Incorporating pistachios into the diet can significantly reduce cholesterol and help to prevent narrowing of the arteries, research suggests. Nuts have a reputaion for being rich in protein, fibre and in many cases their fats are of the healthy type. In 2003 the US Food and Drug Administration allowed nuts — including walnuts, peanuts, almonds and pistachios — to carry a “qualified health claim” asserting there was evidence that they could lower the risk of heart disease, because of their effects on cholesterol.