Gender differences in the protective effects of green tea against amnestic mild cognitive impairment in the elderly Han population

BACKGROUND: Gender differences may contribute to variances in the potential protective effects of tea against cognitive impairment in the elderly. OBJECTIVE: To examine the association between different types of tea consumption and the risk of amnestic mild cognitive impairment (aMCI) along gender lines. METHODS: A cross-sectional study was conducted with reference to 20 communities in China. The sample population included elderly participants aged 60 years or older. A standardized questionnaire was used to collect each participant’s general demographic information. Trained psychologists administrated the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) to assess participants’ cognitive function. An attending psychiatrist evaluated each participant’s cognitive function. Finally, data from 2,131 participants were analyzed to assess the association. RESULTS: With regard to male participants, the percentage of green tea consumption was higher in the normal control group than in the aMCI group (X(2)=4.64, P=0.031). Logistic regression analysis showed that green tea consumption reduced the risk of aMCI in male participants (OR=0.657, P=0.019), and this finding was highly significant in males aged under 70 years (OR=0.376, P=0.002). Regarding female participants across every age group, the results indicated that tea consumption failed to significantly decrease the risk of aMCI (P>0.05). Unlike green tea, black tea and oolong tea were not correlated with a reduced risk of aMCI in terms of gender or age group. Multiple linear regression analysis also revealed that age, years of education, and green tea consumption (B=0.996, P=0.000) were associated with MoCA and MMSE scores, though only in male participants. CONCLUSION: Green tea consumption showed a protective effect against aMCI in males but not in females, particularly in males aged <70 years. However, black tea and oolong tea failed to show any protective effect in either males or females.