Association between caffeine intake and cognitive function in adults; effect modification by sex: Data from National Health and Nutrition Examination Survey (NHANES) 2013-2014

Abstract

Background & aims: The aim of this study was to evaluate the association between caffeine intake and cognitive function.

Methods: In this cross sectional study, we used data from the 2013-2014 National Health and Nutritional Examination Surveys (NHANES). Our research subjects were 1440 adults aged ≥60 years. The individual's cognitive functions were evaluated using the Consortium to Establish a Registry for Alzheimer's disease (CERAD) Word List Learning Test, CERAD Word List Recall Test, Animal Fluency test, and Digit Symbol Substitution Test (DSST). Participants were categorized based on the quartiles of caffeine intake. In each dimension of cognitive, we calculated and used median value as cut-off point and assessed the association between each dimension (binary) and caffeine intake using multiple logistic regression analysis in different models.

Results: In all of the dimensions, only the highest quartile of caffeine intakes was positively associated with the cognitive function in the crude model and also trend existed (P trend <0.05). After adjusting for potential confounders (age, sex, family income, education, marital status, history of disease, sleep disorders, thyroid problems, physical activity, social support, smoking, and some nutrients), the association was marginally significant in CERAD Word List Recall Test (P trend = 0.09), but was not significant in other dimensions of cognitive function. A statistically significant interaction was noted between caffeine intake and gender in relation to the CERAD Word List Recall Test (P = 0.02).

Conclusions: Generally, there was a weak positive association between caffeine intake and cognitive performance in older adults that modified by sex. So that, the relation was stronger among male than female.

Keywords: Caffeine; Cognitive function; Impairment; Interaction; Sex.