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New Evidence Reveals that Saturated Fat Does Not Increase the Risk of Cardiovascular Disease

Andrew Mente, PhD

Assistant Professor, Department of Clinical Epidemiology and Biostatistics, McMaster University

A recent meta-analysis by Siri-Tarino and colleagues evaluated the effects of dietary saturated fat on cardiovascular risk by summarizing the data from 21 prospective cohort studies (n= 347,747; ~30-80 years of age). Sixteen of the studies had coronary heart disease (CHD) as their endpoint, while eight had stroke.

Most of these studies (88%) did not demonstrate a conclusive link between dietary saturated fat and CVD incidence after adjustment for potential confounders, including other nutrients. In fact, two of the studies found a significant inverse association with stroke.¹

The pooled relative risk estimates that compared extreme quantiles of saturated fat intake were:

• 1.07 (95% CI: 0.96, 1.19; p = 0.22) for CHD
• 0.81 (95% CI: 0.62, 1.05; p = 0.11) for stroke, and
• 1.00 (95% CI: 0.89, 1.11; p = 0.95) for CVD.¹

Another recent meta-analysis that we conducted included prospective cohort studies or randomized trials that investigated dietary exposures in relation to CHD. We found that higher intakes of the following dietary components were not significantly associated with an increased risk of CHD:² eggs, meat, milk products, saturated fatty acid and total fat.

We found strong evidence that trans fatty acids and foods with a high glycemic index or load are associated with increased CHD risk. A significant benefit was associated with a Mediterranean dietary pattern (which emphasizes a higher intake of vegetables, legumes, fruits, nuts, whole grains, cheese or yogurt, fish, and monounsaturated fat). Only a relatively small number of cohort studies have shown that either a higher intake of polyunsaturated fatty acids or a lower intake of saturated fatty acids is related to a reduced risk of CHD.² More research is needed to clarify the benefit with respect to polyunsaturated fatty acids.

Highlights

1. Present evidence suggests that saturated fat does not increase the risk of cardiovascular disease.
2. No causal relationship has been established between milk products and cardiovascular risk.
3. Factors associated with an increased risk of coronary heart disease include trans fatty acids and high glycemic-index foods.

Keywords: saturated fat , coronary heart disease , cardiovascular disease , stroke