The debate as to whether moderate drinking is good, bad, or has no effect on health has been ongoing for years. Now, a new study suggests that people—especially women—who give up alcohol can experience better mental health and reach levels of well-being almost on a par with those of lifelong abstainers.

Many people drink socially at, for instance, work functions or family events. Some of us may also relish having a glass of wine or beer with our dinner at the end of a long and tiring day. Numerous people fall into the categories of "light" or "moderate" drinkers. But is this habit harmless, or would all of us be better off abstaining from alcohol? Even among researchers, opinions tend to vary greatly as to whether drinking any amount of alcohol is safe or healthful.

For instance, earlier this year, a study published in The Lancet argued that moderate drinking can increase a person's risk of cardiovascular events. Meanwhile, research featured this month in the journal Alcoholism: Clinical and Experimental Research suggests that older adults who occasionally drink may live longer than nondrinkers. There are also issues surrounding the link between alcohol consumption and mental health. While doctors know that overindulging in alcohol can affect mental well-being, it remains unclear whether people who drink moderately would fare better by becoming teetotalers.

Now, a study from the University of Hong Kong (HKU) has found that adults, and women in particular, who completely give up drinking experience a boost in mental well-being. The study's results appear in the Canadian Medical Association Journal. "More evidence suggests caution in recommending moderate drinking as part of a healthy diet," notes study co-author Dr. Michael Ni.

Quitting may be the best way forward

As part of the research, the investigators first analyzed data collected from 10,386 participants via the FAMILY Cohort study at HKU.

All of the participants were either nondrinkers or reported drinking moderately. The group included people who used to drink, people who had recently started drinking, persistent drinkers, formerly persistent drinkers, and lifetime abstainers.

The researchers define moderate drinking as having 14 drinks (196 grams of pure alcohol) or fewer per week, in the case of men, and 7 drinks (98 grams of pure alcohol) or fewer per week, in the case of women.

Among the participants, the mean age was 49 years, and women made up about 56% of the cohort. Among the male participants, approximately 64% were nondrinkers (including lifetime abstainers and former drinkers). Among the female participants, approximately 88% qualified as nondrinkers.

The research team examined the association between alcohol drinking patterns and mental well-being in this cohort in two waves, which took place throughout 2009–2013. They also compared their data with those of the National Epidemiologic Survey on Alcohol and Related Conditions, which took into consideration a separate cohort of 31,079 people.

"In both cohorts," the researchers specify in their paper, "alcohol measurements were available at two time points over a 4-year period."

First, the investigators observed that people who had never consumed alcohol had the greatest level of mental well-being at baseline. Then, they saw that people who had quit drinking—particularly women—experienced a significant improvement in mental health.

When looking at the FAMILY cohort, specifically, the researchers assessed mental well-being using a 100-point scale. When comparing data from women who used to drink with data from female lifetime abstainers, the former had experienced an improvement in mental health that was on average 1.44 points greater than that of the lifetime abstainers during the follow-up period. These results remained, even after the team adjusted for confounding factors, including socioeconomic status, body mass index, and smoking status.

"Global alcohol consumption is expected to continue to increase unless effective strategies are employed," warns Dr. Ni. Indeed, recent reports show that alcohol intake has increased by about 70% in almost 30 years, at a global level, and experts believe that this trend will continue. For this reason, and based on their current findings, the HKU investigators advise individuals to lay off alcohol—for good.

"Our findings suggest caution in recommendations that moderate drinking could improve health-related quality of life. Instead, quitting drinking may be associated with a more favorable change in mental well-being, approaching the level of lifetime abstainers."

—Dr. Michael Ni