Dietary glycemic index, glycemic load, and risk of mortality from all causes and cardiovascular diseases: a systematic review and dose-response meta-analysis of prospective cohort studies

Abstract

Previous findings on the association of dietary glycemic index (GI) and glycemic load (GL) with mortality are conflicting. The aim of this study was to summarize earlier findings on the association between dietary GI and GL and the risk of cardiovascular disease (CVD) and all-cause mortality. A comprehensive literature search was performed of electronic databases, including MEDLINE (PubMed), Scopus, ISI Web of Science, EMBASE, and Google scholar, up to September 2018. Prospective cohort studies that reported GI and GL as the exposure and all-cause or CVD mortality as the outcome were included in the analysis. The random-effects model was used to estimate pooled RR and 95% CIs of all-cause and CVD mortality. Eighteen cohort studies with a total of 251,497 participants, reporting 14,774 cases of all-cause mortality and 3658 cases of CVD mortality, were included in the present analysis. No significant association was found between dietary GI and all-cause mortality (RR: 1.07; 95% CI: 0.96, 1.19) and CVD mortality (RR: 1.02; 95% CI: 0.87, 1.20). In addition, dietary GL was not associated with all-cause mortality (RR: 1.08; 95% CI: 0.93, 1.27) or CVD mortality (RR: 1.07; 95% CI: 0.92, 1.25). However, the highest dietary GI, in comparison to the lowest one, significantly increased the risk of all-cause mortality in women (RR: 1.17; 95% CI: 1.02, 1.35). No evidence for a nonlinear association between dietary GI or GL and all-cause and CVD mortality was found (P>0.05). This meta-analysis of prospective cohort studies showed no significant association between either dietary GI or GL and all-cause and CVD mortality in men, but a positive association of GI with all-cause mortality in women.