vascular health than we’d been in the past, but
unfortunately, many doctors still dole out outdated advice.
We don’t know everything, but it has become increasingly
clear that if there is a dietary super-villain out there, it is not
saturated fat. In 2010, Dr. Ronald Krauss, a top nutrition
expert in the United States who was involved in coauthoring
many of the early dietary guidelines, concluded in a meta-
analysis that “there is no significant evidence for concluding
that dietary saturated fat is associated with an increased risk
of CHD [coronary heart disease] or CVD [cardiovascular
disease].”^2
Still, the “diet-heart hypothesis”—or the idea that
cholesterol in and of itself causes heart disease—persists.
This hypothesis originates from initial studies on
atherosclerosis, a disease in which plaque builds up to create
a hardening and narrowing of the arteries. In these studies,
plaques from dissected cadavers were found to be filled with
cholesterol. In fact, this is the basis for the catchy, oft-cited
idea that “eating fatty foods clogs your arteries,” which
likens our complex biology to what happens when you pour
grease down a cold drain. Because saturated fat does raise
cholesterol, and cholesterol-rich foods, you know, have
cholesterol in them, reducing intake of both became the
focus of efforts for the prevention and treatment of
cardiovascular diseases. But biology is seldom simple. As it
turns out, cholesterol is often the innocent bystander—
present at the scene of the crime, but rarely the villain itself.
Many nutrition scientists, including Ancel Keys, the
father of the diet-heart hypothesis, try to reduce whole foods
to their constituent “nutrients”—and who could blame