Ketogenic Diet and Cardiovascular Disease

The ketogenic diet, also known as the “keto diet,” is a low-carbohydrate, high-fat dietary regimen that causes the body to burn fat for energy instead of carbohydrates. A number of health benefits have been attributed to the keto diet, including improved cardiovascular health, improved brain function, weight loss, and even reduced risk of certain cancers. In other words, the keto diet is purported to slow the diseases of aging. 

Let’s look at some information about the effect of the ketogenic diet on cardiovascular disease:

The keto diet increases ketones in the bloodstream, which may have beneficial cardiovascular effects. Ketone bodies produced by the liver provide energy to the heart and may improve the function of the vascular endothelium. Cells lining blood vessels that are crucial in the development of atherosclerosis. The anti-inflammatory effects of ketosis may be at least partially responsible for this. In addition, eliminating harmful, simple sugars combined with the potential increase in omega-3 fatty acids may promote cardiovascular health.

The blood lipid profile includes total cholesterol, low-density lipoprotein (LDL, the so-called “bad cholesterol”), high-density lipoprotein (HDL, the so-called “good cholesterol”), and triglycerides (TG). Abnormalities in these parameters are called “dyslipidemia” and constitute a significant risk of cardiovascular disease. 

Several relatively recent studies have shown that the lowest risk of death from cardiovascular disease is with total cholesterol of about 200 to 250, i.e., lower levels are not necessarily positive. LDL, HDL, and TG levels that are very low or very high may be unhealthy. In other words, the effects of cholesterol and TG on cardiac risk are complex and not completely understood.

Other studies underscore the ambiguity of the effects of the keto diet on cardiovascular risk. In a year-long study of overweight adults with type 2 diabetes, TG levels dropped and HDL levels rose; on the other hand, LDL levels also increased, so the net benefit, if any, was unclear. 

The impact of the amount and type of fat consumed on the blood lipid profile and its elements is controversial. A study comparing the keto diet to a standard diabetes diet in overweight or obese patients with type 2 diabetes showed a greater reduction in total cholesterol, LDL, TG, and body weight in the keto diet group. These effects could have been related to the increased consumption of olive oil, avocado, and fish in the keto group rather than ketosis per se. Not all keto diets are equivalent with respect to the types of fat represented. It may be that those with higher content of unsaturated fats produce more beneficial results, but this has not been well studied.

Some researchers attribute the benefits of the keto diet at least in part to weight loss. While the keto diet may help overweight and obese patients lose weight, the weight loss is often temporary. 

In short, there continues to be disagreement among experts regarding the keto diet and cardiovascular risk. Authors of one recent publication stated, “Given the totality of the evidence of the effect of the ketogenic diet on the blood lipid profile, there is certainly a preponderance of evidence of a beneficial effect.” This may be largely based on the keto diet’s anti-inflammatory effects and reduced sugar intake. On the other hand, another recent article from Harvard is entitled, “Keto diet is not healthy and may harm the heart.”

Note: Although I am a physician, the content in this article is not meant to diagnose, treat, cure or prevent illness or disease in the reader – it is for educational purposes only.

References

1. Kim YG, Jeong JH, Han KD, et al. Association between low-density lipoprotein cholesterol and sudden cardiac arrest in people with diabetes mellitus. Cardiovasc. Diabetol. 2023; 22: 36.
2. Li S, Lin G, Chen J, et al. The effect of periodic ketogenic diet on newly diagnosed overweight or obese patients with type 2 diabetes. BMC Endocr Disord 2022; 22:34.
3. Saslow LR, Daubenmier JJ, Moskowitz JT et al. Twelve-month outcomes of a randomized trial of a moderate-carbohydrate versus very low-carbohydrate diet in overweight adults with type 2 diabetes mellitus or prediabetes. Nutr Diabetes 2017;7:304.
4. Dynka D, Kowalcze K, Charuta A, Paziewska A. The ketogenic diet and cardiovascular diseases. Nutrients 2023;15:3368.
5. Corliss J, Keto diet is not healthy and may harm the heart. https://www.health.harvard.edu/heart-health/keto-diet-is-not-healthy-and-may-harm-the-heart, May 1, 2024.