Pistachios are high in protein, fiber, and antioxidants. They also boast several other important nutrients, including vitamin B6 and potassium. Pistachios are among the most antioxidant-rich nuts around. They’re high in lutein and zeaxanthin, both of which promote eye health. Pistachios contain fewer calories and more protein than most other nuts. Also, their essential amino acid content is higher than any other nut.