Whole-grain intake is favorably associated with metabolic risk factors for type 2 diabetes and cardiovascular disease in the Framingham Offspring Study

Background: The influence of whole grains on cardiovascular disease risk may be mediated through multiple pathways, eg, a reduction in blood lipids and blood pressure, an enhancement of insulin sensitivity, and an improvement in blood glucose control. Objective: The objective was to examine the association between diets rich in whole- or refined-grain foods and several metabolic markers of disease risk in the Framingham Offspring Study cohort. Design: Whole-grain intake and metabolic risk markers were assessed in a cross-sectional study of 2941 subjects. Results: After adjustment for potential confounding factors, whole-grain intake was inversely associated with body mass index ((x) over bar: 26.9 in the lowest and 26.4 in the highest quintile of intake; P for trend = 0.06), waist-to-hip ratio (0.92 and 0.91, respectively; P for trend = 0.005), total cholesterol (5.20 and 5.09 mmol/L, respectively; P for trend = 0.06), LDL cholesterol (3.16 and 3.04 mmol/L, respectively; P for trend = 0.02), and fasting insulin (205 and 199 pmol/L, respectively; P for trend = 0.03). There were no significant trends in metabolic risk factor concentrations across quintile categories of refined-grain intake. The inverse association between whole-grain intake and fasting insulin was most striking among overweight participants. The association between wholegrain intake and fasting insulin was attenuated after adjustment for dietary fiber and magnesium. Conclusion: Increased intakes of whole grains may reduce disease risk by means of favorable effects on metabolic risk factors.