Walnuts contain omega-3 fatty acids that have an important role in brain development. A study conducted in Spain revealed that eating walnuts regularly helps mental development in adolescents.
Researchers found that members of the group who ate walnuts for at least 100 days (not necessarily every day) increased their ability to concentrate, with ADHD symptoms reduced for those in this group. The group that did not get walnuts "did not undergo any changes naturally," said researcher Jordi Golfiz, from the Institute of Health Research in Barcelona.