By: Nicole Recine RN MSN CDE
I am frequently asked if elevated cholesterol should be a concern on a ketogenic diet. Many people see a jump in their total cholesterol and/or LDL cholesterol after switching to a higher fat, lower carb way of eating. Their doctors may urge them to stop the diet or start taking a cholesterol-lowering medication. Is there reason to worry?
High cholesterol has become synonymous with heart disease risk. We are endlessly advised to lower our intake of dietary fat as a means to promote heart health. Although most medical professionals will tell you that eating dietary fat, particularly saturated fat, increases your risk for heart disease, the evidence to support this advice is lacking.
Is Cholesterol A Risk On Ketogenic Diet?
This “diet-heart hypothesis” was first proposed in the 1952 when Ancel Keys, a prominent biochemist at the time, suggested that there was a link between the consumption of dietary fat and heart disease. Elevated blood cholesterol was thought to “clog” arteries, causing heart disease. While dietary fat can raise cholesterol in many people, there was never evidence to show that reducing dietary fat or lowering blood cholesterol levels improves cardiac health. Nonetheless, this hypothesis became accepted as fact, and in 1977 the McGovern Committee released the Dietary Goals for the United States. This first edition of the Food Guide Pyramid instructed Americans to restrict dietary fat to less than 30% of total intake.
In the decades to follow, researchers would attempt to find evidence to justify the guidelines, but would continue to come up empty handed. In fact, studies conducted since have shown that there is virtually no association between dietary saturated fat intake, blood cholesterol levels, and heart disease. Further, there is no causal, mechanistic explanation as to how saturated fat or dietary cholesterol independently leads to the formation of atherosclerotic plaque.
What actually happens when we restrict carbohydrate and increase dietary fat?
- Insulin levels drop leading to increased lipolysis (breakdown of fat)
- Blood ketone levels rise and can be used for energy
- Inflammation decreases as evidenced by a reduction in key inflammatory markers
- Specific markers for cardiac and metabolic disease improve
– Normalized blood glucose
– Lower triglycerides
– Increased HDL-C
– Improved LDL particle size
– Normalized blood pressure
It is time we stop basing our understanding of dietary fat and heart disease on an outdated hypothesis that was never proven true. It will likely be some time before official dietary recommendations change. In the meantime, I continue to recommend dietary advice that is based on evidence rather than on guidelines never supported by reliable science.
About The Author:
Nicole Recine is a nurse practitioner that specializes in diabetes. Nicole was a featured speaker at the 2017 KetoCon. Watch her KetoCon presentation.
Sources/References:
Feinman, R. D., Pogozelski, W. K., Astrup, A., Bernstein, R. K., Fine, E. J., Westman, E. C., … Worm, N. (2015). Dietary carbohydrate restriction as the first approach in diabetes management: Critical review and evidence base. Nutrition, 31(1), 1–13. https://doi.org/10.1016/j.nut.2014.06.011
Hu, T., & Bazzano, L. A. (2014). The low-carbohydrate diet and cardiovascular risk factors: Evidence from epidemiologic studies. Nutrition, Metabolism and Cardiovascular Diseases, 24(4), 337–343. https://doi.org/10.1016/j.numecd.2013.12.008
Parodi, P. W. (2016). Dietary guidelines for saturated fatty acids are not supported by the evidence. International Dairy Journal, 52(Supplement C), 115–123. https://doi.org/10.1016/j.idairyj.2015.08.007
Siri-Tarino, P. W., Sun, Q., Hu, F. B., & Krauss, R. M. (2010). Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. The American Journal of Clinical Nutrition, 91(3), 535–546. https://doi.org/10.3945/ajcn.2009.27725
Taubes, G. (2001). The Soft Science of Dietary Fat. Science, 291(5513), 2536–2545.
Teicholz, N. (2014). In The big fat suprise: Why butter, meat, and cheese belong in a healthy diet. (pp. 19–71). Simon & Schuster.
