PurposeTo prospectively assess the association of dietary fiber intake (from different dietary sources) with all-cause mortality in a Mediterranean cohort.MethodsWe assessed 19,703 participants of the SUN (Seguimiento Universidad de Navarra) cohort (mean follow-up: 10.1 years). A validated 136-item FFQ was administered at baseline. We used Cox proportional hazards models adjusted for multiple socio-demographic, anthropometric, lifestyle factors, and prevalent conditions at baseline.ResultsWe observed 323 deaths during 198,341 person-years of follow-up. A significantly inverse linear trend in Cox models was observed for the association of total dietary fiber intake and all-cause mortality after adjustment for confounders (p for trend 0.017). Each additional intake of 5 g/1000 kcal of dietary fiber was associated with a 9% relative reduction in all-cause mortality risk (HR 0.91, 95% CI 0.84-0.99). Considering separate dietary sources in separate models, a significant inverse trend was apparent for fiber derived from vegetables (p for trend 0.001), but it was non-significant for fiber derived from fruit, legumes, cereals, or other sources. Soluble fiber was significantly inversely associated with all-cause mortality in the fully adjusted model (p for trend 0.007), and insoluble fiber was marginally significant (p for trend 0.08).ConclusionsA higher intake of total dietary fiber, and particularly fiber from vegetables, was related to a reduced all-cause mortality in our Mediterranean cohort. Dietary messages to increase the consumption of dietary patterns rich in fiber-rich foods should be broadly disseminated to decrease the alarming rate of chronic diseases and its derived mortality.