Association of low to moderate alcohol drinking with cognitive functions from middle to older age among US adults 

A study explored whether associations exist between low to moderate alcohol drinking and cognitive function trajectories or rates of change in cognitive function from middle age to older age among US adults.
The prospective cohort study was based on participants drawn from the Health and Retirement Study (HRS), a nationally representative sample of US adults, with mean follow-up of 9.1 years. 19 887 participants who had their cognitive functions measured in the HRS starting in 1996 through 2008 and who had participated in at least 3 biennial surveys were included. The mean (SD) age was 61.8 (10.2) years, and the majority of the HRS participants were women (11 943 [60.1%]) and of white race/ethnicity (16 950 [85.2%]).
The main outcome measures were trajectories and annual rates of change for the cognitive domains of mental status, word recall, and vocabulary and for the total cognitive score, which was the sum of the mental status and word recall scores. Participants were clustered into 2 cognitive function trajectories for each cognition measure assessed based on their scores at baseline and through at least 3 biennial surveys: a consistently low trajectory (representing low cognitive scores throughout the study period) and a consistently high trajectory (representing high cognitive scores throughout the study period).
Low to moderate drinking (<8 drinks per week for women and <15 drinks per week for men) was significantly associated with a consistently high cognitive function trajectory and a lower rate of cognitive decline. Compared with never drinkers, low to moderate drinkers were less likely to have a consistently low trajectory for total cognitive function (odds ratio [OR], 0.66), mental status (OR, 0.71), word recall (OR, 0.74), and vocabulary (OR, 0.64). In addition, low to moderate drinking was associated with decreased annual rates of total cognitive function decline (β coefficient, 0.04; 95% CI, 0.02-0.07), mental status (β coefficient, 0.02; 95% CI, 0.01-0.03), word recall (β coefficient, 0.02; 95% CI, 0.01-0.04), and vocabulary (β coefficient, 0.01; 95% CI, 0.00-0.03). A significant racial/ethnic difference was observed for trajectories of mental status, in which low to moderate drinking was associated with lower odds of having a consistently low trajectory for white participants (OR, 0.65; 95% CI, 0.56-0.75) but not for black participants (OR, 1.02; 95% CI, 0.74-1.39). Finally, the dosage of alcohol consumed had a U-shaped association with all cognitive function domains for all participants, with an optimal dose of 10 to 14 drinks per week.
These findings suggested that low to moderate alcohol drinking was associated with better global cognition scores, and these associations appeared stronger for white participants than for black participants. The researchers comment that studies examining the mechanisms underlying the association between alcohol drinking and cognition in middle-aged or older adults are needed.
Source: Zhang R, Shen L, Miles T, et al. Association of Low to Moderate Alcohol Drinking With Cognitive Functions From Middle to Older Age Among US Adults. JAMA Netw Open. 2020;3(6):e207922.