Can a glass of wine a day help prevent depression?

While previous studies have shown that heavy alcohol intake is related to an increase in mental health problems, including depression, a new Spanish study shows those who drink about a glass of wine each day are less likely to be clinically depressed than those who drink more -- or those who don’t drink at all.

The study, published in the journal BMC Medicine, followed over 5,500 Spanish men and women aged 55-80 for up to seven years. No one suffered from depression or had alcohol dependency issues at the beginning of the study.

The lowest rates of depression were seen among those who drank two to seven small glasses of wine per week. This group had one-third the risk of being depressed as those who did not drink. Those who drank slightly more also had a lower risk of depression, though not as large. And the heaviest drinkers seemed to have an increased risk of depression.

Also see: Can drinking champagne help improve memory?

These results remained statistically significant even when adjusted for lifestyle and social factors, such as smoking, marital status, age, physical activity level and diet.

"Lower amounts of alcohol intake might exert protection in a similar way to what has been observed for coronary heart disease," explains lead author Dr. Miguel A. Martínez-González, chair of the department of preventive medicine and public health at the University of Navarra. "In fact, it is believed that depression and coronary heart disease share some common disease mechanisms."

Also see: How you can tell if a man is depressed

Martínez-González is referring to the protective heart health benefits of antioxidants in wine, such as resveratrol. He hypothesis that resveratrol in wine may help repair inflammatory damage to the hippocampal complex in the brain that contributes to depression. Similarly, resveratrol is believed to reduce inflammation in patients with heart disease.

Another possible explanation is that those who drink moderately may have a richer social life, which is known to reduce depression risk.

What are your thoughts on the relationship between drinking and depression? Have you noticed a connection in your life or with those closest to you? Tell us your experience in the comments below.