Dr. Kim A. Williams, the President-Elect of the American College of Cardiology, recently published an essay, “Vegan Diet, Healthy Heart?” which has sparked passionate debate.1 “I didn’t know it would create such a firestorm of everything from accolades to protests,” said Williams.2 His essay describes how his LDL cholesterol level dropped from 170 to 90 within six weeks of adopting a vegan diet. He now encourages patients with diabetes, hypertension, coronary artery disease, and high cholesterol to consider going vegan.
By now, most people recognize the distinction between HDL, the so-called “good cholesterol,” and LDL, “bad cholesterol.” The distinction regarding LDL particle size, however, is just as important, but not universally known. LDL varies by particle size—small and large—and only small particle LDL should be labeled “bad.” Small, dense LDL particles tend to accumulate within the arteries, contributing to arterial plaque.3 Conversely, large, buoyant LDL particles float through the bloodstream and are far less likely to accumulate. Observational studies suggest small-particle LDL predicts heart disease at more than three times the rate of large-particle LDL.4
Neither William’s essay nor the response published in The New York Timesmentioned anything about this important distinction between small and large particle LDL. Most healthy individuals have predominantly higher proportions of large-particle LDL and for these people diets lower in carbohydrates and higher in fat have been shown to promote healthier blood cholesterol levels.5 Some people, however, are genetically predisposed to a phenotype characterized by a predominance of small-particle LDL and for these people diets lower in fat and higher in carbohydrates may promote healthier blood cholesterol levels.6
The Paleo Diet, of course, includes animal foods, some of which contain significant amounts of saturated fat. Dr. Williams stops short of recommending vegan diets for everyone, but readers of his essay might wrongly suppose the Paleo Diet promotes unhealthy blood cholesterol levels and that vegan diets, which are typically lower in saturated fat and higher in carbohydrates, are healthier. This might be true if not for the fact that size does matter regarding LDL—and bigger is better. Research shows that dietary carbohydrates, particularly simple sugars and starches with high glycemic indexes, increase small-particle LDL.7 From a cholesterol perspective, these are the foods to avoid. Saturated fat, on the other hand, increases only large-particle LDL, which is benign.8
And what about Paleo foods like eggs, which contain higher amounts of dietary cholesterol? Dr. Williams wrote about switching to a “cholesterol-free” vegan diet, implying that dietary cholesterol negatively impacts blood cholesterol. The scientific literature, however, doesn’t support this implication. Clinical studies show dietary cholesterol actually reduces small-particle LDL and only increases large-particle LDL, the benign variety, while also increasing HDL, thus promoting proper LDL/HDL ratios.9 Furthermore, according to a recent review, “current epidemiologic data have clearly demonstrated that increasing concentrations of dietary cholesterol are not correlated with increased risk for cardiovascular disease.”sup>10 There’s no reason, therefore, to forgo animal foods. The Paleo Diet naturally promotes healthy blood cholesterol levels.
Christopher James Clark, B.B.A. is an award-winning writer, consultant, and chef with specialized knowledge in nutritional science and healing cuisine. He has a Business Administration degree from the University of Michigan and formerly worked as a revenue management analyst for a Fortune 100 company. For the past decade-plus, he has been designing menus, recipes, and food concepts for restaurants and spas, coaching private clients, teaching cooking workshops worldwide, and managing the kitchen for a renowned Greek yoga resort. Clark is the author of the critically acclaimed, award-winning book, Nutritional Grail.
1. Williams, Kim. (July 21, 2014). CardioBuzz: Vegan Diet, Healthy Heart? MedPage Today. Retrieved August 8, 2014.
2. O’Connor, Anahad. (August 6, 2014) Advice From a Vegan Cardiologist. The New York Times. Retrieved August 8, 2014.
3. Voros, S., et al. (November 2013). Apoprotein B, small-dense LDL and impaired HDL remodeling is associated with larger plaque burden and more noncalcified plaque as assessed by coronary CT angiography and intravascular ultrasound with radiofrequency backscatter: results from the ATLANTA I study. Journal of the American Heart Association, 2(6). Retrieved August 8, 2014 from http://www.ncbi.nlm.nih.gov/pubmed/24252842
4. Lamarche, B., et al. (January 1997). Small, dense low-density lipoprotein particles as a predictor of the risk of ischemic heart disease in men. Prospective results from the Québec Cardiovascular Study. Circulation, 95(1). Retrieved August 8, 2014 from http://www.ncbi.nlm.nih.gov/pubmed/8994419
5. Krauss, RM. (February 2001). Atherogenic lipoprotein phenotype and diet-gene interactions. Journal of Nutrition, 131(2). Retrieved August 8, 2014 from http://www.ncbi.nlm.nih.gov/pubmed/11160558
7. Siri, PW., et al. (November 2005). Influence of dietary carbohydrate and fat on LDL and HDL particle distributions. Current Artherosclerosis Reports, 7(6). Retrieved August 8, 2014 from http://www.ncbi.nlm.nih.gov/pubmed/16256003
8. Dreon, DM., et al. (May 1998). Change in dietary saturated fat intake is correlated with change in mass of large low-density-lipoprotein particles in men. American Journal of Clinical Nutrition, 67(5). Retrieved August 8, 2014 from http://ajcn.nutrition.org/content/67/5/828.short
9. Fernandez, ML., Calle, M. (November 2010). Revisiting dietary cholesterol recommendations: does the evidence support a limit of 300 mg/d? Current Artherosclerosis Reports 12(6). Retrieved August 8, 2014 from http://www.ncbi.nlm.nih.gov/pubmed/20683785