Dietary flavonoid and lignan intake and mortality in a Spanish cohort.

Background: Dietary flavonoids and lignans may protect against several chronic diseases, but there is little evidence on the relationship between flavonoid and lignan intake and mortality. We investigated the association between both all-cause and specific-cause mortality and intake of flavonoids and lignans in the Spanish European Prospective Investigation into Cancer and Nutrition (EPIC-Spain) cohort.

Methods: The EPIC-Spain study follows 40,622 participants (38% men) aged 29-69 years. A validated diet history questionnaire was administered at recruitment. A food composition database was compiled based on US Department of Agriculture and Phenol-Explorer databases. Cox proportional hazards models, adjusted for confounders, were used in the analyses.

Results: During a mean follow-up of 13.6 years, 1915 deaths were reported, with 416 from cardiovascular diseases (CVDs) and 956 from cancer. After adjustment for several potential confounders, the hazard ratios (HRs) for the highest versus the lowest quintile of dietary flavanone and flavonol intakes were 0.60 (95% confidence interval = 0.38-0.94) and 0.59 (0.40-0.88). Total flavonoid intake was also associated with a decrease in all-cause mortality (0.71 [0.49-1.03]). Lignan intake was not associated with all-cause mortality. In cause-specific mortality analyses, using competing risk regressions, doubling total flavonoid intake was inversely related to mortality from CVD (HR for log2 0.87 [0.77-0.98]), but not to mortality from either cancer (HR for log2 0.96 [0.89-1.04]) or other causes (HR for log2 0.97 [0.87-1.09]).

Conclusions: A diet high in flavonoids, particularly in flavanones and flavonols, is associated with a reduction in all-cause mortality, mainly of mortality from CVD.