Green Tea Consumption and Prostate Cancer Risk in Japanese Men: A Prospective Study
Authors: Kurahashi, Norie; Sasazuki, Shizuka; Iwasaki, Motoki; Inoue, Manami
Source: American Journal of Epidemiology, Volume 167, Number 1, 1 January 2008 , pp. 71-77(7)
Publisher: Oxford University Press
Abstract:The incidence of prostate cancer is much lower in Asian than Western populations. Given that environmental factors such as dietary habits may play a major role in the causation of prostate cancer and the high consumption of green tea in Asian populations, this low incidence may be partly due to the effects of green tea. The JPHC Study (Japan Public Health Center-based Prospective Study) was established in 1990 for cohort I and in 1993 for cohort II. The subjects were 49,920 men aged 4069 years who completed a questionnaire that included their green tea consumption habit at baseline and were followed until the end of 2004. During this time, 404 men were newly diagnosed with prostate cancer, of whom 114 had advanced cases, 271 were localized, and 19 were of an undetermined stage. Green tea was not associated with localized prostate cancer. However, consumption was associated with a dose-dependent decrease in the risk of advanced prostate cancer. The multivariate relative risk was 0.52 (95% confidence interval: 0.28, 0.96) for men drinking 5 or more cups/day compared with less than 1 cup/day (ptrend 0.01). Green tea may be associated with a decreased risk of advanced prostate cancer.
Document Type: Research Article
Publication date: 2008-01-01
- The American Journal of Epidemiology is the premier epidemiological journal devoted to the publication of empirical research findings, methodological developments in the field of epidemiological research and opinion pieces. It is aimed at both fellow epidemiologists and those who use epidemiological data, including public health workers and clinicians.