Washington: A 98-year-old American researcher argues that, contrary to popular assumption, dietary cholesterol is good for your heart - unless that cholesterol is unnaturally oxidized (by frying foods in reused oil, eating lots of polyunsaturated fats, or smoking).
The researcher, Fred Kummerow, an emeritus professor of comparative biosciences at the University of Illinois, has spent more than six decades studying the dietary factors that contribute to heart disease.
In a new study, he reviews the research on lipid metabolism and heart disease with a focus on the consumption of oxidized cholesterol - in his view a primary contributor to heart disease.
"Oxidized lipids contribute to heart disease both by increasing deposition of calcium on the arterial wall, a major hallmark of atherosclerosis, and by interrupting blood flow, a major contributor to heart attack and sudden death," Kummerow wrote in the review.
Oxidized fats contribute to heart disease (and sudden death from heart attacks) in an additional way, Kummerow said. He and his collaborators found that when the low-density lipoprotein (LDL, the so-called "bad cholesterol") is oxidized, it increases the synthesis of a blood-clotting agent, called thromboxane, in the platelets.
If someone eats a diet rich in oxysterols and trans fats and also smokes, he or she is endangering the heart in three distinct ways, Kummerow said. The oxysterols enhance calcification of the arteries and promote the synthesis of a clotting agent. And the trans fats and cigarette smoke interfere with the production of a compound, prostacyclin, which normally keeps the blood fluid.
"And that causes 600,000 deaths in this country each year," Kummerow said.
The study has been published in the American Journal of Cardiovascular Disease.