Encore: Why Normal Cholesterol Doesn't Always Mean Low Heart Disease Risk

**Dr. Mark Hyman** (0:00)
Let me ask you this. If cholesterol were truly the main cause of heart disease, then why the half the people who have heart attacks have normal LDL levels? There was a study like 136,000 people had heart attacks with ER, and 75% had a quote normal LDL level. So that begs the question, then what the hell is going on here?
Welcome back to Office Hours. Over the summer, we're revisiting a few of the conversations that resonate with most with our audience, and this one was at the very top of the list. When this episode first aired, it sparked a huge response because it challenged something many of us have been told for decades and that is this, cholesterol is the primary driver of heart disease. Well, it might not be, and we'll find out why if you listen. In this conversation, I dive into the latest science around cholesterol and inflammation, around insulin resistance, and something called ApoB, which is super important to know about, and metabolic health. And I ask whether we've been focusing on the wrong markers all along. What's interesting is that since this episode first came out, the conversation around cardiovascular risk has only continued to evolve. And listening back today, many of these insights feel even more relevant than they did the first time. So whether you're hearing about it for the first time or coming back for a second listen, I think you'll walk away with a different perspective on what really drives heart disease risk and what you can do about it. Let's get into it. So today I want to talk about something I've changed my mind about over the years, cholesterol and heart disease. Now, heart disease is the number one kill of Americans since the 1950s, and yet so many are still approaching it with the same outdated framework that we'd used for decades. Now, for a long time, cholesterol was seen as the enemy. You got to get it as low as possible. You got to avoid fat. You got to take a statin.
And that was what we're all told. That's what doctors are trained in. And that's the story most people still believe. You go to your doctor, they check your labs, they do a cholesterol test, and they do the wrong one, by the way. And that's why at Function Health, we do the right ones, including ones you never get from your doctor, like APO-B, which is far more important than all the other cholesterol tests, and LP-LA, which most people don't check, which is a highly important genetic marker.
So, you gotta know your numbers, but you gotta know the right numbers. So, doctors check your old cholesterol number, they see your LDL is high, they go, LDL, high, let's get lower, take a statin, without really much thought. And that's unfortunate because it's a much more nuanced problem than just a statin deficiency that's causing heart disease. And the latest research shows that we need to think about this differently. With my patients, I've also learned a lot, and how variable people respond to different things. I've had people with extremely high cholesterol that do extremely well on an extremely high-fat ketogenic diet and lower their cholesterol. And other people who are the opposite, who will take a keto diet and actually make their cholesterol worse. So, you've got to really look at individuals and figure out what's going on. Here's what I used to believe. I got trained, like every other doctor, that LDL was the issue. That you had a high cholesterol, high LDL, that causes heart attacks, cause and effect. And the goal was to lower your LDL no matter what, at all costs. Get it as low as possible. We also learned that saturated fat is bad because it can raise your cholesterol, particularly LDL cholesterol. So, the message is pretty simple, but it wasn't accurate for most people. Real life clinical work really changed that simplicity. When you graduate from medical school, you think you know everything, but you start practicing medicine and after 30 or 40 years, you really don't know that much and how everybody's different. And there's not the simplicity that we think applies to certain things like LDL, heart disease, statin, cure. It's just not so simple. We've treated cholesterol like a villain, but the truth is really way more nuanced. What did the old model get wrong? Well, the new science that's emerging has identified a couple of key problems. The first is that total cholesterol is actually a poor predictor of heart disease. Up to 50 percent or even more in some of the studies, of people who have heart attacks have a quote normal LDL level. The risk really comes from something that's not being tested by almost every doctor in the country. I mean, I asked Quest, who is our lab testing partner in Function Health, how many cholesterol tests use the right cholesterol test, which looks at the quality and the size and the number of your cholesterol particles, not just the weight of them, which is what you get with your normal cholesterol test, but the quality and the size, whether they're small or big, whether they're dense or not, and how many of those particles do you have? You know what they said? Less than 1 percent, 1 percent of their tests do this. The second big aha that came actually since I graduated from medical school, probably in the late 1990s, maybe early 2000s, was the insight, particularly from Harvard and the scientist Paul Ritker, who wrote a very seminal paper in the New England Journal of Medicine that it was inflammation that was causing heart disease, not cholesterol.