Serious depression, or major depressive disorder, affects approximately 14.8 million people in the United States each year and is the leading cause of disability in Americans ages 15 to 44, according to the National Institute of Mental Health. While excessive alcohol consumption is considered a symptom or coping mechanism for depression, a new study strengthens previous evidence that moderate wine consumption may actually decrease the risk of this mood disorder. A team at the University of South Carolina School of Medicine found that the red-wine polyphenol resveratrol may reduce inflammation of the brain caused by stress and mitigate depression-related behaviors in the process.
The root of depression varies from person to person, but many cases stem from social stress, or stress spurred by interactions with other people, such as experiences with bullying or the loss of a loved one. These scenarios cause inflammation, the body’s physical reaction to social stress.
“There is a growing body of evidence which suggests that increased inflammation plays a role in the development of depression,” Dr. Susan Wood, the study’s lead researcher, told Wine Spectator. Inflammation, especially in the brain, may be the link between social stress and depression.
Resveratrol, a chemical compound found in red wine, is a natural anti-inflammatory agent. Previous research has found evidence that the compound, which originates in the skin of red grapes and other plants, reduces inflammation in the body. The South Carolina researchers hypothesized that resveratrol could also prohibit neuroinflammation, or inflammation in the brain, and thus prevent ensuing depressive-like behaviors.
In previous research, Dr. Wood’s team created an animal model to test the effects of social stress, by exposing rats to larger, more aggressive “bully” rats. They found that some of the test animals developed both depressive-like behaviors and inflammation, while others experienced neither.
In the new study, published in Federation of American Societies for Experimental Biology, the researchers replicated the experiment, but added resveratrol to the equation. Throughout the trial, the bullied rats were given a daily dose of resveratrol equivalent to the level found in 6 glasses of wine. The rats that had previously experienced neuroinflammation and depressive behaviors did not develop either issue this time. The team concluded that the resveratrol blocked the inflammation that they would have normally seen in the rats undergoing stress.
While the results are promising, “[T]here is a great need for these findings to be validated in human studies,” said Wood. “We hope our research encourages others to explore the clinical effectiveness of resveratrol and other natural agents as effective anti-inflammatory–based antidepressant compounds in humans.”