Summary: Light to moderate weekly alcohol consumption during middle age could help preserve brain function as we get older. Compared to non-drinkers, those who had a drink or two a day tended to have better performance on cognitive tests over time.
Source: University of Georgia
Light to moderate drinking may preserve brain function in older age, according to a new study from the University of Georgia.
The study examined the link between alcohol consumption and changes in cognitive function over time among middle-aged and older adults in the U.S.
“We know there are some older people who believe that drinking a little wine everyday could maintain a good cognitive condition,” said lead author Ruiyuan Zhang, a doctoral student at UGA’s College of Public Health.
“We wanted to know if drinking a small amount of alcohol actually correlates with a good cognitive function, or is it just a kind of survivor bias.”
Regular, moderate alcohol consumption has been shown to promote heart health and some research points to a similar protective benefit for brain health. However, many of these studies were not designed to isolate the effects of alcohol on cognition or did not measure effects over time.
Zhang and his team developed a way to track cognition performance over 10 years using participant data from the nationally representative Health and Retirement Study.
During the study, a total of 19,887 participants completed surveys every two years about their health and lifestyle, including questions on drinking habits. Light to moderate drinking is defined as fewer than eight drinks per week for women and 15 drinks or fewer per week among men.
These participants also had their cognitive function measured in a series of tests looking at their overall mental status, word recall and vocabulary. Their test results were combined to form a total cognitive score.
Zhang and his colleagues looked at how participants performed on these cognitive tests over the course of the study and categorized their performance as high or low trajectories, meaning their cognitive function remained high over time or began to decline.
Compared to nondrinkers, they found that those who had a drink or two a day tended to perform better on cognitive tests over time.
Even when other important factors known to impact cognition such as age, smoking or education level were controlled for, they saw a pattern of light drinking associated with high cognitive trajectories.
The optimal amount of drinks per week was between 10 and 14 drinks. But that doesn’t mean those who drink less should start indulging more, says Zhang.
“It is hard to say this effect is causal,” he said. “So, if some people don’t drink alcoholic beverages, this study does not encourage them to drink to prevent cognitive function decline.”
Also of note, the association was stronger among white participants versus African American participants, which is significant, said Zhang, and prompts further exploration into the mechanisms of alcohol’s effect on cognition.
About this neuroscience research article
Source: University of Georgia Media Contacts: Changwei Li – University of Georgia Image Source: The image is in the public domain.
Association of Moderate Alcohol Drinking with Cognitive Functions Among US Adults Importance Studies examining the association of low to moderate drinking with various cognitive functions have yielded mixed findings.
Objective To investigate 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. Design, Setting, and Participants A prospective cohort study of participants drawn from the Health and Retirement Study (HRS), a nationally representative sample of US adults, with mean (SD) follow-up of 9.1 (3.1) years. In total, 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 data analysis was conducted from June to November 2019.
Exposures Alcohol consumption and aging.
Main Outcomes and Measures 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).
Results The mean (SD) age of 19 887 participants 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%]). 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; 95% CI, 0.59-0.74), mental status (OR, 0.71; 95% CI, 0.63-0.81), word recall (OR, 0.74; 95% CI, 0.69-0.80), and vocabulary (OR, 0.64; 95% CI, 0.56-0.74) (all P < .001). 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; P = .002), mental status (β coefficient, 0.02; 95% CI, 0.01-0.03; P = .002), word recall (β coefficient, 0.02; 95% CI, 0.01-0.04; P = .01), and vocabulary (β coefficient, 0.01; 95% CI, 0.00-0.03; P = .08). A significant racial/ethnic difference was observed for trajectories of mental status (P = .02 for interaction), 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.
Conclusions and relevance 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. Studies examining the mechanisms underlying the association between alcohol drinking and cognition in middle-aged or older adults are needed.