title: No association between tea consumption and risk of renal cell carcinoma: a meta-analysis of epidemiological studies.
abstract: OBJECTIVE
  To evaluate the association between tea consumption and the risk of renal cell carcinoma.
  
  
  METHODS
  We searched PubMed,Web of Science and Scopus between 1970 and November 2012. Two evaluators independently reviewed and selected articles based on predetermined selection criteria.
  
  
  RESULTS
  Twelve epidemiological studies (ten case-control studies and two cohort studies) were included in the final analysis. In a meta-analysis of all included studies, when compared with the lowest level of tea consumption, the overall relative risk (RR) of renal cell carcinoma for the highest level of tea consumption was 1.03 (95% confidence interval [CI] 0.89-1.21). In subgroup meta-analyses by study design, there was no significant association between tea consumption and renal cell carcinoma risk in ten case-control studies using adjusted data (RR=1.08, 95% CI 0.84-1.40). Furthermore, there was no significant association in two cohort studies using adjusted data (RR=0.95, 95% CI 0.81-1.12).
  
  
  CONCLUSIONS
  Our findings do not support the conclusion that tea consumption is related to decreased risk of renal cell carcinoma. Further prospective cohort studies are required.
authors.affiliation: Department of Urology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China. xielp@zjuem.zju.edu.cn
authors.forename: Zheng-Hui
authors.initials: ZH
authors.lastname: Hu
authors.forename: Yi-Wei
authors.initials: YW
authors.lastname: Lin
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
authors.forename: Ye-Qing
authors.initials: YQ
authors.lastname: Mao
authors.forename: Jian
authors.initials: J
authors.lastname: Wu
authors.forename: Xiang-Lai
authors.initials: XL
authors.lastname: Xu
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhu
authors.forename: Shi-Qi
authors.initials: SQ
authors.lastname: Li
authors.forename: Xiang-Yi
authors.initials: XY
authors.lastname: Zheng
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Xie
mesh_terms: D002292:Carcinoma, Renal Cell / Q000209:etiology*; D016021:Epidemiologic Studies; D006801:Humans; D007680:Kidney Neoplasms / Q000209:etiology*; D011379:Prognosis; D012307:Risk Factors; D013662:Tea / Q000009:adverse effects*
chemical_list: D013662:Tea