It runs counter to decades of medical advice, but again and again, researchers are finding that those who drink moderately, and in some cases even those who drink heavily, outlive their sober peers.
In a recent study from the University of Texas, Austin, researchers followed middle-aged subjects into old age and found that while nearly 70 percent of abstainers were dead within twenty years of starting the study, only 60 percent of heavy drinkers and 41 percent of the moderate drinkers had died by that time.
Findings such as this have met with much controversy in the medical community, less because it supports the health benefits of modest drinking, and more because it suggests that those who say no to that evening glass of wine are substantially more likely to die sooner.
Studies show that a little bit of alcohol (less than two drinks a day) can be healthy for your heart. But how could staying away from alcohol shorten your life?
Alcohol or the Lifestyle That Accompanies It?
Some have suggested that other factors associated with drinking frequency are behind this difference in longevity, such as wealth, race, physical activity or even social activity.
For instance, people who are wealthier are more likely to drink, but are also more likely to have good health care, points out Dr. Robert Gwyther, professor of family medicine at the University of North Carolina at Chapel Hill.
Others suggest that moderate drinkers tend to be more social and hence have a stronger social support system -- something studies have connected to increased longevity, especially in old age.
In addition, those who abstain are also more likely to do so because of an existing health problem or because they are recovering alcoholics, and the mystery behind this effect begins to fade.
The Problem of Sobreity
In fact, the University of Texas researchers went into their study expecting "that a substantial part of the health benefits associated with moderating drinking were due to confounding factors associated with alcohol abstention," Charles J. Holahan, a professor in the department of psychology at The University of Texas at Austin and corresponding author for the study said in a statement.
When controlling for age and gender only, researchers saw a significant difference in mortality between drinkers and non-drinkers similar to that found in other studies.
"Controlling for former problem drinking status, existing health problems, and key socio-demographic and social-behavioral factors substantially reduced the mortality effect," Holahan noted, but even then, the effect was still significant.
This means that the "benefit is smaller than we previously thought," but because it still remains after "meticulously" controlling for so many variables, this study provides "powerfully reinforced evidence that this happens," says Dr. David Katz, director of the Prevention Research Center at Yale Medical School.
One issue in this study, is that because of restrictions in the sample, lifelong abstainers were not included, only previous drinkers who had quit. Though past studies have found that even when compared to those who never touch alcohol, moderate drinkers live longer, this study cannot speak to this comparison.
Drinkers Do Best, in Moderation
Most doctors agree that moderate drinking, defined as one or two drinks a day, confers modest health benefits.
Most of the research has focused on the cardiovascular benefits of alcohol: it thins the blood, reducing the likelihood of blood clots, and increases levels of good cholesterol.
A 2010 meta-analysis of data from the U.S., Great Britain, Japan, and Sweden, found that those who consume one to two drinks a day were about 20 percent less likely to die following a heart attack than those who steered clear of alcohol.
Anecdotally, doctors say that less-documented associations with alcohol, such as ties to stress reduction and social prowess, may play a role in the effect as well.
There could also be stress-reduction benefits garnered from unwinding with that end-of-the-day cocktail, says Dr. Alison Moores, an expert in geriatric medicine at the University of California, Los Angeles.
In the study, drinkers were also more social than abstainers, who have fewer close friends and lower quality of friend support, a factor that may play into stress level and emotional health as people age.
Alcohol's Not for Everyone
Does all this add up to a universal recommendation to indulge in a nightly drink? Not necessarily, doctors say.
For one thing, the cardio-protective benefits of alcohol are beneficial predominantly to those middle-aged and older, Gwyther says.
"People should not get the idea as young folks that drinking is good for their health, [especially considering] most addiction to alcohol begins before age 25," he says.
Even moderate alcohol consumption has been tied to an increased likelihood of breast cancer and certain gastrointestinal cancers, Katz says, so those at increased risk for such cancers may not reap a benefit from habitual drinking.
Doctors also warn that these studies should not be used as an excuse to indulge in more than two drinks a day.
Especially for those who have a family history of alcoholism or may be otherwise susceptible to developing an addiction, a daily dose of alcohol may not be an apt prescription, says Dr. Reid Finlayson, professor of psychiatry at Vanderbilt University.
"More is not better, excessive alcohol [use] is a major cause of preventable death and chronic disease in our society and people certainly need that reminder as much as they need to know that light drinking can be healthy," Katz says.