The experts investigated the relationship between alcohol consumption and long-term changes in cognitive function among middle-aged and older adults.
“We know there are some older people who believe that drinking a little wine everyday could maintain a good cognitive condition,” said study lead author Ruiyuan Zhang. “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.”
Light to moderate drinking is defined as fewer than eight drinks per week for women and 15 drinks or fewer for men.
Past studies have shown that the moderate consumption of alcohol promotes heart health, and some research suggests that moderate drinking provides similar protective benefits for brain health. However, most of these investigations were not designed to isolate the effects of alcohol on cognition or measure the persistence of the benefits over time.
For the current study, the team used data from the Health and Retirement Study to track cognition performance of nearly 20,000 individuals over 10 years.
Every two years, the participants had reported on their health and lifestyle, including their drinking habits. The individuals were also tested for cognitive ability throughout the duration of the study, and the results were combined to calculate a total cognitive score.
The researchers analyzed the cognitive test scores and categorized the performance of participants according to whether their cognitive function remained high or began to decline over time.
Compared to nondrinkers, individuals who had a drink or two per day tended to perform better on cognitive tests over the years. Even after accounting for other factors, such as smoking or age, the experts found a link between light drinking and high cognitive trajectories. The optimal amount of alcoholic beverages was between 10 and 14 drinks per week.
“It is hard to say this effect is causal,” said Zhang. “So, if some people don’t drink alcoholic beverages, this study does not encourage them to drink to prevent cognitive function decline.”
The study is published in the journal JAMA Network Open.