Epidemiological studies exploring the role of
flavonoids intake in preventing
type 2 diabetes mellitus (T2DM) showed inconsistent results. Therefore, we performed a meta-analysis of relevant studies to examine the relationship between
flavonoids intake and risk of T2DM. We hypothesized that
flavonoids intake may decrease the risk of developing T2DM.A systematical search in PubMed and Embase until September 2017 was performed to identify eligible prospective cohort studies. The summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random-effect models. Dose-response pattern between total
flavonoids intake and T2DM risk was also estimated.Eight prospective studies were included with 312,015 participants, of whom 19,953 developed T2DM during the follow-up periods of 4 to 28 years. Compared with lower consumption, high intake of total
flavonoids was associated with a decreased risk of T2DM (RR: 0.89, 95% CI: 0.82-0.96). Among
flavonoid subclasses, inverse correlations with T2DM were achieved for intakes of
anthocyanidins, flavan-3-ols,
flavonols, and
isoflavones. Dose-response meta-analysis indicated a curvilinear relationship between total
flavonoids intake and incident T2DM (P for nonlinearity = .042), with a significant risk reduction at an intake of ≥550 mg/day. When assuming a linear pattern, the risk of T2DM was decreased by 5% for each 300-mg/day increment in total
flavonoids intake (RR: 0.95, 95% CI: 0.93-0.97).Our study suggests that higher intakes of total
flavonoids and subclasses (
anthocyanidins, flavan-3-ols,
flavonols, and
isoflavones) are associated with lower risk of T2DM.