meat-based carnivore diets. And some of the concerns is, oh my God, I'm going to have a heart attack because my cholesterol might go high. And it's an unrelenting fear that people have. I continuously get that question.
I try to be a little nuanced about it, but maybe you can talk a little bit about that particular topic, if you don't mind. Yeah. First of all, I can't take credit.
So I actually first learned about this idea from Malcolm Kendrick and he from one of his Scottish professors, I believe. There's been smart people that have come before who have played this pathway. But Before we get on to this actual theory, the elephant in the room is that the reason that we demonize red meat, one of them is largely because it contains saturated fat. And there's this fear that you eat saturated fat, your cholesterol levels in your blood will rise and you'll die of a heart attack.
So the first point that I'd make is that there is no known mechanism by which saturated fat can actually increase blood cholesterol levels. I mean, that probably sounds quite shocking because we've all heard this repeated ad nauseum end on end. And the simple truth is there's not one defined mechanism by which saturated fat in the diet can increase the level of cholesterol, LDL, IDL, VLDL, whatever you talk about, there's no mechanism by which it can actually increase it.
There's two factors at play here. Okay. There's some factors that lower cholesterol and some factors that raise cholesterol.
Now, the main factor that lowers cholesterol is something called fake plant cholesterol called phytosterols. Basically, it's very similar to real human cholesterol, the human cholesterol that we make testosterone out of, that every cell membrane depends on its survival force, thyroid hormone, all of these things that depend on cholesterol. The fake plant cholesterol will disturb the normal physiological functioning, which is a good thing.
And the body understands this because it rejects the vast majority of these plant-based chemicals coming in our diet. And by the way, the way that most people get the highest dose of these fake cholesterol is in seed oils and vegetable oils, including coconut oil. So the body will only allow you to absorb one or two percent, which is a good thing. And interestingly enough, we've got some diseases where people through genetic mutations actually overabsorb this, their body isn't very effective at keeping these plant sterols out. That condition is called cytosterolemia.
And that condition is defined as early, premature, same thing, severe atherosclerotic disease. So people think people having heart attacks in their 30s. And that's because of this fake plant cholesterol, which seed oils, vegetable oils are incredibly rich in. Now, one of the things that these do, because they interfere with the normal function of cholesterol, they lower your cholesterol level.
So now think what happens. Somebody's on a standard Western diet. They're just chowing down massive amounts of these fake plant cholesterols, and then they eliminate them from their diet and replace them with saturated fat. What's going to happen to their cholesterol level? Well, you assume if it's suppressing, it would cause it to rise, correct?
Right. It's going to go up. So you've got the appearance that cholesterol is going up.
But in actual fact, in that situation, what's happening is that your cholesterol is just being restored to a normal, healthy physiological level. One thing that we can't ignore is that we have this U-shaped mortality curve with cholesterol levels. And we know that people, when their cholesterol goes low, then their risk of death is actually significantly, statistically elevated.
But when their cholesterol passes a certain point, their risk of mortality, it's not as steeply rising, but it still does rise. So that does indicate that there's some factors which could cause cholesterol to go higher that may be deleterious. Now, we know it's not saturated fat because there's no mechanism for that.
But there's other things that we do know cause it to go higher. For example, if anybody's sitting in front of a computer now, Google B12 and cholesterol synthesis, and you'll see that the mechanism and the proof that... B12 deficiency leads to an increase in cholesterol biosynthesis. This is well established.
Same is true for folate. So let's say, for example, so these people with slightly elevated cholesterol levels who are exhibiting that increase in mortality, they may be having some nutrient deficiency. Now, it can also be inflammation. There's what we call inflammatory cytokines, these little chemicals that swim around in your blood. And they're associated with inflammatory states like autoimmune disease.
And one of them is called tumor necrosis factor alpha. And we've got pretty solid evidence that TNF alpha is a direct driver of cholesterol synthesis. And here's the kicker. So we've identified that some people.
on ketogenic and carnivore-style diets, their cholesterol levels rise beyond the pale. It's not just to a level where we say that's just a return of normal physiological levels, but they're skyrocketing. And in some of those cases, in some of my patients, what I'm actually identifying is that some of the foods which they've been consuming on carnivore, ketovore-style diets are actually triggering inflammation, not everything that derives from animal is actually necessarily a good food for everybody.