Association between different types of tea consumption frequency and sleep quality with cognitive function among older adults in Qingdao rural area

BACKGROUND: Previous studies have shown that tea consumption frequency or sleep quality is independently associated with cognitive function, but the combined association remains unclear. OBJECTIVE: To investigate the individual and combined associations between tea consumption frequency and sleep quality with cognitive function and analyze whether this association is modified by gender and age. METHODS: The cross-sectional study involved 646 participants from 17 villages in Jimo District, Qingdao, in 2022. Data on tea consumption frequency were collected via a questionnaire. Cognitive function and sleep quality were assessed through the Montreal Cognitive Assessment and Pittsburgh Sleep Quality Index, respectively. Linear regression models were used to analyze associations, with a combined variable for tea consumption frequency and sleep quality constructed to evaluate their combined association. Stratified analysis and interaction tests assessed the moderating effects of gender and age. RESULTS: Higher consumption frequency of green tea (β (95% CI): 0.97 (0.23, 1.70)) or black tea (β (95% CI): 0.78 (0.08, 1.48)) was positively associated with cognitive function. Moreover, higher consumption frequency of green tea combined with good sleep quality was significantly associated with optimal cognitive function (β (95% CI): 1.17 (0.10, 2.31)). Stratified analysis revealed no significant modifying effects of gender or age on the aforementioned associations. CONCLUSION: Increased consumption frequency of green tea, alongside maintaining good sleep quality, is associated with enhanced cognitive function. These findings highlight the value of modifiable lifestyle factors in promoting cognitive health.