title: Association between processed meat and red meat consumption and risk for glioma: a meta-analysis from 14 articles.
abstract: OBJECTIVE
  Epidemiologic studies evaluating the association between processed meat and red meat consumption and glioma risk have produced inconsistent results. Thus, the aim of this study was to conduct a meta-analysis to test the hypothesis that high levels of processed meat consumption could increase the risk for glioma.
  
  
  METHODS
  Pertinent studies were identified by a search of PubMed and Web of Knowledge up to February 2014. Random-effects model was used to combine the results. Publication bias was estimated using Egger's regression asymmetry test.
  
  
  RESULTS
  Fourteen studies involving 3641 cases about processed meat consumption and 3 studies involving 1156 cases about red meat consumption with risk for glioma were included in this meta-analysis. The combined relative risk (RR) of glioma associated with processed meat consumption was 1.25 (95% confidence interval [CI], 1.08-1.45) overall, and 1.28 (95% CI, 1.09-1.50) in the United States. For subgroup of study design, significant association was also found in case-control studies (RR, 1.33; 95% CI, 1.09-1.62), but not in the cohort studies. The association was not significant between red meat consumption and glioma risk (summary RR, 0.89; 95% CI, 0.71-1.12). No publication biases were found.
  
  
  CONCLUSIONS
  Our analysis indicated that high levels of processed meat consumption might increase the risk for glioma, and findings are consistent with the hypothesis. No association was found between red meat consumption and glioma risk.
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Institute of Neuroscience, Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing, China.
authors.forename: Youdong
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing, China.
authors.forename: Dezhi
authors.initials: D
authors.lastname: Zou
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing, China.
authors.forename: Du
authors.initials: D
authors.lastname: Cao
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Institute of Neuroscience, Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing, China. Electronic address: xiepeng@cqmu.edu.cn.
authors.forename: Peng
authors.initials: P
authors.lastname: Xie
mesh_terms: D005910:Glioma / Q000453:epidemiology* / Q000473:pathology*; D006801:Humans; D008461:Meat Products / Q000009:adverse effects*; D000069466:Red Meat / Q000009:adverse effects*; D012307:Risk Factors; D014481:United States / Q000453:epidemiology
keywords: Glioma; Meta-analysis; Processed meat; Red meat