Objective: Evidence from observational studies has suggested that carbohydrate quality rather than absolute intake is associated with greater risk of chronic diseases. The aim of this study was to examine the relationship between carbohydrate intake and dietary glycemic index and several cardiovascular disease risk factors.
Methods: We examined cross-sectional associations between total carbohydrate and dietary glycemic index (GI) intakes and several cardiovascular disease risk factors (CVD) in a sample of 2,941 Framingham Offspring Participants. CVD risk factors included waist, blood pressure, lipids, fasting insulin, fasting glucose, and the insulin sensitivity index (ISI(0,120)). Dietary intake was assessed by a food frequency questionnaire (FFQ) and categorized by quintiles of dietary intake.
Results: After adjustment for potential confounding factors, dietary GI was positively associated with fasting triglycerides (mean: 115mg/dL in the lowest and 127 mg/dL in the highest quintile of intake; P for trend < 0.001), fasting insulin (26.8 and 28.9 microu/mL, respectively, P for trend < 0.0001), and inversely associated with HDL cholesterol (49 and 47 mg/dL, respectively, P for trend 0.003) and ISI(0,120) (26.8 and 25.1, P for trend < 0.001). There was no significant relationship between dietary GI and waist circumference, total cholesterol, LDL cholesterol and fasting glucose. Intakes of total carbohydrate were inversely associated with waist circumference and HDL cholesterol, and positively associated with fasting triglycerides.
Conclusion: These cross-sectional findings support the hypothesis that a high GI diet unfavorably affects CVD risk factors and therefore, substitution of high with low GI dietary carbohydrates may have reduce the risk of CVD.