title: Association of tea consumption and the risk of oral cancer: a meta-analysis.
abstract: OBJECTIVE
  Epidemiological studies evaluating the association of tea consumption and the risk of oral cancer risk have produced inconsistent results. Thus, we conducted a meta-analysis to assess the relationship between tea consumption and oral cancer risk.
  
  
  METHODS
  Pertinent studies were identified by a search in PubMed, Web of Knowledge and Wan Fang Med Online. The fixed or random effect model was used based on heterogeneity test. Publication bias was estimated using Egger's regression asymmetry test.
  
  
  RESULTS
  Finally, 14 articles with 19 studies comprising 4675 oral cancer cases were included in this meta-analysis. The relative risk (95% confidence interval) of oral cancer for the highest versus the lowest category of tea consumption was 0.853 (0.779-0.934), and the association was significant between oral cancer risk and green tea consumption [0.798 (0.673-0.947)] but not in the black tea consumption [0.953 (0.792-1.146)]. The associations were also significant in Asian and Caucasian.
  
  
  CONCLUSIONS
  Our analysis indicated that tea consumption may have a protective effect on oral cancer, especially in green tea consumption.
authors.affiliation: Department of Periodontology and Oral Mucosal Diseases, Qingdao Stomatological Hospital, Qingdao, China. Electronic address: kqwchwang@126.com.
authors.forename: Wanchun
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Pediatric Dentistry, Qingdao Stomatological Hospital, Qingdao, China.
authors.forename: Yu'e
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Periodontology and Oral Mucosal Diseases, Qingdao Stomatological Hospital, Qingdao, China.
authors.forename: Wenyi
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Epidemiology and Health Statistics, Medical College of Qingdao University, Qingdao, China.
authors.forename: Wenlong
authors.initials: W
authors.lastname: Wu
mesh_terms: D006801:Humans; D009062:Mouth Neoplasms / Q000517:prevention & control*; D012307:Risk Factors; D013662:Tea
chemical_list: D013662:Tea
keywords: Meta-analysis; Oral cancer; Tea consumption