Researchers: Rethink Saturated Fat Intake Advice

ROSEMONT, Ill.New research supported by the U.S dairy industry suggests that saturated fat intake has a very limited impact on cardiovascular disease risk, and experts should rethink the saturated fat is bad" dietary advice.

Based on science presented at the 100th American Oil Chemists Society (AOCS) annual meeting in Orlando, Fla., a series of research articles published in the October issue of Lipids examines recent advances in saturated fat and health research.

The relationship between dietary intake of fats and health is intricate, and variations in factors such as human genetics, life stage and lifestyles can lead to different responses to saturated fat intake," said J. Bruce German, PhD, professor and chemist in the Department of Food Science and Technology, University of California at Davis. Although diets inordinately high in fat and saturated fat are associated with increased cardiovascular disease risk in some individuals, assuming that saturated fat at any intake level is harmful is an oversimplification and not supported by scientific evidence."

Results from a research review conducted by Dariush Mozaffarian, MD, MPH, Department of Epidemiology and Nutrition at Harvard University School of Public Health, found that the effects of saturated fat intake on CVD risk depend upon simultaneous changes in other nutrients. For example, replacing saturated fat with mono-unsaturated fat yielded uncertain effects on CVD risk, while replacing saturated fat with carbohydrates was found to be ineffective and even harmful especially when refined carbohydrates such as starches or sugars were used in place of fat. Replacing saturated fat with polyunsaturated fat gave a small reduction in CVD risk, but even with optimal replacement the magnitude of the benefit was very small. Mozaffarian noted it would be better to focus on dietary factors giving much larger benefits for CVD health, such as increasing intake of seafood/omega-3 fatty acids, whole grains, fruits and vegetables, and decreasing intake of trans fats and sodium.

Another review revealed very low-carbohydrate diets can favorably impact a broad spectrum of metabolic syndrome and cardiovascular risk factors, even in the presence of high saturated fat intake and in the absence of weight loss.

Kiran Musunuru, MD, PhD, MPH. Cardiovascular Research Center and Center for Human Genetic Research, Massachusetts General Hospital, focused on the role of carbohydrates and fats on atherogenic dyslipidemiaa new marker for CVD risk often seen in patients with obesity, metabolic syndrome, insulin resistance and type 2 diabetes. He showed that low-carbohydrate diets appear to have beneficial lipoprotein effects in individuals with atherogenic dyslipidemia, compared to high-carbohydrate diets, whereas the content of saturated fat in the diet has no significant effect.

According to the researchers, as long as saturated fat targets remain firmly rooted in dietary advice, nutrient-rich foods that contribute saturated fat to the diet, like full-fat dairy products, will continue to be unduly criticized regardless of their health benefits.

In fact, a recent meta-analysis of epidemiological and intervention studies of milk fat conducted by Peter Elwood, DSc, MD, FRCP, FFPHM, DUniv, Hon DSc, Honorary Professor at the School of Medicine, Cardiff University, found that milk and dairy consumption actually was associated with a decrease in CVD risk.

It is clear that we have barely scratched the surface in our understanding about the biological effects of saturated fatty acids," said Cindy Schweitzer, PhD, Technical Director, Global Dairy Platform.  Scientific meetings where researchers from different disciplines within the field of nutrition share information are extremely important to identify both the gaps in our knowledge and the studies that are needed to answer the important questions about diet and health."