Eisenhower’s cholesterol hit 259 just six days after University of Minnesota physiologist Ancel Keys made the cover of Time magazine, championing precisely the kind of supposedly heart-healthy diet on which Eisenhower had been losing his battle with cholesterol for five years. It was two weeks later that the American Heart Association—prompted by Keys’s force of will—published its first official endorsement of low-fat, low-cholesterol diets as a means to prevent heart disease. Only on such a diet, Keys insisted, could we lower our cholesterol and our weight and forestall a premature death. “People should know the facts,” Keys told Time. “Then if they want to eat themselves to death, let them.”

Scientists justifiably dislike anecdotal evidence—the experience of a single individual like Eisenhower. Nonetheless, such cases can raise interesting issues. Eisenhower died of heart disease in 1969, age seventy-eight. By then, he’d had another half-dozen heart attacks or, technically speaking, myocardial infarctions. Whether his diet extended his life will never be known. It certainly didn’t lower his cholesterol, and so Eisenhower’s experience raises important questions.

Establishing the dangers of cholesterol in our blood and the benefits of low-fat diets has always been portrayed as a struggle between science and corporate interests. And although it’s true that corporate interests have been potent forces in the public debates over the definition of a healthy diet, the essence of the diet-heart controversy has always been scientific. It took the AHA ten years to give public support to Keys’s hypothesis that heart disease was caused by dietary fat, and closer to thirty years for the rest of the world to follow. There was a time lag because the evidence in support of the hypothesis was ambiguous, and the researchers in the field adamantly disagreed about how to interpret it.

From the inception of the diet-heart hypothesis in the early 1950s, those who argued that dietary fat caused heart disease accumulated the evidential equivalent of a mythology to support their belief. These myths are still passed on faithfully to the present day. Two in particular provided the foundation on which the national policy of low-fat diets was constructed. One was Paul Dudley White’s declaration that a “great epidemic” of heart disease had ravaged the country since World War II. The other could be called the story of the changing American diet. Together they told of how a nation turned away from cereals and grains to fat and red meat and paid the price in heart disease. The facts did not support these claims, but the myths served a purpose, and so they remained unquestioned.