By Steven Reinberg
"One drink a day, preferentially wine, may help prevent depression," said lead researcher Dr. Miguel Martinez-Gonzalez, chair of the department of preventive medicine and public health at the University of Navarra, in Pamplona.
But several mental health experts not involved with the study had reservations about the findings. And the research only found an association between moderate drinking and emotional well-being; it didn't prove cause-and-effect.
"Depression and heart disease seem to share some common mechanisms because they share many similar protective factors and risk factors," he said. However, he added that depression prevention is not a reason to start drinking.
"If you are not a drinker, please don't start drinking," he said. "If you drink alcohol, please keep it in the range of one or less drinks a day and consider drinking wine instead of other alcoholic beverages."
The report was published Aug. 30 in the online journal BMC Medicine.
Tony Tang, an adjunct psychology professor at Northwestern University, in Evanston, Ill., said the new research "is consistent with other studies suggesting modest health benefits of very modest drinking."
But, Tang said other factors may be at work in the potential connection between wine and depression. He noted that compared to nondrinkers, those in the Spanish study who drank a moderate amount of wine were more likely to be married men who were also physically active.
Being single or divorced, living alone and being sedentary "are well-established risk factors of depression. Thus, perhaps the correlation between modest drinking and depression is a coincidence caused by these other known factors," he said.
"An adequate social life is the most important factor we know that protects people from depression," Tang said. "Perhaps not drinking is a sign of serious social isolation in Spain while drinking a glass of wine a day is simply a sign of having a normal social life."
For the study, researchers followed more than 5,500 light-to-moderate drinkers for up to seven years. All the participants were part of a large Spanish study on nutrition and cardiovascular health, and were between 55 and 80 years old.
None of the individuals had suffered from depression or had alcohol-related problems at the start of the study. Over seven years, with medical exams, interviews with dietitians and questionnaires, the researchers kept tabs on participants' mental health and lifestyle.
Wine was the most popular drink and participants who drank two to seven glasses a week were the least likely to suffer from depression, compared to nondrinkers.
Eva Redei, a distinguished professor in the department of psychiatry and behavioral sciences at the Feinberg School of Medicine at Northwestern University, in Chicago, also expressed doubts about the direct effect of wine on depression.
"Considering the increase of major depression in the age group examined in this study, the finding of protective effects of moderate alcohol consumption is intriguing," she said.
However, it raises more questions than answers. "Is moderate wine consumption related to increased socialization, decreased cardiovascular events, or as it seems, increased activity? These questions are not answered by this study, but the findings are definitely worth noticing," Redei said.
"Is it possible that 'in vino veritas' [in wine there's truth] reflects a bigger truth?" she asked.