Statement of CSPI Nutrition Director Bonnie Liebman
The recent Tufts study purporting to show that butter is not linked to a higher risk of heart disease misleads the public. It comes as no surprise that a single food like butter is not linked to a higher risk of heart disease. The highly respected Cochrane Collaboration’s meta-analysis of 15 randomized clinical trials concluded that replacing saturated fat (from all sources) with polyunsaturated fats lowers the risk of heart attacks and other cardiovascular events. (That finding is consistent with clinical studies on blood cholesterol levels and well-designed analyses of observational studies). One would not expect any single food to matter, since people who eat butter don’t necessarily eat an overall diet that is high in saturated fat.
Furthermore, the new meta-analysis based its conclusion on cardiovascular disease on only four observational studies, and two of the four studies masked the impact of butter on the risk of cardiovascular disease by statistically “adjusting” for blood cholesterol levels.
The American Heart Association and American College of Cardiology, in partnership with the National Heart, Lung, and Blood Institute, the 2015 Dietary Guidelines for Americans, and other health authorities recommend replacing foods that are high in saturated fat (like red meat, cheese, and butter) with foods that are high in polyunsaturated fats (like nuts, fish, and salad dressings). The new study acknowledges that unsaturated oils and spreads are healthier than butter—the key takeaway message for consumers. Yet most people will simply hear that butter is a harmless or healthy food, thanks to headlines with various permutations of the “butter is back” myth which is based on questionable evidence.