Background:

Previous studies suggest a positive effect of tea intake on cognition. Additional micronutrients that may moderate this association was not previously examined.

Objective:

To examine the association between tea consumption and cognition and explore the interaction between tea consumption and iron intake.

Methods:

Data from the China Health and Nutrition Survey between 1997 and 2011 was used. 4,820 individuals (≥ 55 years) were included in the analyses. Measurement of cognitive function was conducted in 1997, 2000, 2004, and 2006. Tea consumption was self-reported. Food intake was assessed by 24-hour dietary recalls of three consecutive days during home visits between 1997 and 2011. Multivariable mixed linear regression and logistic regression was used to assess the association.

Results:

Tea consumption was associated with reduced global cognitive function decline. In fully adjusted models, regression coefficients (95% CIs) for those who consumed 0 cups/day,< 2 cups/day, 2–3.9 cups/day, and≥ 4 cups/day of tea were 0,–0.09 (–0.55–0.37), 0.05 (–0.34–0.45), and 0.87 (0.46–1.29), respectively. This effect was stronger in adults> 60 years. Tea consumption of≥ 4 cups/day was inversely associated with self-reported poor memory (OR 0.70 (95% CI 0.56–0.86)) and memory decline (OR, 0.73 (95% CI 0.62–0.87)). There was a significant interaction between tea consumption and iron intake in relation to cognition. High iron intake was inversely associated with cognition in non-consumers of tea but not in tea consumers.

Conclusion:

Higher tea intake is associated with reduced cognitive decline in adults and inhibits the adverse effect of high iron intake.