If you’re keto, you’ve heard it before. The single most common response given by people who are not familiar with the ketogenic diet and lifestlye is that you’re going to clog your arteries, get heart disease, and die.
I’m asked all the time how keto people should respond to that objection. I’m asked by keto people about what kind of evidence they can use to prove that keto isn’t dangerous.
I’ll be honest with you, that irritates me.
What irritates me isn’t the fact the keto people are seeking evidence. That’s great. I love that.
What irritates me is that keto people feel like they should be playing defense. You don’t owe anyone an explanation or defense of what you choose to eat.
Your health is your responsibility and you can only answer to yourself. You don’t owe anyone else an explanation for your food.
Okay, so enough about my irritation.
Back to the question: What do you say to someone who claims that keto will result in clogged arteries, cardiovascular disease, heart attacks, or death?
The first thing I say, in response, is: Why do you think that’s true?
The thing is, most people don’t really know WHY they believe that keto is dangerous, they’re just parroting what they’ve heard all their lives. And they have no real basis for their belief.
I mean, they have no real scientific basis for their belief. The idea that high levels of cholesterol is dangerous is known as the Diet Heart Hypothesis. This hypothesis was first put forth by Ancel Keys in 1955. It states that eating high levels of saturated fat will increase your cholesterol, and increased cholesterol will clog arteries and cause heart disease.
The first part of that hypothesis is correct. The second part is wrong.
Eating a lot of saturated fat will increase your cholesterol.
So what? Why is increased cholesterol bad?
Well, it turns out that, in a general sense, it isn’t. But it’s more involved than that. This requires some further explanation. So let’s start from the beginning.
What is cholesterol?
Cholesterol is a type of molecule known as a “steroid alcohol.” Every cell in your body needs cholesterol. 75% of all your average required cholesterol is produced by the body. The rest (25%) is consumed through food. Only animals use cholesterol. The average human body contains roughly 30 to 40 grams of cholesterol, most of which resides in cell membranes. Pretty much every cell can make cholesterol.
Most people are familiar with the two major types of cholesterol molecules: HDL (High-density Lipoprotein) and LDL (Low-density Lipoprotein). And most of the time, these molecules are identified as good and bad, respectively. But, that’s a bit of an oversimplification.
First of all, the “lipoprotein” in this scenario is a special molecule that has one job, transport cholesterol. So when you hear someone talking about HDL or LDL cholesterol, they aren’t really talking about cholesterol, they’re talking about the protein that is wrapped around the cholesterol. These lipoproteins come in different sizes. HDL is a larger protein particle and LDL is a smaller protein particle.
So when you hear about HDL and LDL levels, you’re hearing about the volume of larger and smaller protein particles. Remember, the HDL and LDL are not cholesterol, they are just the shells used to transport cholesterol.
But wait…there’s more.
There are actually two kinds of LDL particles (typically called “patterns”). Pattern A LDL is large, “fluffy,” and buoyant. Pattern B LDL is small and dense. Pattern B LDL proteins tend to get stuck in the nooks and crannies of blood vessels (arteries, especially). These are the primary culprit for “clogged arteries.” Pattern A LDL proteins are too big to get stuck in blood vessels.
So, if you’re keeping track, pattern B is the “bad” LDL and pattern A is the “awesome” LDL. Remember, they aren’t bad or awesome because of their job. Their job is to move cholesterol around the body. They are bad or awesome because of their size. The smaller the transport protein, the worse it is for you.
Okay, so HDL is the bigger form of lipoprotein, pattern A LDL is the bigger form of LDL. Both of those are considered “good.” So, when it comes to cholesterol transport proteins, bigger is better.
REMEMBER: The cholesterol INSIDE LDL and HDL are the same. It’s only the size of the molecule that is wrapped around the cholesterol that differs.
What does a cholesterol test mean?
It’s these differences in molecule sizes that allows us to measure the different kinds of lipoproteins. So when you hear someone refer to their HDL or LDL numbers, they are talking about the number of HDL or LDL molecules in their blood. In general, more HDL is good. In general, less LDL is good.
But, hang on, remember that there are two sizes of LDL particles: particle A (awesome) and particle B (bad).
The standard cholesterol test does not measure LDL particle sizes (LDL-P). It only measures TOTAL amounts (total cholesterol, total HDL, and total LDL). But with no insight into the actual lipoprotein sizes, the LDL number isn’t necessarily an accurate representation.
The problem with this is that it’s the B particles that cause the biggest problems. Remember, since particle B molecules are very small, they are the ones that get stuck in nooks and crannies of the arterial and vascular walls. Having more B particles will be bad. But, having more A particles won’t necessarily be bad. But if all you get is the TOTAL LDL (which is typical), you have no idea of your actual particle composition. So it’s possible that a high LDL number, without any context or further testing is not a problem at all.
The solution is pretty simple. Request an LDL-P test to get an idea of your LDL particle makeup.
HDL, since it’s considered a good cholesterol lipoprotein, is okay if it’s higher in number.
What is the relationship between keto and cholesterol?
In short, a well-formulated ketogenic diet will likely increase your cholesterol. The reason for this is that keto emphasizes a large amount of saturated fat in the diet, and high levels of saturated fat will increase cholesterol. Now, because of Ancel Keys, we’ve be taught that high cholesterol is a problem. However, putting it bluntly, Ancel Keys was wrong. In this meta-analysis of 21 well-formulated studies the conclusion was that there is absolutely no relationship between high levels of cholesterol and heart disease or cardiovascular disease.
In fact, in this study, keto was shown to favorably affect biomarkers such as cholesterol, as they relate to heart disease.
So keto will increase your cholesterol (likely), but increased cholesterol has no scientific causal relationship to any sort of heart disease or cardiovascular disease. In fact, studies like the one above show that keto has BENEFICIAL impact.
Keto will increase your cholesterol, because your body is getting more cholesterol from food. So guess what your body will do when you increase the dietary cholesterol…that’s right, it’ll stop producing its own cholesterol. Since 75% of your cholesterol is made inside your body, if you increase the amount that you eat, your body will cut that 75% down. Your body isn’t stupid. It knows what it needs.
So eat more fat. Enjoy. And tell the other people that cholesterol is perfectly okay.
Or just ask if you can have their bacon.