It might be logical to think that a ketogenic diet, which is high in fat, must be high in bad cholesterol. But in fact, nothing could be further from the truth. Plenty of modern scientific and nutritional research shows that high-fat, low-carb diets can optimize cholesterol levels and improve your heart health.
To understand the relationship between a keto diet and cholesterol, let’s first define some terms. What exactly is cholesterol?
First we must understand that there are two classifications of fats in the body: triglycerides and cholesterol. Triglycerides are fatty-acid molecules that store energy for later use, and can be broken down for energy. Too many triglycerides in the blood can increase risks of developing diabetes, cardiovascular illnesses and other life-threatening diseases.
Cholesterol is a waxy lipid produced in the liver that support functions in the body, such as building hormones, maintaining the integrity of cell membranes, and aiding in the absorption of vitamins.
About 75% of cholesterol is produced inside of your body and the remaining 25% of cholesterol is typically consumed from animal protein. When talking about cholesterol, you may hear some common terms such as HDL and LDL. It’s important to note that these are not cholesterol molecules, but lipoproteins that help transport cholesterol around the body. Let’s go over some of these terms.
You may have heard HDL often referred to as “the good cholesterol.” HDL transports cholesterol around the body, and collects and returns unused cholesterol back to the liver to be recycled or destroyed. That’s how HDL prevents other cholesterol from accumulating and clogging arteries.
Some studies have shown that HDL cholesterol may also have anti-inflammatory effects. There needs to be more research done on HDL cholesterol, but overall, there is consensus among clinicians and scientists that HDL-cholesterol is healthy for the body.
LDL, or low-density lipoprotein, is frequently known as “the bad cholesterol”, but is a little bit more complex than that. Unlike HDL, LDL molecules move slowly through the bloodstream and are vulnerable to oxidizing agents known as “free radicals.” Once oxidized, LDL can easily burrow itself into the walls of your arteries and impede cardiovascular function. This triggers an inflammatory response in which white blood cells called macrophages rush to eat up the LDL, which can cause further buildup.
Many people consider higher levels of LDL to be unhealthy, but the size and density of these particles matter, too. The cheapest and most common test for measuring LDL is known as LDL-C, will measures the concentration of cholesterol transported by LDL in the blood.
The second method is called LDL-P, which measures the number of LDL particles in the blood. Recent research shows that it is important to know both the size and density of the LDL particles, as larger LDL particles are considered to be healthier for the body. Where does keto fit in with all of this? According to a recent meta-analysis published in the British Journal of Nutrition, a study was conducted between people on a low-carb ketogenic diet and people on a low-fat diet.
After a year, the results were staggering: The group on the keto diet showed double the average increase in HDL compared with the low-fat group. The authors concluded that carbohydrate-restricted diets improve levels of HDL, and thusly, help to boost cardiovascular health.
Other studies have been concluded on LDL, showing that a low-carbohydrate diet has favorable effects on LDL particle concentration, LDL particle size, and quantity of VLDL particles. In one of the more convincing meta-analysis done, lauric and stearic acids, found in coconut and animals fats, respectively, can favorably affect HDL cholesterol levels. Because these fats are so abundant in a keto diet, total-to-HDL cholesterol ratios are improved.
Studies have further shown an improvement for blood sugar and triglyceride levels when carbs are replaced with fat. So, when you restrict carbohydrates and the majority of your calories come from animal fats, coconut oil and unsaturated fats, like fish, nuts, avocado, and olive oil, it is highly likely that you will improve your cholesterol levels and lipid profile. With all that said, cholesterol is a complex and nuanced topic, so if you want more information or a deeper dive into the source material for some of these studies, be sure to read through the article “The Ketogenic Diet and Cholesterol” on Ruled.Me.