For more than a generation now, saturated fat has been high on what might be called the nutritionist’s most wanted list: an artery-clogging villain whose appearance in the form of, say, a cheeseburger oozing grease has practically screamed, “Heart attack!”
But this week, in the equivalent of a not-guilty verdict for a suspect everyone thought had wielded the gun, came shocking news from scientists: “Eh, saturated fats aren’t so bad after all.”
In a massive new study published in the journal Annals of Internal Medicine and led by docs from Cambridge University and the Harvard School of Public Health, researchers reported they found no link—repeat, no link—between consumption of saturated fats and heart attacks or other cardiovascular problems. Saturated fats are found mostly in meat and dairy products.
“My take on this would be that it’s not saturated fat that we should worry about,” lead author Dr. Rajiv Chowdhury of Cambridge told The New York Times.
It’s baffling news (especially for anyone who took the time to try to understand what the hell was the difference between HDL and LDL cholesterol), but it’s not completely surprising. Earlier studies, such as one published in 2010, came to similar conclusions.
But the current study is undoubtedly one of the largest to try and rid saturated fats of their almost murderous reputation. Chowdhury and his colleagues pored over almost 80 studies involving more than half a million people looking for evidence that saturated fat consumption correlated with higher rates of heart disease, and they found none. The study did, however, confirm the long-standing link between trans fat and heart problems.
Critics, such as Harvard nutrition professor Frank Hu, said that one reason Chowdhury's analysis came to the conclusion that it did is that people who cut back on saturated fats replaced the calories with other unhealthy foods. That wouldn't show saturated fats aren't bad for you, just that they're no worse than poor substitutes. And it's true that studies have demonstrated the ability of a vegan diet to prevent and even reverse the effects of heart disease.
Experts were also quick to caution that such findings shouldn’t be taken as evidence that saturated fat is good for you. If it’s not the serial killer it’s long been made out to be, it isn't the guy you want to march down the aisle to the altar with either. “It’s not a beneficial effect but not a harmful effect” is how one study coauthor put it to NPR.
As Alice H. Lichtenstein, a nutritionist at Tufts University and lead author of the dietary guidelines for the American Heart Association, tells the Times: “It would be unfortunate if these results were interpreted to suggest that people can go back to eating butter and cheese with abandon.” Lichtenstein notes that prior studies have indeed found that avoiding saturated fats in favor of foods high in polyunsaturated fats (think fish, nuts, and certain vegetable oils) reduces the risk of heart disease.
For its part, the AHA isn’t budging on dietary guidelines that encourage minimal consumption of saturated fat; in a statement it indicated, “The study published Monday doesn’t change the American Heart Association recommendation of a diet that’s rich in fruits and vegetables, whole grains, nuts, fish and unsaturated fats.”
Other health experts, including some involved in the recent study, agree. Dr. Dariush Mozaffarian, associate professor at the Harvard School of Public Health and coauthor of the study, takes the line of many experts, telling NPR that people should shift from the high-carb, highly processed, and (yes) saturated-fat-laden foods that have come to define the Western diet to one that focuses on “minimally processed whole foods,” such as fruits, vegetable, fish, and nuts (with a bit of cheese and meat thrown in).
Lead author Chowdhury has even stronger words about carbs, telling the Times: “It’s the high carbohydrate or sugary diet that should be the focus of dietary guidelines. If anything is driving your low-density lipoproteins [i.e., “bad” LDL cholesterol], it’s carbohydrates.”