Dietary fiber intake and risk of gastric cancer: The Japan Public Health Center-based prospective study.

Evidence of the association between dietary fiber intake and gastric cancer (GC) risk from prospective studies is limited. We examined the association between dietary fiber intake and GC risk in a large prospective study. A total of 91 946 eligible Japanese aged 45 to 74 years (42 773 men and 49 173 women) participated in a population-based cohort study (Japan Public Health Center-based prospective study). From a validated food frequency questionnaire with 138 food items, total and food source-specific dietary fiber intake was calculated as exposure. The hazard ratio (HR) and the 95% confidence interval (CI) of GC incidence according to quintile of dietary fiber intake were examined after adjusting for confounding factors. In total, 2228 GC cases (1559 men and 669 women) were observed during the 15.0 years follow-up. Total dietary fiber intake was not associated with GC risk; however, a marginally increased risk trend because of high HR in the highest quintile of total fiber intake was found in women (HR [95% CI] in Q5 vs Q1: 0.95 [0.79-1.14], P for trend .30 in men, HR [95% CI] 1.25 [0.98-1.61], P for trend .05 in women). Stratification by tumor location did not change the results. A marginal but not significant inverse trend was observed regarding cereal fiber intake and GC risk in men. Total dietary fiber intake was not associated with GC risk. Further studies are warranted to confirm this association.