Over the last couple of years, the US government has had to back away from decades of dietary recommendations and health directives. Now whole milk may be the next line of retreat. Not only did science find no connection between whole milk and cardiovascular disease more than 40 years after urging people to stop using it, it turns out the science behind the initial recommendation was flawed — and known to be so at the time:

Whether this massive shift in eating habits has made anyone healthier is an open question among scientists, however. In fact, research published in recent years indicates that the opposite might be true: millions might have been better off had they stuck with whole milk.

Scientists who tallied diet and health records for several thousand patients over ten years found, for example, that contrary to the government advice, people who consumed more milk fat had lower incidence of heart disease.

By warning people against full-fat dairy foods, the U.S. is “losing a huge opportunity for the prevention of disease,” said Marcia Otto, an assistant professor of epidemiology at the University of Texas, and the lead author of large studies published in 2012 and 2013, which were funded by government and academic institutions, not the industry. “What we have learned over the last decade is that certain foods that are high in fat seem to be beneficial.”

Note that this finding does not limit itself to the now-widely accepted point that replacing saturated fats with carbohydrates turned out to be a terrible idea, and pushed Americans further toward obesity. In this case, the fat in whole milk appears to be beneficial in itself. That hypothesis became the focus of a new series of tests, one that focused on actual consumption of dairy fat against development of heart disease, rather than correlation on overall diet. Surprise:

Otto and Mozaffarian used a blood sample for each of more than 2,800 U.S. adults. Using the blood sample, they could detect how much dairy fats each had consumed. And over the eight-year follow up period, those who had consumed the most dairy fat were far less likely to get  heart disease compared to those who had consumed the least.

So how did the US government conclude that whole milk should be discouraged? By claiming the science was settled when it actually wasn’t:

But even as a Senate committee was developing the Dietary Goals, some experts were lamenting that the case against saturated fats was, though thinly supported, was being presented as if it were a sure thing.

“The vibrant certainty of scientists claiming to be authorities on these matters is disturbing,” George V. Mann, a biochemist at Vanderbilt’s med school wrote in the New England Journal of Medicine.

Ambitious scientists and food companies, he said, had “transformed [a] fragile hypothesis into treatment dogma.”

Golly, doesn’t that sound … familiar? At least no one suggested locking up saturated-fat “deniers” at the time.

Perhaps the best lesson from these retreats from disastrous health directives over the last four decades is that government should get out of that business entirely. And while they’re exiting the dietary-diktat business, they should exit the climate-change business as well.