Sugar Plays Greater Role in Heart Disease Than Saturated Fats

A new study claims that the effect of consuming a diet high in sugar on atherosclerotic coronary heart disease (CHD) is more detrimental than that of saturated fat.

Researchers at Saint Luke's Mid America Heart Institute (Kansas City, MO, USA) and Albert Einstein College of Medicine (New York, NY, USA) reviewed the evidence to date linking saturated fats and sugars to CHD, and concluded that while dietary guidelines continue to recommend restricting intake of saturated fats, this recommendation follows largely from the observation that saturated fats can raise levels of total serum cholesterol, thereby putatively increasing the risk of atherosclerotic CHD.

However, they claim, total serum cholesterol is only modestly associated with CHD, and more important than the total level of cholesterol in the blood may be the number and size of low-density lipoprotein (LDL) particles that it contains. Different saturated fats may have different effects on LDL and on broader CHD risk, based on the specific saturated fatty acids (SFAs) they contain. And since people eat foods, not isolated fatty acids, some sources of SFAs may pose no risk for CHD, or possibly even be protective.

As such, advice to reduce saturated fat in the diet without regard to nuances about LDL, SFAs, or dietary sources could actually increase people's risk of CHD. In particular, when saturated fats are replaced with refined carbohydrates, changes in LDL, high-density lipoprotein (HDL), and triglycerides may increase the risk of CHD. Additionally, diets high in sugar may induce other abnormalities associated with higher CHD risk, including elevated levels of glucose, insulin, and uric acid, impaired glucose tolerance, insulin and leptin resistance, non-alcoholic fatty liver disease, and altered platelet function.

The researchers also found that a diet high in added sugars can cause a 3-fold increased risk of death due to cardiovascular disease (CVD). But sugars, like saturated fats, are a diverse class of compounds; monosaccharide, fructose, and fructose-containing sweeteners (such as sucrose) produce greater degrees of metabolic abnormalities than does glucose, and may present greater risk of CHD. The researchers therefor concluded that sugar consumption, particularly in the form of refined added sugars, are a greater contributor to CHD than saturated fats.

They therefore recommend that dietary guidelines should shift focus away from reducing saturated fat and replacing saturated fat with carbohydrates, specifically when these carbohydrates are refined. To reduce the burden of CHD, guidelines should focus particularly on reducing intake of concentrated sugars, specifically the fructose-containing sugars like sucrose and high-fructose corn syrup in the form of ultra-processed foods and beverages. The study was published in the January 2016 issue of Progress in Cardiovascular Diseases.

“After a thorough analysis of the evidence it seems appropriate to recommend dietary guidelines shift focus away from recommendations to reduce saturated fat and towards recommendations to avoid added sugars,” said study coauthor James DiNicolantonio, PharmD, of Saint Luke's. “Most importantly, recommendations should support the eating of whole foods whenever possible and the avoidance of ultra-processed food.”

Related Links:
Saint Luke's Mid America Heart Institute
Albert Einstein College of Medicine