Abstract
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 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.
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