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

Abstract

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 (X²=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.

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Keywords:

• gender difference
• green tea
• amnestic mild cognitive impairment
• protective factor

Acknowledgments

This work was supported by grants from the China Ministry of Science and Technology (2009BAI77B03), Shanghai Jiao Tong University School of Medicine (15ZH4010), and Shanghai Jiaotong University School of Medicine and Institute of neuroscience, Chinese Academy of Sciences (2015NKX003).

Disclosure

The authors report no conflicts of interest in this work.