In the last few years the virtues of a low-fat diet have gradually come undone, though some “nutritional anthropologists” keep the faith like those Japanese soldiers in the island jungles who refused be believe World War II was over. Yesterday the Washington Post reported on how the full data from a major nutrition study that helped cement the old conventional wisdom was never fully analyzed, but might have saved us from error (and saved some lives) if it had been:
It was one of the largest, most rigorous experiments ever conducted on an important diet question: How do fatty foods affect our health? Yet it took more than 40 years — that is, until today — for a clear picture of the results to reach the public. . .
Today, the principles of that special diet — less saturated fat, more vegetable oils — are included in the Dietary Guidelines for Americans, the government’s official diet advice book. Yet the fuller accounting of the data indicates that the advice is, at best, unsupported by the massive trial. In fact, it appears to show just the opposite: Patients who lowered their cholesterol, presumably because of the special diet, actually suffered more heart-related deaths than those who did not. . .
The new researchers, led by investigators from the National Institutes of Health and the University of North Carolina, conclude that the absence of the data over the past 40 years or so may have led to a misunderstanding of this key dietary issue.
“Incomplete publication has contributed to the overestimation of benefits and underestimation of potential risks” of the special diet, they wrote.
Good thing this could never happen with climate science. What’s that you say?
But Broste suggested that at least part of the reason for the incomplete publication of the data might have been human nature. The Minnesota investigators had a theory that they believed in — that reducing blood cholesterol would make people healthier. Indeed, the idea was widespread and would soon be adopted by the federal government in the first dietary recommendations. So when the data they collected from the mental patients conflicted with this theory, the scientists may have been reluctant to believe what their experiment had turned up.
“The results flew in the face of what people believed at the time,” said Broste. “Everyone thought cholesterol was the culprit. This theory was so widely held and so firmly believed — and then it wasn’t borne out by the data. The question then became: Was it a bad theory? Or was it bad data? … My perception was they were hung up trying to understand the results.”