Higher habitual intakes of flavonoids and flavonoid-rich foods are associated with a lower incidence of type 2 diabetes in the UK Biobank cohort

Aim: To examine associations of a flavonoid-rich diet—captured by a Flavodiet Score (FDS)—the major flavonoid-rich food contributors, and flavonoid subclasses with incident type 2 diabetes (T2D) in the UK Biobank. Materials and Methods: Among 113,097 participants (mean age 56 ± 8 years; 57% female) with ≥2 24-h dietary assessments, flavonoid intakes were estimated using USDA databases. Multivariable Cox proportional hazards models assessed associations with incident T2D. Results: Over 12 years, 2,628 incident T2D cases occurred. Higher FDS (Q4 vs Q1; ≈6 vs 1 servings/day of flavonoid-rich foods) was associated with a 26–28% lower T2D risk (HR 0.74–0.72; 95% CI 0.66–0.84 and 0.64–0.81; Ptrend <0.001). Each 1-point increase in FDS was associated with 5–6% lower risk (HR 0.95–0.94). Mediation analyses suggested partial mediation by lower body fatness and basal inflammation, and improved kidney and liver function. Food-based analyses showed inverse associations for tea (HR 0.79), berries (HR 0.85), and apples (HR 0.88), while among subclasses, higher intakes of anthocyanins, flavan-3-ols, flavonols, flavones, polymers, and proanthocyanidins were associated with 19–28% lower risk. Conclusions: Higher consumption of flavonoid-rich foods is associated with lower T2D risk, potentially via benefits to adiposity/sugar metabolism, inflammation, and kidney and liver function. Increasing intakes of specific flavonoid-rich foods may help reduce T2D risk.