Purpose: To investigate the association between green tea consumption and mortality from all causes, cancer, and cardiovascular disease (CVD) among elderly people.
Methods: In a population-based, prospective cohort study, a total of 14,001 elderly residents (aged 65-84 years), randomly chosen from all 74 municipalities in Shizuoka, Japan, completed questionnaires that included items about frequency of green tea consumption. They were followed for up to 6 years, from December 1999 to March 2006. Consequently, 12,251 subjects were analyzed to estimate the hazard ratios (HRs) for all-cause mortality, cancer, and CVD.
Results: Among 64,002 person-years, 1,224 deaths were identified (follow-up rate, 71.6%).
The multivariate Hazard Ratios and 95% confidence intervals (CIs) for CVD mortality compared those who consumed seven or more cups per day with those who consumed less than one cup per day, were 0.24 (0.14-0.40), 0.30 (0.15-0.61), and 0.18 (0.08-0.40) for total participants, men, and women, respectively. [Note: an HR of 1.0 would mean no difference in risk of CVD mortality between the groups drinking 7 or more cups daily and those drinking less than 1 cup. Thus the HR of 0.24 would represent a 76% lower risk of death associated with cardiovascular disease during the 6-year tracking period for the 7 cups-or-more group.]
Although green tea consumption was not inversely associated with cancer mortality, green tea consumption and colorectal cancer mortality were inversely associated with a moderate dose-response relationship.
• Green tea consumption is associated with reduced mortality from all causes and CVD.
• This study also suggests that green tea could have protective effects against colorectal cancer.
Source: Annals of Epidemiology, Oct 2009;19(10):732-9. PMID: 19628408, by Suzuki E, Yorifuji T, Takao S, Komatsu H, Sugiyama M, Ohta T, Ishikawa-Takata K, Doi H. Department of Epidemiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan. [E-mail: firstname.lastname@example.org]