A new clinical study from the University of Barcelona shows that walnuts, in addition to lowering cholesterol, improve artery elasticity, thus increasing blood flow (Circulation, 2004, vol. 109, no. 13).

Unlike other nuts, walnuts are rich in alpha-linolenic acid, as well as the amino acid L-arginine and the gamma-tocopherol form of vitamin E, which researchers say help improve vascular flexibility and prevent harmful vascular blockage.

—Pamela Emanoil