Does the Keto Diet Increase Cholesterol?
One of the most common concerns that people have when starting a ketogenic diet
is whether it will increase their cholesterol. It’s a perfectly understandable concern –
– after all, we’ve been told for decades to watch our consumption of saturated fat
because it can increase cholesterol and the risk of heart disease.
Studies show, however, that even though low-density lipoprotein (LDL) levels can
sometimes increase on a keto diet, keto can also improve overall cholesterol profiles
and reduce the risk of heart disease. As it turns out, the concept of cholesterol is
much more complicated than we tend to think.
Cholesterol Levels vs. Particle Size
When we think of cholesterol, we typically think of cholesterol levels. We know that
high LDL is bad, and high high-density lipoprotein (HDL) is good. But cholesterol
level is just one marker of cardiac health. It’s cheap and easy to measure, so it’s long
been the standard of evaluating cholesterol in the blood.
Another important metric is particle size, which may be an even better indication of
heart disease risk. LDL exists in different sizes. Some LDL particles are large and
fluffy, others are small and dense. The small, dense particles are more dangerous.
Studies have found that people with high levels of small LDL particles have three
times the risk of coronary heart disease.
Larger LDL particles may have a protective effect. One study found that higher levels
of large LDL particles are associated with lower levels of plasma triglycerides.
Elevated triglycerides are a risk factor for heart disease. High carbohydrate
consumption is the major driver of both elevated plasma triglycerides and smaller
LDL particles, according to Stephen Phinney, MD, Ph.D., and Jeff Volek, Ph.D., RD,
authors of The Art and Science of Low Carbohydrate Living.
The Effects of the Keto Diet on Cholesterol
Phinney and Volek note that the keto diet does two important things in terms of
cholesterol. First, the keto diet “significantly and consistently” increases LDL
particle size. Low-fat, high-carbohydrate diets have the opposite effect and lead to
higher levels of smaller, more dangerous LDL particles.
Second, the keto diet increases levels of HDL cholesterol (the good kind) by as much
as 20.6%. Higher levels of HDL have been shown to help lower the risk of
cardiovascular disease and may also reduce chronic inflammation and the risk of
Together, this increase in LDL particle size and HDL concentrations contribute to
decreased risk of death from heart disease, even if LDL concentrations increase
If you are considering adopting a ketogenic diet and cholesterol is a concern for you,
you may want to find a doctor who is familiar with the effects of low-carbohydrate
diets on cholesterol, and who can monitor your cholesterol markers as you
progress. Relying primarily on LDL levels to evaluate heart disease risk may lead
you to miss a large part of the picture, and thus reject a dietary approach that can
offer numerous health benefits.