Daily Walnut Consumption May Improve Mood in Young Adults

A clinical trial suggests that daily walnut consumption can positively impact mood in young adults. The research, led by the University of Barcelona and supported by the California Walnut Commission, involved 31 healthy young adults aged 24 who consumed 40 grams of walnuts per day for eight weeks. During the intervention period, participants showed a significant reduction in overall mood disturbance, accompanied by decreased levels of anger and fatigue.

The study, published in Food & Function, also explored potential biological mechanisms linked to gut microbiota and serotonin metabolism. Researchers propose that polyphenols in walnuts, specifically ellagitannins, are metabolized by gut bacteria into compounds called urolithins. These urolithins may play a role in gut-brain communication, potentially explaining the observed mood benefits.

These findings build upon complementary 2025 research from the same team, which found that walnut consumption increased a biomarker associated with melatonin, a key hormone for sleep regulation. Taken together, both studies suggest that regular intake of walnuts could contribute to overall well-being by influencing both mood and sleep.

While the results are promising, the researchers note the study's small sample size, primarily composed of females. Further research is recommended to confirm these findings over longer durations and in more diverse populations.