UCSF: Cutting Ultra-Processed Food Improved Depression — SkimNews
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- UCSF researchers reported that 20 participants with depression who cut ultra-processed food intake by more than 85% showed moderate to large improvements across three depression measures, with anxiety scores also improving modestly.
- The pilot study, published Sept. 23, 2026 in JAMA Psychiatry and funded by the NIH, is described as the first to compare the same participants before and after shifting from their usual ultra-processed diet to healthier foods, using a crossover design where two groups alternated diets for four weeks each.
- All 20 participants had a high BMI and at least one metabolic disorder such as hypertension, diabetes, or elevated LDL cholesterol; 14 also had anxiety; the average age was 44 and 70% were female.
- Corresponding author Nyasha Chagwedera hypothesized that ultra-processed foods damage the gut lining, creating "low-grade, chronic inflammation throughout the body that either directly causes depression or makes people more vulnerable to it" — a "leaky, out-of-balance gut."
- Chagwedera also noted that ultra-processed foods trigger dopamine-driven cravings, with food companies working with scientists to find "just the right amount of sugar, salt, and fat that make you want to eat more and more."
- Senior author Andrew Krystal said the pilot "successfully established the viability" of a larger trial, with phase 2 enrollment expected to begin in 2028.
Why it matters: For the 20 pilot participants — all of whom had depression plus a metabolic disorder like hypertension or diabetes — swapping packaged snacks and fast food for whole foods coincided with measurable symptom relief across three depression scales, giving NIH-backed researchers enough signal to greenlight a larger phase 2 trial with enrollment targeted for 2028.
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