title: Dietary fiber intake reduces risk for gastric cancer: a meta-analysis.
abstract: OBJECTIVE
  The association between dietary fiber intake and gastric cancer risk has been investigated by many studies, with inconclusive results. We conducted a meta-analysis of case-control and cohort studies to analyze this association.
  
  
  METHODS
  Relevant studies were identified by searching PubMed and Embase through October 2012. We analyzed 21 articles, which included 580,064 subjects. Random-effects models were used to estimate summary relative risks. Dose-response, subgroup, sensitivity, meta-regression, and publication bias analyses were performed.
  
  
  RESULTS
  The summary odds ratios of gastric cancer for the highest, compared with the lowest, dietary fiber intake was 0.58 (95% confidence interval, 0.49-0.67) with significant heterogeneity among studies (P < .001, I(2) = 62.2%). Stratified analysis for study design, geographic area, source and type of fiber, Lauren's classification, publication year, sample size, and quality score of study yielded consistent results. Dose-response analysis associated a 10-g/day increment in fiber intake with a significant (44%) reduction in gastric cancer risk. Sensitivity analysis restricted to studies with control for conventional risk factors produced similar results, and omission of any single study had little effect on the combined risk estimate.
  
  
  CONCLUSIONS
  In a meta-analysis, we show that dietary fiber intake is associated inversely with gastric cancer risk; the effect probably is independent of conventional risk factors. The direction of the protective association of dietary fiber was consistent among all studies, but the absolute magnitude was less certain because of heterogeneity among the studies. Further studies therefore are required to establish this association.
authors.affiliation: Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Jiangsu Province, China.
authors.forename: Zhizhong
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Jiangsu Province, China.
authors.forename: Gelin
authors.initials: G
authors.lastname: Xu
authors.affiliation: Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Jiangsu Province, China.
authors.forename: Minmin
authors.initials: M
authors.lastname: Ma
authors.affiliation: Department of Neurology, Nanjing First Hospital, Nanjing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Jiangsu Province, China. Electronic address: xfliu2@yahoo.com.cn.
authors.forename: Xinfeng
authors.initials: X
authors.lastname: Liu
mesh_terms: D004043:Dietary Fiber / Q000008:administration & dosage*; D006801:Humans; D012306:Risk; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000209:etiology / Q000517:prevention & control*