Tea consumption and cognitive health in Chinese older adults: A propensity score matching and weighting analysis.

Background: The association between tea consumption, especially different types, and cognitive function has not been adequately explored. This study aimed to investigate the associations of tea consumption, including status, frequency, and type, with cognitive function, considering selection bias.

Methods: We used data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) in 2018(N = 8498). Cognitive function was measured by Mini-Mental State Examination (MMSE). Logistic and linear regression were applied to assess the associations of tea consumption with cognitive impairment and cognitive scores, respectively. Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were used to balance characteristic differences between groups.

Results: The characteristics of tea consumption status, frequency and type were well balanced between groups after using PSM and IPTW. Drinking tea was associated with less cognitive impairment (OR_adjusted:0.84, OR_PSM:0.84, OR_IPTW:0.87) and higher cognitive scores (Coefficient_adjusted:0.29, Coefficient_PSM:0.33, Coefficient_IPTW:0.29). Regular tea drinkers may have better cognitive function than those who never or rarely consumed (P_trend < 0.05 for both methods). Green tea drinkers had lower prevalence of cognitive impairment (OR_adjusted:0.71, OR_IPTW:0.75) and higher cognitive scores (Coefficient_adjusted:0.45, Coefficient_IPTW:0.54). Men, uneducated, and those with annual income>10,000 RMB were more likely to benefit from flower tea. Significant interactions of tea consumption with age, education and income were observed.

Conclusions: Tea consumption, especially regular and green tea consumption, was associated with less cognitive impairment and higher cognitive scores, even after PSM and IPTW adjustments. Flower teas may have potential protective effect that is worth further study. Age, education and income have synergistic effects with tea consumption on cognitive function.