10 Superfoods for Spring
Good for: Mood
Walnuts are packed with tryptophan, an amino acid your body needs to create the feel-great chemical serotonin. (In fact, Spanish researchers found that walnut eaters have higher levels of this natural mood-regulator.) Another perk: "They're digested slowly," Dr. Katz says. "This contributes to mood stability and can help you tolerate stress."
Try this recipe: Walnut Coffee Cake