Pistachio nuts are not only delicious, but also nutritionally wholesome. They have high amounts of proteins, minerals and fat, predominantly monounsaturated, like that found in olive oil. They are also an excellent source of antioxidants, vitamins E and B6, and iron, calcium, manganese and potassium, among others. Pistachio nuts help reduce bad cholesterol, increase hemoglobin levels and prevent heart problems.