Daily Walnut Consumption Linked to Better Mood in Young Adults

The study, led by Dr. Maria Izquierdo-Pulido at the University of Barcelona, observed 31 participants with an average age of 24. Published in the journal Food & Function, the research indicates that the benefits of walnuts extend beyond general nutrition, potentially influencing emotional health through the gut microbiota. By metabolizing walnut polyphenols, the gut produces urolithins, which the research team linked to increased levels of 5-HIAA, a primary metabolite of serotonin.

These findings build upon a 2025 study from the same group, which found that regular walnut intake also increased melatonin biomarkers, suggesting a dual benefit for sleep and mood. While the current results are promising, scientists caution that the sample size was small and predominantly female. Further investigation is required to determine if these emotional and biological advantages apply across broader age groups or to individuals currently managing mood disorders.