title: Association between dairy intake and gastric cancer: a meta-analysis of observational studies.
abstract: OBJECTIVE
  Observational studies have given inconsistent findings on the relationship between intake of dairy products and gastric cancer. We therefore conducted a systematic review with a meta-analysis of observational studies to summarize available evidence on this point.
  
  
  METHODS
  We searched the electronic literature databases of PubMed (Medline), EMBASE and the Chinese Biomedical Literature Database up until August 30, 2013. All studies were limited to the English language. Random-effects models were used to pool study results between dairy products consumption and the risk of gastric cancer. We also performed subgroup, publication bias and sensitivity analysis.
  
  
  RESULTS
  Eight prospective studies and 18 case-control studies were included in our analysis, with a total number of 7272 gastric cancer cases and 223,355 controls. Pooled relative risks of all studies showed no significant association between dairy intake and gastric cancer (odds ratio [OR]: 1.09, 95% confidence interval [CI]: 0.96-1.25). When study design was separately analyzed, population-based case-control studies showed a positive association between dairy intake and gastric cancer risk (OR: 1.36; 95% CI: 1.07-1.74), whereas no associations were shown by hospital-based case-control studies (OR: 0.86, 95% CI: 0.72-1.02) or cohort studies (OR = 1.01, 95% CI = 0.91-1.13).
  
  
  CONCLUSIONS
  The meta-analysis shows that no clear association apparently exists between consumption of dairy products and gastric cancer risk. Further well-designed cohort and intervention studies should be conducted to verify this lack of association.
authors.affiliation: Department of General Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Shu-bo
authors.initials: SB
authors.lastname: Tian
authors.affiliation: Department of General Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Jian-chun
authors.initials: JC
authors.lastname: Yu
authors.affiliation: Department of General Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Wei-ming
authors.initials: WM
authors.lastname: Kang
authors.affiliation: Department of General Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Zhi-qiang
authors.initials: ZQ
authors.lastname: Ma
authors.affiliation: Department of General Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Ye
authors.affiliation: Department of General Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Zhan-jiang
authors.initials: ZJ
authors.lastname: Cao
mesh_terms: D016022:Case-Control Studies; D003611:Dairy Products / Q000009:adverse effects*; D004032:Diet; D006801:Humans; D064887:Observational Studies as Topic; D016017:Odds Ratio; D011446:Prospective Studies; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000209:etiology*