A small study published in JAMA Psychiatry suggests that cutting back on ultra-processed foods may lead to lower depression and anxiety scores.

A study published September 23 in JAMA Psychiatry found that participants who reduced their ultra-processed food (UPF) intake by more than 85% experienced significant improvements in depression symptoms. The research involved 19 participants who followed both their usual diet and a low-UPF diet in separate, randomly assigned phases. During the low-UPF phase, participants reported lower scores on standard measures for depression and anxiety.

Study Findings and Methodology

Participants in the study maintained their existing medication, therapy, exercise, and sleep routines throughout the research to isolate the impact of diet. On the PHQ-9 depression scale, average scores dropped from 8.68 during the usual diet phase to 5.53 during the low-UPF phase. Researchers noted that while the results are promising, the study was limited by its small sample size and reliance on self-reported data, necessitating larger future trials.

Potential Links Between Diet and Mood

Experts suggest several mechanisms may link UPFs to mood, including the gut-brain axis. UPFs are often low in essential fiber, vitamins, and minerals, and may contain additives like artificial sweeteners that can disrupt the gut microbiome. Because the gut produces a significant portion of the body's serotonin, these disruptions may interfere with neurotransmitter production. Additionally, diets high in UPFs may lack the antioxidants found in whole foods, potentially increasing oxidative stress.

Practical Dietary Shifts

Preventive Cardiology Dietitian Michelle Routhenstein suggests that individuals looking to reduce UPF intake should focus on sustainable, gradual changes rather than immediate overhauls. She recommends identifying frequent sources of UPFs and replacing them with minimally processed alternatives like frozen vegetables, canned beans, or plain yogurt. The goal is to shift toward a nutrient-dense eating pattern rather than attempting to eliminate all processed foods.