Packed with potassium and antioxidants, pistachios get their pale green color from lutein, a carotenoid with antioxidant properties. In Iran, where the nuts appear in dishes from polow to baklava, the pistachio is known as the “smiling nut.” Perhaps that’s because of its health value, or maybe because the nuts, which burst their shells partially open when they ripen, appear to
be smiling.

Southerners go nuts for their native pecans. After all, what would we do without pralines or pecan pie? Pecans—from an Algonquin word meaning “a nut that requires a stone to crack”—are plenty good for you. Nutritionists believe that their plant sterols can lower bad cholesterol. Considered a delicacy by the early American colonists, pecans grow on trees that can live 300 years or more.

Walnuts pack a nutritional punch (even baked into brownies). In traditional Chinese medicine, the nut is said to provide anti-inflammatory benefits to asthma sufferers. Known to the Romans as “Jupiter’s royal acorn,” walnuts originated in ancient Persia. Today, California produces more than 90 percent of the commercial crop in the United States.