Pistachios have been shown to be effective in preventing lung cancer, as well as other types of cancer. In addition, this cholesterol-free nut is a great source of phosphorus, which helps strengthen bones and teeth. Pistachios are very high in fiber, too. In fact, they boast one of the highest fiber contents of all nuts. They have one of the highest amount of antioxidants, also high in lutein—an antioxidant proven to prevent macular degeneration.