High dietary glycemic load is associated with increased risk of colon cancer.

High dietary glycemic load (GL) has been inconsistently associated with risk of colon cancer. We analyzed data for 1093 incident cases and 1589 controls in a population-based case-control study of colon cancer to further clarify the GL-colon cancer relationship. GL was assessed using a self-administered food frequency questionnaire. Cases had a significantly higher GL intake (mean = 136.4, SD = 24.5) than controls (mean = 132.8, SD = 25.2) (P = 0.0003). In a multivariate unconditional logistic regression model, the odds ratios (ORs) for colon cancer increased significantly with increasing GL: compared to the bottom quartile of GL, the ORs (95% CI) for the 2nd through the upper quartiles were 1.38 (1.06, 1.80), 1.67 (1.30, 2.13), and 1.61 (1.25, 2.07), respectively (P trend < 0.0001). Stratified analyses showed that the association was more pronounced among older participants [ORs (95% CI) for the 2nd through the upper quartiles were 1.35 (0.91, 2.00), 1.87 (1.29, 2.71), 2.02 (1.39, 2.95), respectively] than among younger participants [ORs were 1.46 (1.02, 2.10), 1.53 (1.09, 2.15), and 1.35 (0.96, 1.91), respectively] (P int = 0.02). Our results provide support for the hypothesis that a diet with high GL increases the risk of colon cancer.