Caffeine and alcohol intakes and overall nutrient adequacy are associated with longitudinal cognitive performance among U.S. adults

Among modifiable lifestyle factors, diet may affect cognitive health. Cross-sectional and longitudinal associations may exist between dietary exposures [e.g., caffeine (mg/d), alcohol (g/d), and nutrient adequacy] and cognitive performance and change over time. This was a prospective cohort study, the Baltimore Longitudinal Study of Aging (n = 628-1305 persons depending on the cognitive outcome; ∼2 visits/person). Outcomes included 10 cognitive scores, spanning various domains of cognition. Caffeine and alcohol intakes and a nutrient adequacy score (NAS) were estimated from 7-d food diaries. Among key findings, caffeine intake was associated with better baseline global cognition among participants with a baseline age (Age_base) of ≥70 y. A higher NAS was associated with better baseline global cognition performance (overall, women, Age_base <70 y), better baseline verbal memory (immediate and delayed recall, Age_base ≥70 y), and slower rate of decline or faster improvement in the attention domain (women). For an Age_base of <70 y, alcohol consumption was associated with slower improvement on letter fluency and global cognition over time. Conversely, for an Age_base of ≥70 y and among women, alcohol intake was related to better baseline attention and working memory. In sum, patterns of diet and cognition associations indicate stratum-specific associations by sex and baseline age. The general observed trend was that of putative beneficial effects of caffeine intake and nutrient adequacy on domains of global cognition, verbal memory, and attention, and mixed effects of alcohol on domains of letter fluency, attention, and working memory. Further longitudinal studies conducted on larger samples of adults are needed to determine whether dietary factors individually or in combination are modifiers of cognitive trajectories among adults.