Walnuts are unique among nuts because they contain almost entirely healthy, polyunsaturated fats (13 grams) including 2.5 grams of omega-3 alpha-linolenic (ALA) per 1-ounce serving. "In fact, walnuts are the only nut with a high amount of ALA, which has been associated with benefits for heart health, brain health, and inflammation," Bazilian explains.2 This is good to know as omega-3 ALA cannot be made by the body and therefore must come from foods.