They are legal, but the skins can be really tough for newbies. Avoid pink dyed or salted nuts because they often have starch added. You can get unsalted, unroasted pistachios at the health food store and then roast them yourself. For instructions see, Pistachio Nuts
Dr. Andrew Weil
Pistachios are a healthy snack in moderation. They can help reduce the risk of heart disease. They are rich in the amino acid arginine, phytosterols and unsaturated fat – all of which promote heart health. They are a good source of polyphenol antioxidants, which protect against oxidative stress and inflammation. They can promote eye health and provide fiber.
Pistachios have heart-healthy fats and a very good nutritional profile. The California Pistachio Commission says a one ounce serving of pistachios (about 47 nuts) provides more fiber than a half cup of spinach, or an orange or apple. They are good sources of vitamin B-6, thiamin, copper, phosphorus, and magnesium. An ounce of pistachios is about 165 calories, too.
A Brief History of the Pistachio
Archeologists discovered pistachio nuts at a dig site in Jarmo (near NW Iraq) that dates back to 6750 BCE, but then a large gap exists until around 2000 BCE when the nuts began wider cultivation. Jumping much later to 1854 when Charles Mason, a seed distributor in California brought the pistachio to this country. Today California is the 2nd largest producer of pistachio nuts after Iran.
They Grow on Trees
The trees grow 30+ feet tall with 4 to 8 inch long leaves. The fruit has a hard shell that changes from green to yellow/red when ripe, then splits partially open. Splitting is a trait selected by humans. Each tree produces around 50,000 nuts every two years!