Low, moderate drinking tied to better cognitive function later in life

Light drinking may be linked to better cognitive function later in life, according to research published in JAMA Network Open.

Ruiyuan Zhang MD, MS, of the department of epidemiology and biostatistics at the University of Georgia College of Public Health, told Healio Primary Care that the finding “implies that low-to-moderate alcohol drinking is associated with better cognitive function outcomes among middle-aged or older men and women in the United States.”

Zhang and colleagues conducted a prospective cohort study of participants from the Health and Retirement Survey, which includes a nationwide representative sample of middle-aged and older adults. Those included in the study completed cognitive assessments from 1998 through 2008 and participated in at least three biannual surveys that collected health and economic information.

The researchers categorized participants as never drinkers, current drinkers and former drinkers based on their responses to questions on alcohol consumption. Current drinkers were then categorized as heavy drinkers — women who drank 8 or more drinks per week and men who drank 15 or more drinks per week — and low to moderate drinkers.

A total of 19,887 participants with a mean age of 61.8 years were included in the study. Of those, 18.9% were former drinkers and 35.5% were current drinkers. Among current drinkers, 85.2% were low to moderate drinkers.

Zhang and colleagues found that low to moderate drinking was significantly associated with both higher cognitive function trajectory and lower rates of cognitive decline compared with never drinking.

Compared with never drinkers, low to moderate drinkers were less likely to have consistently lower trajectories for total cognitive function (OR = 0.66; 95% CI, 0.59-0.74). They were also less likely to have consistently low trajectories for mental status (OR = 0.71; 95% CI, 0.63-0.81), word recall (OR = 0.74; 95% CI, 0.69-0.81) and vocabulary (OR = 0.64; 95% CI, 0.56-0.74).

The researchers also found that low to moderate drinking was associated with decreased annual rates of total cognitive decline (beta coefficient = 0.04; 95% CI, 0.02-0.07) mental status (beta coefficient = 0.02; 95% CI, 0.01-0.03), word recall (beta coefficient = 0.02; 95% CI, 0.01-0.03) and vocabulary (beta coefficient = 0.01; 95% CI, 0.0-0.03).

Zhang and colleagues observed a significant racial/ethnic difference in mental status trajectories, as low to moderate drinking was associated with lower odds of a consistently low trajectory in white participants (OR = 0.65; 95% CI, 0.56-0.75) but not in Black participants (OR = 1.02; 95% CI, 0.74-1.39).

According to the researchers, the dosage of alcohol consumed has a U-shaped association with cognitive function domains among all participants, and the optimal dose ranged from 10 to 14 drinks per week.

Zhang said the benefits of cognitive function do not outweigh the risks associated with alcohol consumption.

“We found that light drinking associated with better cognitive outcomes, but heavy drinking did not,” he said. “The U-shaped relationship also showed that after the drinking dosage passed the moderate level, the risk of low cognitive function increased very fast. It is widely known and well-studied that excessive alcohol drinking is harmful to multiple organs; our study added more evidence on it.”

Therefore, he recommended that physicians suggest that patients who drink limit their consumption to a moderate or lower level.

For those who do not drink, Zhang noted that they should not start drinking for the potential benefits to cognitive function, “because alcohol could affect multiple organs of the human body and have short-term or long-term adverse effects such as motor vehicle crashes, violence and some cancers. There are other ways to prevent cognitive declines, such as exercise and reading.”