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More to the point, the U.S. continues to have one of the highest rates of heart disease in the world. Last year more than a million Americans suffered heart attacks; more than half of them died as a result. Because most of the victims are in their prime productive years, mainly men in their 40s and 50s, the economic and social toll is huge, leaving aside the tragic personal waste. According to the National Heart, Lung and Blood Institute, deaths from heart attacks cost an estimated $60 billion in medical bills, lost wages and productivity, or more than last year's total Medicare budget.
For decades, researchers have been trying to prove conclusively that cholesterol is a major villain in this epidemic. It has not been easy. Cholesterol is, after all, only one piece in a large puzzle that also includes obesity, high blood pressure, smoking, stress and lack of exercise. All of these play their part in heart disease "like members of an orchestra," explains Pathologist Richard Minick of the New York Hospital-Cornell Medical Center.
To make matters more complicated, an individual's susceptibility to these factors depends on inherited traits. Thus, while a fatty diet and smoking may mean early death for one man, another can puff away, gorge on steaks and banana splits and still live to a ripe old age.
Cholesterol has been perplexing researchers since 1769, when French Chemist Poulletier de la Salle first purified the soapy-looking yellow-white substance. Despite its bad reputation, cholesterol is essential to life: it is a building block of the outer membrane of cells, and it is a principal ingredient in the digestive juice bile, in the fatty sheath that insulates nerves, and in sex hormones such as estrogen and androgen. Although most of the cholesterol found in the body is produced in the liver, 20% to 30% generally comes from the food we eat.
Doctors first became suspicious about cholesterol, particularly the cholesterol in diet, when they looked inside the diseased arteries of heart attack victims. There, instead of smooth, supple vessels, they saw what looked like brittle, old pipes, clogged and hardened by deposits of cholesterolthe condition now known as atherosclerosis. In 1913, Russian Pathologist Nikolai Anitschkow showed that he could produce similar deposits, or plaques, in the arteries of rabbits just by feeding them a diet rich in cholesterol. Subsequent research further supported the connection between diet and cardio-vascular disease. Epidemiologist Ancel Keys conducted a landmark study in seven nations beginning in 1947. He discovered direct correlations between a country's incidence of heart disease, the level of cholesterol in the blood and the amount of animal fat in the national diet. The Finns, with the fattiest diet, had the highest cholesterol levels and the highest rate of heart disease; the Americans, with a diet only slightly less rich, were a close second. But the Japanese, who eat a diet low in fat, had the lowest cholesterol levels and the least cardiovascular disease. Their rate of fatal heart attacks was one-fourth the American incidence. A later study showed that when Japanese emigrated to the U.S. and adopted a Western diet, their incidence of heart disease soared to ten times that of their countrymen in Japan.