Black walnut Black walnut is a tree. The fruit (nut) is often eaten as a food. The nut, the shell of the nut (hull), and the leaf are sometimes used to make medicine.Black walnut is eaten as part of the diet to lower the risk of heart disease, but there is no good scientific evidence to support this use.
How does it work?
Black walnut contains high concentrations of chemicals called tannins, which can reduce pain and swelling and dry up body fluids such as mucous.