The Limited Evidence for Reducing Saturated Fat Intake for Cardiovascular Disease: A Commentary on the Cochrane Collaboration Review.

The new Dietary Guidelines for Americans have sparked a controversy, wherein the advocation of foods rich in saturated fat is regarded as "antiscientific" and a strong evidence base is cited regarding the reduction of saturated fat in the diet. The Cochrane Collaboration reviews are typically considered the most authoritative on the topic, as evidenced by the nearly 1500 citations of their most recent publication demonstrating a clinically meaningful reduction of 17% in cardiovascular events when replacing saturated fat with other nutrients, namely carbohydrates and polyunsaturated fats. Crucially, however, despite the authors stating the exclusion of studies with multiple dietary modifications, in 8 of the 10 studies analyzed for cardiovascular events, the intervention group differed notably in terms of energy intake and weight loss, and/or the amount of care and attention afforded by the researchers. Because all these factors may have independent effects on cardiovascular health, the present commentary contends that the observed effects cannot reasonably be attributed to the reduction of saturated fat in the diet. To establish the effects of saturated fat intake on cardiovascular health, trials exercising a greater degree of control on dietary aspects other than the variable of interest are needed.