Gender differences in tea, coffee, and cognitive decline in the elderly: the Cardiovascular Health Study

Abstract

Although caffeine can enhance cognitive function acutely, long-term effects of consumption of caffeine-containing beverages such as tea and coffee are uncertain. Data on 4,809 participants aged 65 and older from the Cardiovascular Health Study (CHS) were used to examine the relationship of consumption of tea and coffee, assessed by food frequency questionnaire, on change in cognitive function by gender. Cognitive performance was assessed using serial Modified Mini-Mental State (3MS) examinations, which were administered annually up to 9 times. Linear mixed models were used to estimate rates of change in standard 3MS scores and scores modeled using item response theory (IRT). Models were adjusted for age, education, smoking status, clinic site, diabetes, hypertension, stroke, coronary heart disease, depression score, and APOE genotype. Over the median 7.9 years of follow-up, participants who did not consume tea or coffee declined annually an average of 1.30 points (women) and 1.11 points (men) on standard 3MS scores. In fully adjusted models using either standard or IRT 3MS scores, we found modestly reduced rates of cognitive decline for some, but not all, levels of coffee and tea consumption for women, with no consistent effect for men. Caffeine consumption was also associated with attenuation in cognitive decline in women. Dose-response relationships were not linear. These longitudinal analyses suggest a somewhat attenuated rate of cognitive decline among tea and coffee consumers compared to non-consumers in women but not in men. Whether this association is causal or due to unmeasured confounding requires further study.

Fig. 1

Relationship between tea and coffee consumption versus non-consumption and cognition and cognitive decline by gender. Tea and coffee estimates are from a fully adjusted model using IRT 3MS score and including both tea and coffee consumers, regardless of the level of consumption (≥5 cups per year). Non-consumers of tea and coffee comprise the reference group (<5 cups per year). IRT 3MS scores are scaled such that the mean score at baseline is 100 and the standard deviation is 15. The approximately 1 point difference between tea or coffee consumers at baseline thus represents 1/15 of the standard deviation.