A handful of walnuts a day lifted young people's mood in a Barcelona trial

Forty grams of walnuts — roughly a handful — eaten every day for eight weeks left healthy young adults feeling measurably better. In a randomised controlled trial at the University of Barcelona, published in the journal Food & Function, 31 young adults in Spain saw their overall negative emotional states fall during the walnut weeks compared with a control period, with anger and fatigue dropping too. Their urine told a matching story: levels rose for urolithin, a compound the gut makes from walnut polyphenols, and for a key metabolite of serotonin, the chemical closely tied to mood. 'The association points to a new direction for studying the relationship between walnut consumption, gut microbiota and emotional well-being,' said Professor Izquierdo-Pulido, who led the study. It is a small trial, supported by the California Walnut Commission — but a deliciously simple hint that food and mood really are connected.

SDG 3 · Good health and well-being