By Вen Li
A study published in the New England Journal of Medicine on Jan. 20 reveals that moderate alcohol consumption enhances cognitive function in women.
The researchers wrote: “We found that older women who consumed up to one drink per day had consistently better cognitive performance than nondrinkers. Overall, as compared with nondrinkers, women who drank 1.0-14.9 g of alcohol per day [about one drink] had a decrease in the risk of cognitive impairment of about 20 per cent. Moreover, moderate drinkers were less likely to have a substantial decline in cognitive function over a two-year period. We found similar inverse associations for all types of alcoholic beverages.”
The drinking habits of research participants, grouped into non- moderate, and heavy drinkers, were tracked over 25 years using surveys. Cognitive function was determined using the a series of memory recall tests for general cognition and verbal memory. Researchers found that moderate drinkers of beer, wine, or liquor benefited equally from a 20 per cent decrease in cognitive decline.
“For participants who were 70 to 81 years of age, drinking 1.0-14.9 g of alcohol per day was cognitively equivalent to being approximately a year and a half younger,” the authors noted. No additional benefit was found for the group who consumed 15.0-30.0 g/day.
They added that the beneficial effects of light alcohol consumption took two years to come into effect, speculating that light alcohol consumption results in permanent but subtle changes in the brain and heart.
“Several mechanisms have been proposed to explain the association of moderate alcohol consumption with better cognition. The most plausible relates to the consistently lower rates of cardiovascular disease among moderate alcohol drinkers in many studies. This risk reduction has been attributed partly to alcohol-induced elevations in HDL cholesterol and reductions in fibrinogen and other thrombotic factors. Thus, moderate intake of alcohol may also help preserve brain vasculature, may prevent subclinical strokes, and could thus result in better cognitive function.”
The results are consistent with results from a series of previous studies on the subject, but the authors caution that factors other than alcohol consumption may affect their measures of cognitive function.
“We cannot exclude the possibility that women with poor cognition decreased their alcohol intake (reverse causation). This seems unlikely, however, since we specifically excluded heavier drinkers and limited our analyses to those with stable patterns of alcohol intake.”
“Finally, there may be uncontrolled confounding. Moderate drinkers had several favourable health characteristics that may influence cognitive function, such as a decreased incidence of diabetes. However, analyses that excluded women with diabetes yielded similar results. Adjustment for many potential confounders had little effect on the results, suggesting that confounding is unlikely to explain the observed associations.”
The authors did not report on research involving other age or gender cohorts, so it is unclear if university-aged students would benefit from mild alcohol consumption.