ZOE Science & Nutrition - How to prevent heart disease, according to science

Episode Date: November 9, 2023

Heart disease is among the top five causes of death globally, and it’s the first in the United States and United Kingdom. In the U.S., it causes 1 in 5 deaths. But what is heart disease, exactly? Can we take steps to avoid it? Prof. Eric Rimm, of the Harvard T.H. Chan School of Public Health, is here to enlighten us.  In today’s episode of ZOE Science & Nutrition, Jonathan and Eric explore what we can do to reduce our chances of getting heart disease.  If you want to uncover the right foods for your body, head to zoe.com/podcast, and get 10% off your personalized nutrition program. Follow ZOE on Instagram.  Timecodes: 00:15 - Intro 01:07 - Quick fire questions 02:10 - Biggest myth about Heart Disease 03:2 6 - What is Heart Disease? 08:03 - What is a stroke? 10:29 - What are the differences in Heart Disease symptoms between men and women? 12:51 - Did you know that… 14:24 - The multi-decade diet study 21:24 - The 4 ways to lower chances Heart Disease 28:16 - Weight and Heart Disease 32:09 - What can you do to reduce Heart Disease risk? 34:30 - Exercise and Heart Disease risk 37:11 - Body Weight and Heart Disease risk 38:01 - Diet and Heart Disease risk 41:06 - Sleep and Heart Disease risk 46:18 - What is the cutting edge research in Heart Disease? 49:35 - Summary 53:18 - Conclusion Mentioned in today’s episode:  Optimal dietary patterns for prevention of chronic disease from Nature Medicine Frequency, type, and volume of leisure-time physical activity and risk of coronary heart disease in young women from Circulation Diet, lifestyle, biomarkers, genetic factors, and risk of cardiovascular disease in the Nurses’ Health Studies from the American Journal of Public Health Download our FREE guide — Top 10 Tips to Live Healthier: https://zoe.com/freeguide Is there a nutrition topic you’d like us to explore? Email us at [e-mail] and we’ll do our best to cover it. Episode transcripts are available here.

Welcome to ZOE Science and Nutrition, where world-leading scientists explain how their research can improve your health. Today we learn about heart disease and how to prevent it. In the US, one in every five deaths is caused by heart disease. How likely you are to develop it depends on a lot of things. Some of these, like your genes, you can't do anything about. But many other risk factors are under your control. I'm excited to have Eric Rimm on the show to tell us more.

Eric is a professor of epidemiology at the Harvard Chan School of Public Health. He's also one of the world's top 100 most cited scientists. He conducts huge studies to understand the impact of food and lifestyle on your risk of chronic conditions like heart disease. Eric, thank you very much for joining me today. Thanks for having me, Jonathan. Great to see you. It's a real pleasure and fun to be able to do this in person in Boston. So we have a tradition here, which we always start with a round of quickfire questions. The rules are that you can say yes or no, or if you absolutely have to, you can give us a one sentence answer.

This is very hard for professors, but they do normally manage it. Are you willing to give it a go? Yes. Fantastic. Well, that's a good start. Okay. If I don't sleep enough, does this increase my risk of heart disease? Yes.

See, that wasn't too bad. If my parents had heart disease, am I at higher risk? Yes. I'm approaching 50. Have I left it too late to significantly reduce my chance of having a stroke or heart attack? No. Very good news for me and for many listeners, I know. Are the symptoms of heart disease exactly the same in women as in men? No. We'll definitely come back to that. Is it possible to reduce high cholesterol without drugs? Yes. Okay. Last one. And you don't just have to say yes or no.

What's the biggest myth that you often hear about heart disease? One of them, maybe what you said is that people think, oh, I'm already 50 years old. There's nothing I can do about it now. Yeah. I think the other one is that I'm on drugs now. There's nothing that I don't have to worry about it anymore. Drugs are just something you can take to help you, but there's a lot that can still be done after you're taking medication. So just taking drugs is not enough. Taking drugs helps a lot, but there's so much more you can do yourself after that to further reduce your risk. Sounds exactly like the conversation I have with my dad. So actually, as some of our listeners will know,

my father was diagnosed with high cholesterol in his 20s, so when he was very young. And as a consequence, really just, actually even before I was born, so my whole childhood was very much influenced by the advice that doctors gave then to my father about what you do if you have high cholesterol. And so that impacted the food we had and all of that was with the aim of reducing his risks of heart disease. So this is something that has definitely been sort of present in my life. I also think sadly that

pretty much all the advice he was given would have made matters worse rather than better. Maybe we just start at the beginning, just really simply, what is heart disease? That is, it's an intriguing question, because when people think of heart disease, they think heart attack is the only form of heart disease. But there's a lot of different forms of heart disease. It can be a valve problem, it can be where your heart just gets worn out from pumping. And it can be the classic heart disease, which is when you get atherosclerosis built up on the inside of your arteries and a blood clot happens, it clogs your arteries

and doesn't allow oxygen to get to your muscle, which causes a heart attack. So there's a lot of other things that we call heart disease, but I think probably the main one that your listeners are worried about is am I at risk for a heart attack? The pump failure one,

which is called congestive heart failure, is something that more and more people are worrying about is, am I at risk for a heart attack? The pump failure one, which is called congestive heart failure, is something that more and more people are worrying about. People that are overweight for decades and have high blood pressure for decades, when they get to be 80 years old, the heart gives up. And it's not because there's a blood clot that stopped blood flow. It's congestive heart failure. Your heart is just not as good and efficient as pumping. And so the essence of the heart attack is sort of like these tubes that the blood is going through, getting sort of more and more restricted until one day it gets blocked. Is that right? Yeah, I mean, I always try to think of analogies of this. And some of it is like,

you buy a new house and the drain in the shower works really well because the pipes are brand new and the water flows down. And after years of stuff in your shower, whether it be hair or dirt, you know, eventually it starts to clog up the outside of the pipe. And that's kind of what happens with your arteries is that even, you know, heart attacks take a long time to happen. So you can start in your twenties and your heart attack doesn't happen until you're 50 or 60. And I think just to make sure I've understood, this is not a quick process. You're saying amazingly that even, you know, you can look in people in their 20s and already see the start of these pipes getting like blocked. So it's a multi-decade experience. Yeah, it is. It's a multi-decade experience. And most chronic diseases are of that nature. But heart disease is one that I think that has been the best mapped out, that you can see this over many decades. And you can see it go faster among people who smoke a lot. And, you know, sometimes people get signals. You get a little bit of chest pain. You feel a little pain down your arm. You think, oh, I have angina. Maybe I'm having a heart attack. And you can go in and say, oh, that person is 70% occluded. And occluded means 70% blocked.

Yeah, 70% blocked. Yeah. Sorry. Thanks. And so, you know, the question is, what do you do with someone like that? You can put them on drugs. You can go in and try to, you know, balloon them out. Or you can, hey, say, you know, it's time for you to change your lifestyle. You need to stop smoking. You need to lose weight. You need to change your diet. Let's talk about things that we can do to help you. And your father probably had that, whatever, 40 years ago. And some of the advice back then was not what we know now. And we probably would give your father very different advice if that happened today. And I definitely want to get into that.

Just before I do, you know, there's a few other terms that I think I often hear people use. One is cardiovascular disease. And I guess I'm interested, there's a few other terms that I think I often hear people use. One is cardiovascular disease. And I guess I'm interested, is that the same as heart disease? And the other thing is people often mention stroke at the same time as heart attack. Could you just unpack that for me? Yeah, sure. I mean, cardiovascular disease is everything in your vasculature, and that includes stroke. And so we talk about stroke or a heart attack, or sometimes people

get intermittent claudication where you kind of get that occlusion in your arteries in your legs and you start feeling leg pain. And so all of that. And vasculature is just like any tube that is carrying my blood? There you go. Yes. That's a good way to think about it. And in most Western countries, the US, Canada, UK, Australia, the number one and the number three or the number one and number four cause of death is heart attacks and strokes. So when we say cardiovascular disease, we are talking about what most people die of in Western countries. Yes, we know cancer is usually number two or number three in that group, but cardiovascular disease really represents, when you look at mortality, you know, pre-COVID, what people were dying of was heart disease and strokes.

And could you explain the stroke? Because I think you have this very nice explanation for sort of ultimately how you get the heart attack. How does a stroke fit in? Because I think about that as like, it feels like it's something completely different. It also feels like something that people worry about maybe more now than when I was a child, while at the same time, it feels like they worry maybe a little less about heart attack. Yeah. And some of that is just our understanding of the causes of that. So you mean they might have thought it was a heart attack and now they have a better understanding that maybe- Well, we know how to treat it a little bit better and we're doing a

better job of bringing heart disease rates down. And a stroke is complicated because a stroke is not one thing. A stroke can be, you know, a blood vessel in your brain bursting or a blood vessel in your brain getting clogged. And those are both called stroke. They're different stroke types, but the causes of those two different types of stroke are quite different. In Western countries, most of the strokes are where an artery gets clogged, like a heart attack, and it's like essentially a heart attack in the brain, and you can't get blood through to the brain, and parts of the brain die, and that's why people lose function. They can't control the side of their face, or other things happen when you have an occlusion that we call an ischemic stroke, essentially means a blocked artery to the brain.

At the other kind of stroke where the blood vessel bursts, you know, then you have essentially blood bleeding in your brain, which also can cause, you know, tremendous complications. And so for the stroke that you're describing, you're saying where it's sort of most common if you're listening to this in a country it's it's again a blocked blood vessel this is the same process that you're describing it's just that ultimately instead of the vessel being by your heart it's in your it's in your brain yeah something quite different it's it's how the cause of it is different um a lot of the ischemic strokes or blockage strokes are where you have a clot somewhere else in your body and it travels up to your brain and and blocks because the arteries in your brain are a bit smaller than the big ones that take blood to your heart. So it is a little bit harder to understand. There's many different causes of stroke and some are short term and probably some are 10 or 20, 30 years of having high blood

pressure and not treating your blood pressure or not changing what you do to reduce your blood pressure. Well, I think as we talk about this, it'd be interesting to understand what can affect just the heart attacks you're talking about and what can also be beneficial as we're talking about this broader cardiovascular disease. Yeah. And some of them are the same. Some of the same risk factors you may have for strokes as you have for heart attacks, and some of them are different. Before we start to talk about those risk factors, I actually just wanted to come back to this answer that you gave right at the beginning about how symptoms for men and women were not exactly the same.

And I know you've written a lot of papers actually looking specifically at women's risks from heart disease. And it's a topic we talk about on the podcast quite a lot about how, in general, women's health has been really understudied in science. And in fact, often historically, maybe women weren't even participating in studies. Could you tell us a bit about what those difference in symptoms are? You know, it is true, you know, angina, which is sort of the early pain that you may feel, is different in women and men. And when you talk

to cardiologists, and historically what they would say is that, you know, they would downplay a woman with symptoms to say, oh, I have a little chest pain. Oh, it must be something else. And the chest pain in men would be stronger. Or just how they report it to the doctor. You know, some of it was like, you know, it's a female response to a clinician versus a male response to the clinician and the clinician's response to hearing those symptoms. So some of it may be that they were actually closer than we thought. And perhaps maybe the clinician was not taking it seriously because they've been told, well, you're not likely to have a heart attack because you're a woman based upon faulty data.

So that, right. And whether it was faulty, yeah, some of it was faulty data and some of it was just perceptions in historical. So now that, I think that has changed a lot. There's a much more, much greater recognition by national organizations of heart disease in women and heart disease is still the number one killer of women. So pretty shocking, actually, isn't it? I'm not saying that everybody intentionally did that necessarily. But it's pretty shocking that if

it's like the number one killer of women, it could have been missed in this way. I don't know if you know, but how much of that is from like the lack of the studies and how much of it comes from maybe, you know, a lot of sexism and things that we would have had 60 years ago, which hopefully is a lot better. Yeah. Historically, a lot of it was, we just didn't study women. And, you know, some of the first studies really in the fifties and sixties were almost exclusively among men. And so we studied men, this is what happened, and you treat men because there were men's studies. It wasn't until the 70s and 80s and some of our work and some other work around the globe where people said, oh, we really need to look in a female population. And you needed a really big population. If you're

studying 40-year-olds, there's not a lot of women that have heart attacks when they're in their 40s, so you really needed large populations. So that was the other problem is that, oh, we have the Framingham Heart Study. It has, whatever, 3,000 men and 2,000 women. That just wasn't enough to see heart attacks. You could see changes in cholesterol. You could see these other things, but you really needed to have studies that were 50,000 or 100,000. And now over time, we have many of those studies in men and women. And we can explain a lot of heart attacks just by seeing what people choose to do in their life. And I don't want to shock the audience saying, oh my gosh, number one killer. I mean,

there's 10 times more women that die of heart disease than die of breast cancer. So 10 times more women die of heart disease than breast cancer. So I'm shocked. And I imagine that a lot of listeners are quite shocked. Well, no one wants breast cancer of heart disease than breast cancer. So I'm shocked. And I imagine that a lot of listeners are quite shocked. Well, no one wants breast cancer or heart disease. And part of it is that there's a lot of women that are diagnosed with breast cancer. And we know how to treat it. And the long-term survival among women that are treated with breast cancer is very good. And what they die of is heart disease.

Sometimes they get breast cancer again 10 or 20 years later or get some other cancer. But a lot of what they die of is heart disease. You asked me the question, you know, if your parents had a heart attack or had heart disease, does that put you at risk for heart disease? It does. But do we know why? Well, some of it is probably genetics, but probably if your parents had bad lifestyle choices and it led to a heart attack, they probably trained you how to do the same thing because you probably ate poorly as a child and you probably didn't exercise much. And, you know, you probably had all those other lifestyles factors that your parents had that led to their risk of heart disease. That makes sense.

And I think it's a great transition to talk actually about the studies that you've been involved with. I know that some of these studies are huge, right? Like more than 100,000 people. Again, I think our listeners have sort of discovered that's incredibly rare in science, right? Most studies, particularly things that are trying to understand things like nutrition, they might be on 20, 40, 50 people rather than these enormous numbers. So it's very exciting and I think allows you to do things that otherwise are really hard. Can you tell us a little bit about what you've been trying to figure out about heart disease? And maybe we go from there.

Sure. Again, it's been exciting to be part of this research team for so long with so many great people that have expertise in different areas. But the true underlying reason to start three of these studies was the Nurses' Health Study 1, the Nurses' Health Study 2, and the Health Professionals Follow-Up Study. The reason we started these studies was to capture information about free-living individuals. They were all in the US for these studies. Free-living makes them sound a bit like chicken. Sorry. No, no, no. What is a free-living individual?

Means they're not coming into a clinic. They're not sick. These were- Doesn't mean they're not in jail. Just to clarify. Okay. General population, they worked as professionals. So there were nurses and dentists and osteopaths and people that worked in professional careers. But every two years, we send them a very detailed questionnaire saying, tell us about yourself. And we have very careful ways of asking them about their diet. And we've spent a lot of time figuring out the

best way to ask someone about their diet. But the strength of these studies is one is that people who are in these studies want to stay in them. They respond every two years to a questionnaire, which is amazing. I mean, a lot of studies that are done like this have a questionnaire at the beginning and they just follow people. Just like, tell us about yourself, and then we just follow you for 20 years, and we go back and look at what you said 20 years ago to see if we can predict who has a heart attack. In our studies, every two years, we send them a questionnaire saying, hey, how's it going? And it takes them about a half hour to fill out. And in the middle of that is, hey, have you had any diagnosis of any diseases over the last two years?

And that can be from, you know, benign breast disease to heart disease to stroke to, you know, I fell down and fractured my hip. So it gives us the opportunity to then go back and look at all of the questionnaires that led up to that time to say, could we statistically try to predict who had a heart attack, who fell down and broke their hips? And do we have enough information to kind of draw statistical models to say, ah, these are the things that we can best predict, in my case, who's going to have a heart attack? And we don't just trust them. When they say, oh, I had a heart attack, you want to go back and get their medical records and have, you know, we have a cardiologist that review them and go, oh, okay, this is a standard definition. This person clearly had a heart attack. It's interesting. 25% of the people report a heart attack and they really didn't have a heart attack. We get the medical record. I'm really surprised. I thought that I could understand that some things are hard to tell,

but a heart attack, in my mind, you're like walking along and then suddenly you collapse on the ground and, you know, the ambulance is there. It feels like you'd know if you had a heart attack. I mean, well, some of it is that like the details of how they worked it up wasn't enough for us to say it's a heart attack. We say, oh, it's probably a heart attack. But five or 10% of the people really probably just had too much onions for dinner. They had some chest pain and they want to tell us they had something. So they write it down. It's a heart attack. We'd go back and get their medical records. They say, oh, it's not a heart attack. So if someone says they had bypass surgery, everybody reports that properly because you don't accidentally have bypass surgery and

not know what it is. I hope not. I agree that that I would. And, you know, things like colon cancer and breast cancer, and some of it is we go back and get the medical records so we can figure out what type of breast cancer and all the other details from the pathology report. But heart attacks really are, are the enzymes elevated? You know, do we have these two or three other clinical things? And we say, okay, it's a heart attack. But the... Okay. So you're able to really guarantee that it meets a particularly sort of tight clinical definition. So this gives you a really accurate data to look at. And then the beauty of it is we can go back and look not just at what they told us 30 years ago

when they started the study, but also did they change anything over their life? And most adults, think about yourself, whoever's, if you're listening to this, have you been doing the same thing since you were 21 years old or since you were 16 years old? And most people have not, you know, some people maybe smoked for 10 years and then stopped. Some people used to exercise and then stopped. Some people didn't exercise, had kids and then figured out how to exercise with their kids. So all those things change your risk of having a future heart attack. Yeah, I'm thinking that I drink a lot less than when I was 20, but I also have children, so I sleep a lot less than when I was 20. So we'd want to put those things into a statistical model. And I'd like to compare you

to someone else who has done a lot of other those things similar, but, you know, maybe didn't change their diet or maybe didn't exercise or maybe, you know, did sleep as well. So it's not a clinical trial where we truly randomize people. But since the studies are so large, we have 240,000 women that we've been following statistically and medically for 30 or 40 years. So there's a tremendous amount of information. You know, some of the women are now over 100 years old. So it's, I mean, it is a lifespan. And there are really important things you can do in your 30s and 40s that are important for protecting yourself. And I think it's a great example. We talk about this quite often about like some of the challenges of really trying to understand human health is that you're trying to measure people who live the same length of time as we do, right? So it's not like you sometimes meet scientists who are doing things on mice or

something, right? And they can get these results really fast because mice don't live very long. But ultimately, you're interested in things that happen towards the end of your life that really affect your quality of life. And that takes a long time. So I think what's amazing is this study has been started such a long time ago. So it's almost like you have this time machine, right? You look back on what happened. And it's similar to Tim's twin study in the UK, where again, because it's 30 years old, you get this amazing ability to look back. And this is what makes, I think, the science of human health much harder than lots of people realize who come from elsewhere, because there's no shortcut to the time. And nutrition is one of the most challenging things to study. Some of it is like what was available to buy in the 70s and 80s in terms of food supply

is different. So we have to take some of that into consideration. There are times in just in the human humanity that, you know, this was available back in the 70s, 80s, and it's no longer available or science has changed. And now we have different types of food. So we, to the best of our ability, we try to take that into consideration. Nutrition is even harder than something like physical activity because physical activity, you can do it or you cannot do it. And there's obviously different kinds of way doing physical activity, but eating,

we kind of all need to do that. So if you suddenly stop eating something, that means you're going to replace it with something else. And that's the true challenge of studying nutrition and dietary patterns. Hi, I want to take a quick break here and tell you about something new we've created, a free guide that will kickstart your journey to better gut health. Now, if you're a regular listener of this podcast, you're no doubt already aware of how important the gut microbiome is.

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Emails and actionable tips that are designed to put you in control of your gut health. To get yours for free, simply go to zoe.com slash gut guide. Sorry, we've teased our listeners a long time. So I think, no, no, no, don't apologize. No, no, not at all. But I think they're like, okay, so what have you found out? So what has this told you about the risks for heart disease? So there's been several studies that we've done in our groups of men and women. And what we tried to do is suppose you would just look at someone's choices in life, like pretend someone doesn't even go to the doctor, doesn't give their blood, doesn't whatever. And really, can you make choices at home? And if you made the right choices,

what percent of heart attacks could we get rid of? And what we found is that just simple things like a healthy body weight, exercise, not smoking, and a healthy diet. And in the healthy diet, we put in a little bit of alcohol for people that drink, but you can explain 60 to 80% of heart attacks. So if everybody just did those four choices and did them in a healthy way, you could get rid of probably 70 to 80% of heart attacks in women and 60 to 70% of heart attacks in men. And the number one killer is heart disease. So if you can get rid of something, which 60 to 80% of it, just by making healthier lifestyle choices. And we even in our studies and men and women, we see even people, as you mentioned earlier, who are in their forties and fifties and be making, maybe taking medication for high blood pressure or high cholesterol. Even those populations that make healthy choices can get rid of 60% of their risk of heart attack. So I just want to make sure I got that. You're saying that even if you are in your 40s or 50s, and maybe you've got all of those risk factors or many of those,

if you make a real change to your lifestyle, you can really dramatically reduce your chance of having a heart attack? That's amazing. It's a three or four-fold drop in risk of heart disease. And it's 50% to 70% of the heart disease that happens among people who are taking medicine you could get rid of if people exercised, had a healthy weight, had a good diet, and didn't smoke. So just to make sure I understand, let's say somebody's listening to this right now who's in their mid-50s, how much can they reduce their

risk of heart attack if, let's say, they're maybe not at the healthiest thing and they were to really make a big change? Yeah. So the way we looked at it, it was to just give people a simple score, you know, zero through five. How many of these things do you do that are healthy? And the cutoff for exercise is like a half hour a day. And you don't have to do it a half hour every day if you just have, you know, two and a half to three and a half hours a week of moderate to vigorous activity. If you had that, then you get a one. If you don't, you get a zero. And then we kind of classified people based on a healthy diet, and we gave people in the top 40% of a diet, we gave them a one

if they had a healthy diet and zero if not. And if you smoked, you got a zero. If you didn't smoke, you got a one. So you can see it's in a healthy weight as if you have a BMI under 25. So these are just relatively simple cutoffs. And we were just counting people zero, one. So you could have a zero all the way up to a five. And if you had a five, which means you were healthy in all of those, and therefore your risk of heart disease was three to four times lower than people who are zeros. And it was still two to three times lower than people who are zeros and it was still two to three times lower than people who are one so it's and it's a beautiful very nice linear scale the more healthy things you have the lower your risk of heart disease so so just to make sure i've got it you're saying you had

this way because there's a lot of complicated data to make it quite simple so you gave everybody like a score between one or five basically it was was quite simple criteria. It sounds like they die. It's like a one or a zero, right? And we know that it's oversimplified. Way simplified. So it's quite simple. And you saw this enormous, you said like a three to four time difference in likelihood of getting a heart attack from, you know, people with like zero versus five coming back,

I guess, to this question about, okay, but I can see that if I've done that since I'm 20, I'm great. But do you have people in your sample who like really changed that maybe they were only scoring one or two and they went to four or five in their fifties. And was that able to make a big change or now you're like, okay, it's a bit better, but it doesn't really matter. Yeah, no, that's, that is the most important question is like, what can I do about it? And, and our populations were large enough that we had some people that did change that went from a 1 to a 5.

And some people stayed at a 1. And people that went from a 1 to a 5, like, have the risk of heart disease. They have the risk of heart disease. So, like, don't ever, it's never too late is really the message. Which is an amazing message. So, saying even in your 50s, I think many of us have sort of felt like it's all too late right you're sort of stuck with all the choices you made you're saying even if you haven't made any of those right choice until your 50s you can half your risk of heart disease at that point if you are to make a um a set of changes yeah i mean that's and that's

we have to generalize over everybody there i'm sure some people do better than other people because of what all the differences that we know from genetics to microbiome and all the other things that your guests have talked about. So that means, on average, it's about a halving of risk for people that really, truly have made change. And that is in your 40s, 50s, and 60s, which I think is the richness and the uniqueness of this study. If you follow people for 40 years, you can watch them go through life. And, you know, we don't know why they chose to go from a one to a five. What is it that someone was living unhealthy or living in a way? Maybe they had young kids that just couldn't do anything because they had three kids and they were just

trying to deal with their kids. Their kids got a little older. Finally, they said, okay, I now have time to exercise. I can now lose a little bit of weight and I can now think about eating healthy. So they suddenly had a point in their life where they could live healthier and they could have the risk of having it. I think that makes sense. It's funny. I'm meeting someone tomorrow and he's explained like he's going to the gym for like two hours tomorrow morning.

And I was like, that's just the definition of not having any children in the house anymore. I was like, just thinking, well, I can imagine doing that in my twenties. I could see that once your kids are maybe like late teenagers on, you can imagine. But otherwise, it's obviously totally impossible. Yeah, right. You can, you know, some people get exercise equipment at home. Some people walk their dog. I'm not saying you can't do any exercise, but I am saying you can see how there's a lot more opportunity.

You know, you get a lot more opportunity, potentially. It's particularly, you know, if you've had something like children and family responsibilities can make this very hard. We have people taking care of sick parents that we've studied and we try to look, what is the impact of having to take care of a sick parent on your risk of heart disease? And it actually increases your risk of heart disease. Why is it? Because one, there's probably added stress, but probably two is just for the reason you said, I have to be there. I have to be the nurse for my mother. She's ill. She had a stroke. And so if I'm taking care of my mother,

then I can't exercise. And sometimes I have to eat quickly. And so I eat fast food and have fish and chips instead of making something that's healthier. So there's a lot of reasons. Some of it's probably behavioral and stress. And some of it is just the choices that they can make. It's quite sad, actually, to hear. I mean, we have an expert who studies trauma and PTSD, and it's the same thing.

People who have early life trauma because they've witnessed a violent event or other causes of trauma who then go on to have PTSD also have a one and a half to two times fold risk of having a heart attack. Probably because of the stress involved, but probably because it leads them to bad choices, bad lifestyle choices because of the mental health anguish they're going through. So I guess you're able to pick up a lot of complexity in this. I think just before we talk about what can you do and maybe dig into it in a bit more detail, one of the things you've mentioned is around weight. And I think for a lot of people historically, I think the view has been, well, if you're not overweight, then you don't need to worry about heart disease. And I think that for many of us, this sort of affects the way they think about things. Is that true? Yeah. There's no question that people of all sizes and shapes have heart attacks and strokes.

And there are a lot of other biological things going on among normal white people. There's more adverse things going on among overweight and obese people. Obviously, they're much higher risk of diabetes, which puts you at risk for heart attacks. But you can get a heart attack while appearing to be, you mentioned this sort of, I know, it's a slightly arbitrary scale, the BMI with a lot of questions about whether there could be something better, but you're saying, you know, with these people who are in your below 25, they can still have heart attacks. Yeah. In our scale, BMI was only one of those five points. So if the only thing that you have is a BMI and you have a point, you have a one point, but you don't exercise,

you have a bad diet and you smoke. And, a lot of the reason that people are normal weight or underweight, healthy weight, is because they smoke and smoking, people who smoke weigh three or four kilograms less on average. I digress. Nonetheless, we do have people that have a point only because they're what we call healthy weight, and they don't do anything else, and they still have an elevated risk of heart attack. So there's a lot of other things, inflammation and lipids and high blood pressure that can go on among someone who's a healthy weight. I ended up doing one of these body scans when I took part in one of our first ZOE studies that sort of gave the first data that we use. So this was about five or six years ago. And I remember the nurse was really shocked as she looked at the scan because, you know, for those of you on audio, like I'm not a particularly big person.

I would say you are quite healthy weight, yes. But what was interesting was that it turned out that I do have fat on my body. It's just all nicely nestled sort of around the organs in my belly and not everywhere else. And the nurse was really surprised because it sort of wasn't obvious. And she did these all the time. So it goes to show that, you know, it wasn't totally obvious. And I was, I was told afterwards, well, actually that's really bad. Like actually, um, it's not really like your overall weight, which is so important. It's actually more where it's located. And so in my case, sadly, it was all stuck right in the middle where it

shouldn't be. So even though actually like on a BMI scale, people would have said that I was fine. Actually, once you do this more detailed analysis, that is a real risk factor. And that's some of what I described of men versus women is that women, they would be less likely to have that in the, between the ages of 18 and 55 or something like that, that they carry their fat in different places. What you described was visceral fat, which is around the organs, which, you know, there are many people now who are doing studies of the types of fat around each of the organs and how it impacts it, if there's fat around the liver or on the kidneys. So, you know, I think that does put you at modestly increased risk, but there's probably lots of other things that you do that, you know, would help prevent that risk.

I've changed my diet quite a lot since then, so I'm looking forward to re-scanning. I'm hoping that I will have managed to make some improvement. I mean, that's why when we talk about exercise, we talk about not just aerobic exercise, but resistance training so that people, when they do gain weight, it's muscle mass and not fat mass. So it's good to have muscle throughout the body. That helps with insulin sensitivity and helps with a lot of other biological factors, plus people have lower cholesterol. You know what, Eric, I think it's a brilliant transition. Okay, people have listened to all of this. You terrified them, like number one and number four, cause of death.

I think most people are thinking, I'd like to not die. And in fact, also, I'd like to have this quality of life for a long time. So given all of this amazing study, I think you also have some good insight into what people can do to reduce that risk. And I'd love to just talk through, like, what are the top things that anyone listening can do that could actually reduce their risk here? Yeah, I mean, some of the things are clear, you know, smoking versus not smoking. Everybody who does smoke should try to find programs. And so

that may be very obvious. And is vaping much safer? Some of the short-term studies would suggest that vaping is as detrimental as smoking it's just that you know something is not burning so you probably won't have some of the impacts long term that you get from a cigarette but some of the exposures you get from vaping yeah i would strongly recommend people not to vape as well we just you're pretty negative yeah pretty negative but you're pretty negative yeah i mean we haven't been able to put it in our models. Yeah, we actually have a new study that my colleague, Jorge Trevorrow, is studying younger people that are in their teens and 20s.

And we do have a fair bit of vaping there. So we'll be able to look at the impact on diabetes and weight gain and things like that that happen over time. We don't have that yet. So we're working on it. But you're, you know. Yeah, I'm anti-vaping and anti-smoking. And I think that's, I think any most public health professional would say that.

And, you know, yeah, I'm not going to get to the details of, you know, transitioning off of smoking. That's fine. If going to vaping helps, that's good. But that, you know, try to work off everything. Stop smoking. Vaping is not as bad as smoking, but it's definitely not a sort of harm-free activity in your mind. And so after that, it's physical activity. And that also is a choice. And I think, you know, physical activity, you know, it's best if it's moderate to vigorous

so that you're sweating. So if you go for a light walk with a dog, it's nice if you pick up the speed a bit. And I do think resistance training is important. Something where you are doing weight-bearing exercise. And some of that can be as simple as, you know, being in your own TV room, you know, standing up, sitting down, standing up, sitting down. So you're, it's, you know, it's some of it's aerobic, but some of it is truly impacting, you know, weight-bearing exercise. And some people, as you said, go to the gym and lift weights, or, you know, you can just be at home and doing pushups. There can be things that- We talk about weight-bearing in quite a lot of different contexts. Why,

and a lot of that is also, we often talk about with people talking about just sort of your quality of life, for example, that if you lose this strength, but why do you think it impacts your risk of these sort of heart attacks and strokes? How does it link between exercise and those? Yeah, I mean, we see a lot of that with age that as women become postmenopausal and men get older, you just naturally lose muscle mass. And so a 70 year old man can weigh less than they did when they were 55, but they're at higher risk because they've lost muscle and they've gained fat and, you know, they may look to get on a scale and weigh the same, but it's, it's all, it's more adipose and less muscle. And is the muscle helping with the heart?

I'm just trying to understand. Is it the muscle that's helping reduce the heart disease or is it something? Yeah, it's probably a lot of it's just the muscle because muscle pulls glucose out of the bloodstream. The muscle is very biologically active in beneficial ways. Obviously, muscle can help for lifting and not falling and you know other things like that but it's not just that like the muscles actively it's really interesting you're saying it's really active organs they're active they're i think that's a surprise for most people yeah as opposed to just lifting weights the muscle feels like a very inactive organ until

you're i'm moving my arms back and down but i i think most of us think about muscles very much as as like a tool to move something but you're saying you can actively help to sort of counteract these these things that are affecting yeah very very biologically active resistance training reduces your risk of diabetes and heart disease and you're right there's the group of 17 to 25 year olds or whatever that are doing it for whatever physical appeal but it's really when you get to your 30s 40s and 50s that people stop they think about exercises i got to go out and you know i have to go for a run or i have to go to the gym and get on a treadmill or whatever and we while you're at the gym you know lift weights for 20 minutes i think that is there some shift it does that mean that we're now

like science in general has got like more convinced or more interested about the importance of muscle rather than just doing exercise? Is that part of it? Because I do feel that what you're saying is going to be a surprise for a lot of people. And I think you're like, oh, it's sort of obvious. Everyone in science has known this for the last decade or two, but often that's a bit the- No, I think it's a shift. Yeah, I think it's in the last decade. And my colleague, Ai-Men Li, is one of the leaders in the world in physical activity. And there is, there are clear physical activity guidelines that say aerobic and resistance training and resist as you age that resistance training, that muscle building, or it's really just muscle saving. In some cases, you don't think of a 70 year old, you know, pounding weights like

a 21 year old, because they want to have physical appeal. What you're trying to do is keep you from losing muscle mass mass because biologically that's what happens. What you're trying to do is keep you from losing muscle mass because biologically, that's what happens. Your hormones shift as you age and your body loses muscle mass. So you have to retain that to keep your risk down. Hi, I love that you're listening to this. It means a lot to me and the whole team who put such a lot of hours into this podcast each week.

We release this show for free without ads to help millions of people improve their health with cutting-edge science. In return, all I ask is that you help us on this mission. If you know someone who'd benefit from listening to this episode, please send them a link to this show. And if you haven't already, hit follow wherever you're listening right now. Thank you, and on with the show. So you talked about smoking and exercise. What else can you do? So then we talk about body weight, and body weight, I wish there was a switch that you could flip and say, oh, I'd like to lose 10 kilograms. And we saw over COVID

how a lot of people gained weight. Here was this time where everybody was stressed and locked in their houses and probably eating poorly and doing other things. And a lot of people gained weight, present company included. And so I think that you can see how it can happen pretty fast. Most of the time, it's not the case. People gain a half a kilogram or a kilogram a year on average in their adult life. If you look at people in our cohorts, we measure things in pounds here. But in our large studies, men were gaining a half a pound to a pound and women were gaining a pound to a pound and a half per year for 30 or 40 years. And that can lead to long-term risk. So the last thing I haven't talked about is diet. And that's the thing that has

changed a lot. The science is so much better now than it was 30 or 40 years ago when your father was diagnosed with high cholesterol at age 22. And he probably told him to stop eating butter and eat margarine, which was partially hydrogenated vegetable oil, which probably did him much worse by doing that. And then he went on low-fat diets, as you said, and that was a terrible thing that this country did in the 70s and 80s and probably was spread out throughout the world, is people were pulling fat out of food, healthy fat out of food, and putting in highly processed carbohydrates, which I'm sure you have talked to many people about. And that... There's not a lot of people, nobody wants to put their finger on supporting that anymore.

It's interesting. It's definitely one of those things where no one was ever in favor. But I know that the science, you know, I think to be fair, right? There were- Science was nowhere near as good then. And, you know, I think even now there are still some people that would say, no, no, no, you should have a low-fat diet.

There are some people that do okay on low-fat diets. Low-fat diets don't taste good. And so most people can't stay on them for a long time. But, you know, I have a few friends who are vegetarians and don't add vegetable oil to their foods and eat 15% of calories from fat. And there's good science. If you eat it, the rest of your diet is healthy and you have low fat, you can do it. Most people can't stay on it for more than three months or six months. And I think we haven't talked a lot about personalization, but I'd say that's something

Zoe believes a lot in. So I don't know, Is that something that you see at all in your data? Because obviously you're looking at a lot of these averages. But do you feel like there's one answer for everybody or actually that there's likely to be something more personalized? I think you are leading the way in understanding personalized nutrition. And I think there is something to that. In our large cohorts, we've collected 100,000 bloods from women and 20,000 bloods from men, and we've collected stool samples from 20,000 women to get their microbiome. So I think we will be able to tease out that. And some of our early studies in the microbiome clearly show that,

that some people who eat dietary fiber do have much lower levels of inflammation, but not everybody. And you can say the same for coffee. Some people have coffee had tremendous benefit, and some people had less benefit. But in our larger studies, when we have the diet questionnaire, and we don't have the poop of everybody, and we don't have the genomes of everybody, what we can look is at the average. And there are just dietary patterns that show up that people live longer clearly they're at lower risk of heart disease of cancer of respiratory diseases you know lower risk of dying from anything by being in these healthy dietary patterns because i i think that you know we obviously believe i

think the personalization is fascinating as you go to the next level equally well i've yet to meet anyone who says oh some people don't need to do any exercise so it feels like you know there's um uh there's a range or that i've yet to meet anyone who says oh i think some people be fine on a diet of ultra processed food all day long right so this is always about this yeah i don't know anybody like that i have i haven't yet to meet a scientist genetic won't help you with that know where your microbes i'm really interested now one thing that you haven't mentioned so far is sleep. Is there any evidence of sleep impacting heart disease? Yeah. I mean, the sleep studies that we have done is some of it is like, if you take someone's body weight, you take someone's diet, you take someone's physical activity and they're smoking,

that explains a lot of it. And if you'd plug sleep into it, there may be a small additional benefits. But I think some of the reasons that people sleep better or not is because they exercise during the day. They're actually tired. You know, they ate a certain diet that doesn't keep them up at night. So there's all these things we talk about are a little correlated. You know, if you have a lot of coffee at 7 p.m. at night and, you know, you drink five glasses of wine, that's going to impact your sleep. So you can see there's correlations that we try to tease out. And when we do tease that out, sleep is still important. I think it's important more for things like, we're just finishing a paper that's just going to be published on high blood pressure and diabetes. So I think some of the impacts of sleep

are on more short-term factors that are risk factors for heart disease, but are measured more short-term. And some of it is that sleep differs every night, that some people fluctuate in their sleep. And some people say, oh, you know, five, you know, a week ago I had one really bad night's sleep, but the rest of the time I was doing okay. So some of it is variability in sleep itself. And so I think, you know, we try to capture it, but I don't think we do as good a job of measuring people's overall sleep intensity than we do of their diet or their physical activity patterns. And so where does that leave you? Somebody's listening to this and they're sleeping very badly and they're having, you know, way less than seven to eight hours.

Is that a risk factor for heart disease or not yeah i mean we do see that it's a modest risk factor heart disease for people that sleep a lot less than seven hours and a lot more than eight hours there's all sort of like it's bad if you sleep too long yeah and some of that just you know maybe the underlying reasons like why is someone sleeping 11 hours a day and they may have other conditions that are leading to that but yeah so i think the question is can you change that you know oh i only sleep five hours a day and they may have other conditions that are leading to that. But yeah, so I think the question is, can you change that? You know, oh, I only sleep five hours a night. I feel fine. You know, should those people be taking something to help them sleep longer? I don't think we know the answer to that. There haven't been large trials where you give someone a sleeping

medication and they sleep three hours longer. I don't know if that changes their heart disease risk. Okay. So I'm getting the message that it has some impact, but it's definitely like quite a bit lower for you than some of the other groups. And some of it is less studied. The intensity of studying sleep is much less than what we've studied for obesity, physical activity, and diet, and smoking over the last 40 years. Got it. So then we may not have the level of data that understands it in as close a way. And I mean, maybe just to sort of wrap that up together, imagine somebody is listening to this. And I think sometimes, you know, it's easy to say all these things, but it can be hard

in our busy lives. And I think it'd also be hard if you have all of these patterns of behavior and where you are to say, like, you can really make a change. Do people have to like solve all of this to change this? And I think you already mentioned weight, for example. I think all the evidence talking to lots of people is that reducing your weight is extremely hard. And we also see this somewhere with our own participants.

Some lose enormous amounts of weight, other than not so much for a lot of complex reasons. So I think that's when I think for a lot of people, it's like, well, I know that's really difficult. I know you're saying, well, if you can't really make a difference to that, it doesn't really matter. Or actually, if you can shift even one of these things, is that going to make a difference? Yeah, it definitely makes a difference. I mean, I think trying to shift any one of these things makes a difference. And for some things, you can flip a switch and you're changing it the next day.

If you can say, I'm going to decide to exercise. Tomorrow, I'm going to start on a half hour a day. I'm going to walk every day, blah, blah. So that's an easier switch to flip than say, tomorrow, I'm going to lose 10 kilograms. Losing weight takes a while. And if you're losing it very fast because you're going on some radical diet, usually means you're going to gain it back. Almost everybody who loses it very quickly can't keep it off because your body just takes

six months or a year to metabolically adjust. In the field, most people now don't look at a study unless it's gone for a year or two to look at compliance, to look at long-term staying on the diet and to losing, keeping the weight off because most of the studies that were short-term, you know, staying on the diet and to losing, keeping the weight off because most of the studies that were short-term people gain the weight back. And that's another way of saying what really matters is sustainability of what you do. Don't be frustrated. Don't, nothing doesn't make sense to do anything which is short-term. It only makes sense to do

something which is going to be a long-term change in your lifestyle. Right. You have to buy into it saying, okay, I realize I'm going to make a change. I'm not going to get order out food three times a week that's highly processed and chips and whatever. I'm going to make a change that this is important to me. So I may spend an extra half hour preparing food at home that's healthier, dark green leafy vegetables, that's fruit, that's healthier protein. So I think you have to consciously make that decision because it's not going to be magical for losing weight. Amazing. Eric, can I ask one final question? I think it's very exciting going

through all of this. And I'm just curious, since we have you here right now, what are you most excited about in terms of sort of the research that you're working on now that you might maybe be coming back and talking to us about in the next couple of years? Yeah, I think, as I said, we know in general the healthy diet is beneficial. And the healthy diet is no processed meats, actually as little as possible of red meats and having sufficient amounts of whole grains and having plenty of healthy fat, vegetable fats and legumes, beans and plant protein and coffee, maybe a little alcohol, polyphenols from berries. All those things are good.

And, you know, reducing sugar-sweetened beverages, those things seem to be beneficial across all of our populations. But as you know, that is an average. That means if I take 300,000 people and look at those that have a lot of sugar-sweetened beverages and bacon and processed meats, they are at higher risk of diabetes and at higher risk of heart disease. Maybe there's some people that are a little less high and some people that are very high risk. And so how do we figure that out? And some of that is, obviously, the work that you're doing is trying to dig a little deeper, know about their genetics, know about the microbes that are in their body that's processing that. So I am excited about that because we are starting to see signals where we know people

are slightly different and how do they respond. What I would really love is not only to see how people would respond, but can I give you something that can change? So if you really like coffee and 40% of the people maybe don't respond and don't get the great benefits of coffee, you can tell those 40% of the people maybe don't respond and don't get the great benefits of coffee, you can tell those 40% not to drink. But what would happen if I had a microbe that I knew that you could take and that microbe would take up residence and say, ah, it's now going to do all the beneficial things for your coffee. So I think it's really both areas. It's understanding the

science of who responds to who, and then saying, what can I do about it? And I would love it if it's not a drug. I would love it not to be like, oh, take this magic, and then saying, what can I do about it? And I would love it if it's not a drug. You know, I would love it not to be like, oh, take this magic pill, and then coffee would be beneficial for it. I would love it if we said, oh, that coffee will be really beneficial for you if you ate more whole grains and fed those bugs so those bugs grew more, and then you would get the benefits from coffee. So that's the passion for me is that I would like to take you, Jonathan, to say here's what you need, here's what you're going to eat, and this is how it's going to change your

overall health. No, I think that's, well, obviously when you're talking about personalization and starting to understand also how this interacts with our micros and things like that is very exciting to me. I'm hopeful that that is sort of the next stage of our discovery. We're working on it. It's an expensive process and there's a lot of data to collect, but we have 40 years of data before this. So we actually have a lot of information we can use to help us understand. And I think it's amazing what you've been able to do with these studies from 40 years ago.

And I think, you know, the big shift of what's possible now, right, is this amazing way you can use digital devices to collect all sorts of things that just weren't possible, obviously, in the past and the ability to start to do a lot of tests on people. As you said, free living, right? Like actually in their homes. Organic free living. In their homes. As we are those of us who are only going to be participants.

You mean at home? All right, okay. You know, because suddenly you get these results which previously were only possible if you went into some like, you know, super duper lab at Harvard or wherever. Then you only could do it in 20 people because you had to come into a lab and two days so i think that's very exciting about the next year eric thank you so much i would like to do a quick summary which we're always doing just please let me know if i get any of this wrong so i think we started off by talking about what is heart disease and you had this brilliant analogy of like you

move into your house in your 20s and it's brand new and the pipes are all fine. And slowly over time, it gets blocked and blocked and blocked. And if that completely blocks, you can have a heart attack. And the same process can end up being one of the reasons that you have a stroke. And this is affected by things slowly over a great period of time that it's a complete myth that women don't die from heart disease. It's actually the number one cause of death for women, which I was really shocked to hear about. And it feels like that comes from a lot of lack of study and assumptions, which we now know are wrong. And this is something that you look at a lot. And to be aware, there might be some difference in the way that women

might report symptoms. And that might also be part of why it's been understudied. You said amazingly that even if you're in your 50s, you can still halve your risk of heart disease if maybe you haven't been making all the best possible lifestyle choices for yourself when you were to make a change, which is, I think, a fantastic story that it's not too late. There's hope, yes. Which really cheers me up when I look at my son who like everything seems effortless. He's like getting bigger every minute. Everything seems a lot harder at this point. And then you talked about what are the things that you can really focus on. And the first thing you said was like stopping smoking if you are smoking. And interestingly, if you have transitioned to vaping as a way to get out of this, it's probably better than smoking. But I mean, you said the data

is not there, but I think you were pretty strong. You felt like this is probably not good. You should be really trying to figure out how you can get off that as well. Definitely. Talked about exercise. And I think the thing that I was particularly struck by is how interested you are, not just in cardio exercise, but stuff that actually ensures that you either are growing your muscles or as you're getting older, maintaining them because it's been this big shift in science saying these these muscles are like active, they're playing this really big role in supporting your health. So stuff that therefore involves some way lifting some weight, some resistance. So I think that was really, I think a surprise for me, for a lot of

people, that your body weight affects your risk. So we know that it's really hard to reduce it, thinking about like, what's your diet and how do you make sure that it's really hard to reduce it, but certainly thinking about what's your diet and how do you make sure that it isn't on that sort of steady increase that you described year after year that puts you at risk. Diet, and clearly this is all the healthy things that we talk about often. And then I think we talked a little bit about sleep, and I think my takeaway was your sleep can have an impact. It's a bit lower probably than these other factors, but it's also a bit less studied than in the past.

So it's possible that you may come back in a few years' time and revise this a little bit. Yeah. Did I get it okay? You did. I mean, I think the challenge is the healthy diet part. And, you know, so many people want to go on a fad, crazy diet because they heard someone talk about something and someone lost three kilograms in a month. And I think we should try to avoid that. We know so much about a healthy diet that the extremes usually only work short term. No. And I think

that obviously at ZOE, we believe in this passionately. And I think one of the things we talk a lot about is the only good diet is one that you can stick with for a long period of time. And it's got to be one where it can't be so extreme that you can never eat things you want. And it's got to be sustainable. And I think best of all, if it can be personalized to you, that also means if it's good for you, it's going to be much more supportive of you. Like it's easy because I think a lot of this is about, you know, can you stick with things? So we are sold there, Eric. Great. Thank you so much.

I thought that was absolutely fascinating. And I hope we can get you back in the future to talk about the new research you're working on. All right, great. Thanks for the conversation. It's a pleasure. Thank you. All right, thanks. Thank you, Eric, for joining me on Zoe's Science and Nutrition today.

We've learned that good nutrition is a powerful way to reduce our risk of heart disease. If you want to understand how to support your body with the best foods for you so you can have many more healthy years to come, then you may want to try Zoe's Personalized Nutrition Program. You can learn more and get 10% off by going to zoe.com slash podcast.

As always, I'm your host, Jonathan Wolfe. Zoe's Science and Nutrition is produced by Yellow Hewings Martin, Richard Willan, and Tilly Fulford. See you next time.