ABSTRACT
Purpose:
To investigate the effects of coffee consumption and caffeine intake on cognitive performance in older adults, with a particular focus on the potential mediating role of alkaline phosphatase(ALP).
Methods:
We analyzed data from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2014, involving 2,254 participants aged 60 and older. Cognitive performance was assessed using the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) test, Animal Fluency test, and Digit Symbol Substitution Test (DSST). To establish causal relationships between coffee consumption, caffeine intake, ALP levels, and cognitive performance, we employed methodologies such as Mendelian randomization, protein quantitative trait locus analysis, and protein-protein interaction networks.
Results:
The NHANES study revealed significant findings regarding coffee consumption and cognitive performance. Compared to non-coffee consumers, individuals consuming ≥ 480 g/day of coffee had a significantly lower odds of low CERAD scores, with an adjusted OR of 0.58 (95% CI: 0.41-0.82) in the fully adjusted Model 4. Similarly, those consuming caffeinated coffee 477.9 g/day) had an OR of 0.56 (95% CI: 0.34-0.92). A comparison of the lowest quartile of ALP intake with the highest quartile showed an OR of 1.82 (95% CI: 1.16-2.85), indicating a negative correlation with cognitive performance. Mendelian Randomization (MR) studies suggested that increased coffee intake is associated with cognitive impairment progression, while coffee consumption may protect against Lewy body dementia (OR = 0.2365, 95% CI: 0.0582-0.9610). Additionally, coffee/caffeine intake affected serum ALP (OR = 0.86, 95% CI: 0.79-0.93) and cognitive ability (OR = 0.95, 95% CI: 0.92-0.98), both indicating protective effects. Finally, the IGFLR1 gene exhibited a moderate colocalization with ALP, suggesting potential therapeutic significance.
Conclusions:
This study provides evidence of a positive correlation between coffee consumption, caffeine intake, and cognitive performance in older adults, with ALP potentially contributing to this relationship. These findings underscore the importance of considering dietary factors in cognitive health management for aging populations, highlighting the need for further research to clarify the specific mechanisms involved.
