Saturated fat intake has been linked to increased total and LDL cholesterol levels, both of which can increase risk for cardiovascular disease (CVD). As a result, the 2010 Dietary Guidelines emphasize consuming fewer foods with saturated fats.
Saturated fats are solid at room temperature and are commonly found in butter, animal (beef, chicken, pork) fat and shortening. Whole-fat dairy products (milk, cheese, yogurt) are also a source of saturated fat, making them a target for reducing saturated fat consumption. However, dairy products provide a variety of other important nutrients (calcium, vitamin D, potassium), which is why it’s recommended that Americans substitute whole-fat dairy products with low-fat dairy products rather than eliminate them altogether.
In addition to saturated fat, dairy products have a complex array of nutrients that might actually reduce CVD risk. A review of short-term intervention studies revealed that replacing carbohydrates and unsaturated fat with saturated fat from whole milk and butter increases LDL — theoretically increasing risk for CVD. However, whole-fat dairy products may also increase HDL cholesterol, potentially mitigating or lowering the LDL:HDL ratio, and thereby having a neutral or perhaps beneficial effect on risk for CVD. A more recent review by Markey et al. suggests that with the exception of butter, dairy products are not associated with an increased risk for CVD, and may actually reduce the risk. Both of these reviews suggest more human studies on the relationship between dairy intake and risk for CVD are necessary.
Not all dairy products may be the same. While whole-fat dairy products are often studied under one category, there is the possibility that cheese, yogurt and milk have their own unique impact on CVD risk factors. When comparing cheese and butter intake matched for fat content, Hjerpsted et al. found that after six weeks, compared to butter, cheese actually lowered LDL cholesterol. Sonestedt et al. investigated the relationship between fermented dairy products, such as yogurt and cultured sour milk, and CVD risk. In a group of more than 26,000 individuals, they found a significant inverse association, with the difference between the highest and lowest categories of fermented milk intake being related to a 15 percent lower incidence of CVD.
Together, these studies suggest that fermented whole-fat dairy products, including yogurt and cheese, may lower CVD risk. Ultimately, more human studies that separate the classes of dairy products, including those that look at specific nutrients and mechanisms involved, are necessary before any recommendations can be made.
In addition to calcium, potassium and iodine, dairy products also provide fats that aid the absorption and utilization of the essential fat-soluble vitamins D and A. As an alternative to skimming the saturated fat from dairy products, supplementing the cow’s diet with plant oils or oilseeds can change the fatty acid profile of the milk, replacing the saturated fat with heart-healthy unsaturated fat. While some studies show a reduction in CVD risk when saturated fats are replaced with unsaturated fat, evidence from dairy products specifically is lacking. Currently, the RESET (REplacement of SaturatEd fat in dairy on Total Cholesterol) study that began in late 2013 is comparing the impact of these “modified” dairy products to standard dairy products on CVD risk.
While more human studies are necessary, ultimately, balance and moderation are key. With overall good health, low-fat milk as part of a daily breakfast routine, supplemented with an occasional indulgent whole fat yogurt or cheese product in a reasonable portion, may turn out to be beneficial for CVD risk. The appearance of “modified” dairy products on grocery shelves may also be something to look out for in the coming years.
- Hjerpsted, J., Leedo, E., & Tholstrup, T. (2011). Cheese intake in large amounts lowers LDL-cholesterol concentrations compared with butter intake of equal fat content. The American Journal of Clinical Nutrition, 94(6), 1479-1484.
- Huth, P. J., & Park, K. M. (2012). Influence of dairy product and milk fat consumption on cardiovascular disease risk: a review of the evidence. Advances in Nutrition: An International Review Journal, 3(3), 266-285.
- Markey, O., Vasilopoulou, D., Givens, D. I., & Lovegrove, J. A. (2014). Dairy and cardiovascular health: Friend or foe?. Nutrition Bulletin, 39(2), 161-171.
- U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2010. 7th Edition, Washington, DC: U.S. Government Printing Office, December 2010.
- Siri-Tarino, P. W., Sun, Q., Hu, F. B., & Krauss, R. M. (2010). Saturated fat, carbohydrate, and cardiovascular disease. The American Journal of Clinical Nutrition, 91(3), 502-509.
- Sonestedt, E., Wirfält, E., Wallström, P., Gullberg, B., Orho-Melander, M., & Hedblad, B. (2011). Dairy products and its association with incidence of cardiovascular disease: the Malmö diet and cancer cohort. European Journal of Epidemiology, 26(8), 609-618.
- Tholstrup, T. (2006). Dairy products and cardiovascular disease. Current opinion in lipidology, 17(1), 1-10.