Green Tea Consumption and Mortality among Japanese Elderly People: The Prospective Shizuoka Elderly Cohort
Received 31 October 2008; accepted 11 June 2009. published online 23 July 2009.
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 HRs 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. 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.
Conclusions
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.
aDepartment of Epidemiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan
bDivision of Community Care, Saku Central Hospital, Nagano, Japan
cTobu Child Support Center of Shizuoka Prefecture, Shizuoka, Japan
dNational Hospital for Geriatric Medicine, National Center for Geriatrics and Gerontology, Aichi, Japan
eProgram of Health Promotion and Exercise, National Institute of Health and Nutrition, Tokyo, Japan
Address correspondence reprint requests to: Etsuji Suzuki, MD, PhD, Department of Epidemiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama. 700-8558, Japan. Tel: +81(JPN)-86-223-7151 (ext. 7175). Fax: +81(JPN)-86-235-7178.
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