title: A population-based, case-control study of green tea consumption and leukemia risk in southwestern Taiwan.
abstract: OBJECTIVE
  This study investigated the association between green tea consumption and leukemia.
  
  
  METHODS
  A total of 252 cases (90.3% response) and 637 controls (53.4% response) were enrolled. Controls were matched for cases on age and gender. Information was collected on participants' living habits, including tea consumption. Green tea was used as a standard to estimate the total amount of individual catechin consumption. We stratified individual consumption of catechins into four levels. Conditional logistic regression models were fit to subjects aged 0-15 and 16-29 years to evaluate separate associations between leukemia and catechin consumption.
  
  
  RESULTS
  A significant inverse association between green tea consumption and leukemia risk was found in individuals aged 16-29 years, whereas no significant association was found in the younger age groups. For the older group with higher amounts of tea consumption (>550 units of catechins), the adjusted odds ratio (OR) compared with the group without tea consumption was 0.47 [95% confidence interval (CI) = 0.23-0.97]. After we adjusted for smoking status and medical irradiation exposure, the overall OR for all participants was 0.49 (95% CI = 0.27-0.91), indicating an inverse relation between large amounts of catechins and leukemia.
  
  
  CONCLUSIONS
  Drinking sufficient amounts of tea, especially green tea, which contains more catechins than oolong tea and black tea, may reduce the risk of leukemia.
authors.affiliation: Environmental and Occupational Medicine and Epidemiology Program, Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA. kuo550221@yahoo.com.tw
authors.forename: Yau-Chang
authors.initials: YC
authors.lastname: Kuo
authors.forename: Chu-Ling
authors.initials: CL
authors.lastname: Yu
authors.forename: Chen-Yu
authors.initials: CY
authors.lastname: Liu
authors.forename: Su-Fen
authors.initials: SF
authors.lastname: Wang
authors.forename: Pi-Chen
authors.initials: PC
authors.lastname: Pan
authors.forename: Ming-Tsang
authors.initials: MT
authors.lastname: Wu
authors.forename: Chi-Kung
authors.initials: CK
authors.lastname: Ho
authors.forename: Yu-Shing
authors.initials: YS
authors.lastname: Lo
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.forename: David C
authors.initials: DC
authors.lastname: Christiani