This article reported the results of a survey to assess an association between green tea consumption and a lowered incidence of functional disability, such as stroke, cognitive impairment, and osteoporosis in nearly 14,000 elderly Japanese. After adjusting for confounding factors such as previous health status, diet, social support, etc., the authors found higher amounts of green tea consumption were associated with lower incidences of functional disability in what may be the first reported study to have proven this relationship. Even so, clinical trials may be needed to confirm this observed protective effect of green tea consumption.
American Journal of Clinical Nutrition
Background: Previous studies have reported that green tea consumption is associated with a lower risk of diseases that cause functional disability, such as stroke, cognitive impairment, and osteoporosis. Although it is expected that green tea consumption would lower the risk of incident functional disability, this has never been investigated directly.
Objective: The objective was to determine the association between green tea consumption and incident functional disability in elderly individuals.
Design: We conducted a prospective cohort study in 13,988 Japanese individuals aged >65 y. Information on daily green tea consumption and other lifestyle factors was collected via questionnaire in 2006. Data on functional disability were retrieved from the public Long-term Care Insurance database, in which subjects were followed up for 3 y. We used Cox proportional hazards regression analysis to investigate the association between green tea consumption and functional disability.
Results: The 3-y incidence of functional disability was 9.4% (1316 cases). The multiple-adjusted HR (95% CI) of incident functional disability was 0.90 (0.77, 1.06) among respondents who consumed 1-2 cups green tea/d, 0.75 (0.64, 0.88) for those who consumed 3-4 cups/d, and 0.67 (0.57, 0.79) for those who consumed >5 cups/d in comparison with those who consumed <1 cup/d (P-trend <0.001).
Conclusion: Green tea consumption is significantly associated with a lower risk of incident functional disability, even after adjustment for possible confounding factors.