According to an article in the New York Times in the field of anti-aging and longevity, scientists are trying to avoid death by conducting experiments on themselves, like taking multiday fasts, dosing themselves with the diabetes drug metformin, or drinking milk laced with high doses of a type of vitamin B that might defend against aging.

How's it working out? So far, not so good. For example, in the 1930s a nutritionist named Clive McCay designed a low-calorie diet for his lab rats that gave them all the nutrients they needed but kept them as thin as supermodels. He claimed that his rats lived to the equivalent of 130 human years. Dr. McCay applied his theories to himself, nibbling on morsels from his own fields. But he didn't make it to 130. Though trim and athletic, he had two strokes and died at 69.

Later, researcher Roy Walford stuck to a 1,600-calorie-a-day diet. In the 1980s, he wrote "The 120 Year Diet" and then followed it up with "Beyond the 120 Year Diet." He became a cult figure to thousands of CRONies ("calorie restriction with optimal nutrition" enthusiasts) who hoped to live past 100. He died at age 79.

Some of the biggest names in dieting, organic agriculture, and preventive medicine died at surprisingly young ages. The wild-foods enthusiast Euell Gibbons was far ahead of his time in his advocacy of a diverse plant diet—but he died at age 64 of an aortic aneurysm. The nutritionist Adelle Davis helped to wake millions of people to the dangers of refined foods like white bread, but she died of cancer at 70. Nathan Pritikin, one of the foremost champions of low-fat diets, died at 69, nearly the same age as Dr. Robert Atkins, who believed in the opposite regimen.

Then there is Jerome Rodale, founder of the publishing empire dedicated to health. In 1971, Dick Cavett invited Mr. Rodale onto his TV show because Rodale had been hailed as "the guru of the organic food cult." Mr. Rodale, 72, took his chair next to Mr. Cavett, proclaimed that he would live to be 100, and then made a snoring sound and died. (The episode never aired.)