title: Cruciferous vegetables intake and the risk of colorectal cancer: a meta-analysis of observational studies.
abstract: BACKGROUND
  Epidemiological studies have reported inconsistent associations between cruciferous vegetable (CV) intake and colorectal cancer (CRC) risk. To our knowledge, a comprehensive and quantitative assessment of the association between CV intake and CRC has not been reported.
  
  
  METHODS
  Relevant articles were identified by searching MEDLINE. We pooled the relative risks (RR) from individual studies using a random-effect model and carried out heterogeneity and publication bias analyses.
  
  
  RESULTS
  Twenty-four case-control and 11 prospective studies were included in our analysis. When all studies were pooled, we yielded a significantly inverse association between CV (RR: 0.82; 95% confidence interval 0.75-0.90) intake and CRC risk. Specific analysis for cabbage and broccoli yielded similar result. When separately analyzed, case-control studies of CV intake yield similar results, and the results from the prospective studies showed borderline statistical significance. Moreover, significant inverse associations were also observed in colon cancer and its distal subsite both among prospective and case-control studies.
  
  
  CONCLUSIONS
  Findings from this meta-analysis provide evidence that high intake of CV was inversely associated with the risk of CRC and colon cancer in humans. Further analysis on other specific CV, food preparation methods, stratified results by anatomic cancer site, and subsite of colon cancer should be extended in future study.
authors.affiliation: State Key Laboratory of Oncogene and Related Genes & Department of Epidemiology, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, No. 25, Lane 2200, Xie Tu Road, Shanghai 200032, PR China.
authors.forename: Q J
authors.initials: QJ
authors.lastname: Wu
authors.forename: Y
authors.initials: Y
authors.lastname: Yang
authors.forename: E
authors.initials: E
authors.lastname: Vogtmann
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.forename: L H
authors.initials: LH
authors.lastname: Han
authors.forename: H L
authors.initials: HL
authors.lastname: Li
authors.forename: Y B
authors.initials: YB
authors.lastname: Xiang
mesh_terms: D001937:Brassica; D019607:Brassicaceae; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000178:diet therapy* / Q000453:epidemiology* / Q000473:pathology; D006801:Humans; D011446:Prospective Studies; D012307:Risk Factors; D014675:Vegetables