Ketogenic diet and cholesterol, are they related?

Cholesterol, despite being demonized throughout the years by the scientific and medical community, is necessary. The body needs cholesterol to function properly at all levels (from cells to tissues to organs). Funny enough, diet is one of the so called “dangers” or “causes” for high cholesterol. Therefore, people who are trying to follow a healthy diet tend to avoid it, and people who want to do a ketogenic diet are most likely afraid because of all the fat. That’s why it is important to speak about the interactions between a ketogenic diet and cholesterol to relief and clarify fears and doubts.

What is cholesterol?

Let’s start from the basics. Cholesterol is one of many organic molecules in the body. It is often described as a “waxy” or “fatty” substance and that’s because it is a lipid. It is found in 2 states, unesterified and esterified. Unesterified cholesterol can be absorbed by your body, while esterified cannot. However, esterified cholesterol can be turned into unesterified cholesterol through “digestion” (to avoid technicalities) if it’s required.

Where do you find cholesterol?

Cholesterol is a molecule synthesized by animal cells, meaning we can find it amongst the animal kingdom (humans included). This means two things; First, that we already contain cholesterol (in fact, the majority of your body’s cholesterol is synthesized by the liver, around 2000mg, if you’re curious). And Second, we can find cholesterol in foods coming from the animal kingdom; from beef to milk.

What does cholesterol do?

Well, to picture its importance let me tell you something you might already know: All animal cells have membranes. Now, let me tell you something you might NOT know: Cholesterol represents a good amount of the cell’s membranes (Around 30%, in fact). And what’s its job? Well, put in simple terms, it gives mobility to the cells.

On top of that, cholesterol is the precursor of many substances your body needs such as hormones (like estrogens, androgens and progestogens) and bile acids. This means cholesterol plays a very important role in hydration homeostasis, sexual drive, digestion, mood, immune response, and so on.

What about “good cholesterol” and “bad cholesterol”?

You may have heard of HDL (high density lipoprotein) and LDL (low density lipoprotein), also called good and bad cholesterol respectively. Well for starters, let me tell you something, the majority of lipid panels do not measure the cholesterol level itself, but the quantity of “carriers”. And when we speak about LDL and HDL, is not only quantity that matters but quality (size). This means that the “usual” lipid panels are not the very best at providing an accurate picture of your health state.

HDL as well as LDL have a place and a purpose to be, you may think about LDL as a bandaid which helps healing, and HDL as the cleaning personal. So, when one artery becomes damaged, LDL brings up cholesterol and helps with the healing process, after that, its HDL’s job to come and clean up. This is when things come up together, if you have too much LDL and low HDL, there is a higher chance for the “cleaning” not to be done properly and start building a “plaque”. However, this is where the quality comes into play, since LDL’s size influences the oxidation (small ldl particles oxidize much faster), to a point where some people argue if low and small LDL is worse than a higher LDL with larger size. Check out the following video.

Ketogenic diet and cholesterol

So, what happens to your cholesterol levels when you are on a ketogenic diet (consuming plenty of fatty foods, a lot of them containing cholesterol)? Good question. Well, a ketogenic diet promotes the usage of fats for fuel, this means you consume more and you also use more. In term the fat levels on your bloodstream (triglycerides/cholesterol) remain more or less steady. But not only that. A high fat consumption diet increases the size of LDL particles which seem to contribute less to the buildup of plaque in your arteries. Finally a high fat consumption diet increases the HDL (so called good cholesterol) levels, which appears to be, yet another benefit of the ketogenic diet.

Why do we believe cholesterol is so bad?

Well, it all comes down to a really shady and tricky misinterpretation of statistics quite a few years ago. I’d be lying if I’d tell you I know all the details, so please, watch the following video if you’re interested. And if you rather read up on it there’s a whole series of articles on Peter Attia’s blog, called “the straight dope on cholesterol”, you can start reading them by clicking on the name.