ZOE Science & Nutrition - How to beat heart disease: 8 habits you must fix | Dr. Nour Makarem

Episode Date: August 28, 2025

Heart disease is the world’s biggest killer—and it often strikes without warning. It’s responsible for around 1 in 5 deaths in the US. While these figures are deeply worrying, heart disease is not inevitable.  Decades of research have unearthed many of the risk factors associated with heart health, like poor diet or a sedentary lifestyle. In this episode, Dr. Nour Makarem outlines the latest scientific discoveries in this field and unveils some less-familiar risk factors. Drawing from large-scale population data and the latest wearable tech, she uncovers what makes heart disease so hard to spot, and what we can do today to prevent it.  Nour is a cardiovascular epidemiologist at Columbia University, whose research focuses on how our behaviors—like sleep, stress, and daily rhythms—impact heart disease risk. Her research has helped shape the American Heart Association’s Essential Eight guide to heart health. Unwrap the truth about your food 👉 ⁠Get the ZOE app  🌱 Try our new plant based wholefood supplement - Daily 30+ *Naturally high in copper which contributes to normal energy yielding metabolism and the normal function of the immune system Follow ZOE on Instagram. Timecodes 00:00 What is heart health? 01:50 Can poor sleep make you age faster? 03:25 What is heart disease? 06:01 Why high blood pressure is called the ‘silent killer’ 07:44 Heart disease is the leading cause of death, but it’s highly preventable 08:54 How good lifestyle choices can add an extra decade of healthy life 10:32 Good heart health can make you biologically 6 years younger 12:19 The 6 pillars of good sleep you’ve never heard of 13:54 The shocking sleep habit that can double your risk of heart disease 15:02 How much can your sleep schedule vary before it becomes a risk? 16:19 Why how you feel about your sleep is a key health metric 19:43 The surprising link between not sleeping enough and gaining weight 22:02 Are sleep tracking devices actually helpful? 24:19 It's never too late to improve your heart health, even with bad genes 27:32 The best time to eat breakfast for a healthier heart 32:20 The American Heart Association's 8 essential habits for a healthy heart 33:39 The recommended amount of exercise you need per week 34:17 Is vaping a risk for your heart? 36:30 The growing health crisis almost 40% of people are facing 37:54 Cholesterol isn't the only number that predicts your heart attack risk 39:50 Why sleeping in is also bad for your heart health 40:55 Avoid these stimulants before bed for better quality sleep 42:12 The single most surprising risk factor for your heart 📚Books by our ZOE Scientists The Food For Life Cookbook Every Body Should Know This by Dr Federica Amati Food For Life by Prof. Tim Spector Free resources from ZOE Live Healthier: Top 10 Tips From ZOE Science & Nutrition Gut Guide - For a Healthier Microbiome in Weeks  Mentioned in today's episode Redefining Cardiovascular Health to Include Sleep: Prospective Associations With Cardiovascular Disease in the MESA Sleep Study. Multidimensional Sleep Health Is Associated with Cardiovascular Disease Prevalence and Cardiometabolic Health in US Adults. Variability in Daily Eating Patterns and Eating Jetlag Are Associated With Worsened Cardiometabolic Risk Profiles in the American Heart Association Go Red for Women Strategically Focused Research Network Have feedback or a topic you'd like us to cover? Let us know here. Episode transcripts are available here.

Welcome to Zoe, Science and Nutrition, where world-leading scientists explain how their research can improve your health. Heart disease is still the number one killer globally, responsible for around one in five deaths in the US. While these figures are deeply worrying, heart disease is not inevitable. Science has shown that there are simple, achievable lifestyle changes that you can make now that will significantly reduce your long-term risk. Today, I'm joined by Dr. Nora McCarrum, a cardiovascular epidemiologist at Columbia University, whose research focuses on how lifestyle factors impact heart disease risk.

Her work is helping reshape prevention science and shows that daily rhythms play a surprisingly important role in keeping your heart young. It's not just what you eat, it's when you eat it. She also explains how sleep can be your secret weapon against heart disease. By the end of this episode, you'll understand exactly what you need to do to protect your heart. Noor, thank you so much for joining me today. That's great to be here. Thank you so much for having me. So we always like to kick off the show at Zoe with listener questions, and we have a rapid-fire Q&A, and we have one strict rule.

Okay. It's designed for scientists to be hard. You can say yes or no, or if you have to, a one-sentence answer. Okay. Can poor sleep make you age faster? Yes. Do heart disease risk factors affect men and women in the same way? No.

Does your ethnic background play a part in your risk of heart disease? Yes. Does when you eat impact heart health? Of course, yes. And finally, what's one thing that most people do wrong when trying to look after their heart? People sleep on sleep. People don't prioritize their sleep and don't realize that sleep is in a really important way to prevent heart disease. My grandfather died of a heart attack.

And it's also true, as my family tells me, I'm a bit of a hypochondriac, so I can worry about my health. And so I've definitely had like chest pains in my life and wondered if this is the first sign of a heart attack. And I'm pleased to say, nor it never has been. It's been like indigestion or like some sort of minor muscle, you know, twinge after being at the gym. And despite all of that, I really want to keep my heart healthy. It's definitely something like that I feel is really important. Now, I know you've got a lot of great advice and that the heart health essential eight that you were involved in creating is something that we will definitely get to.

But before we go there, I'd like to sort of provide some context because every time someone talks about heart disease, like I find it quite complicated. So firstly, just that word heart disease. Like I think everyone is like, oh, I'd like to avoid a heart attack, but what is heart disease? Basically, it's the narrowing of the arteries or the vessels in our body that supply blood to our heart, which of course is necessary for pumping blood. to all of our organs so that we can function. And heart disease begins with the narrowing of

those arteries, the decrease or eventually even the abrupt stop to that supply of blood to our heart that can lead us to having a heart attack. And this is a process that happens for a lot of people over multiple decades of life before we get to that bad outcome of having a heart attack or a stroke in the case of the brain. Now, I've also heard doctors often talk to me about high blood pressure. Has that got anything to do with this heart disease you're talking about? Yes. So high blood pressure, or what we call hypertension, is actually the number one cause of heart disease. It's the number one cause of dying from heart disease.

Making sure that our blood pressure stays in the normal range is one of the best things that we can do to prevent developing cardiovascular disease or having a heart attack or a stroke. I'm actually really shocked to hear you say that high blood pressure is the number one cause of heart disease and heart attacks. Would you help me to understand what it is? Yes. Blood pressure refers to the pressure on the walls of those blood vessels when our heart pumps and also when our heart is not pumping. So that's what those measures correspond to. We have an upper reading when we measure our blood pressure, which is the systolic blood pressure.

And then we have the slower reading, which is the diastolic blood pressure. Both of them have been linked to future risk of heart disease and to heart disease outcomes. But generally the measure on the top, the upper reading is the one that I would say, is more strongly related to our future risk of heart disease. And is there a simple way that you can explain to me, I guess, how this high blood pressure and this narrowing of arteries links to the thing I guess we're all scared of, which is a heart attack, which I think of as like my heart stops. I don't study the physiology of high blood pressure.

I study more about how lifestyle affects blood pressure and the preservation of heart health. But in general, you can think of it as a lot of pressure on the inner walls of the vessels. it creates damage, and then that kind of facilitates the development of dysfunction in that wall, the deposition of fat in that wall that eventually accumulates and leads to that blockage before we get to the adverse outcome, which is the heart attack or the stroke. Thank you. That's actually really clear. I've often heard heart disease called the silent killer. Yes. Why is that? Well, blood pressure actually is also what is called the silent killer, because a lot of people go about their daily life, and unless you measure your blood pressure,

there's no way of knowing that you have high blood pressure unless you're regularly monitoring or seeing your physician every year. So in a way, blood pressure is the silent killer because if you're not checking, you might have high blood pressure and eventually develop the heart attack or the stroke. And so I won't just be aware that I have high blood pressure. There's no symptoms of high blood pressure. None at all. No. So that's kind of why for the most part, it doesn't have any kind of overt symptoms. So people can really miss it. And like I said, essentially what you're missing is the number one risk factor of developing a heart attack or a stroke. Well, that's rather terrifying. Yeah. So I guess one of the messages here is that you should be monitoring your blood pressure. Yes, exactly. So that's something

very positive that you can do for your heart is to monitor your blood pressure because if you do fall outside of that normal range or that healthy range, there are steps that you can take, of course, to lower it and to prevent progression into the bad outcome, which is the heart attack or a stroke. Now when I was brought up, I was brought up on the one hand, definitely to think like something like heart disease is like rather scary. But on the other hand, there wasn't really anything you could do. Like your genes pretty much determined what was going to happen. And if it wasn't that, it was sort of like how you're brought up as a child. So once that was done, it was all done. And I think of my dad often was like, oh, you know, as he would eat whatever

he chose to eat, which is not normally probably the healthiest thing. Like none of it matters anymore anyway because at this point, I mean, it was many, many years. It probably would have been 40 when he said that. Is that true? Is this all locked down by the time we're 18? No, I think the interesting thing about heart disease is that so much of heart disease is actually preventable. It's interesting because it's the leading cause of death here in the United States, in the UK, and just generally globally. But it's the chronic disease, I would say, that is very much preventable. actually here in the United States, there's estimates that if all Americans had good heart health, we can prevent 2 million cardiovascular disease outcomes in the United States, which is huge,

if you think about it. So it's absolutely false that if you have a family history of heart disease or you have a genetic predisposition, that there are no steps that you can take to prevent having a heart attack or a stroke. And if I follow all the lifestyle advice, I know you're going to take us through this podcast, can I reduce my risk of heart disease a lot? Are we just talking about like a few percentage points? No, you can reduce your risk of cardiovascular disease a lot. Studies generally show that people who take those steps that we're going to talk about

and end up having high heart health can cut their risk of having a heart attack or a stroke by more than half. Having good heart health, A, it can lower your risk of developing a heart attack or a stroke. B, it can extend the years of your life. You live healthy. so the years of your life, you live without chronic disease, including cardiovascular disease. There are some studies that show estimates that you can essentially add 10 years to your life that you live healthy without chronic disease. So having high heart health and making those lifestyle changes can give you

an extra decade of life. One of the things the team was telling me about your research is that it's about biological aging and the link to heart health. And it sounds like there's some link between that maybe and what you were just describing to me. Can you tell us about that? This is actually a newer area of my research program that I am exploring, which is kind of the link between heart health, biological aging, mortality, or the risk of developing a heart attack or a stroke, what you're saying is correct. We find that in general individuals who have a healthy lifestyle and therefore high heart health tend to age at a slower rate than individuals who have low heart health or who live an unhealthy lifestyle. And of course, biological aging is kind of a mechanism or a pathway

way that links our lifestyle to our risk of developing the bad outcome of a heart attack or a stroke. So when we slow down our body's aging process, we probably also are slowing down or lowering our risk of developing a heart attack or stroke. You know, there's been different studies by different teams that have really explored this question and showing, you know, obviously different estimates in terms of how much or by how many years you reduce your biological aging. But I've seen anywhere, you know, in the work that we've done, people who have high heart health tend to be six to eight years younger biologically than individuals who have low heart health. And Noor, when you say like their biological age or they're five to six years younger,

could you help me to understand what that means? It doesn't mean like literally their birth date has changed. No, it means that your body's age or your physiologic age is lower than your chronologic age. So let's say that you are 40 years old. You live a very healthy lifestyle and you have high heart health biologically or physiologically your body on the inside resembles more a 34-year-old even though your chronologic age or the age, you know, based on the year that you were born, is 40. You described it as on the inside. So this isn't like about sort of my appearance on the outside. It's about...

So aging manifests in many ways. There's physical attributes to aging. So it could manifest on the outside in terms of how you look. You could look younger. But it also refers to the physiology inside your body that predisposes you to developing various diseases. So when you are physiologically younger, you're less likely to develop a chronic disease essentially. So it's something all of us want. That's exactly it, yes. Well, I feel like you've painted first this terrifying picture that we might all be walking around with the silent killer

inside us, but then saying actually there's a lot that we can do to reduce that risk. Before we go into the advice, I'd like to discuss some more about areas of your research, because I know you've run some really interesting studies, particularly around sleep and circadian rhythms. I'd love for you to tell us about them and definitely to make sure we explain what circadian rhythms are as you do so. Sleep and circadian rhythms, those are two things that are very much intertwined and related, but they're also distinct. So let me start with sleep.

So my work on sleep is focused more on what we call sleep health, which is kind of recognizing that sleep health is not just the absence of sleep disorders. A lot of people, when they think about sleep, they think about insomnia symptoms, which is difficulty falling asleep or staying asleep, or having sleep apnea, which is, you know, related to breathing during sleep and snoring. But sleep health is a distinct concept from having those sleep disorders. It refers to more adopting positive, achievable sleep habits that can help us to optimize our health and that promote what we call healthy longevity, so having a long healthy life.

there's been many kind of ways to define this concept of sleep health, but right now I would say one of the most widely accepted ways or definitions of sleep health is a construct that is based on six things. So the first thing is sleep duration or how much we sleep every night. And I would say that this is the most well-studied aspect of our sleep health. The second one I would say is sleep regularity. And this is something that people don't think about very much, but this refers to essentially how consistent are your sleep and wake time every day? Do you tend to go to bed at the same time each day and do you tend to wake up at the same time each day? And in general, what studies show is that people who have regular sleep schedules, so who tend to go to bed and wake up at a similar

time each day, those individuals tend to be at a much lower risk of heart disease and a number of other chronic conditions. And studies are showing that people who have these irregular sleep patterns have double the risk of heart disease. It's very similar to what we see for things like established risk factors for heart disease like diabetes and smoking and obesity. So it's kind of this new risk factor that's emerged and we're seeing that, wow, it really can substantially increase someone's risk of developing heart disease. There's a lot of studies now that show that even individuals who get enough sleep every night, if their sleep is irregular, they're still at higher risk of developing hypertension and, you know, cardiometabolic diseases. So that was slightly

terrifying. You're saying this is potentially as bad as smoking to have this really inconsistent sleep and wait time. Just one question before we move on. How perfectly do you need to go to bed at 10 p.m. every night in order for this to count as regularity versus what you're describing as irregular and this massive risk factor. People always ask that because no one can go to bed and wake up at exactly the same time every day, right? So I always say to people as long as you your sleep timing is not varying by more than 30 minutes to an hour each day. You should be okay. That's the practical advice that I would give. We start to see this substantial increase in risk for people whose sleep timing varies by an hour and a half, two hours, more than that each day. That's when

you really start to see this kind of doubling in the risk of cardiovascular disease. So as long as you stick to this like 30 minute to an hour window, you can lower your risk. Point number three of sleep health. Point number three is the timing of sleep when we sleep. We think that going to bed earlier is linked to lower risk of heart disease. Generally, if the midpoint of your sleep is earlier than 4 a.m., that's considered to be protective. But I would say that this aspect is a little bit less studied than the other aspects when it comes to sleep health. The fourth point is sleep satisfaction. So this is just like the subjective experience of feeling like your sleep is restorative and feeling rested when you

wake up. I know it sounds like a very subjective thing, you know, but it's actually been something that has been linked to heart disease, even over and beyond things that we can measure objectively, like how much someone sleeps. I'm not totally surprised to hear that because I think one of the things that's been really interesting that Zoe working with the scientists here looking at impacts of nutrition is that they all started very skeptical about self-reported impacts around energy and mood. And what's interesting is that as we scaled up the study, They've started to say, oh, no, we're completely convinced because these correlations are incredibly strong and these reports about mood or this is really real. But historically, they said they were sort of brought up that if you can't measure it, you know, with a blood test preferably, it's sort of not real science.

And like something self-reported about how you feel, that's sort of not the thing that's done as a scientist. I don't know if any of that is true also in heart health. Yeah, no, it's true. And I think, you know, it really underscores how much sleep is a sign of well-being, really. You're not always able to capture that from a biomarker or blood test. You know, that's something that extends beyond that. In a way, how well we sleep can be a marker of how stressed we are in our life. Two more.

Sleep efficiency, which is related to what we were just talking about. And this really refers to the amount of time in bed we are actually sleeping. and of course having a higher sleep efficiency is a good thing. And the final one that is also related to all the metrics that I just discussed is daytime alertness. It doesn't seem like it's, you know, an aspect of sleep health because it's not referring to you when you're sleeping. But daytime alertness or daytime sleepiness is the opposite one is also a marker of sleep health

because obviously someone who is experiencing excessive daytime sleepiness who is dozing off, you know, on the subway or at work, that's a marker of sleep that is not restorative and poor sleep health. And so when you look at all of these things together, you get like a sort of quantification of somebody's quality of their sleep? We look at them together because it's a way for us, first of all, to acknowledge that sleep is multidimensional. So it's not just one thing. It's not just how much we sleep. But also it allows us to measure kind of the gradient of healthy sleep. And when we look at them together, we find stronger associations with a number of chronic diseases. So in one study that we did,

we looked at those individual metrics separately, and there were many of them, you know, were linked to chronic diseases like heart disease and diabetes and obesity and hypertension, et cetera. But when we look at them together, we find much more strong, consistent associations with all of those chronic disease outcomes. So what that tells us is basically that the whole is greater than the sum of its parts, that when you improve your sleep as a whole, the health benefits are just going to be much more pronounced. And Nora, you just mentioned, as well as sleep, a whole bunch of other factors. And I think I heard you say, along with things like diabetes, did I hear you talk about obesity

as well? Mm-hmm. So the quality of your sleep is actually related to putting on weight? Yes. All of the aspects of sleep that I just discussed actually have been linked to risk of obesity. There's very strong, robust associations between not. getting enough sleep and weight gain. You know, there's many explanations for this. An obvious explanation is when you spend more time awake, you're more likely to eat and therefore you're more

likely to have a higher caloric intake. There's been studies, you know, linking, restricting your sleep to, you know, your energy expenditure, even how much energy your body uses. It doesn't really compensate for the amount of time you're awake and the amount of calories that you're bringing in. So you're more likely to end up in a net positive with your calories and that can promote weight gain over time and increase your obesity risk. And what you're saying when I pull all this together is it's not as simple as just when you went to bed, like gone on into the bed and when you left. It's actually like these six things you put together give you this much more complete

picture of the quality of your sleep. I mean, I think the best way to think about it is to compare it to diet, right? When we think about our diet, do we just think about one thing? You know, do we think about, oh, I'm just going to pay attention to how much sugar I put in my tea? No, you think about your diet as a whole, right? You think about, you know, am I eating clean proteins? Am I avoiding, you know, processed foods? am I paying attention to my salt intake? And similarly, when you think about your sleep,

you can't just think about one aspect of your sleep. You also have to have this kind of holistic framing of how you think about your sleep health. And that's kind of how the field of sleep research has shifted. Very similarly to how the field of nutrition shifted. You know, if you look up the old studies on diet, it used to be like, you know, how do whole grains impact this? Or how does olive oil impact that? But now when we study diet, we look at dietary patterns as a whole. We look at a Mediterranean-style diet. We look at other types of plant-based diets. So now our thinking on sleep has shifted as well. We think about it more kind of like as a sleep pattern as a whole, not just about one metric. Fascinating. I'm thinking for a second now about like the sort of devices

that we get to measure sleep. And there's lots of them. Do they capture in general this overall sleep health that you're describing? Or are they really just in this old world of like, sleep duration as the way that they're giving you feedback? So different devices measure different things, right? But I think that self-monitoring, so like those wristwatches, the different types of trackers that people use, this is a very good way actually to pay attention to your sleep or to keep track of how well you're sleeping. If you're, you know, looking at your sleep watch and you're seeing that you're sleeping five to six hours every night, maybe it's time to pay attention and to find ways to get more sleep to get to that optimal sleep duration that you need every night. Self-monitoring

and keeping a sleep diary, for example, are really good ways to keep track of your sleep health, but you also have to pay attention to what your body is saying. It's funny. You're getting to the habit of checking in the morning whether or not you slept well, even though the truth is you already know. For example, I tend to do it particularly when I've slept badly and I want the justification of like the quantification that I feel bad because I know I slept badly. I went to bed too late, which I now realize is very bad for my heart. Got up too early because I had too many things to do. That's really interesting. A lot of people say what you just said to me, which is essentially that I don't think I have good sleep health because I'm just thinking of this past week

and I had to wake up super early and go to bed late and I'm not getting enough sleep. And so my sleep is bad. Any improvement in your sleep during your life is going to have a benefit on your risk for developing heart disease. There was a large study that was done that was published in the past couple of years that I thought was fascinating. They measured people's sleep health over several years and they kind of looked at people who had consistently good sleep during their life, people who had consistently bad sleep in their life, people who had good sleep and then went to bad sleep and people who had the opposite, bad sleep and then their sleep improved in their life. And the fascinating thing that they found is that all of the groups compared to the group that had consistently unfavorable sleep

had lower risk of heart disease. So this tells you that even if you pass through phases in your life where you can't have good sleep because of external circumstances or because of work or stress or, you know, something bad happened in your life where, you know, you're not feeling well anymore and you're not able to get good sleep. Working towards having good sleep for, even if it's, if you can't always do it, will still have some benefit, will still carry some benefit. And this benefit is there regardless of genetic predisposition to heart disease. So that was another fascinating thing that they found is that if you improve your sleep, regardless of your genetic profile, you will still have a lower risk of heart disease. So even if I've been

speaking really badly for 55 years and now I go and improve my sleep, that can make a difference to my heart health? That can still make a difference. It's never too late. One thing that we always find in this lifestyle research, whether it's diet or sleep, is that we always find kind of a dose response association. So the more you do, the greater the health benefits. I really always like to reiterate this point because I do think that when it comes to living a healthy lifestyle, people get overwhelmed sometimes, people think, oh, I can't have this perfect diet. I can't have perfect sleep. And that makes sense. We all pass through transitions, life stages, life events that make it hard sometimes to do all those things consistently. So the important thing to remember is

always that progress is better than perfect. Any step, any improvements that you can make will have benefits. And the same applies to sleep. I would love to switch now to this other research you talked about before about circadian rhythms? So just like we talked about sleep health, there's this kind of very related concept, which is called circadian health. And as it relates to the work that I do, it's kind of thinking about how we can align our lifestyle behaviors with our innate circadian rhythms, which are essentially the innate rhythms in our physiology and metabolism that are regulated by the internal clocks in our body. And so there are many things that influence circadian health that are environmental factors. Obviously, light is a big one since,

you know, the master clock in our brain that regulates our circadian rhythm is kind of regulated by light. But when it comes to lifestyle, it's also kind of being mindful of the timing and regularity of our behaviors. Let me start, first of all, with our 24-hour behavioral cycle, which consists of our physical activity and our sleep, right? When we think about the 24-hour period, we're either asleep or we're in the daytime engaging in some form of physical activity or sedentary behavior. So what that line of research has shown is that individuals whose overall 24 hour rhythm is characterized by greater day-to-day regularity in those sleep-wake patterns and even in the physical activity patterns, people who have a restful sleep period and who have

greater wake time activity, if you're taken together, this can kind of lead to a more robust circadian rhythm and can lead to, again, this lower risk of various chronic diseases. This is when it comes to our physical activity and our sleep. Now, in parallel to this, of course, there's the timing of our food intake. And food is a really kind of powerful signal because the timing of our food intake essentially regulates the clocks in our various organs, which are involved in metabolism. So when we eat at what we call conventional circadian times, and I'll have to jump back to say what that is, you know, we can have better health.

I do want to note, though, that a lot of this research on when we eat is kind of relative to clock time. So there's a whole line of research, including my own, where we look at the timing of food intake and how it relates to health. And generally what we see is that individuals who eat breakfast early tend to have better cardiometabolic health, so lower blood pressure, lower blood sugar, lower risks of obesity, and collectively this leads to a lower risk of developing heart attacks and strokes. Similarly, individuals who tend to eat less at dinner time or who avoid late night eating also tend to have lower risk of all these chronic conditions. And then there was one study that we did, which was one of the earliest studies on this,

where we show that also just like I talked about sleep regularity, so going to bed and waking up at the same time each day, we found that people who had consistent eating timing patterns day to day also had lower blood pressure, waist size, lower body weight, and lower blood sugar. So what this tells us is that people who also have consistent timing of their eating occasions may potentially also have a lower risk of chronic disease and better health. But I like to say this with caution for two reasons. First, because kind of the science on this is, I would say, less developed than the science on sleep.

And the second thing is that a lot of this research, particularly on the timing of food intake, is kind of about the timing of food intake relative to clock time. But we need also studies that kind of relate the timing of food intake to circadian timing, which is what your body considers to be late night eating or, you know, early morning eating. And there is much less research on that just because we have not found a way to very easily measure circadian timing of food intake in a population study. There's like no easy test to do that. If I understand rightly what you're saying is this sort of 24-hour clock,

This circadian rhythm seems to be really important also for potentially our risk of heart disease. Yes. And this is now not just when we sleep, but you're saying there's also this rhythm about when we exercise, when we eat. There's also like a rhythm, like our regular pattern of the body. So today, you're eating patterns in New York are maybe different than your eating patterns over the weekend. If you were in London, for example, based on the studies that we have so far, this inconsistency in eating timing may be predisposing you to heart disease. There's two distinct things here. There's when you eat and is when you eat consistent day to day.

The first question, which is when you eat, a lot of the work on that has been when you eat relative to clock time. So when do you eat breakfast? When do you eat dinner? And generally, what the science shows so far is that people who have earlier eating patterns, so people who have an earlier breakfast, who eat dinner earlier, who don't eat a lot of their calories late at night, tend to have better heart health and tend to be at lower risk of cardiovascular disease. Now, the issue with this is this is relative to clock time. Our individual circadian rhythms, to your point, vary from person to person.

So something that is considered, maybe considered late eating for me, may not be late eating for you. We're not there yet in terms of the science to know, like, what those personalized recommendations should look like. The other issue, which is separate but related, is how consistent is our eating timing day to day? Do we eat breakfast and dinner and lunch within the same time frame every day or no? and there is also, again, very early stages, but there is some evidence pointing to the fact that this may be similar to what we see for sleep, where if your eating timing is inconsistent day to day, it may be predisposing you to heart disease because we're seeing that there's associations with higher blood sugar, higher blood pressure, higher body weight for individuals who have inconsistent eating timing patterns. So overall, if your schedules are consistent, your sleep wake patterns are similar day to day, and also your physical activity patterns are similar day to day. That should be associated with more rhythmicity and therefore better health. With that being said, we consistently find that greater activity when your physical activity when you're awake is always protective. I feel like I have to say this because I don't want to be sending the message that if I work out one day at 2 p.m.

And then the next day I can only work out at 4 p.m. Then maybe I shouldn't do it because it's not consistent. No, it's always better to exercise greater activity, better health outcomes. With one in five deaths caused by heart disease, it's no wonder people are worried. If you know someone who could benefit from the tips and advice we've provided today, please share this episode with them right now. They'll thank you for it in the long run. We've learned that sleep is incredibly important for a good heart health,

so is like trying to live within these like daily circadian rhythms. I'd love now to put that into context with sort of your overall, advice to someone on how to reduce the risk of a heart attack, how to ensure that our heart is healthy. And I understand that you've been part of a group that's come up with the American Heart Association's new advice, which I understand is called Life's Essential 8. The Life's Essential 8 essentially is a way for us to think about heart health, recognizing that heart health is not just the absence of heart disease. It's a much more broad and positive construct. And the best way to characterize it in a way that is, I guess, easily measurable

is to think about these eight health factors and eight health behaviors that are in the life's essential eight. And the reason that we focus on these eight is, A, they've been very strongly linked to heart disease risk, but B, they're all modifiable. And that's a really key point here, is that they're all things that we can modify to lower our risk of developing heart disease. So the eight factors are, I'll start with maybe the health behaviors. The first one is, of course, to eat better. So eating a healthier diet. There are many healthy diets that are recommended as part of this, I guess, recommendation. There's the Mediterranean style eating pattern, which I'm sure you're familiar with. We have the dietary approaches to stop

hypertension, the dash diet, which is actually very, they're all overlapping in that they all emphasize plant-based foods. So fruits, vegetables, legumes, whole grains, lean proteins, fish, healthy oils, limiting processed foods and sugar, and sodium, of course. The second one is staying physically active. So again, physical activity. So it's 150 minutes per week, so two and a half hours approximately of moderate to vigorous physical activity. If someone is doing vigorous physical activity, it's like 75 minutes is the recommendation.

For context, moderate physical activity is, for example, brisk walking or dancing, whereas vigorous is more something like running and swimming. The third one is, of course, not smoking or avoiding nicotine. I should say now, not just not smoking cigarettes, but also this refers to vaping and also secondhand smoking. So just avoiding all of that altogether. And is vaping a risk for heart health? Yes.

So the literature on that is obviously not as extensive as cigarette smoking, just because vaping is a newer phenomenon, I should say. But in general, the recommendation is not just for cigarette, and cigars and pipes, it's also for vaping products as well. The fourth one, my favorite one, is the sleep health one. And this is the newest metric that was added. And then the other four are all health factors. So like we talked about, managing your blood pressure. So keeping your systolic and diastolic blood pressure under 120 over 80. These are set up that the health behaviors kind of inform the health factors. So to improve the health factors, you have to address

the health behaviors. So if I did the things like eating better and getting more sleep, I can reduce my blood pressure? Yes, exactly. Got it. Of course, if someone is already in the hypertension category, there's also obviously medication use. And the way that kind of you get scored on those metrics considers that as well. Can medication significantly reduce your risks of heart attacks as a result of the blood pressure? Yes, of course. So having blood pressure that is well managed by medications definitely lowers. So if you're listening to this and you're not been really good about taking your blood pressure medication? Yes, you should. If someone has hypertension, yes, then they have to see their physician and potentially get pharmaceutical

treatments for it as well beyond just the lifestyle piece. And then the same thing applies for managing blood cholesterol, blood glucose. And of course, the final one is body weight status, which they measure by BMI, so keeping a healthy body weight. And so those last ones, if I play back, you said blood sugar, blood pressure, but cholesterol and weight, so that those last three, these are again measures that if I see the doctor, they'll judge. So very high blood sugar is diabetes. Yes. And with blood sugar too, we have to pay attention to pre-diabetes. You know, with blood sugar, you can either typically measure your A1C, which is more of a measure of your kind of of your longer term blood sugar control over the past three months. Or you can get measure your

fasting blood sugar, as many of us do in a routine blood test. You want your fasting sugar to be less than 100, your A1C to be less than 5.7. But we also have to pay attention to pre-diabetes. It's essentially a fasting blood glucose between 100 and 1205. So it's the state that's in between having normal blood sugar, but also you're not in the diabetes range yet. The reason we have to pay attention to this is because it's become increasingly prevalent. Here in the U.S., you know, the prevalence of pre-diabetes has become very high. It's almost 38%, 40%, very high. And more than half, of those individuals, it will eventually progress to type 2 diabetes. So a very important high-risk state to intervene at, to kind of reverse those trends to avoid progressing to type 2 diabetes.

And this is related to your diet again? With pre-diabetes, oftentimes, yes, the first thing to do would be a lifestyle change, yes. So diet, sleep, physical activity. And then you mentioned high cholesterol and weight. These are similarly factors driven a lot by what you eat. Yes. For cholesterol, We look at non-HDL cholesterol for a lot of individuals that is, of course, influenced by what we eat. It's influenced by our body weight, physical activity levels. And just one question, Nora, I feel that for a lot of people I know, when they think about their heart health, the cholesterol number is the number that they think about as their heart attack risk. And I can think of a number of people like that.

Are they right to feel like that is the direct measure and like the one number that really matters for their heart health? number that really, really matters, but it's not the only number that matters. Let's say someone has normal blood cholesterol. If you have normal blood cholesterol, but you have hypertension, you really have to pay attention to your risk of heart disease because, again, like I said, hypertension is the leading risk factor for heart disease. But there's always a debate, I feel, between scientists who study cholesterol and scientists who study blood pressure about what is more important. And both of them are extremely important, of course, but quantitatively at the population level, the risk factor that leads to the most heart attacks and strokes is blood pressure. So you can't look at your

cholesterol without looking for your blood pressure. In the U.S., we've seen a doubling in the number of people who now have both diabetes and blood pressure. The take-home message from this is that if someone has high blood sugar, they should check their blood pressure to see if that's high too. And similarly, if they have high blood pressure, check your blood sugar, check all of them. because we're seeing an increasingly like clustering of those risk factors together. I would love to conclude by going back to the sleep health that we talked about earlier. You've talked a lot about sleep regularity, which I think to me sounds really is very new. And you said it's really important.

You know, you said that I can like double my risk of heart disease if my sleep regularity is really bad. What should I be doing in order to try and make my sleep regularity? good. Thinking about your sleep health holistically. So not just thinking about one aspect of your sleep, thinking about all of the aspects and trying to make them to optimize all of them. The easiest thing to get enough sleep and to make sure that your sleep is regular is to have a regular fixed sleep schedule. So making sure that you try to go to bed and wake up at a similar time each day and making sure that that schedule ensures that you get the seven to eight hours of sleep at night because that's what the recommendations are, but not more than nine, because both

short sleep and long sleep have been linked to higher risk of heart disease. So for every hour of sleep less than the recommended seven to eight hours, you increase your risk of heart disease by 6%. That's an estimate. And then for every hour beyond the recommended seven to eight hours, so more, you have a 12% higher risk of cardiovascular disease. The second thing I would say is practicing good sleep hygiene, which refers to kind of the sleep environment and the habits that you can practice to put yourself in the best position to sleep well every night. I always say that good sleep starts in the day. It's not just at night. So in the daytime, making sure that you get plenty of sunshine, making sure that you're physically active in the daytime, that's all been linked

to better sleep health at night, making sure that you don't nap too much in the daytime because that can also disrupt your sleep. So if you do have a nap, make sure it's only 20 to 30 minutes. make sure it's earlier in the day. So before 3 p.m., ideally it would be midday, so in the midpoint of when you wake up and when you go to bed. Of course, avoiding stimulants before bedtime. So this includes nicotine and caffeine. The caffeine, you know, it's good to keep that just to the morning because if you drink coffee, let's say at noon, you still have caffeine in your system at midnight. Smoking similarly, I mean, you shouldn't smoke, but if you do smoke, try not to smoke within the two hours before bedtime. And similarly, alcohol to alcohol, actually, people think that it helps them sleep

and it's true. It can help you fall asleep, but it impacts the quality of your sleep if you drink before bedtime. So again, trying to not drink very close to bedtime within two hours at least can help to make sure that the alcohol intake doesn't impact your sleep quality. One of the things I definitely noticed as I've got older is all of the things you mentioned affect me much more than when I was 20. So now I can't drink something. I cut myself. I'm on tea rather than coffee. I cut myself off by 4 p.m. Because it just, before I be like, I could definitely have a cup of tea before I went to bed. Alcohol, I could drink a few glasses. It wouldn't affect me now. It's really tragic. But like one

glass of wine and I really feel it through my sleep. So I definitely, I'm more sensitive. Yeah, it can make your sleep more fragmented. So it affects the sleep quality in that sense. Thank you so much, Nora. I would have to do a quick summary. Please correct me if I've got any of this wrong. So the first thing that brings to mind is this idea of sleep regularity, that you should be trying to go to bed at the same time every night. And rather stunningly, if you are going more than like one and a half or two hours outside of that, you can double your risk of heart disease. So it's an immense increase in this risk. On the other hand, you said, well, if you can keep it within 30 minutes, you're fine. I have to admit, I don't know about everybody else, but there's no way I currently keep it within 30 minutes.

I think about all the devices in my life and Netflix, and it's the weekend, so I want to stay up. So it's really interesting, like much tighter, much bigger focus on that than I was expecting. You also talked about how important sleep duration is for heart health. And there, I think the advice was less surprising, sort of seven to eight hours. But again, what was surprising is how important that was for my heart health. That's not, you know, just about feeling good and all the rest of it. I think overall I was struck that the lifestyle that I change can have such a big impact. I think you said I could cut in half my risk of heart disease.

I could get an extra decade of healthy years if I went from, you know, sort of poor habits around heart health to like really good ones. There were a number of other factors around sleep. And so sleep is a lot more complicated than just when you go to bed and when you wake up. And a lot of those other factors seem were affected by what I'm doing during the day. So you were saying, like, if I have better sleep hygiene, a lot of that is what I'm doing, you know, during the day, not napping, like, managing my devices or the rest of it. So sleep is really important. So is living in line with, like, my own rhythms.

You're talking about the circadian rhythm. So it's not really like a clock time. It's like having this regular pattern. So it's all right to go to bed at 9 p.m. or 11 p.m. If you've got the right circadian rhythm and you're getting the right hours of sleep. sleep. It's not like everyone in the whole world has to go to bed at 9.05. And then you took us through this life's essential AIDS, and we'll put a link in the show notes to that. Interesting, you started with food, which is always science and nutrition. So I love that that is the number one thing

that we're talking about for heart health. And the advice about eating better, I think, is very much what we talk about all the time. Well, people, I will say this too, that I don't think I mentioned, is that eating those diets that we talked about, the Mediterranean-style diets and the plant-based diets tends to promote higher sleep quality at night. So actually eating better too is another in the daytime is a strategy to have restorative sleep at night. And that's what the science says. I love that.

The second one, not surprising, was about staying active, doing more exercise. And I think, again, we've had many podcasts talking about all the different ways that it helps you. But it's really interesting that it's like helping your heart, as well as your bone health, as well as your brain health. Like, it's clear that the food we eat and the exercise just seems to come up over and over again.

smoking, and I guess that's how I first thought about smoking and heart disease, so that makes sense. Vapes apparently are not a way to escape from this. Sleep we've talked about, and then you have these things about managing, like the outcomes, like managing your blood pressure as the number one risk. So if you haven't had it measured, you should get it measured. Managing your blood sugar, that's really important and very effective by your diet. Being aware of where your cholesterol is, managing it, but it's not the only thing that determines your risk of heart disease. No, never think that cholesterol is the only marker of your risk of heart disease, always also measure blood sugar and blood pressure and your body weight.

And I was going to say, last but not least, managing your weight, that having a BMI that was too high, having, you know, living with obesity or overweight, is also a significant risk. And again, these things like all wrap in together. But I think to finish up, the good news that I'm taking away is, If you make these lifestyle changes that overlap with many other things, you sort of profoundly reduce your risks here and you can, you said, also live for many more years. You live longer and you live healthier.

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