Depressed? A Healthy Diet Can Help

CC BY-SA 2.0. Sean Winters

Various healthy diets are shown to ease symptoms of depression, and they work even better for women.

Doctors and scientists know that a junk food diet can harm mental health. But apparently, until now, there has been no overall evidence that eating right can help. A new study changes that.

Dr Joseph Firth, at The University of Manchester, and colleagues found that "existing research has been unable to definitively establish if dietary improvement could benefit mental health." So they set out to conduct a meta-study on the hypothesis that a healthy diet affects symptoms of depression and anxiety.

A meta-study takes data from studies that have already been completed in order to accumulate a large body of evidence which can be analyzed to answer new questions. Dr. Firth and team found 16 suitable studies ("randomized controlled trials (RCTs) of dietary interventions reporting changes in symptoms of depression and/or anxiety") involving over 45,000 participants.

The study found that various types of diets - for weight loss, targeting fat reduction, or focused on nutritional value (nutrient density) - all showed benefits for reducing the symptoms of depression. Dr. Firth explains:

"This is actually good news. The similar effects from any type of dietary improvement suggests that highly-specific or specialized diets are unnecessary for the average individual. Instead, just making simple changes is equally beneficial for mental health. In particular, eating more nutrient-dense meals which are high in fiber and vegetables, while cutting back on fast-foods and refined sugars appears to be sufficient for avoiding the potentially negative psychological effects of a ‘junk food’ diet."

In general, the study did not show a reduction in the symptoms of anxiety - but when the sub-population of women was evaluated the results showed that diet may be effective in helping control anxiety among women. Additionally, the depression-related benefits are more significant for women.

The study proves the need to evaluate the use of these healthy and natural approaches to mental welfare, either to replace or support pharmaceutical and other therapeutic interventions. But until the science of why a healthy diet correlates to less depression becomes more clear, eating healthier seems like a good first step to fight the "darkness."

The full study, The effects of dietary improvement on symptoms of depression and anxiety: a meta-analysis of randomized controlled trials, is published in the journal Psychosomatic Medicine.