The Peter Attia Drive - #203 - AMA #34： What Causes Heart Disease？

00:00:00.000 Hey everyone, welcome to a sneak peek, ask me anything or AMA episode of the drive podcast.

00:00:16.500 I'm your host, Peter Atiyah. At the end of this short episode, I'll explain how you can

00:00:20.460 access the AMA episodes in full, along with a ton of other membership benefits we've created,

00:00:25.440 or you can learn more now by going to peteratiyahmd.com forward slash subscribe.

00:00:31.140 So without further delay, here's today's sneak peek of the ask me anything episode.

00:00:39.240 Welcome to ask me anything episode number 34. I'm once again joined by Nick Stenson. In today's

00:00:45.100 episode, we do a super deep dive answering a lot of questions that have been accumulating around

00:00:50.300 atherosclerotic cardiovascular disease. Now, atherosclerosis, of course, is the number one

00:00:55.580 killer in the developed world. It affects basically everybody. So you undoubtedly know somebody who's

00:01:01.200 affected by this, if not you. So we thought it was really time to kind of focus deep on this.

00:01:05.640 So for this reason, we combined a lot of previous questions that have come in into this episode.

00:01:09.600 And so we discuss a lot of things here. We discuss why everybody should care about atherosclerosis.

00:01:12.980 We talk about exactly what it is and try to explain how it comes about. Now, it's important to spend a

00:01:17.680 lot of time on this, because if you want to understand how to prevent it, you really need

00:01:22.500 to understand how it's caused. And then that'll give you some sense of what the markers are and

00:01:28.420 what the markers don't tell you and what they do tell you. So we look at why it's not a disease that

00:01:33.180 only affects old people, but why it really takes hold at an early age. And you need to be aware of

00:01:37.940 this. If of course you want to present it, we talk about cholesterol, blood work, what these numbers

00:01:41.500 mean, what's typically run, what's not run, what metrics I like to look at and what you should be

00:01:46.380 concerned over. We also get into a question that comes up a lot, which is, can cholesterol levels

00:01:50.240 be too low? So if you're taking medications to lower cholesterol, what happens if your

00:01:54.420 cholesterol levels get really low? What are the risks of that? From there, we answer questions

00:01:58.100 around coronary artery calcium scores or CACs, CIMT, CT angiogram, and a whole bunch of other things

00:02:03.820 along that. So if you're a subscriber and you want to watch the full episode of this and video,

00:02:07.920 you can do so on the show notes page. And of course, we'll have the show notes that include a whole

00:02:11.740 bunch of details. Worth pointing out here before I start, this is an episode where I probably have

00:02:16.940 more figures than any other episode I've done. So even if you're not someone who likes to look at

00:02:21.820 the graphics, I think this is the one time you probably want to make an exception and watch the

00:02:25.820 video. If you're not a subscriber, you can still catch a sneak peek of this on our YouTube page. So

00:02:30.000 without further delay, hope you enjoy AMA number 34.

00:02:32.380 Hey Nick, how are you doing? I'm not doing too bad. How are you doing?

00:02:41.300 I'm good. We got a doozy today. More so than usual. I know. I'm bracing myself for the intensity of this

00:02:47.200 discussion. We've accumulated, I don't know, almost an endless supply of questions on heart disease in

00:02:53.380 one format or another, the specifics around lipids, atherosclerosis in general, these things like

00:02:59.240 that. And so as is often the case, I think we've accumulated a critical mass of questions that we

00:03:04.020 can now organize them into a coherent and thoughtful discussion around all things related to atherosclerosis.

00:03:11.400 So I know you've done an amazing job taking these questions and organizing them in a way that makes

00:03:17.520 for hopefully a logical discussion. So let's take it away.

00:03:21.140 The hope is a lot of this stuff we're going to talk about today, we could dive in so deep. So many of

00:03:26.180 these questions could be their own AMA, but what we thought as a team was, it'd be just much better

00:03:31.340 to touch on all these aspects. So people who listen top to bottom can just get a really good

00:03:36.380 understanding of what this is, why they should care about it, how they should think about it.

00:03:41.020 On that note, what we thought would be important is just answering the first question, which is why

00:03:45.360 should someone care about this? It's such a complex topic. Why is it important for people to put the

00:03:52.880 time in to really think through and understand it? It really starts with the ubiquity of this disease

00:03:58.300 and its assault on human longevity. People have probably heard me say this before, but atherosclerosis

00:04:05.380 is really the only inevitable disease of our species. Cancer, while prevalent with aging and dementia,

00:04:12.420 while prevalent with aging, do not appear inevitable the way atherosclerosis does. So not everybody dies

00:04:18.900 from atherosclerosis, but I think to my knowledge, everybody dies with it, assuming they live long

00:04:24.700 enough. So you have a condition that, as I said, is inevitable, is ubiquitous. Also, I think based on

00:04:32.560 what you're going to hear me talk about today, we know a lot about this condition and we really have

00:04:38.920 tools to mitigate it. To me, that's the reason you want to really understand this. The impact is huge

00:04:47.000 and the tools that we have are also huge. So again, we talk about longevity. Longevity has two parts,

00:04:54.480 healthspan, lifespan. The lifespan part comes down to delaying the onset of chronic disease,

00:04:59.160 of which this is the most common chronic disease. So you can think of a couple of different paths to

00:05:05.700 get there, but really the two biggest risk factors, I am putting smoking aside for a moment, which is

00:05:11.480 a very straightforward behavioral risk factor. In terms of less clear behavioral risk factors, the two

00:05:17.900 biggest are clearly hypertension, high blood pressure, and lipid abnormalities. And that's the one we're

00:05:23.140 going to focus on here. So atherosclerotic cardiovascular disease, we'll just abbreviate

00:05:27.520 ASCVD for short, is really what we're here to talk about. As we get started on this topic, Peter, I think

00:05:34.380 we have people who listen to this podcast of all ages, young, old, everywhere in between.

00:05:39.560 And I think it's a common thought for people under 30, 40, even some people under 50, where they're

00:05:47.440 just like, this is something that only affects old people. I'll think about this when I'm older,

00:05:51.760 but right now it doesn't really affect me. How would you answer the question in its basic form of,

00:05:56.940 isn't this just a disease of old age? And why should those people who think that not just shut off the

00:06:02.120 podcast at this point and instead continue to listen and continue to put in the effort?

00:06:06.280 Probably have told this story before. And if not, or if folks haven't heard it, I think it's worth

00:06:12.800 hearing again, right? I remember in sort of my first year pathology lecture in medical school,

00:06:17.040 the pathologist said, what's the most common presentation for a first heart attack? So if a

00:06:23.000 person is having their first heart attack, what is the most common thing that they will present

00:06:27.500 with? That's the terminology we use in medicine. And of course the hands shot up, chest pain being the

00:06:32.380 obvious. Nope, that's not it. Nausea. Nope, that's not it. Left arm pain. No, that's not it.

00:06:38.520 And it was a trick question. Of course, the answer was sudden death. The answer was that over 50% of

00:06:44.740 people's first heart attack is fatal. Now the good news is today that number is a little bit less. It's

00:06:51.360 probably slightly below 50%, but that's still a staggering number. Now, another way to think about

00:06:56.880 this is through the lens of understanding the age distribution of people who have their first major

00:07:05.160 adverse cardiac offense. So that is a heart attack, stroke, or sudden death due to one of those. If you

00:07:11.400 don't mind, Nick, pull up figure one. This graph shows the age distribution for both male and female

00:07:18.780 in the United States in terms of these incidents. I think the easiest graph for me to look at here

00:07:27.100 is the one on the right, total annual events. And what you can focus on is the first two bars. That is the

00:07:39.100 bars that are for people up to the age of 65. So if you look at the male bars, which are the darker bars,

00:07:47.880 you can see that the sum total of those two bars, slightly below 25%, slightly above 25%,

00:07:54.200 the implication of that is over 50% of men who are going to have a cardiac event in their life

00:08:02.200 will have it before the age of 65. And for women, you do the same exercise. You can see that it's one 0.92

00:08:09.980 third of women. So it's clear that there's a shift in time and that women, while subject to the exact

00:08:17.520 same burden of disease seem to experience it about a decade later, still fully one third of women are 0.98

00:08:23.820 going to have their first cardiac event, which is going to be heart attack, stroke, or death as a

00:08:28.400 result of those things before the age of 65. And a little over 50% of men will be in that camp. So

00:08:34.480 as we're going to talk about in this episode, that's not the whole story. It's even more compelling

00:08:40.380 to care about this when you're young, when you understand how long it takes for this disease to take

00:08:45.360 hold and the implications therefore for prevention. The most sobering thing for me, when you look at

00:08:50.340 this is it's not even the 50% under 65. It's almost the, especially for males, the almost 25% under 54.

00:08:59.000 And especially when we get to what we get to later, which is for that to happen to someone who's 45,

00:09:05.420 50, it doesn't mean it started two years earlier. Right. And so I think it's pretty crazy when you see

00:09:11.780 these type of stats laid out, how it creates that shift in your mind around why you should care about

00:09:18.640 this. I think what we need to do is first almost step back and look at what exactly is ASCVD. I think

00:09:28.240 people have to understand what it is to then really understand how it comes about, how to think about

00:09:34.640 prevention. So what do you think the best way to walk people through in a relatively simple form,

00:09:41.080 what this disease is? I'll explain it at a high level now. And I think we should go through it in

00:09:46.460 some detail in a moment, but the pricey on this would be that ASCVD is a disease state characterized

00:09:52.520 by the deposition or the buildup of cholesterol more clearly or more rigorously sterols, which include

00:09:58.980 cholesterol and phytosterol in the artery wall. It initially starts as something called a fatty streak,

00:10:05.380 which I'll explain in a little bit more detail later. And then it later consolidates into things

00:10:10.440 called plaques. And these can ultimately lead to a reduction in blood flow. And of course,

00:10:15.920 it's this reduction in blood flow that leads to what's called ischemia. Ischemia is the reduction

00:10:21.820 in blood flow and therefore the resulting tissue damage that occurs to the heart is what results in

00:10:28.340 a heart attack, which can be fatal depending on the amount of the cardiac tissue that is impeded from

00:10:35.060 appropriate amount of oxygenation. To have this disease, you don't have to be obese. You don't have to

00:10:39.780 have high blood pressure or things of that nature. It's really a question of the cholesterol in your

00:10:45.560 blood. That's really what defines the disease. So the essential condition of atherosclerosis is the

00:10:50.140 presence of cholesterol in the artery wall, which by the way, is not necessarily related to the

00:10:55.180 measure of cholesterol in circulation, which we will talk about in great length. And although these

00:11:00.200 often coexist, patients with cholesterol in their arteries do not necessarily have to have

00:11:05.880 coaggravating factors such as high blood pressure, diabetes, obesity, family history, smoking, all

00:11:12.420 these things that exacerbate it. You mentioned cholesterol a few times, and obviously it's a

00:11:16.840 topic that's been talked about on more podcasts than I can even count or recall right now. But for

00:11:22.700 this conversation, can you define cholesterol just in its simplest form so everyone's aware of exactly

00:11:29.020 what we're talking about as we're going to get into kind of the more nitty gritty?

00:11:32.320 Cholesterol is an organic molecule that resides in the lipid family. So we typically characterize

00:11:39.420 these molecules by their solubility in water, and this is a not soluble in water molecule. So it is a

00:11:47.340 hydrophobic molecule. And I think the easiest way to sort of picture those things is to think about oils.

00:11:53.140 So if you took an oil like olive oil and you poured some of it into a cup of water, you would

00:11:59.860 immediately see what it means to have a hydrophobic substance in contact with something which is the

00:12:06.500 ultimate hydrophilic substance, water, right? So they repel each other. Now, of course, cholesterol is

00:12:11.560 about one of the most important molecules in the body. To be clear, if we didn't have the ability

00:12:17.740 to make cholesterol, we would cease to exist. In fact, you couldn't be born without the ability to do

00:12:23.280 this. There are rare genetic conditions that impair the ability to make cholesterol, and these are

00:12:29.240 uniformly fatal. Why do we need cholesterol? There are broadly two things that cholesterol is essential

00:12:36.280 for. The first is that they contribute heavily to the cell membrane of virtually every cell in the body.

00:12:44.860 So cells are actually kind of fluid things, spherical things. And what allows them to have that fluidity

00:12:52.880 and what allows them to have membrane channels that allow things in and out of them is the cholesterol

00:12:58.380 layer that forms the membrane. And secondly, cholesterol is an essential substrate for the

00:13:04.780 production of some of the most important hormones in the body, cortisol, estrogen, testosterone. It's

00:13:09.720 also essential for the creation of bile acids, which are necessary to be able to digest food. So the

00:13:15.480 mantra that I like to say is no cholesterol, no life, period. You should put that on a bumper sticker on

00:13:20.760 your car. Just roll around Texas with that guy. No, I think that's great. The next section we're going to go

00:13:26.540 through, which has the potential to be a little deeper than a lot of what this conversation is, which is how

00:13:33.500 this all comes about. And luckily, and a quick shout out to Tom Dayspring, who created a bunch of images that

00:13:41.000 we're going to look at. This kind of allows us to dive into this. And so for people who are listening to this, if you can

00:13:48.320 watch a video, it's probably going to be really helpful, but otherwise the show notes will also

00:13:52.560 have all these images. But why don't we look at and discuss, Peter, how does ASCVD come about?

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The Peter Attia Drive - April 18, 2022

#203 - AMA #34： What Causes Heart Disease？

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