Regular consumption of walnuts may lengthen attention spans, increase fluid intelligence, and lessen ADHD symptoms in adolescents. The Lancet published the associated study. Alpha-linolenic fatty acid (ALA), a form of omega-3 fatty acid that is important for brain development and function, is abundant in walnuts. The purpose of the current study was to determine how walnut fat consumption affected adolescent neurodevelopment. To do so, they recruited 771 secondary school students aged 11 to 16 years old from 12 different high schools in Barcelona, Spain. The adolescents were randomized into two groups: one receiving no intervention and one receiving 30g packets of walnuts to consume daily over six months.