Dietary Glycemic Load and Glycemic Index and Risk of Cerebrovascular Disease in the EPICOR Cohort

BACKGROUND Studies on the association of stroke risk to dietary glycemic index (GI) and glycemic load (GL) have produced contrasting results. OBJECTIVE To investigate the relation of dietary GI and GL to stroke risk in the large EPIC-Italy cohort (EPICOR) recruited from widely dispersed geographic areas of Italy. DESIGN We studied 44099 participants (13,646 men and 30,453 women) who completed a dietary questionnaire. Multivariable Cox modeling estimated adjusted hazard ratios (HRs) of stroke with 95% confidence intervals (95%CI). Over 11 years of follow-up, 355 stroke cases (195 ischemic and 83 hemorrhagic) were identified. RESULTS Increasing carbohydrate intake was associated with increasing stroke risk (HR = 2.01, 95%CI = 1.04-3.86 highest vs. lowest quintile; p for trend 0.025). Increasing carbohydrate intake from high-GI foods was also significantly associated with increasing stroke risk (HR 1.87, 95%CI = 1.16-3.02 highest vs. lowest, p trend 0.008), while increasing carbohydrate intake from low-GI foods was not. Increasing GL was associated with significantly increasing stroke risk (HR 2.21, 95%CI = 1.16-4.20, highest vs. lowest; p trend 0.015). Dietary carbohydrate from high GI foods was associated with increased both ischemic stroke risk (highest vs. lowest HR 1.92, 95%CI = 1.01-3.66) and hemorrhagic stroke risk (highest vs. lowest HR 3.14, 95%CI = 1.09-9.04). GL was associated with increased both ischemic and hemorrhagic stroke risk (HR 1.44, 95%CI = 1.09-1.92 and HR 1.56, 95%CI = 1.01-2.41 respectively, continuous variable). CONCLUSIONS In this Italian cohort, high dietary GL and carbohydrate from high GI foods consumption increase overall risk of stroke.