Dietary glycemic index, glycemic load and mortality: Japan Public Health Center-based prospective study

Purpose Long-term associations of dietary glycemic index (GI) and glycemic load (GL) with mortality outcomes remain unclear. Methods The present analysis included 72,783 participants of the Japan Public Health Center-based Prospective Study. Participants who responded to the 5-year follow-up questionnaire in 1995–1999 were followed-up until December 2015. We estimated the risk of total and cause-specific mortality associated with GI and GL using Cox proportional hazards regression models. Results During 1,244,553 person years of follow-up, 7535 men and 4913 women died. GI was positively associated with all-cause mortality. As compared with the lowest quartile, the multivariable HR for those who had the highest quartile of GI was 1.14 (95% CI 1.08–1.20). The HRs for death comparing the highest with the lowest quartile were 1.28 (95% CI 1.14–1.42) for circulatory system diseases, 1.33 (95% CI 1.14–1.55) for heart disease, 1.32 (95% CI 1.11–1.57) for cerebrovascular disease, and 1.45 (95% CI 1.18–1.78) for respiratory diseases. GI was not associated with mortality risks of cancer and digestive diseases. GL showed a null association with all-cause mortality (highest vs lowest quartile; HR 1.04; 95% CI 0.96–1.12). However, among those who had the highest quartile of GL, the HRs for death from circulatory system diseases was 1.24 (95% CI 1.05–1.46), cerebrovascular disease was 1.34 (95% CI 1.03–1.74), and respiratory diseases was 1.35 (95% CI 1.00–1.82), as compared with the lowest quartile. Conclusion In this large prospective cohort study, dietary GI and GL were associated with mortality risks.