CHICAGO–Consuming carbohydrates with high glycemic index—an indicator of how quickly a food affects blood glucose levels—appears to be associated with the risk of coronary heart disease (CHD) in women but not men, according to a report in the April 12 issue of Archives of Internal Medicine, one of the JAMA/Archives journals (2010;170[7]:640-647).
The European Prospective Investigation into Cancer and Nutrition study (EPICOR) study investigated the association of glycemic index and dietary glycemic load with CHD in a large and heterogeneous cohort of Italian men and women. Researchers studied 47,749 volunteers (15,171 men and 32,578 women) who completed a dietary questionnaire. Researchers calculated participants overall carbohydrate intakes as well as the average glycemic index of the foods they consumed and the glycemic loads of their diets.
During a median of 7.9 years of follow-up, 463 CHD cases (158 women and 305 men) were identified. Women in the highest carbohydrate intake quartile had approximately twice the risk of CHD than did those in the lowest quartile, with no association found in men (P=0.04). Increasing carbohydrate intake from high-GI foods was also significantly associated with greater risk of CHD in women, whereas increasing the intake of low-GI carbohydrates was not. Women in the highest glycemic load quartile had 2.24 times the risk of CHD than did those in the lowest quartile, with no significant association in men (P=0.03).
Researchers reported the differences in the sexes could be because the adverse changes associated with carbohydrate intake, including triglyceride levels, are stronger risk factors for heart disease in women than in men. “We tentatively suggest the adverse effects of a high glycemic diet in women are mediated by sex-related differences in lipoprotein and glucose metabolism, but further prospective studies are required to verify a lack of association of a high dietary glycemic load with cardiovascular disease in men,” they concluded.
High-carbohydrate diets increase the levels of blood glucose and of harmful blood fats known as triglycerides while reducing levels of protective high-density lipoprotein (HDL) or “good” cholesterol, thereby increasing heart disease risk, according to background information in the article. However, not all carbohydrates have the same effect on blood glucose levels. The glycemic index is a measure of how much a food raises blood glucose levels compared with the same amount of glucose or white bread. A related measure, the glycemic load, is calculated based on the glycemic index of a given food and also on the total amount of carbohydrates it contains.
