Dietary complex carbohydrates and low glycemic index/load decrease levels of specific metabolic syndrome/cardiovascular disease risk factors

The purpose of this systematic review was to assess randomized controlled trials from 1998 to 2006 to determine whether these studies provided adequate and consistent evidence to define the patterns and roles of dietary simple and complex carbohydrates (CHOs), including dietary glycemic index, that affect specific metabolic (plasma triglycerides [TG], cholesterol, high-density and low-density lipoproteins, C-reactive protein, and blood pressure) and cardiovascular disease (CVD) risk factors in men and women. A high intake of dietary fructose and glucose increases TG in men but not in women; high dietary sucrose elevates fasting plasma TGs in women. High dietary complex CHO diets elevated plasma TG in men and women. The type of CHO appears to be an important factor in lowering TG levels and other metabolic syndrome factors. Low-fat, high-complex CHO diets in overweight subjects showed improvement in total serum cholesterol level but may be associated with CHO-induced hypertriglyceridemia. A high-polysaccharide and high-fiber diet that may reduce total and low-density cholesterol, primary CVD risk factors, by more than 10% may be clinically significant. A high-dietary glycemic index may exacerbate the proinflammatory process in women. A diet with low-moderate CHO has been recommended to decrease the risk of metabolic syndrome and CVD. Additional studies are needed to further replicate the effects of different dietary approaches on these and other metabolic syndrome factors in both men and women of different ethnicity in varying age groups.