Drinking wine may reduce an individual’s risk for developing depression, due in part to anti-inflammatory compounds found in grapes, a recent study suggests. The findings, however, contradict a large body of research that claims alcohol has demonstrable links with increased depression.

Wine’s historically medicinal properties and contemporary health benefits have been studied time and time again; the heart-healthy alcohol contains powerful antioxidants, prevents gallstones, reduces the risk for diabetes, and forestalls dementia, but less agreement has been conferred about its ability to boost mood. Adding to the debate is a recent study of wine drinkers in Spain, published in BMC Medicine, which found a decreased risk of depression in people who drank moderate amounts of wine during the week.

Researchers from PREDIMED analyzed the drinking habits of 5,500 individuals over the course of seven years. Participants ranged from 55 to 80 years old and had no history with depression. Wine was the most often consumed alcoholic beverage among subjects.

Over the course of the study, researchers monitored the rate of alcohol consumption, mental health, and subjects’ lifestyles through yearly visits, repeated medical tests, questionnaires, and interviews with dieticians. At the seven-year mark, 443 people reported being diagnosed with depression.

Not all levels of wine consumption yielded the same decreases in depression risk. Light to moderate drinkers, those who drank a daily average of five to 15 grams of alcohol, had lower risks than those who had opted not to imbibe. Moderate drinkers showed even lower risks for depression than the light to moderate cohort. Researchers used a baseline of nine grams of alcohol per glass of wine as their reference.

“Lower amounts of alcohol intake might exert protection in a similar way to what has been observed for coronary heart disease,” said senior author Professor Miguel A. Martínez-González, from the University of Navarra. “In fact, it is believed that depression and coronary heart disease share some common disease mechanisms.”

Lower Depression Rates: Chemical Or Psychological?

Researchers also point toward a compound found in grapes that can have anti-inflammatory properties, which prior studies have suggested can relieve depressive symptoms in patients. In one study, light to moderate alcohol consumption and leisure time physical activity (LTPA) were “independently associated with lower levels of high sensitivity C-reactive protein (CRP), a predictor of cardiometabolic risk. In contrast, depression, ranging from low mood disturbance to major depressive disorder, has been associated with elevated CRP.”

While researchers took into account subjects’ age, race, education, level of physical activity, and marital status in determining the factors lowering depression’s risk, one avenue that remained unexplored was degree of socialization. Indeed, the report notes the “trial includes an older, traditional Spanish Mediterranean population, that consumed chiefly wine, and mainly in a context of socialization with family or friends,” but doesn’t consider the link between decreased depression rates and greater social presence.

A 2001 Danish study found the link between wine and mental health was largely a byproduct of robust, fulfilling social interaction — the wine itself serving mainly as a conduit, or facilitator.

“Our data demonstrate that wine drinking is a general indicator of optimal social, cognitive, and personality development in Denmark. Similar social, cognitive, and personality factors have also been associated with better health in many populations,” the researchers concluded. “Consequently, the association between drinking habits and social and psychological characteristics, in large part, may explain the apparent health benefits of wine.”

Other contradictory findings point to the study’s methodology as its reason for arriving at a conclusion opposite that of previous studies, which saw alcohol consumption linked with greater depression risk.

Susan Ramsey, associate professor of psychiatry and human behavior at the Warren Alpert Medical School at Brown University, said the PREDIMED study was highly selective because it only considered people who never had depression. People with a history of the illness, she said, may see less remarkable results if they consume similar quantities of wine.

"The ability to generalize from the findings of this study to other populations is very limited," Ramsey told LiveScience. "At this point, it would be premature to make any recommendations regarding alcohol or wine consumption as a means of preventing the onset of depression.”

Sources: Gea A, Beunza J, Estruch R. Alcohol intake, wine consumption and the development of depression: the PREDIMED study. BMC Medicine. 2013.

Suarez EC, Schramm-Sapyta NL, Vann Hawkins T, Erkanli A. Depression inhibits the anti-inflammatory effects of leisure time physical activity and light to moderate alcohol consumption. Brain, Behavior, and Immunity. 2013.

Mortensen EL, Jensen HH, Sanders SA, Reinisch JM. Better psychological functioning and higher social status may largely explain the apparent health benefits of wine: a study of wine and beer drinking in young Danish adults. Archives Of Internal Medicine. 2001.