Saturated Fat and Cardiovascular Diseases: The Role of Milk Products in Reducing Risk

Arne Vernon Astrup, MD, DSc

Chairman, Department of Human Nutrition, Faculty of Life Sciences, University of Copenhagen; Director, Danish Nordea Foundation, OPUS Research Centre

Current dietary recommendations advocate reducing saturated fatty acid intake to decrease the risk of cardiovascular disease. However, a growing body of evidence suggests that milk products, including cheese, may reduce cardiovascular disease risk despite their saturated fatty acid content.

Highlights:

Saturated fat in and of itself is not associated with an increased risk of cardiovascular disease; its source is of much greater relevance.
Replacing saturated fatty acids with polyunsaturated fatty acids reduces cardiovascular disease risk slightly.
There are no clear benefits in replacing saturated fatty acids with carbohydrates or monounsaturated fatty acids.
Milk products (including full fat, such as cheese) appear to be associated with a reduced risk of cardiovascular disease and type 2 diabetes.

Saturated fat and cardiovascular disease risk

The evidence from epidemiological, clinical and mechanistic studies is consistent in finding that coronary heart disease risk is modestly reduced when polyunsaturated fatty acids replace saturated fatty acids.1 However, there is no evidence of any benefit in substituting carbohydrates or monounsaturated fatty acids for saturated fatty acids,1 and there is no clear association between saturated fatty acid intake, insulin resistance and diabetes risk.1

Milk fat and cardiovascular disease risk

In a recent U.S. prospective cohort study, higher trans-palmitoleate levels, found in full-fat dairy, were associated with a three-fold reduction in the incidence of type 2 diabetes ( ptrend <0.001) as well as significantly lower C-reactive protein levels and insulin resistance.2

Another recent prospective study showed that biomarkers of milk fat were significantly inversely related to a first myocardial infarction in women (with a similar trend in men) and also found an inverse association between myocardial infarction and reported intakes of cheese (in both men and women) and fermented milk (only in men).3

Focus on food

Recent research emphasizes the fact that the overall effect of a food on cardiovascular disease risk cannot be assessed by its content of saturated fat.1 Several observational studies suggest that cheese protects against cardiovascular disease, and experimental studies show that cheese consumption does not produce the effects on blood lipids that would be expected from its saturated fatty acid content. Lorenzen et al. have shown that this phenomenon is partly explained by the high calcium content of cheese. Foods high in saturated fatty acids that are also high in calcium not only do not produce the expected increases in LDL cholesterol but do produce a beneficial increase in HDL cholesterol.4

These data are supported by two recent meta-analyses indicating that milk-product intake is associated with a reduced risk of cardiovascular disease5,6 and type 2 diabetes.5