Green tea and coffee intake and risk of cognitive decline in older adults: the National Institute for Longevity Sciences, Longitudinal Study of Aging.

Abstract

To examine the association between green tea and coffee intake and cognitive decline in older adults. A prospective cohort study. The average intake of green tea and coffee in the previous year was assessed through a dietitian interview using a dietary questionnaire. A Mini-Mental State Examination (MMSE) was conducted up to six times biennially. Cognitive decline was screened using the MMSE; its incidence was defined as the first time a score of <27 points was obtained in a biennial test from the baseline. Hazard ratios for incidence of cognitive decline were estimated according to the intake of the two beverages using multivariable Cox proportional hazard regression, controlling for sociodemographic and lifestyle factors. The National Institute for Longevity Sciences, Longitudinal Study of Aging (NILS-LSA) in Japan. Men (n 620) and women (n 685), aged 60-85 years, from the NILS-LSA. During a mean of 5·3 (sd 2·9) years of follow-up, 432 incident cases of cognitive decline were observed. Compared with participants who consumed green tea <once/d, the multivariable hazard ratio (95 % CI) was 0·70 (0·45, 1·06), 0·71 (0·52, 0·97) and 0·72 (0·54, 0·98) among those who consumed green tea once/d, 2-3 times/d and ≥4 times/d, respectively (Ptrend < 0·05). No significant association was found between coffee intake and cognitive decline. The intake of green tea, but not coffee, was shown to reduce the risk of cognitive decline in older adults.