Methods  We examined dietary fiber intake in relation tototal mortality and death from specific causes in the NIH (NationalInstitutes of Health)-AARP Diet and Health Study, a prospectivecohort study. Diet was assessed using a food-frequency questionnaireat baseline. Cause of death was identified using the NationalDeath Index Plus. Cox proportional hazard models were used toestimate relative risks and 2-sided 95% confidence intervals(CIs).

Results  During an average of 9 years of follow-up, weidentified 20 126 deaths in men and 11 330 deathsin women. Dietary fiber intake was associated with a significantlylowered risk of total death in both men and women (multivariaterelative risk comparing the highest with the lowest quintile,0.78 [95% CI, 0.73-0.82; P for trend, <.001] in men and 0.78[95% CI, 0.73-0.85; P for trend, <.001] in women). Dietaryfiber intake also lowered the risk of death from cardiovascular,infectious, and respiratory diseases by 24% to 56% in men andby 34% to 59% in women. Inverse association between dietaryfiber intake and cancer death was observed in men but not inwomen. Dietary fiber from grains, but not from other sources,was significantly inversely related to total and cause-specificdeath in both men and women.

Conclusions  Dietary fiber may reduce the risk of deathfrom cardiovascular, infectious, and respiratory diseases. Makingfiber-rich food choices more often may provide significant healthbenefits.