Higher habitual dietary flavonoid intakes have been consistently associated with lower mortality and chronic disease risk (1). However, the role of flavonoid diversity has never been investigated. We aimed to investigate the independent roles of flavonoid intake quantity and diversity on the risk of all-cause mortality and major chronic disease incidence. In this cohort study, 124,805 UK Biobank participants [mean (SD) age: 60.2 (7.8) years; ~55% female] were followed for up to 11.8 years. Flavonoid intakes were estimated from repeated 24-hour dietary assessments and diversity calculated using our novel method which factors for both the variety and distribution of consumption. Associations with all-cause mortality and incidence of cardiovascular disease (CVD), type 2 diabetes (T2DM), total cancer, respiratory disease, and neurodegenerative disease were assessed using Cox models. Following mutual adjustment and after accounting for socio-demographic, lifestyle and dietary factors, both a higher quantity and a wider diversity of dietary flavonoid intake associated with a significantly lower risk of all-cause mortality and several chronic diseases: comparing higher (Quintile 5) to lower intakes (Quintile 1), the Hazard ratios (95% CIs) for quantity and diversity respectively were 0.84 (0.76–0.92) and 0.86 (0.78–0.95) for all-cause mortality, 0.88 (0.81–0.96) and 0.90 (0.82–0.98) for CVD, 0.75 (0.66–0.84) and 0.80 (0.70–0.91) for T2DM, 0.92 (0.85–0.99) and 0.92 (0.85–0.99) for cancer, and 0.91 (0.86–0.97) and 0.92 (0.86–0.98) for respiratory disease; only intake quantity associated with neurodegenerative disease risk [Q5 vs Q1: 0.80 (0.68–0.94)]. We then tested for interactions between quantity and diversity of flavonoid intake (across all outcomes), and although none were observed (all p > 0.05) the independent associations still suggest there is a benefit to consuming a higher diversity beyond that of simply consuming a high quantity (and vice versa). In conclusion, consuming both a higher quantity and wider diversity of dietary flavonoids appears better for longer-term health than higher intakes of either component alone.
References