Saturated fatty acids and coronary heart disease risk: the debate goes on

Recently published meta-analyses of cohort studies and randomized controlled trials (RCTs) have challenged the link between saturated fatty acid (SFA) intake and coronary heart disease (CHD) risk. This review considers the outcome of these studies in the context of other evidence.

Recent meta-analyses of cohort studies suggest that reducing SFA intakes has little impact on CHD risk when replaced by carbohydrates. The evidence for benefits on CHD risk of replacing SFA with unsaturated fatty acids in cohort studies is stronger and is also supported by data from a recent Cochrane analysis of RCTs of dietary SFA reduction and CHD risk. This review highlights the challenges of cohort studies involving diet because of the changing patterns of dietary behaviour and other multifactorial risk factors. The studies included are normally conducted over many years and are often dependent on a single measurement of dietary intake.

The link between SFA intake, plasma cholesterol, and CHD risk is based on a broad range of evidence including mechanistic studies, RCTs of surrogate end points and clinical outcomes, as well as multinational population comparisons. Public health nutrition policy should continue to take into account the totality of evidence with recognition of the limitations of dietary cohort studies.