Last week, Rajiv Chowdhury, an epidemiologist at Cambridge University, reported in the Annals of Internal Medicine that an exhaustive review of studies on fats in the diet had found no evidence that eating saturated fat increased the risk of heart disease.
“My take on this would be that it’s not saturated fat that we should worry about” in our diets, he told Anahad O'Connor at The New York Times.
Science writers who reported that finding were then left with the problem of how to account for decades of research and advice that seemed to say the opposite.
They struggled.
The conclusion seems to be that nobody is quite sure how to reconcile the old advice with the new finding. Here is the best that five reporters could come up with:
1. Let's start with O'Connor at the Times. She tracked down Frank Hu, a professor of nutrition and epidemiology at Harvard, who said the findings "should not be taken as 'a green light' to eat more steak, butter and other foods rich in saturated fat." Looking at saturated fats and other nutrients in isolation could be misleading, he said, adding, "I think future dietary guidelines will put more and more emphasis on real food rather than giving an absolute upper limit or cutoff point for certain macronutrients.” Clear?
2. Cari Nierenberg at LiveScience, by way of The Huffington Post. She spoke to Linda Van Horn, a professor of preventive medicine at Northwestern, who said, "the paper questions the strength of the evidence underlying recommendations for eating a lot of polyunsaturated fats or limiting saturated fats. But the study stops short of making clear exactly what 'high' and 'low' mean, as well as determining what people's total fat intake should be." She concluded: "The findings don't change anything that is in the American Heart Association (AHA) recommended diet because the study does not say that saturated fat is not a problem." Beware the double negative.
3. Allison Aubrey at NPR. Dariush Mozaffarian of Harvard told her, contrary to what we've long been told, that saturated fat has a relatively neutral effect. It's "not a beneficial effect but not a harmful effect," he said. So is saturated fat good or bad? The answer, Mozaffarian told her, depends on what you're eating instead; replacing saturated fats with carbohydrates has no benefits. "Not everyone is convinced by the new studies," Aubrey writes. Which leaves us–where?
4. "Eat All the Fried Chicken You Want," screams the headline on Jacqueline Leo's story at her startup The Fiscal Times. (Leo is the former editor in chief of Reader's Digest and Consumer Reports.) Leo doesn't track anyone down; she does the interpretation herself. "It’s not that LDL cholesterol, also known as the 'bad cholesterol' found in saturated fats, is suddenly good for you. Just that the connection between saturated fat and cholesterol is more complicated," she writes. And "finally, you don’t have a green light to overeat — so don’t go gorging on fried chicken. Eating fat is not an excuse for being fat."
5. An unbylined story at The Economist. "Those who micromanage their diets instead of following Michael Pollan’s sensible rule of thumb—eat food, not too much, mostly plants—may be thrown into confusion by a paper just published in the Annals of Internal Medicine," it begins. And it likewise tries to do without the services of an outside expert. "Dr Chowdhury and his colleagues are not suggesting that the amount of fat you eat has no bearing on your risk of having a heart attack. What their research does suggest is that, trans-fats aside, the type of fat may not matter." Does the research suggest that? Not according to the other reports. The Economist, like those who micromanage their diets, has apparently also been thrown into confusion.
It's a tough assignment, trying to sort out what we should do now. My take? If you want to lower your risk of heart disease, you'll probably have to be hungry a lot. That's from an unpublished longitudinal study with a sample size of one. And it's a least as good as some of the advice being dished out by the experts.
-Paul Raeburn
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