The Evidence against Saturated Fat: Epidemiological Studies

Of the vast quantities of imperfect data that were interpreted to support the diet-heart hypothesis, much came not from clinical trials but from large epidemiological undertakings, of the kind that Keys had pioneered with his Seven Countries study. These are studies where the diets of populations are not changed in any way: they are simply observed over time, and at the end, investigators try to link health outcomes such as disease and death back to their subjects’ dietary patterns. Researchers had done these kinds of studies earlier—on the Italians in Roseto, the Irish, the Indians, and others—but those efforts had all been much smaller. The new studies followed thousands of people over many years, and their results made a highly influential contribution to the growing body of scientific papers that were used by experts to support the diet-heart hypothesis.

Stamler inherited one of the earliest of these studies, involving two thousand men who worked at the Western Electric Company near Chicago. The men were medically evaluated and their diets measured from 1957 onward. In the paper’s abstract, which is often the only part of scientific papers that busy doctors and scientists ever read, Stamler wrote that his results supported cholesterol-lowering through diet. But the results, after twenty years of study, actually showed that diet affected blood cholesterol only a tiny bit and that the “amount of saturated fatty acids in the diet was not significantly associated with risk of death from CHD [coronary heart disease],” as the authors wrote. It seems clear that Stamler could not countenance such results. In the discussion section of the paper, he and his colleagues dismiss their own data outright and immediately move on to talk about other studies that did have the “correct” outcome.

When I asked Stamler about that, he said, “What we showed was that saturated fat had no independent effect on end points.”

“So, in the end, saturated fat in the diet didn’t matter, right?” I asked.

“It had no INDEPENDENT effect,” Stamler yelled, meaning that on its own, it didn’t matter. The Western Electric Study has nevertheless been regularly cited in support of the diet-heart hypothesis.

​

Abstract

​

"Since the Fall of 1957, a long-term study of coronary heart disease has been in progress at the Hawthornie Works of the Western Electric Company in Chicago under the auspices of the University of Illinois College of Medicine and Presbyterian-St. Luke 's Hospital. The study was unidertaken in the belief that coronary heart disease was a disease resulting from the interplay of multiple factors and that there was indeed to delineate these factors further. The data presented herein represent the initial compilation of data centering on this problem; a discriminiate functional analysis is to be undertaken next. The report which follows has been made possible through the efforts of a large group of physicians and other scientists who have volunteered their time in the project to permit the accumulation of a large body of data, a portion of which is presented below. Acknowledgment must also be made to the Western Electric Company, which has been most cooperative and helpful throughout, to its employees who have participated in the study, and to the agencies and donors partially recognized below* who have financed the survey since its inception."