we need yet. What's the one thing that I should do to keep healthy in later life? Wow, you make it difficult, Jonathan. One thing. Well, probably if I was going to do one thing, it's to keep as physically active as I can.
Starting point is 00:03:06 And last question I have, does chronic inflammation earlier in our life play a role in aging? Yes, undoubtedly. Brilliant. And I think we definitely want to get into all of those topics. Just before we do, I wanted to say what a pleasure it is to have you on the podcast. So many of our listeners will have used the Zoe COVID study during the pandemic. And what they may not realize is that Claire was absolutely critical as we crazily put that together in the first few weeks, because Claire with Tim basically figured out all the questions that we needed to ask people right at the very beginning before we understood anything really about COVID, about how we should try and understand
Starting point is 00:03:45 what was happening with people's health and sort of their background health conditions. So Clare, it is wonderful to have you on the show. It's great to be here, John. And I was just thinking, actually, as I did that, that, of course, I was locked away in my house, like so many people, and you were actually out in these wards and visiting people in residential homes who were very old and quite frail. And that at this point, basically, we had no idea whatsoever about what was going on or even what the disease was.
Starting point is 00:04:13 And so you were sort of my picture into the front line. Well, that's right. I mean, it was such a difficult time and we're still feeling it now, actually. And right at the beginning of the pandemic, I was quite concerned about the lockdown, to be honest. And I remember saying to my husband, I'm not sure whether or not the pandemic, the illness itself, or the effect of lockdown are going to be the greatest on aging overall. And certainly, even patients I saw yesterday, still saying that actually the social isolation, the inactivity that lockdown brought for them
Starting point is 00:04:46 really made a difference to them and their development over the last couple of years. And I think that's certainly true. But you're right, Jonathan, we were also obviously in settings where older people, frail people were getting COVID. And we saw the range of different symptoms that people could get. And of course, the sort of devastation that it brought on everybody within the care home sector at that time when they were so isolated from family members. And Claire, maybe we could just sort of start at the beginning. So what is ageing? What's happening in our bodies as we age? Because this is your area of speciality, but it's slightly mysterious. I was thinking about this this morning and it's one of these words, like we all understand it,
Starting point is 00:05:31 you know, you learn it as a small child, but what is it? So interesting. When we look at almost any function, be it cellular or be it a sort of complex function like being able to walk or do specific tasks or even breathe out in a lung function test. We see that over childhood to early adulthood, our performance improves. And then we get to about the 40s and it sort of plateaus. Some features actually continue to grow. For example, your ability to use words and so on. Interesting. Maybe a measure of wisdom. But most things actually then start to plateau off in terms of the functional performance, the maximum function people can reach and then gradually decline. And actually how they change is very individually specific. So one person might actually reach that plateau later,
Starting point is 00:06:27 decline less. Another person may reach it earlier, decline quicker. Also, there's a bumpy road. It's not sort of uniform how people change over time. So that's why actually what we see in populations is that individuals get more different from each other as they age. So there may be some 80-year-olds who are completely fit as a fiddle, able to really engage in every way that they used to when they were 40, and others that have lost their independence and are functionally dependent on others. And Claire, do all those different functions you have, do they tend to decline in the same way? Because I could think that maybe my physical health might deteriorate faster than my mental health or I guess lots of people listening to this call are thinking what they're
Starting point is 00:07:11 really scared about is the reverse, right? That physically, maybe that's okay, but their mental capability declines. Do these two tend to sit together or are they all sort of coming off this plateau you're describing sort of getting worse than in your 40s. Are they all completely independent? No. So very interesting. They don't change all the same and they don't change the same in individuals. So in other words, some people may have a particular problem with their bone health and that accelerates faster than their cognition and so on. And we've looked at what actually is similar across these different patterns. And we've seen that actually the genetic factors that are related to change in ageing over time are actually quite small, and they're very different between different organ systems. There are some environmental factors that really are shared between different organ systems. So in other words, there seem to be
Starting point is 00:08:02 some things within our environment, we're using twin studies to pick this out, that drive organ ageing across all systems. And also the environmental component to change over time is really important. And that's why I've shifted my emphasis of my research onto trying to really unpick what are those environmental factors that we could change maybe and improve ageing for older people. And I guess this is through this massive UK twin study that you're the clinical lead on, is trying to understand why do people age and at different rates? And I think you're saying that actually our genes turn out not to be as big a part of that as maybe you had thought?
Starting point is 00:08:43 Yeah, that's right. So genes contribute quite strongly to that peak that each one of us can achieve, say in our 40s, 50s, whatever. But it doesn't really contribute that much to how we change after that. So what you're saying is, if I'm going to be a great violinist or a great author or just really strong in the gym, the genes are an important part of that, but then how much I maintain that or how much I deteriorate as I get older is no longer really about the jeans. Is that right, Claire? That's right. I would say there's a lot of people on this call who have definitely hit their 40s. Some may be
Starting point is 00:09:23 well past that. So they're all interested in, okay, so how do I maintain this? Good news, because your genes, you can't change. So what are the factors that are then influencing it? Yeah, so well, I guess the two biggest factors probably that we know about, and it's not so easy necessarily to change them. The first one is physical activity, physical fitness, doing stuff, using your body, even standing up more, being less sedentary. Actually, that's a really big driver. And it's really interesting to me that it's not just a driver of physical health and bone health. It's also a driver of a healthy immune system. And it's also a driver of a healthy brain.
Starting point is 00:10:02 Oh, that's amazing. So I think that's probably not what most of us are expecting. I think we all know that we should do more exercise, right? Like I think you'd have to be living under a rock not to have heard this. But I think generally we associate that with your physical ability. But you're saying it's not just that, it also affects things like your immune system, which you would think had nothing to do with whether or not you were being physically active. Is this something that has been known for a long time? Or is this more recent science? No, no, this is quite recent science. Actually, there's studies which have shown really in the last 10 years that actually, physical activity really sort of strong physical
Starting point is 00:10:38 activity changes your immune system makes it much more similar to younger people. A team had a look at the total body physiology and also the immune cells in the blood of people who did a lot of cycling very regularly. So they were very physically active older adults. And they saw that their blood cells, their immune cells were similar in performance to very much younger people and very different from most sedentary older adults. And they sort of came up with this idea that actually maybe all the aging that we see around us is not necessarily because of aging, it's because of increasing physical inactivity, which then drives changes. And I think that's partly true. And it certainly seems to be that physical activity and physical fitness, it doesn't
Starting point is 00:11:25 mean going to the gym and being sort of super sort of athletic about it necessarily. But it is really good driver of health across the board. That's really interesting. And so beyond bone health and physical health and immune system, does physical activity affect anything else beyond that? Certainly. And this is what I saw within my PhD when I was looking at cognitive aging. So I was looking at why some older adults, their cognitive function really changes very much, even though they don't necessarily have dementia. And over 10 years, we saw that the strongest driver was actually physical performance right back at the beginning.
Starting point is 00:12:01 And that not only affected their cognitive performance on tests, but also you could see very clear differences in the brain structure and function of those individuals that performed more physical activity at the beginning than those that didn't. That's, I think, really exciting. I'd love to talk a bit more about it. One question that came up a lot actually from listeners that you haven't really touched on yet is around the microbiome. And, you know, the question is, you know, what role, if any, does the microbiome, these trillions of bacteria in our gut, have on aging? Yeah, so very interesting. So as we develop through childhood, our microbiome shifts very significantly as we change our
Starting point is 00:12:39 diet. Then it tends to sort of become your own personal microbiome that is actually different from other people's but it stays stable stays with you throughout your sort of 20s 30s 40s 50s then we see as sort of like as people start to age and start to become frail there are changes that happen within the microbiome and it was quite difficult to pick out actually at the beginning whether or not that was because the body is changing and the host, therefore us, becomes slightly less of a good place to live for these microbes. Or is it that actually there's an interaction where the microbes are also driving health? And the answer is probably actually both. And we see now some new studies coming out, there are intervention studies showing that actually you can change the microbiome and that change is associated with health.
Starting point is 00:13:30 And I think some of your own research on the twins has been looking at microbiome and aging. Is that right, Claire? Yeah, that's right. So we were one of the first that sort of looked at in the community population, the relationship between microbiome parameters of features in the microbiome composition in the gut, this is in stool, and the development of frailty. And we saw that even in sort of quite early stages, we could see differences. And actually within twin pairs, we could see that frailer twins had a microbiome which was distinct from their sisters who were not frails. So one of the things that
Starting point is 00:14:05 we're really interested in trying to understand aging is to look at identical twins and non-identical twins as well who share genetics but they don't share lots of factors around an environment and they actually don't share a lot of their gut microbiome. We see that the gut microbiome on average about 17% of the variation in the gut microbiome is down to genetic factors. So the majority is not down to genetic factors. It's down to environmental factors like diet. Which is amazing, isn't it? So you're saying there's only 17% of what you see in their microbiome is controlled by their genes. This is surprising, isn't it, compared to what you would have expected when you thought about genes controlling us 20 years ago? Yeah, I mean, I'm not sure whether
Starting point is 00:14:49 it's surprising. I mean, when I say 17%, there are some specific elements of the microbiome that are a bit more heritable than that. And there are lots that are less heritable. So it's on average 17%. But the point is, is that actually, your genetic factors don't necessarily drive what's within you, that actually environmental factors and things that necessarily drive what's within you, that actually environmental factors and things that happen to you along the course of life are probably really important. And we know that from early studies, looking at even mode of delivery, say, for example, for individuals can change the microbiome, how many antibiotics they receive during life, all of these kinds of things, they're environmental factors. So it's not that surprising that genetics doesn't thrive the microbiome very much. But it does go to show that, you know,
Starting point is 00:15:29 we can't focus all our attention as we thought perhaps in 2000 on genetics to understand disease. As a result, you can have two identical twins who later on in life, look quite different. Is this right, Claire? And then you were explaining about the microbiome differences. Could you just sort of bring us back to that? Yeah. So I've been very interested in understanding using twins, why different people might age differently. And so we have within the cohort, some individuals where one twin is slightly frailer or has a particular disease, whereas another twin is less frail or doesn't have that particular disease. And so we're looking at the biomarkers that we collect in them beforehand to see which ones can explain the difference in how they age.
Starting point is 00:16:12 And indeed, we found differences in microbiome between individuals. And the specific groups of microbes that we found that were associated with being more robust are also actually the exact same bugs that we see are associated with adherence to diets like the Mediterranean diet. So this is coming back to this sort of idea that the gut microbiome is shaped by the diets that we eat and that it is related to aging. But it's then taken sort of like some other intervention studies that we and others have done to show that actually we can change some of these outcomes for individuals if we deliver microbiome interventions. So we've got a very exciting trial that we've not yet
Starting point is 00:16:57 published, but it's just going to be coming out early in the spring, which basically shows this within a small number of individuals. And we need further larger studies to really show this, but I think it's really exciting. And what does a small study show, Claire? So it shows that prebiotics that people have taken matched against a placebo that looks exactly identical, where we compare cognition within individuals taking the placebo or taking this prebiotic, we can see in just 12 weeks a difference in their outcomes in terms of their cognitive function. That's amazing. You're looking at all of these pairs of identical twins.
Starting point is 00:17:36 They have the same genes, but actually you're seeing one of them is ending up frailer, you said, than the other. You're then looking at their microbiome and you're seeing that they've got these very different bacteria. And then the question is, is the bacteria partly causing this or is it just as a result of the frailty? And you're saying, I think you're saying it can work in both directions, but there's some really exciting evidence and you're talking about a new study you're about to publish that shows actually you can shift the microbiome and then see it actually affect the things that you look at in terms of aging and frailty and mental cognition. Is that right, Claire? Yeah, that's right. And interesting that when we've done this, we've done it in the early stages of the development of condition. And I think this is really important because some of the
Starting point is 00:18:21 studies trying to affect the microbiome in very late stages of frailty development found it much more difficult to change things. So I think if there's a message that comes from that, it is that we need to be acting and changing our aging early enough. Yeah. It doesn't have to be right back in our twenties, but we need to be thinking about things ahead of time and starting to change things sort of when we're 50, 60, 70, rather than waiting till we're really frail. And I think, look, that's really interesting. I'm sure everybody's listening is thinking, OK, so I'd like to make sure that I'm not frail. I want to make sure that I don't get dementia.
Starting point is 00:18:59 You know, I'd like to be of high quality of life for as long as possible while knowing that I can't ultimately probably postpone death. What evidence is there to show that sort of aging and the chronic conditions that come with age can be avoided or slowed down rather than just it's going to happen and you're sort of locked into this? So that's interesting because of course there are some conditions where it's an either or, it's a true binary, so you have it or you don't have it. And these we call diseases. And they're what medical science has been really good at treating, diagnosing and treating. And that's one of the things that we've done well at in the 20th century, really. But there's another set of conditions which are more indolent and gradual, which is around sort of things like your muscle function. So the development of something called sarcopenia,
Starting point is 00:19:45 so thin muscles and poor muscle function, which is much more subtle and really difficult to sort of say, this is when it's happening. And those things that develop really gradually, those things potentially we can change the rate that they develop much more simply. So I think it kind of depends on what sort of condition you're talking about. In a sense, if we intervene earlier, so you don't wait till you're 80 and you're in a really bad way, if you intervene earlier, actually, you can really make a change. Is that right, Claire?
Starting point is 00:20:14 Yeah. So I think what your question was saying was saying, are you just putting it off or can you change the development of it overall? So in some things, like for example, Alzheimer's is a good case in point. We know that there are some, for example, genetic factors which lead to an increased risk of Alzheimer's. But we also know that if someone has that genetic risk, they can very significantly delay things by taking care of physical activity, taking care of other conditions, making sure their blood pressure is controlled and their cholesterol is controlled and their vascular risk is controlled as well. So we know that we can really push the boundaries of something like that, which has a sort of fairly strong genetic component. Whereas other conditions like our ability to walk up the stairs, that's something where,
Starting point is 00:21:03 you know, if we do it right, we could actually escape that problem completely. There are some things that maybe it's a disease that ultimately we may not be able to avoid. And there are others, you're saying that maybe actually we're always going to be able to have, you know, for example, the physical capability to walk up and down the stairs. There's actually no reason to think that you couldn't maintain that forever throughout your life. That's the hope, yes. Well, I like that. It sounds very positive. And you've talked about physical activity. You've touched a little bit on the microbiome. What are the other modifiable factors that there's evidence for that they can really affect the rate at which we age and whether there's poor health as we age. So I think the third thing that's really interesting,
Starting point is 00:21:52 and there's a lot of growing evidence, is around infections. And it's really interesting and hot topic around COVID-19, for example. I mean, we've seen an illustration of how people who have had COVID-19, especially right early in the illness, had an increased risk of then going on to get cardiac events, diabetes diagnoses, things like this. Even when you adjust for risk factors for COVID in the first place. What I think that does is that actually illustrates what happens in all infectious diseases, actually. And when you look at something like influenza, you see the same things, which are mainly a short-term risk, but there is a risk that goes on for several months after an infective
Starting point is 00:22:35 episode. And so I think this is something that is very interesting. And I think, you know, probably affects lots of aging systems. And I certainly see within my patients that, say, having recurrent urinary tract infections is something that really kind of adds and drives the development of conditions like dementia as well. That makes sense. So, Claire, you've touched already like a couple of times on sort of Alzheimer's and dementia. And I'd love to talk a bit more about this.
Starting point is 00:23:05 And at a personal level, it's something that's really touched my family, as I suspect it has for many people who are listening. So my grandmother got Alzheimer's, she got it pretty early, she was in her 60s. It came on quite rapidly. I think anyone who's experienced, it's a horrible thing for everybody,
Starting point is 00:23:23 both for the person who's experiencing it to start with, and then just for the whole family outside. And I know that my father who is in his seventies now, I think this is the thing he's most scared of actually. It's not dying. It's this idea that he will get Alzheimer's. He's incredibly mentally active. He's still working full time, all of these things. And so I think that I also share some of this fear. It feels like one of the scariest things that might happen to one because you realize there's this big difference between, you know, the point that you die and actually you could have this whole period before where it's not only that it's terrible for you, but you can see, you know, the pressure on your family is so high. What does your research tell you, I guess, about whether there's anything we can do about,
Starting point is 00:24:11 you know, Alzheimer's and dementia more broadly, maybe start to help us understand what's going on perhaps, but then given that, is there anything we can do about it? Yes, I share with you the anxiety about this, but also not so much anxiety, but, you know, really wanting to try and do something both to help individuals that I see as my patients and I share with you the anxiety about this, but also not so much anxiety, but, you know, really wanting to try and do something both to help individuals that I see as my patients and also to try and do research to sort of underpin things a little bit and work out how we can change things. So dementia is an umbrella term where someone has, because of a cognitive change, a change in global cognitive function, is no longer able to carry out
Starting point is 00:24:45 activities that are required to be independent. And that has to be going on for at least six months, and it needs to be progressively changing. So that's the sort of clinical definition of dementia. But of course, there are multiple things that can cause that. And the three main causes of dementia in this country are Alzheimer's disease, vascular dementia, and Lewy body dementia. And Alzheimer's disease and Lewy body dementia share similarities, and they are to do with protein deposition within cells in the brain, which then neurotoxic over time. And then they affect the brain cells, and they tend to affect certain areas of the brain first. So in Alzheimer's, the area of the brain that's affected first is really the parahippocampus and hippocampus.
Starting point is 00:25:32 These are areas that are recording systems for memories. And they're also, interestingly, involved in spatial location as well. And so the things that go first in Alzheimer's disease usually are the short-term memory. So you can't remember what was said five minutes ago or 10 minutes ago, but you can remember your past, your childhood really well. But the recording system is broken, as it were, because of the areas of the brain that are affected first. And so we see it within different dementias, we see slightly different patterns. But the thing is that that cognitive change happens quite a long time after
Starting point is 00:26:11 the disease process is actually starting within the brain. And so this is the problem is that by the time you actually have those short-term memory loss problems, it could be that that's something that you perceive, which is actually more related to sort of anxieties and other pressures. But actually, if it is because of a dementia, it's often been there for 7, 10, 15 years. Now, that's where this whole issue around what can we do to prevent it sort of comes because the proteins that are laid down in the brain, we don't know exactly why they're laid down.
Starting point is 00:26:42 And there's some really interesting hypotheses that actually say that they might be laid down in response to bacteria, actually. This area is not really understood, but this might explain partly why actually just busting and getting out those proteins doesn't seem to be the clear solution that people were hoping 10 years ago it would be. So the question is, what can we do? Well, we know that systems in the brain already clear those proteins. And those systems are immune cells, but they're also the system of flow around the brain that helps the brain to clean itself out. And that's helped very strongly by good sleep architecture. So it's one thing that we haven't talked about today is sleep and how actually sleep might be one of the things that we could do to help increase the ability of our brains to cope with these proteins that gradually develop over time. And then immune system, again, the real importance there of good dietary uptake. And then, of course, we've got to support the brain in other ways to be as active as we can.
Starting point is 00:27:45 And so making sure that our hearing and our vision are optimized actually early on is really important. So there's some new evidence coming out now that says that wearing a hearing aid actually prevents or release delays that onset dementia. That's amazing. So you're saying that just being able to hear better. More inputs, brain stimulate more, may affect how you present, but also actually helps your brain function. And so does that tie into, because I guess what you haven't mentioned there, but maybe you're just getting onto this, is this idea of your brain sort of being like a muscle and having to do stuff. So if it's like thinking it's struggling with something new, you know, it's interacting. Is that real science or is that just like nonsense that people, you know, talk about on the internet? What does the real science tell us, Claire?
Starting point is 00:28:35 So it's really interesting because there's definitely evidence that doing cognitive tasks, as it were, can really improve the performance and change brain structure actually as well. Really interesting. But what's curious about it is, is that sort of like you routine things that you might do on a computer or whatever, tend to train certain areas and certain functions, but they don't necessarily have crossover onto other areas. And that's why I was really interested in the physical activity effect, because physical fitness and performance seems to have effects on the whole brain. So it's something to do with cardiovascular, but also maybe hormones that are produced by muscles as they're working
Starting point is 00:29:10 and the immune effects that actually change the whole brain. But we talked at the beginning about social isolation and being socially active and being engaged with your community. These are things that pull on loads of different tasks of your brain. So that is really good, you know, full body workout, as it were, just being socially active. And that's probably what underpins why social activity is so important to maintain a healthy brain. Let me ask a bit more about that, actually, because that's interesting. I'd assume that the social activity was important because of this sense of emotional bonding and warmth. I'm somebody, I get really miserable, Claire, if I'm on my own. I'm not really well set up for home working because I like people around me. As soon as my wife comes home or I kiss my home, I'm really
Starting point is 00:29:56 happy. I'm always wanting a hug. I'm needy like a puppy dog or something like that. And so I think about social interaction, I guess, as being like, I need that warmth. But it sounds like you're talking about something a bit different, which is, well, you're having a conversation with somebody and it's making your brain have to work. Is it actually that second part that is really important to sort of keep us healthier for longer? Oh, well, fascinating question. I'm not sure how I would design a study to really unpick the two of those. So there isn't a big research study that explains the difference between these two? Yeah, interesting. There probably are attempts to try and do that. But I think it's actually,
Starting point is 00:30:32 I mean, the nub of the matter is, it's probably both, isn't it? For a starter, why are we here if we can't enjoy each other and contribute to enjoyment of others? But yeah, no, I think there are things otherwise. Social activity is actually very cognitively taxing. That's why we've developed such a big brain is to be socially interactive. This is Zoe, Science and Nutrition. So although we've touched a little bit in places on diet, I'll have a lot of complaints if we don't talk a bit more specifically around diet and how this ties into this conversation around sort of dementia more broadly. Is there any evidence around diet linked to this? Absolutely. Yeah. So there are quite a lot of longitudinal studies that show that increasing fruit and vegetable consumption can improve cognitive function. Fewer studies that really show that very convincingly
Starting point is 00:31:26 with dementia and few studies that show that it's quite difficult to do, except for Zoe, really big intervention studies for long enough that can show changes on outcomes like dementia. But there are observational studies like, for example, the twin study, but there are others all around the world actually that show the quality of fruit and vegetables is associated with reduced risk of dementia and cognitive impairment later in life. And also potentially, you know, reducing red meats and animal sources of food and actually changing more to a plant-based diet. Early research coming out showing that that's probably beneficial for cognitive aging. And I know this is one of the areas that you're involved with us, in fact, on the Zoe Health Study, because I think we're fascinated to understand more about
Starting point is 00:32:15 what might impact dementia. And I think there's lots of hypotheses, right, that improve diet quality, improve microbiome health, these things might really impact it. And as everywhere, right, the quality of nutritional research has been limited by just the small scale of the studies and maybe the limited quality of the data and the fact that it's very challenging to follow what people eat over many years. Yeah, so it's such a challenging area to research. Actually, one of the reasons why it's so challenging is because actually diets are very different in different groups. And of course, diets that are really good for you that have lots of fruit and vegetables require a certain sort of like
Starting point is 00:32:55 educational background to really create them. And also, they do require some cost change, you know, it is cheaper still probably to have a white bread, white rice, low vegetable diet. And that's one of the issues is that many of the studies have found it difficult to unpick these relationships between social factors, which drive, for example, poverty, which drives a lot of risk of disease and diet. But I think we could turn that all on its head as well to say that actually diet is something that probably explains a lot of social inequalities in health outcomes. What we need to do is do large enough studies that are really powered and are randomized, proper randomized control trials to really get away from that possible confounding.
Starting point is 00:33:46 I think that's right. And it's obviously particularly bad in countries like the US and the UK, where we do see this massive difference and a huge amount of ultra processed food. I think if we were having this conversation in Italy, people would be less convinced by what you just said. They'd be like, well, of course, they have poverty in just the same way, but actually just in general, far lower levels of ultra processed food and a lot more people cooking food, even if their income is very low, that is just much more based on whole foods. That is not to diminish the problem, which is a huge problem, whether you're anywhere in the developed world. But I guess it suggests it's not impossible to imagine that you might be able to improve it, because I think this is not as true across all rich countries. And again, if you go into Asia,
Starting point is 00:34:34 you again see this difference. So in part, it feels like we've got ourselves into this. Absolutely. And overall, a plant-based diet is what is consumed by the majority of the world that have a lot less income than in Western countries. So it's completely not impossible to change our diet to be much more potentially healthy for a whole range of diseases, including potentially dementia. But the wherewithal to do that is quite challenging within our current Western environment. The pressures are not sort of like balanced in a way which is going to promote equality of access. So that's something that I think we've just got to do work on actually, as a scientific community, as well as a nation. Amazing. I also had a bunch of questions
Starting point is 00:35:18 around menopause. And Claire, I'd love to understand what we know at the moment about how menopause might play into aging and these age-related risks. Fascinating. Well, I wonder whether some of your listeners might be really interested to think about why we have a menopause and the fact that, for example, we're one of very, very few organisms that have a menopause. And so the other organisms, as far as I remember, are groups of whales, killer whales and pilot whales that have a menopause. But for example, dogs, they don't have a menopause. Horses, whatever, they don't. And scientists have thought for a long time why that might be the case. And actually, back in the 60s, this hypothesis, a grandmother hypothesis was developed.
Starting point is 00:36:02 It says that actually the reason why women have a menopause is because in order for our offspring to succeed, it's actually highly beneficial for women to not have kids at the same time as their kids, basically, or at least have some space. There's some space that happens. So basically the whole reason behind menopause is so that women can be functionally helpful to their daughters who are child rearing. And so it's meant to be a functional thing. Yeah, it's a really functional thing. But the fact is that in that process of going through the menopause, there are significant changes that happen to a woman, which then, you know, affect her at that time. But hopefully, once she gets through that, actually, she can be very
Starting point is 00:36:45 functionally active and so on. So it's not so much related to aging. I think we've got to think of it as a developmental phase, which is actually useful and functional. It's not there for no reason. It's very specifically there in humans. And we should make the most of it. But that does not say that there are certain challenges that happen as women go through the menopause. Usually average age is about 50, which just like any sort of like developmental phase, just like adolescence, takes some adjusting try and pull this together into sort of actionable advice for our listeners. And I think what they're always hoping for is sort of what are your top tips to help us age and stay healthy? So having listened to this, I think we're all taking away this view that there's a lot that you can do. If you were advising them right now on the things that they should think about doing in order to maximize those healthy years, what would you be saying?
Starting point is 00:37:49 So I think number one, as we said, keeping physically active doesn't mean going to the gym. It means doing those steps. I'm a great believer in sort of step counters, but also just doing one third more than you did before. That's the first thing. The second thing is around diets, sort of like really trying to change diets to more high fibre and plant-based sources of proteins, probably the best evidence for ageing overall. And then the third thing is around making sure that our sensory systems are at tip top. So making sure that we get hearing aids and visual aids that really help us sort of really interact with life so that we can keep that social interaction driving forwards. If I'm allowed another, I'm allowed another one, one more?
Starting point is 00:38:38 You can have as many as you want, Claire. I think our listeners are just, you know, they'll be writing it down right now. We talked about social activity and that's why sensory sort of things are really very important. But the other thing is sleep. Investing in a good quality sleep is probably very important for aging, not just dementia and Alzheimer's, but also other sources of aging. I think that sounds brilliant. And so, Claire, I think last question, because we had this and I just love the question. Now we got to sort of towards the end here.
Starting point is 00:39:09 What's the biggest myth about aging that you commonly hear? Well, I think it's this thing. It's all wear and tear. It's inevitable. All of us know it's not inevitable by looking around us at the differences between people of the same age. Now, the differences aren't actually driven very much by genetics. The differences are driven mostly by environmental factors. So find that really robust, amazing person that you know, and ask them what they do and try and mirror that. Well, for me, that's Tim Spector. I don't know about you, Claire, but Tim is basically like this walking advertisement
Starting point is 00:39:48 for how we would all like to be. I won't say his age, I get in trouble, but he's a bit older than both of us and it's pretty impressive. Of course, the only thing is he's never allowed to tell anyone when he does have a cold and I'll let you all into a secret, which is even Tim does still get colds.
Starting point is 00:40:03 But it's sort of like it breaks this idea of him being basically Superman. And he's pretty close. I mean, he's in fantastic shape. And what's interesting is he's clearly following all of the things that you described, Claire, with a very big focus, obviously, on the diet and the health of the diet, but very physically active as well, very engaged in terms of the cognition and everything you're talking about. So that's really interesting. I mean, the other thing I think about is my parents who are both working. So apparently being a workaholic then is potentially good for a long life, which seems like the exact opposite of what I was taught as a child, that overwork
Starting point is 00:40:42 kills you. I'm pretty sure that there is sort of that idea, but maybe I'm taken away from this, that overwork is just fine. Well, interesting. I suppose it does depend on whether or not it really stresses you out and whether it gives you enough sleep. If you're a workaholic and you're loving it
Starting point is 00:40:57 and you're getting enough sleep and you're not too stressed, then that's probably ideal. That's really interesting. They used to talk about this, like the stress would kill you and give you heart attacks in the 60s. That's really interesting. They used to talk about this, you know, like the stress would kill you and give you heart attacks, right? In the 60s, right? This is all the story.
Starting point is 00:41:08 But I think we've now decided this was mainly the diet, isn't it? Or the alcohol or the smoking, probably the smoking. I'm thinking about that sort of whole madman idea. More than just working is what causes you stress per se. It's, as you said, it may be unhappy working. What do you think? Yeah, that's interesting. But you see, what was driving the diet?
Starting point is 00:41:29 What was driving the alcohol? What was driving the smoking? Could it be the other way around, actually? That yes, that those things were really important, but the common driver is stress. And I think, you know, we see that in stressed animal studies. We see that in social inequalities. I think stress is still a big factor,
Starting point is 00:41:45 but it acts through these other things. And it's not something that we can't necessarily try and change for us and for other people. You know, if the work is driving stress, actually, this is pretty bad. If the work is actually maybe part of what you're enjoying and giving you purpose in life, it could actually be very beneficial. Absolutely. Brilliant. Claire, thank you so much. I really enjoyed that. It's such fun to have you on the podcast. I'm going to try and do a little summing up of what we covered and we've gone in a lot of places.
Starting point is 00:42:14 So I'm going to do my best and please correct me if I've got it wrong. So firstly, we said that aging is the sort of natural process where most of our abilities are getting better until maybe our 40s. For many of us, it plateaus, and then it declines at very different rates for different people. You had, interestingly, a huge focus on physical exercise, much more than I was expecting. I think you then talked about dementia. This is this disease that starts a long time before the symptoms. So again, there, you can't you can't just wait till you've got it.
Starting point is 00:42:46 You've got to think about it. Interesting. You then lay it on sleep, talked a lot about diet. And then I thought the last thing that I really hadn't heard before was fascinating is you can't expect your brain to work well if you can't hear properly, if you can't see properly, if you're not interacting with other human beings. And I think a very positive sign, right? Very positive message. You really can push out aging a lot further. Is that fair?
Starting point is 00:43:10 That's very good. I'm amazed, Jonathan. You've managed to summarize it extremely well. My wife has been telling me I should really get my hearing tested for the last two years. And I've been like ignoring her because I'm like, I don't really want to admit I might be getting older. But now I'm like, okay, apparently it's going to affect my health. I'm looking into it straight after this podcast. Fantastic. Claire, it was such a pleasure. Thank you so much. And we look forward to having you back again in the future. Thank you very much, Jonathan. It's great to talk to you.
Starting point is 00:43:36 It's a pleasure. Bye-bye. Thank you, Claire, for joining me on Zoe's Science and Nutrition today. If based on today's conversation, you're worrying about aging and wondering how to eat the best foods for your body, then you may want to try Zoe's personalized nutrition program. Your Zoe membership gives you meal and recipe recommendations and scientifically backed nutrition advice on how to eat for your best health so that you can feel more energetic, improve your gut health and reduce the risk of long-term disease. Your personalized nutrition program is based on our scientific research and the results
Starting point is 00:44:10 of your personal at-home test. If you're interested in learning more about Zoe, you can head to joinzoe.com slash podcast and get 10% off your purchase. If you enjoyed today's episode, please be sure to subscribe and leave us a review as we love reading your feedback. If this episode left you with questions, please send them in on Instagram or Facebook and we will try to answer them in a future episode. As always, I'm your host, Jonathan Wolfe. Zoe Science and Nutrition is produced by Fascinate Productions with support from Sharon Fedder, Yela Hewins-Martin and Alex Jones here at Zoe. See you next time.

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