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.