Sixty thousand miles long. That’s the length of the tube system inside us that transports blood, oxygen, and nutrients to the cells throughout our bodies.
If these tubes fail, the result can be fatal. In some cases, it’s a heart attack. In others, it’s a stroke, when the blood supply to the brain is disrupted and brain cells are damaged or killed.
Heart attacks and strokes are a major cause of death in developed countries — but we can take action to reduce the risks.
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In this episode, Jonathan talks with a world-renowned physician, scientist, and speaker to gain insights into how looking after this magical pipework could slow aging.
Dr. William Li is a leading specialist in blood vessels and preventive health, and the author of countless papers on the topic. He possesses a gift for communicating about this complex subject in terms we can all understand.
If you want to uncover the right foods for your body, head to joinZOE.com/podcast and get 10% off your personalized nutrition program.
This podcast was produced by Fascinate Productions.
[00:00:00] Jonathan Wolf: Welcome to ZOE Science & Nutrition, where world-leading scientists explain how their research can improve your health.
Inside every one of us, there's an immensely complex system of tubes that transports blood oxygen and nutrients to the cells in our body.
This system is 60,000 miles long. That's enough tubes to stretch three times around the world. If these tubes fail, the result can be fatal. In some cases, it's a heart attack in others it's a stroke, where the blood supply to the brain is disrupted and brain cells are damaged or killed. Together heart attacks and strokes are a major cause of death in developed countries.
High blood pressure can ultimately cause your blood vessels to burst or become blocked. For this reason, the condition has earned an ominous nickname, the silent killer, and it affects one in four adults, but there's good news. We can take action to reduce the risks.
In this episode, you'll learn how to keep your heart and blood vessels in good condition. You'll also get a unique insight into how looking after this magical pipe work really could slow down aging. My guest is Dr. William Li, a world-leading specialist in blood vessels and preventative health and the author of countless papers on the subject.
Luckily for us, Will has a gift for communicating this complex subject in terms we can all understand.
Dr. William Li, thank you for joining me today. Why don't we start as always with our quick-fire round of questions from our listeners? And the first question I have is can food improve the flow of blood to your heart?
[00:02:00] Dr. William Li: Yes.
[00:02:02] Jonathan Wolf: Can you reverse existing damage to your blood vessels with food?
[00:02:06] Dr. William Li: Yes.
[00:02:08] Jonathan Wolf: Amazing. Can you reduce cholesterol without statins?
[00:02:12] Dr. William Li: Absolutely. Yes.
[00:02:15] Jonathan Wolf: All the yeses today. Is there a link between the health of our blood vessels and dementia?
[00:02:20] Dr. William Li: Yes.
[00:02:22] Jonathan Wolf: And finally, are there foods that can slow down aging?
[00:02:26] Dr. William Li: Yes, absolutely.
[00:02:28] Jonathan Wolf: All right. Well, I should just have somewhere you're gonna say no, but I think that's a great, great start. And I think our listeners are already like, oh, okay. I'm really surprised by some of this. What myth around eating for a healthy heart most annoys you?
[00:02:41] Dr. William Li: You know, as somebody who studies blood vessels and circulation, which is what the heart is all about, the thing that really irritates me is when people think that just simply working out, whether it's jogging, going to the gym, lifting that that'll actually guarantee that you're gonna be heart healthy. In fact, that's only a bit of the solution.
[00:03:03] Jonathan Wolf: Oh, that's fascinating. All right. We're definitely gonna talk some more about that.
Will, what are your three tips for living longer?
[00:03:10] Dr. William Li: Three tips. Number one, get good quality sleep. I'm a doctor. I went through training. I was deprived of sleep for years, which subtracts years off of your life. So get some good rest. Second, eat healthily. And what that means is gonna be different for every individual. But bottom line is that listen to your body because your body knows what actually is not so good for you when you feel bad. And there's a huge literature on studying what's actually good for you. Mostly plant-based foods. And we can talk more about that. And then the third thing really is to stay physically active.
That doesn't mean you have to jog, swim, or run a marathon. What it means is that you have to actually move.
[00:04:02] Jonathan Wolf: Brilliant. And I think everybody here knows that their heart is really important, right?
Anyone in the last a hundred years has been told about that. I think most of us and I'm included have never really thought about our blood vessels. And I know that blood vessels have been the center of your research. Can you start maybe by explaining why our blood vessels matter?
[00:04:21] Dr. William Li: Yeah. Well, you know, I'm a physician, I'm a scientist, I'm a vascular biologist, which means I study blood vessels and the cardiovascular system. And here's a little fact that most people don't know, first of all when it comes to your heart, which is about the size of your fist, that's the best kind of surrogate measure of what it looks like in your chest. This heart, this beating muscle is connected to 60,000 miles of blood vessels.
That course throughout your body.
[00:04:48] Jonathan Wolf: 60,000 miles!
[00:04:51] Dr. William Li: 60,000 miles. Now, if you were to pull out all the blood vessels in your body and line them up end to end, you'd form a thread that would wrap around the Earth twice. Now you can imagine how important blood vessels are when they're connected to the heart this way, because your heart, every beat, every pump, jets out blood through these highways and byways that bring the blood, the nourishment, the oxygen you breathe all the growth factors to every cell in every organ of your body.
[00:05:21] Jonathan Wolf: I've suddenly discovered that there are 60,000 miles of a blood vessel inside me, which is amazing wraps around the earth twice. Not something to try at home, I guess. How does it link then from these blood vessels to actually impacting, you know, our heart health, which I think is the thing we think about what's going on, and how does that link?
[00:05:39] Dr. William Li: Yeah. Well, you know, I'm sort of trying to give people a view that they may not have thought about, right?
Because most people think of the heart, you go jogging, you hear the lub-dub and the soundtrack of your heart beating, but here's something most people don't know. Is that when we were all in our mother's womb forming one of the first organs that we formed, it isn't your brain, isn't your liver, isn't your bones.
It's actually your heart and your circulatory system. And they all form pretty much at the same time. And they form with these things called stem cells. So imagine just dropping a group of marbles on the ground and they randomly kind of fall on the carpet. They roll around and they don't look like anything.
Those are your stem cells that say, day five day, seven after conception, when dad sperm met mom's egg over the course of the next weeks, those marbles coalesce together, and they begin to organize themselves to form these channels. They call them first lakes, blood lakes before they form tributaries before they form streams.
And that's basically at the end of the day, they're left with one additional area, which is the heart, which is special because it actually has muscles, special muscles that will actually pump, and its own electrical system. And so basically when you think about how your heart and your blood vessels are actually connected together, they were formed together at the very beginning.
All right. So what happens to your heart will impact your blood vessels, your circulation, and therefore your organs, and what happens to your blood vessels actually impacts the heart as well. So if you have very stiff blood vessels, now blood vessels are actually very elastic, so basically when your heart pumps, they will stretch to accommodate the blood.
Because the normal capillary, the smallest blood vessel at the very, like, just getting into your organs to feed your cells, that's the thinness of a human hair. That's a human capillary. Now to jet blood through that, in fact, the diameter of that blood vessel is smaller than a single blood cell. So even for a healthy blood cell to get through that end channel, it has to stretch to allow things through.
[00:07:51] Jonathan Wolf: Oh, wow. So everything I think about this, like these tiny little elastic things...
[00:07:55] Dr. William Li: Yeah.
[00:07:55] Jonathan Wolf: That is opening and closing to squeeze through like literally my blood cells...
[00:07:59] Dr. William Li: That's right.
[00:07:59] Jonathan Wolf: And without my blood cells, my organs are in trouble. Is that right?
[00:08:03] Dr. William Li: Without your blood cells pumping through delivering that oxygen, carrying oxygen-rich red blood cells, very quickly and I'm talking about within seconds, your organs start feeling starved. Think about getting choked. You can't breathe, alright? And then soon it turns blue just like you would be blue in the face. And shortly after that, your organs stop functioning properly. And when they actually stop functioning properly, they start to malfunction. The ultimate malfunction, whether it's in the liver, whether it's your kidney, whether it's your brain. I mean, the ultimate brain malfunction is you have a stroke. By the way, everything I'm talking about in your organs also can happen to your heart. So when there's a malfunction of your heart, because it's not getting enough blood flow, it can also happen.
The heart has its own circulation, which is pretty amazing, not surprising, but amazing. When the heart's own circulation gets clogged or too stiff and it blocks split flow, then you have a heart attack. And so the things that we hear about heart attack, stroke, cardiovascular disease, these are all problems of that giant system. That 60,000-mile system that formed was one of the first organs to form in your mom's womb.
[00:09:15] Jonathan Wolf: So I need this stretchiness in order to deliver down these capillaries. And I think we've all, maybe heard a little bit about this idea of it being blocked. Is that the same as not being stretchy? Or is that actually something different, Will?
[00:09:26] Dr. William Li: Right. Well, think about this. So think about a big sock that you put in your foot through, right? So the sock has to stretch like the sock you pull out of a drawer, it's actually pretty thin. It looks too thin for your leg to go through, but, because it's stretchy, you can actually put your foot and then your ankle all the way through it. Right?
[00:09:43] Jonathan Wolf: Yep. I'm familiar. I fought with my daughter this morning to do exactly that as I seem to end up doing many mornings because it turns out that it's a lot easier to put your foot through the sock when the other person is helping rather than pulling it in the other direction.
[00:09:55] Dr. William Li: Right, right.
[00:09:55] Jonathan Wolf: So I understand the analogy.
[00:09:57] Dr. William Li: Now when that sock is no longer stretchy. It's stiff. Imagine spraying concrete around that sock, or maybe even pouring concrete into the sock. Okay. And now try to put your foot through it. It's not gonna go through very easily, right? It's stiff. There's no stretchiness.
And that's actually what happens as we naturally get older. And particularly when we're eating, what is the so-called Western diet. Now we can talk about that in more detail, but we eat a diet that's not so good for our circulation. What happens is that a blood vessel?
Let me just kind of give you a little more detail about the stretch. The reason a blood vessel can stretch has to do with how it's designed. A blood vessel has got different aspects of its wall.
Cut a blood vessel in half and look at its cross section and you'll see there's a thin lining on the outside. There's a little muscle on the out, beyond that so the muscle can allow it to stretch. And on the inside, there is a lining of cells, very special cells called endothelial cells, "endo" because they're on the inside. Endothelial cells. These are the liner cells of a blood vessel. So think about Saran Wrap. That's how thin it is. Okay? Lining the inside of your blood vessel.
[00:11:09] Jonathan Wolf: Cling film for those of us in the U.K.
[00:11:12] Dr. William Li: Yup. Clear film. So basically that's the blood vessel. The muscle helps it stretch the wall helps it stretch the clear sheet on the inside. That is a special layer. That layer is slippery. It's like the surface of an ice skating rink, that's been polished and buffed before the first skaters get on it. And the reason that the endothelial slippery layer is so important is that blood cells slide right along it. They don't stick.
[00:11:43] Jonathan Wolf: Got it. So I'm sort of thinking now, bet it's like you're in a tunnel, but all the walls are covered in like a bit like Teflon, I guess, on my pans or something. Right? Like something very non-stick. Is that a way to think about this?
[00:11:55] Dr. William Li: Well, we'll have to talk about the Teflon in your pan from a healthy eating perspective, but yes, that's exactly what it is. And I used the idea of an ice skating ring because many people have spent a winter holiday look. It could be outdoors. It could be in, sort of a skating rink or just think about the Olympics, right? So when the ice is fresh and ready for the day's first skaters, it is slick. It is smooth.
[00:12:20] Jonathan Wolf: And everything just starts at one end. It goes all the way to the other end.
[00:12:23] Dr. William Li: Yep. Take off your sweater and throw it on the ice. And it'll go all the way across the ring, right? Now, as long as that lining is perfectly smooth. Everything will glide right along. Now, what happens when you actually smoke a cigarette? Okay, the nicotine, the chemicals, the harsh chemicals, it damages that Teflon layer.
It damages that liner, that transparent liner, going back to the ice skating ring analogy, it would be like, if you took a rake and you just raked the ice and scuffed it up, now try to throw a sweater on it. It's just gonna stick right there. It won't slide. And so that roughening of the inner lining can actually make blood cells clot, stick and form a clot.
That is the beginning of the end. When I say the beginning of the end, that starts to narrow the blood vessel, and the blood vessel starts to get stiffer. You don't actually have that stretchiness. Plaques and fat can actually build on the inside of the wall.
[00:13:26] Jonathan Wolf: And what is a plaque, Will?
[00:13:28] Dr. William Li: A plaque is a thickening, you know, like a plaque on your teeth. Any kind of a thing that builds up on your teeth, right?
So a plaque in a blood vessel is similar to what you would find in your teeth, but it's on the inside layer. And it, what it does is it makes it stickier. It makes it narrower. It makes it stiffer, all the things you don't want in a healthy blood vessel.
[00:13:50] Jonathan Wolf: That makes sense. And I can see if I'm trying to deliver anything through this, and it's starting to get more and more constricted. I mean, it doesn't sound, it's sort of obvious to a layman, right? It doesn't sound good if I'm trying to push something through and the pipe is getting more and more, more furred up, you know, I have a toothbrush for my teeth, right?
For this situation with plaque, is there a toothbrush in this situation or is this a sort of one-way direction? This is just gonna get worse and worse as we get older and we fur up these blood vessels?
[00:14:16] Dr. William Li: Well, this is actually the most exciting thing. When I went to medical school, we thought it was a one-way street. Meaning once you start narrowing and stiffening the blood vessels, the only way you could do it is we used to think about it like a clogged toilet. Right? Like, we've all experienced that. The toilet's supposed to flush, but all of a sudden is not flushing anymore. It backs up. Terrible. What do you have to do? You have to have to plunge it.
[00:14:39] Jonathan Wolf: Call the plumber!
[00:14:40] Dr. William Li: Or you have to snake something down and clear it, right?
[00:14:44] Jonathan Wolf: Yep. Yeah.
[00:14:44] Dr. William Li: And so that's what I was taught when I was in medical school.
You've got to call the heart plumber, the cardiologist, the interventional cardiologist, who basically will stick a roto rooter, which is like a coil in your groin. Snake it up through the blood vessels in your groin, into the blood vessels in your heart. And literally roto rooter it, like basically drill out that clog to clear the toilet.
[00:15:07] Jonathan Wolf: So it is a bit like brushing your teeth, fancier technology, but...
[00:15:11] Dr. William Li: Exactly. Well, and then of course it would clog back up. And so what they then invented in the medical world are stents, which are literally little Teflon or metal coated stents that would strut the blood vessel open. Right?
Think about Mission Impossible. You get this little thin thing, you put it into the blood vessel soul, and then boom. It opens up and now it's actually stenting open. Forcing open the blood vessel. Now that sounds good because you solved the immediate problem of the lack of blood flow, but actually, guess what? That actually also damages the natural elasticity, stretchiness of the blood vessel.
Now you've got basically an iron tube stuck inside your blood vessels. That's not normal and that's not good. So then we developed statins, which are drugs aimed at actually lowering the amount of stuff that could clog. Fatty deposits can clog, the plaque on the walls. Statins actually work pretty well.
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They work by metabolically lowering the amount of cholesterol and other lipids, fatty things that float around near your blood. If you've ever cooked bacon, you know, that after the raw bacon starts frying up and the wonderful bacony smell is in the air and you take the bacon out, you know, that you're left with a pan of grease, right?
Now you're going off eating your brunch or what have you, you come back to the pan after breakfast and what do you actually have? You've got this congealed mess. Imagine that congealed, white creamy, thick stuff, that bacon grease, imagine that is actually sluicing through your blood.
[00:16:52] Jonathan Wolf: Doesn't sound good, right? Like nobody's gonna suggest that this sounds like a good thing to be going on inside you.
[00:16:58] Dr. William Li: No, and that's what statins were designed to do is to sort of try to cut through that grease like a detergent and lower the levels in your blood. Sounds like a good idea, but here's the problem. Statins, which are capable of actually preventing the build-up to some extent, have a lot of side effects, actually. I mean, it's a billion-dollar blockbuster area of pharmaceuticals, and many, many people are on them, but you know, statins can damage your muscles, can damage your kidney, can damage your liver. There are all kinds of things. Every drug has an effect and the potential for a side effect or an unwanted effect.
So not particularly a great solution. And frankly, I'm a doctor. I was trained to write prescriptions, but my own practice, my own mindset of how to help a patient, if you have or are forced to give somebody a prescription, my goal has always been to figure out from the beginning, when you're gonna take the person off the prescription, so they no longer need the drug.
Now you need to find a different solution. And so this is different than running a prescription and putting somebody on a drug for the rest of their life. Like how many of us know people like that, or even doctors who actually think that way? My view is that medicines can be life-saving, but if you put somebody on medicine, the goal ideally, is to figure out how you're going from the beginning and when you're going to take them off it.
So now research actually has then discovered that there are foods and lifestyle issues that can actually reverse all the things that damage the elasticity, the flow that can block your circulation. I mean, we started at the very beginning, right? We just started saying, drop those marbles, their stem cell, they haven't formed, and then they form and they work perfectly when you're a baby.
And over the course of your life, during aging and over the course of maybe less than salutary dietary habits, you're eating foods that are not so good for your circulation. You get the clogging cigarettes, smoke damages, that smooth ice, and now it's sticky, alright? You know, can we avoid stents? I think we can.
Can we use drugs? Yeah, I think we can, but can we use diet and lifestyle to reverse that clogging that prevents and reverse? That is actually what's remarkable because scientists now discovered it's possible to not rely on the drugs or the hardware that I was taught, we, that doctors, the medical community has to use.
[00:19:29] Jonathan Wolf: And Will, before we talk about the food that you could use to do that, could we maybe talk about the first half? Because you gave this example of smoking has been one of the things that can cause damage, and I'm sure most listeners here are saying either they once smoked and they stopped or that they no longer smoke because there has been this amazing decline in smoking, right? Is one of the great sorts of public health improvements. If I compare with levels when I was a kid.
What else is causing this? And I think, you know, obviously, this is a podcast where people are very interested in food. Is what we eat linked to the damage to these blood vessels in the first place?
[00:20:02] Dr. William Li: Yeah. Well, I mean, before we go to sort of how to fix the problem, let me tell you how our blood vessels are perfectly evolved to be able to function with our food. So let's think about that. 60,000 miles of highways and byways, the lakes and tributaries and creeks and streams that are inside our body that our very life actually depends on having to coexist harmoniously with the foods that we eat.
So just like a river and a stream, you know, there are all kinds of things that float through your stream and your rivers, right? It's not one thing. There are a lot of different things. Similarly, we can eat lots of foods and our blood vessels can handle them, that lining can handle it just fine. What are the things that our body is designed to actually handle? Mostly plant-based foods.
So basically, if we eat fruits and vegetables, nuts, and legumes seeds, the nutrients that we absorb from them actually are beneficial and they protect that smooth lining. They keep the ice on the ice skating, very slippery, alright.
That's beneficial for our body and you know, every now and then you eat that piece of bacon. You talked about the bacon and the grease, and you're gonna dump some of that grease into your bloodstream. It's less than you would have in the pan after you make a, you know, package of bacon, but it's still there.
Now, fortunately, even though that will actually circulate through your bloodstream once or twice after you've had your big brunch with bacon and it tastes great, the fact of the matter is if you continuously live a life pattern of eating lots of fatty foods, saturated fats, red meats, I mean, look, I actually love food.
So I mean, I don't love to eat, but I enjoy food. And I appreciate the culinary history that cultures actually have. So look, I'm not afraid to tell your viewers and listeners that I've enjoyed a great ribeye steak, like anyone else, alright? But the problem is that if you actually have that all the time, you have bacon all the time, you have lots of greasy, fatty foods, all the time, and hamburgers all the time.
What happens is that your bloodstream is not that well adapted for that huge amount of fat that continuously circulates. That's what your doctors measure. Go to your GP and get your blood drawn. PCP, we call in America, primary care doctor, physician. What are you getting? You're getting a cholesterol test, a blood lipid panel. And that's actually just a test that looks like, what are the levels of the lipids in your system? If you eat very unhealthy foods, your lipids will naturally go up because you're flooding your system with fat.
Now that can be on top of other damage that unhealthy foods are doing. We do know that for example, and this is a pretty brand spanking new, that the gut bacteria, in our body, the healthy gut bacteria. There are about 39, 40 trillion bacteria that we know that are inside our gut, and these gut bacteria, which we call, the microbiome, actually play a critical role in getting rid of the fats that are floating around in our bloodstream and helping our metabolism move smoothly.
So it's not just eating the fat, but if we eat foods like ultra-processed foods with lots of additives, synthetic, preservatives chemicals, alright? Too much sugar, too much alcohol, all the things that, you know, like present-day conventional wisdom tells us are not so good for us.
I don't think there's any mystery to most people who have access to the internet or the media to be able to figure out, what foods that are not so good for our health. Here's the latest breaking information. Those foods that are not so good for us, not only can clog up our blood vessels, they damage our gut microbiome.
They damage our healthy gut bacteria. When we damage the gut bacteria, what do I mean damage? Think about your gut bacteria as an ecosystem like the great barrier reef with this incredibly dazzling array of organisms that all live harmoniously and do something for the environment.
In this case, the environment's your body. And one of the things they do is help to lower the lipids. They help to improve your cholesterol. They help blood flow smoothly. They help protect the lining of your blood vessels. Now you damage those protector bacteria. Suddenly, your blood vessels are even more vulnerable.
And so it's not just having the fat, it's also damaging the bacteria. And so there are all kinds of things that we can eat. Ultra-processed foods, too much red meat, and too many fatty foods, all contribute and conspire together to thwart the natural resilience of our circulation.
[00:24:33] Jonathan Wolf: These are topics, I think, that we talk a lot about on this show. So it's fantastic to hear these links back to heart health. Just before moving off it, we had a lot of questions about high blood pressure. Does high blood pressure fit into this story about what's going on with all of these vessels? Or is this a completely different thing that's going on inside us?
[00:24:51] Dr. William Li: Yeah. Well, so here, let's kind of review a little bit about what actually blood pressure means, right? So you go to the doctor's office or you, you do this at home. You put on a cuff, usually at the bottom part of your upper arm, and you blow it up. And then there's like a little meter that actually clicks off. And the blood pressure, it's two numbers. They call it the systolic of a top number. And diastolic is the bottom number. Without having to go into other physics of what all that means. It's two numbers, blood pressure.
[00:25:21] Jonathan Wolf: That's all I've ever understood. So that's great that I don't need to understand more. Thank you, Will.
[00:25:25] Dr. William Li: Well, I'll break it down in ways that actually matter to what we're talking about. The first number called systolic is your reflection of how fast and hard, the heart pumps the blood out. So if you look at the ideal blood pressure, you know, which basically it's an ideal, it's like 120 over 80 or 120 over 70, okay? That first number 120, that's 120 millimeters of mercury jetting out. Okay, that's a good amount. If you go to a 130, 140, 150, 160, like you're getting to, it's like driving on a highway, you know, speed limit, 40 miles per hour. Can't translate miles to kilometers, but...
[00:26:07] Jonathan Wolf: Our Canadian listeners will forgive you. It's okay.
[00:26:09] Dr. William Li: But then you actually put your pedal down and now you're going to 60. Now you're going to 70. Now you're going to 80, 90. Now you're redlining the car, alright? And you know, just from sitting behind a driver's seat, you're going too fast, alright? And your car's telling you you're going too fast. That's a similar way of jetting that blood out faster and harder with more force. And that's when you start to get into high blood pressure, 140, 150.
[00:26:36] Jonathan Wolf: Why am I having to push it harder than I did when I was younger? Why am I now having to do this?
[00:26:43] Dr. William Li: Because the heart has to actually get a healthy bolus of blood, delivering oxygen and nutrients to all those cells, 60,000 miles. When the arteries and the blood vessels that are pumping through are stiff, it has to pump a little bit harder in order to get it out.
[00:27:02] Jonathan Wolf: And that compression, that the thing that's causing this problem is that entirely about the blood vessels through the rest of your body?
[00:27:09] Dr. William Li: Not entirely because many things can cause high blood pressure.
But because we were talking about clogging, that's one of the consequences of the clog. Now, if the heart is actually racing too fast and the body can't compensate for it, it can also raise blood pressure.
There's another part of it, which is the back pressure. That's the second number of the blood pressure, the diastolic, right? We talked about the two numbers. The first one is the jet. The second one is the back pressure because there's always a little pressure. If we didn't have some back pressure in our bodies all the time, we'd be fainting. We'd no blood to our brain. So that back pressure is basically what we call the resting or diastolic pressure.
If that's too high, we've got a lot of tension in the circulation as well. Fluid overload. You can have too much fluid in your system. So there are lots of things that can cause high blood pressure. Here's the consequence. When you have continued, relentless, unremitting, high blood pressure, you gotta think about what happens. Like that tension, that jetting, that pressure builds up and your organs suffer.
Either they're not getting enough blood and they may be starved of the blood, or they're actually not getting the right delivery of those nutrients in the right way. That is actually very damaging over time. That's why high blood pressure is a silent killer. It sneaks up on you. It can exist and you don't even know it.
[00:28:32] Jonathan Wolf: Because you don't feel anything, right?
[00:28:34] Dr. William Li: You don't feel it until it becomes catastrophic.
[00:28:37] Jonathan Wolf: How important is the blood vessel part of this story for high blood pressure? Is it just like a little part? Is it important? If I'm worried about blood pressure.
[00:28:46] Dr. William Li: I would say blood pressure at blood vessels, they go hand in hand, but clogging of the blood vessels is not the only issue, not the only problem.
There are many other components, but I would say blood vessels are involved in every aspect of blood pressure. And by the way, remember the stretchiness. If your blood vessels are elastic, like the sock out your drawer, we talked about when the pressure's high, it just stretches a little more and the pressure comes down.
And so when your blood vessels are stiff, when there's a lot of jets, it can't stretch, now your blood pressure's gonna go up.
[00:29:18] Jonathan Wolf: Right. Got it. And I know from another conversation we've had that, I think on average, we lose some of this elasticity with age isn't that right? Because I happen to know my co-founder Tim has ridiculously elastic blood vessels for his age.
It was something that Sarah discussed. So again, the question a lot of people were asking is, how much of this is just inevitable, right? You're getting older. So there's nothing you can do about it. How much of it is just like, it's your genes? You know, my grandfather sadly passed away because of a heart attack.
So clearly there's some potential genetic predisposition. How much of it is explained by this and how much actually can diet really affect what's going on, you know, over these years and decades?
[00:29:56] Dr. William Li: Well in the same way that we talked about how diet can help protect your blood vessels by eating healthy foods that preserve, protect, and even regenerate renew the lining wrap on the inside your blood vessels.
Foods can actually help you maintain that youthful elasticity of the blood vessels. So foods that are harmful can actually cause it to clog up. And so there is clearly value for longevity, for resiliency throughout your aging process for eating healthier foods.
And likewise, if you nurture an unhealthy lifestyle, okay, you smoke, you don't exercise, you eat unhealthy food, right? By the way, a footnote on it, you know, back in the day, that's actually how most doctors lived their life. They had all the stress. They were, you know, I remember being in training in a hospital and they had actually a smoking room for doctors, which was ridiculous right?
But the point is that you can do bad things to your circulation, your cardiovascular disease, and your blood pressure, or you could do good things. I think what you're trying to get at is, is it destiny that our blood vessels are going to get damaged over time? Or are there ways that we can slow that process down or perhaps even reverse that process?
The answer is, and this is what's quite striking, it's possible to take somebody who has existing established blockages in their blood vessels, who would otherwise be required a stent, the plumber, call the plumber, put the equipment in or requiring drugs like the statins, alright? That if you actually give them an intensive regimen of lifestyle change, starting with their diet, you cut down or cut out the saturated meats, no red meat, remove that.
Okay. And you upend their dietary equation by putting them on high-fiber foods, fruits, and vegetables with high fiber. What does that do? Oh, it feeds your gut microbiome. Now your gut bacteria are happier. They restore their community, their ecosystem. Now they're working in your favor, alright? This lifestyle change.
Now you can eat foods, more foods, fruits and vegetables, nuts and legumes, seeds that actually then renew, regenerate the damaged lining. So, you know, just like our skin renews itself and our hair for most people renews itself, right? Which is why we need a haircut. And the skin sheds, which is why people have dandruff, alright? There's a renewal of the blood vessels. If you eat foods, lots of foods that actually have healthy bioactive, natural chemicals that can stimulate regeneration.
So an example would be anthocyanins that are present in dark chocolate or they're present in blueberries. They will actually help to renew and replace those old damaged liner cells in your blood vessels.
Now you're actually regenerating damaged tissue. So what's quite fascinating with an intensive lifestyle change, starting with a diet, replacing unhealthy fats with healthier fats, omega threes, okay? Are better than butter and palm oil and lots of other less-than-healthy fats.
Cut down the amount of oil. Omega-3s are a very healthy form of fats. You can get them from nuts and seeds. You can also get them from seafood, which is known to be heart-healthy. You're actually protecting the liner.
You are starting to dissolve by replacing and regenerating the liner, okay? You're actually also dissolving some of the plaques that have accumulated. So it's sort of like mother nature's toothbrush using the natural substances that are present in your foods and you can replace and reverse heart disease.
Diet, by the way, is only part of the equation. There are other things like regular physical activity. That's helpful. Why does that? It gets the blood, your juices flowing, literally. Gets your blood flowing. That's important for reversing heart disease of stress and lowering stress. And sleep.
[00:34:08] Jonathan Wolf: This sounds great. It's very much in line, interesting with the advice for things that have got nothing to do with blood vessels. It's always interesting how much alignment there is at the maximum level.
Are there real clinical trials and studies that support this? Because I think some people will be listening saying, you know, well reversing, you know, heart damage, that sounds a bit radical. You know, I know that Will's a doctor, but you know, are you way out on the ledge? Is there the data to support what you're saying?
[00:34:31] Dr. William Li: Well, first of all, I was a skeptic on this for many years. Okay. I'm part of a cadre of life scientists that actually I've been involved with biotech drug development.
So for me, my wheelhouse actually has been to develop the latest new drugs. And actually, I've been involved with developing stem cell therapies and gene therapies for our heart disease. So I'm not a kale waiver. Okay. I'm not somebody that's sort of stepped away from the fold.
[00:34:57] Jonathan Wolf: For those of you on video, you'll see, that Will doesn't look like a kale waiver either. But if you're just on audio, you know, it's harder to, harder to tell, but yeah.
[00:35:05] Dr. William Li: So I believe in medicines, I believe in advancing medicines, and I was a skeptic I'm like, how can lifestyle do it? But I have to say from the very beginning, we know that after you have a heart attack if you go for what they call cardiac rehabilitation, cardiac rehab, that's what every patient leaving the hospital undergoes to recover from a heart attack.
It's a manner of actually diet and lifestyle and reduction. And if you really take it pure clinical studies that have actually compared interventions to lifestyle management, I would cite the work of Dr. Dean Ornish, who is a professor at the University of California, San Francisco, and he's at the preventative medical research Institute.
He's actually done a career of probably 40 or 50 years worth of research, looking at the reversal of heart disease that does not require the hardware and pharmaceuticals. Again, it's not a silver bullet. It is not a one-step deal.
It is a pretty big commitment for somebody who's lived their life to actually suddenly be scared straight and that, because you've had a heart attack or you've had a big warning sign and now you need to actually change your diet and find new ways to eat that bring you joy, and then to learn how to lower stress. I mean, how many of us live in a continuous state of stress, especially if we're building a career?
[00:36:32] Jonathan Wolf: I'm running a startup, doing this podcast, have children. I'm a hundred percent in a permanent state of stress, Will.
[00:36:39] Dr. William Li: And I can tell you training in medicine. I mean, just being a doctor, going through the training is high stress all the time. That's not good for us. And so one of the reasons why people that work at a high level of stress, probably like you and me, is that's why we enjoy vacation so much.
Is that when we take a break, our body truly thanks us for it. Our minds also do as well. Our gut bacteria also thanks us for it because we tend to be more active and probably eat slightly healthier things and take it easy on ourselves. And so I think this idea of self-renewal is very important for not only preventing disease but reversing disease.
And that's why I'm trying to emphasize it is definitely possible to reverse heart disease. It's not, you know, just pop a pill in your mouth and swallow it, chase it down with a drink of water. It's a commitment to a better lifestyle, a healthier lifestyle.
[00:37:35] Jonathan Wolf: I don't think you're saying to people that everyone should stop taking their statins, who has currently got them from doctors.
I think I don't believe you're saying that is that right, Will? You're saying that there is ultimately this enormous impact that you can have through your diet and your lifestyle, which, you know, there's real scientific data to support. Is that fair? Am I putting words in your mouth?
[00:37:54] Dr. William Li: No, no, you are absolutely correct.
And as I said, I'm a medical doctor trained in that hardcore, using all the tools in our toolbox. And as I said, I'm actually involved with developing the next generation of treatments for heart disease and stroke, and many other cancer and many other conditions. So I'm a big believer in using the best tools.
But what I said at the very beginning, my own philosophy is that if you put somebody on medicine, the goal should always be as a doctor to figure out how to get them off the medicine. And if all you do is renew the prescription over and over and you just tell the patient, just take it. That's what you need to do.
We're not doing enough. And I think what patients and people need to realize is that if you actually have cardiovascular disease, there's a tour of healthcare that you could do for yourself. Doesn't rely on a doctor. There's no anesthesia required. It doesn't require a pharmaceutical. It requires something that you do at home, which is caring for your heart health. And that's done with diet, physical activity, sleep, and stress management.
[00:38:59] Jonathan Wolf: I think it's brilliant. I wanna make sure, you know, we don't run out of time cause I really wanna talk a bit about aging. Cause we've talked a lot, obviously about heart health and you know, we're very conscious if that might affect the ultimate length of your life.
But at first glance, aging doesn't seem very linked to heart health. To me, it doesn't really seem obviously linked to your core research about blood vessels, but I know we were having a discussion, prior to this call and we were talking about aging and dementia. Could you tell us a bit about how your research has taken you here? What the links are with sort of all of these things about our blood vessels?
[00:39:32] Dr. William Li: First of all people think of aging in a very particular snapshot-y sort of way, right? We think about our grandparents. We think about a picture of an actor that we know who's now, you know, at the twilight of their career or their life.
And look at all that gray hair. Look at all these wrinkles. That's a snapshot of time. Here's the reality. The moment we are born, the moment the doctor delivered us and gave us that little swat on the butt to allow us to take our first breath. That's when the aging clock starts. We are aging from the moment we are born.
[00:40:06] Jonathan Wolf: That's very depressing!
[00:40:08] Dr. William Li: Well, but I would say that's only because our social construct of aging is looking at the terminal components of our life. But if you rethink aging in a different way and say, you know what? Aging is completely normal. It starts from the time we were born and we just continuously advance you know?
[00:40:31] Jonathan Wolf: So don't think about it as getting better and then getting worse, which I think after all my children are all terribly keen to be older, and then that suddenly switches, doesn't it? For different people of different ages? You know, I think, I remember a long time ago, 20–30 seemed like somehow that was a tip, but I know other people who, frankly, didn't get there till they were 50 or 70.
[00:40:51] Dr. William Li: Well, you know, so here's an interesting thing when I was in medical school. Which was in the 90s, we were looking at the average longevity of people to be like in the early 70s, 72. Now people live to 86, 87, and 88 routinely, right? And so think about that from a societal perspective, our whole society, when we live in a country and a nation that has means, and resources, everyone actually gets older.
By the way, here's another thing for you a hundred years ago, you know, like most people only live to like 40 or 50, like, so we've pretty much doubled our lifespan. I mean, here we are like, you know, bitching and moaning about like, you know, not living to a hundred or, or aspiring to live 120, I would say step back and take a look at the big picture a hundred years ago, we didn't live half as long as we live now. So now we're actually living into our 80s.
[00:41:48] Jonathan Wolf: Brilliant. Well, thank you so much. We've covered a lot of stuff. And I always try at the end to try and do a summary. I think this could be particularly challenging, but I'm trying to do that just to capture the key things that we discussed today.
So I think we sort of off with this amazing fact that there are 60,000 miles of blood vessels in each of us. Aging starts from the day we are born and specifically for our blood vessels, you know, they start to stiffen, which is a big problem because you're describing how tiny the ones are at the end, in order to feed all of our different organs and they can end up getting blocked, whether it's from smoking, but also through the sort of Western diet that we tend to eat.
This is quite heavily related to high blood pressure, which you said is a silent killer because many of us aren't really aware of it. But the good news is, you know, it's not just destiny. We're not entirely, stuck with you know, the genes we were born with.
And in fact, even more positively we could actually reverse some of this damage. That's not just about stopping it. It's possible to reverse it. We can actually reduce some of these blockages. And of course, there's modern medical science. You talked about stents or statins, but actually, I think you were really saying that lifestyle change would be at the top of your proposal with these things really being secondary. Is that right?
[00:43:00] Dr. William Li: That is completely correct. Well, summarized.
[00:43:04] Jonathan Wolf: Brilliant. Will, thank you so much for coming on. I really enjoyed that. There are many other topics that we could have covered and I hope we'll have a chance to talk about some of those other ones in the future.
[00:43:14] Dr. William Li: Thank you very much. It's always a pleasure to speak to you and look forward to continuing our conversation.
[00:43:19] Jonathan Wolf: Brilliant. Bye-bye.
[00:43:20] Dr. William Li: Bye-bye.
[00:43:23] Jonathan Wolf: Thank you to Dr. William Li for joining me on ZOE's science and nutrition today. We hope you enjoy today's episode. If you did, please be sure to subscribe and do leave us a review as we love reading your feedback. If this episode left you with any questions, please send them in on Instagram or Facebook, and we will try to answer them in a future episode.
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As always, I'm your host, Jonathan Wolf. ZOE Science & Nutrition is produced by Fascinate Productions, with support from Sharon Feder and Alex Jones here at ZOE. See you next time.