heart disease

Things That Won't Kill You Volume 4: Saturated Fat Part II: Cholesterol Myths

Feb 5 2010

image In retrospect, this probably could have been an entirely separate article in the "things that won't kill you" series, as many people still believe that dietary cholesterol (i.e. cholesterol in food) is a bad thing. For example, the article that image was taken from claims:

If you get too much dietary cholesterol (over 300mg a day) the extra cholesterol will accumulate in the walls of the blood vessels, making your LDL (bad) blood cholesterol levels rise. Over time, your arteries will become narrower, which can cut off the blood supply to your heart (causing a heart attack), or your brain (causing a stroke).

However, that's pretty easily dismissed—even Ancel Keys, "Monsieur Cholesterol" himself, never argued that dietary cholesterol was related to serum cholesterol or heart disease. In a 1952 article in Circulation, the journal of the American Heart Association, Keys noted that although rabbits and chickens that eat high-cholesterol diets will develop high cholesterol and atherosclerosis, or hardening of the arteries:

No animal species close to man in metabolic habitus has been shown to be susceptible to the induction of atherosclerosis by cholesterol feeding…. Moreover, even in the favorite species for such  experimentation, the herbivorous rabbit, the necessary concentration of cholesterol in the diet is fantastically high in comparison with actual human diets. Moreover, there is reason to believe that man has a greater power of cholesterol regulation than does the rabbit or the chicken. From the animal experiments alone the most reasonable conclusion would be that the cholesterol content of human diets is unimportant in human atherosclerosis.

Two "moreovers" in one paragraph, people! “Most reasonable conclusion”! Moreover, five decades of subsequent research haven't given anyone any reason to think differently. In 1997, Keys was even more direct:

There’s no connection whatsoever between cholesterol in food and cholesterol in blood. And we’ve known that all along. Cholesterol in the diet doesn’t matter unless you happen to be a chicken or a rabbit.

Research done in the interim on the relationship between diet and heart disease in humans like the Framingham and Tecumseh studies showed no relationship between cholesterol consumption and blood cholesterol or heart disease. I'm not even going to modify this with "probably" or "as far as we know": There is no reason to believe that how much cholesterol you eat has any effect on your health.

But that doesn’t stop the AHA from recommending that “most people…limit cholesterol intake to less than 300 mg per day” and claiming that “an egg can fit within heart-healthy guidelines for those people only if cholesterol from other sources — such as meats, poultry and dairy products — is limited.” Despite repeated studies showing that egg consumption is not associated with higher serum cholesterol, myocardial infarction, cardiovascular disease, or all-cause mortality. Read more