A diet that emphasizes fruits, vegetables, fish oil and nuts over sugar and saturated fats may be good for more than residents’ physical wellbeing. It also may help ward off symptoms of depression, Australian researchers have shown.

The full study appears in PLOS One. Investigators divided 76 participants with depression and unhealthy eating habits into two groups. One group was put on a Mediterranean-style diet for three weeks, whereas the other kept its usual eating habits.

Depression scores for the first group fell from the “moderate” range to the “normal” range. This cohort also reported lower anxiety and stress levels. Scores for the other group did not change, however.

Heather Francis, Ph.D., a lecturer in clinical neuropsychology at Macquarie University in Sydney, said investigators were surprised by the discovery. The next step, she added, is to demonstrate the physics behind the changes. Numerous previous studies have linked poor diet with increased inflammation, which can be a risk factor for depression.