Diet-Heart Hypothesis

As George Mann wrote at the end of his career in 1978, a “heart Mafia” had “supported the dogma” and hoarded research funds. “For a generation, research on heart disease has been more political than scientific,” he declared.

Ahrens chose a nine-member task force representing the full range of scientific views on the diet-heart hypothesis. The panel deliberated for several months over each link in the chain of the diet-heart hypothesis, from eating saturated fat, to total cholesterol, to heart disease. The results, however, were not exactly welcome news to diet-heart supporters like Hegsted or Keys. For instance, one issue the panel agreed upon was that the evidence condemning saturated fat was not persuasive. Moreover, the most they could say about fat generally was that it could be linked to heart disease only indirectly. The core problem was, as it had always been, the near-absence of clinical trial data on the low-fat diet, leaving only epidemiological studies. These studies, as we know, could show association but not prove causation. They had been enough for the Hegsted camp but not for the Ahrens camp.

The final report from the Ahrens task force in 1979 made it clear that the majority of its members remained highly skeptical of the idea that reducing fat or saturated fat could deter coronary disease. The group hadn’t explicitly said that the dietary goals would do harm, however, and so Hegsted chose to take this as a green light. Using the same tenuous logic as did Keys in assuming that he was right until proven wrong, Hegsted asked rhetorically: “The question . . . is not why should we change our diet, but why not? What are the risks associated with eating less meat, less fat, less cholesterol?” The view in ascendance among nutrition experts was that Americans should “hedge their bets” against heart disease by reducing dietary fat until more evidence emerged. Hegsted imagined that “important benefits could be expected,” and he could not imagine the costs. Ahrens’s committee countered that the principle of “doing no harm” demanded harder proof before proceeding with a change in the American diet, but Hegsted was not persuaded by this argument. And ultimately, the USDA was accountable not to academic scientists but to the US Congress, which had ruled definitively in favor of a new low-fat regime.

The New York Times essentially took a poll: “at least 18 other health organizations and the Federal Government supported a reduction in fat and cholesterol,” wrote the editors, with only the academy and the American Medical Association on the other side. The diet’s potential costs—an increased heart disease risk from the carbohydrates, an increased risk of cancer from polyunsaturated oils, or a lack of adequate nutrition for children—were not part of the discussion. The Times concluded, “The Federal Government still thinks a prudent person should eat less fat and cholesterol. Unless the academy can authoritatively demonstrate Government error, a prudent person will do just that.”

Here, then, was the new reality: a political decision had yielded a new scientific truth. Contrary to the normal scientific method, which requires that a hypothesis be tested before it can be considered viable, in this case politics short-circuited the process, and an untested hypothesis was elevated as the reigning doctrine, presumed to be right until proven wrong.

For the academy’s report, the death knell was surely sounded on June 1, 1980, when the New York Times ran a front-page story about two board members and their ties to industry: Robert E. Olson, a biochemist at St. Louis University School of Medicine, had consulted for the egg and dairy industries, and Chairman Harper for the meat industry. These accusations were true. But again, corporate food interests were attempting to influence both sides of the debate. At the same time that two board members had been found to have ties to the meat, dairy, and egg industries, two other members of the academy’s board were food company employees, one with the spice maker McCormick and Company, and another with the Hershey Foods Corp. And from the start, the board had been funded by the Nutrition Foundation, whose members included General Foods, Quaker Oats, Heinz Co., and Corn Products Refining Co., among other major food corporations.

Even despite this powerful lobby, the board had stood firm against the new low-cholesterol, low-fat diet recommendations. “Our attitude at the time,” said Chairman Harper unapologetically in an interview when he was eighty-four years old, “was that if you had a competent person who was an adviser to a food company, there was no reason why they shouldn’t serve on the board.”

The press and public knew little of these widespread entanglements on all sides of the debate. They only picked up the impression that meat packers and egg farmers were corrupt, a view fostered by the press coverage. The health dangers of saturated fats had already come to be taken so much for granted by this point that pro-animal-food voices were presumed to have ulterior motives. Critics called Toward Healthful Diets “conspiratorial” and “slipshod,” and US Representative Fred Richmond of New York stated openly that lobbyists for the food industry “must have been at work here.”

The furor over the report startled academy scientists unaccustomed to this public gnashing of teeth. Philip Handler, head of the academy, told a friend that Toward Healthful Diets received more attention than had all the academy’s numerous other erudite publications in recent years. “We were naïve about the politics,” he said, and quipped, “you lose some, you lose some.”

In the summer of 1980, the House and the Senate each held hearings on the report, and the academy’s reputation was raked over the coals. “Without too much doubt, the [House] committee’s intention was to crucify Handler,” judged Science magazine. Indeed, wrote the Washington Post editorial board, the report had “soiled” the board’s and the academy’s reputations for giving “careful scientific advice.” The report had been a rigorous and fair-minded effort and contained far more expert analysis than did Mottern’s, but publicity is powerful, and the widespread disparaging view of the board’s work on the Toward Healthful Diets report has unfortunately endured until today. Because the academy is one of the few scientific groups that provides checks and balances against the work of other authoritative bodies on the subject of nutrition and disease (the others being the NIH, the USDA, and the AHA), the collapse of the academy’s skeptical report on this issue was a significant event, for it left no formal scientific group to weigh in as the opposition.

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