Simple dietary change may ease depression symptoms in 30 days, study finds

Preliminary research has found that reducing the consumption of ultra-processed foods may be linked to alleviating depression symptoms in some patients within a relatively short period.

The study, published in JAMA Psychiatry and reported by Science Alert, was led by researcher Nyasha Chagwedera from the University of California. It involved 15 adults who regularly consumed large amounts of ultra-processed foods and had experienced depression for an average of 13 years. The average age of participants was 44.

Researchers compared participants' conditions during two four-week dietary periods. In one period, participants followed a diet low in ultra-processed foods, while in the other, they maintained their usual eating habits. This allowed researchers to compare the effects of both dietary patterns on the same individuals.

Ultra-processed foods include many industrially produced products and packaged snacks that are convenient, inexpensive, and appealing in taste. However, researchers note that heavy reliance on these foods may have health impacts beyond weight gain or chronic diseases, potentially affecting mental health as well.

According to the study, results showed a greater reduction in depression symptoms during the low ultra-processed food diet compared to the usual diet period. However, researchers emphasized that the improvement could not be attributed solely to dietary changes, as participants also showed progress compared to baseline even during their usual diet.

Participants' average scores on the PHQ-9 depression scale were about 12.8 at the start of the study, dropping to 8.68 during the usual diet period, suggesting that multiple factors may have contributed to improved mental health.

Researchers believe one possible explanation is the reduction in sugar, fat, and calorie intake when cutting back on ultra-processed foods. Other hypotheses suggest that certain contaminants or additives used in food processing may be linked to health and psychological effects.

The study team stressed that current results primarily assess the feasibility and acceptability of this type of diet among participants, while findings related to depression and anxiety remain exploratory and require further scientific validation.

Researchers called for larger and more precise studies that include objective measurements of ultra-processed food consumption and investigate possible biological mechanisms explaining the link between diet quality and mental health.

This study adds new evidence to growing research connecting dietary habits and brain health. However, it does not yet prove that reducing ultra-processed foods is a direct treatment for depression, but suggests it may be part of a supportive strategy to improve mental well-being.