Walnut

Walnuts are the top nut for Brain Health. They have a significantly high concentration of DHA , a type of Omega-3 fatty acid.
DHA – among other things has been shown to protect brain health in newborns, improve cognitive performance in adults and prevent age related cognitive decline.
Just a quarter cup of walnuts provides nearly 100% of the recommended daily intake of DHA.

Safety profile : Some people may be allergic to walnuts.