Flavonoid intake is associated with lower mortality in the Danish Diet Cancer and Health Cohort

TLDR

Flavonoids, plant‑derived polyphenols, have been linked to health benefits, but evidence on cancer mortality and the role of lifestyle factors remains limited. This prospective cohort followed 56,048 Danish Diet Cancer and Health participants for 23 years, linking dietary data to national registries and recording 14,083 deaths. Moderate habitual flavonoid intake was inversely associated with all‑cause, cardiovascular, and cancer mortality, plateauing at about 500 mg/day, with stronger, more linear effects in smokers and heavy alcohol consumers, highlighting the potential of flavonoid‑rich foods to reduce mortality in these groups.

Abstract

Flavonoids, plant-derived polyphenolic compounds, have been linked with health benefits. However, evidence from observational studies is incomplete; studies on cancer mortality are scarce and moderating effects of lifestyle risk factors for early mortality are unknown. In this prospective cohort study including 56,048 participants of the Danish Diet, Cancer, and Health cohort crosslinked with Danish nationwide registries and followed for 23 years, there are 14,083 deaths. A moderate habitual intake of flavonoids is inversely associated with all-cause, cardiovascular- and cancer-related mortality. This strong association plateaus at intakes of approximately 500 mg/day. Furthermore, the inverse associations between total flavonoid intake and mortality outcomes are stronger and more linear in smokers than in non-smokers, as well as in heavy (>20 g/d) vs. low-moderate (<20 g/d) alcohol consumers. These findings highlight the potential to reduce mortality through recommendations to increase intakes of flavonoid-rich foods, particularly in smokers and high alcohol consumers.