The gradiated folds of a walnut mimic the appearance of a human brain and provide a clue to the benefits of it in the activity of the brain. Walnuts are the only nuts which contain significant amounts of omega-3 fatty acids. They may also help head off dementia. An American study found that walnut extract break down the protein-based plaques associated with Alzheimer’s disease. Researchers at Univerisity in Boston found walnuts reversed some signs of brain aging in rats.