Dietary glycemic load, glycemic index, and associated factors in a multiethnic cohort of midlife women.

BACKGROUND: Dietary glycemic load (GL) and glycemic index (GI), indicators of the postprandial glucose and insulin response to carbohydrate composition of diet, have been suggested as independent risk factors for cardiovascular disease and diabetes. However, current knowledge about the distribution, correlates, and major contributors of these measures in human populations is limited.

OBJECTIVE: To describe the intakes and correlates of GL and GI in African American, Caucasian, Chinese, and Japanese women in the Study of Women's Health Across the Nation (SWAN).

DESIGN: Data are from 2025 women participating in SWAN, a multi-ethnic, community-based cohort study of women transitioning into menopause. GL and GI were estimated from dietary information obtained in the fifth year of the study using a modified Block food frequency questionnaire. The relationship of GL and GI to dietary factors and selected demographic measures, including race/ethnicity and lifestyle factors, was examined using bivariate and multivariate analyses.

RESULTS: GI and GL were consistently lower in Caucasian women than in African American, Japanese, or Chinese women. Education was inversely associated with GL and alcohol consumption was inversely associated with GI among all ethnic groups. The association between family income and glycemic measures varied across ethnic groups. GI was positively associated with consumption of grains and potatoes and inversely associated with consumption of fruits, juices, dairy foods, protein sources, and sweets among all ethnic groups.

CONCLUSIONS: It is important for researchers to consider factors such as ethnicity, family income, and alcohol intake as potential confounders when investigating the associations of GL and GI with disease.