Can improving your diet improve your mental state? That may sound a bit farfetched, but several observational studies over the years have suggested that diet can indeed influence the risk for depression, independent of education, socioeconomic status, and other potential confounding factors. Now the first controlled clinical trial on the link between diet quality and depression lends stronger support to the idea.
Dubbed SMILES (Supporting the Modification of lifestyle In Lowered Emotional States), the Australian study, published in BMC Medicine in January 2017, enrolled people who had moderate to severe depression and poor diets at the start and randomized them into two groups:
- A diet group received ongoing personalized nutrition counseling on how to follow a modified Mediterranean diet. Participants were encouraged to eat whole grains, vegetables, fruits, legumes, low-fat and unsweetened dairy foods, nuts, fish, lean meats, and olive oil; reduce refined grains, sweets, fried or fast foods, processed meats, and sugary drinks; and consume moderate alcohol.
- A social support (control) group discussed neutral topics such as sports and music with a trained “befriender” or engaged in board games and other activities, over the same time frame.
After 12 weeks, the diet group had a greater reduction in depression and anxiety symptoms than the social support group, even with variables such as weight loss taken into account. Moreover, more participants in the diet group (32 percent versus 8 percent) achieved depression remission. These encouraging findings—which come out of the new field of nutritional psychiatry—provide preliminary evidence for dietary improvements as an “efficacious treatment strategy” for depression, the study concluded.
Diet may influence depressive illness by affecting inflammatory and oxidative stress pathways, brain plasticity, and possibly the gut microbiome, according to the researchers. “Moreover, behavioral changes associated with food (cooking/shopping/meal patterns) are an expected outcome of a nutrition intervention, and these changes in activity may also have a therapeutic benefit,” they wrote. As a bonus, improving diet may improve physical illnesses that often occur with depression.
Keep in mind: While the study results are promising, it’s not known if the effects of the diet would persist over time. Also, no diet is a substitute for antidepressant medication if one has been prescribed.
Also see Dealing with Depression Without Drugs.