Archeologists have (thus far) dated the oldest specimens to about 7,600 years found in Peru. Cultivation spread as far as Mesoamerica where the Spanish conquistadors found peanuts being offered for sale in the marketplace of Tenochtitlan (Mexico City). The plant was later spread worldwide by European traders.
Peanuts are rich in nutrients, providing over 30 essential nutrients and phytonutrients. Peanuts are a good source of niacin, folate, fiber, magnesium, vitamin E, manganese and phosphorus. They also are naturally free of trans-fats and sodium, and contain about 25% protein (a higher proportion than in any true nut).
While peanuts are considered high in fat, they primarily contain “good” fats also known as unsaturated fats. One serving of peanuts contains 11.5 g unsaturated fat and 2 g of saturated fat. In fact, peanuts have been linked well enough to their heart-healthy benefits. In 2003, the Food and Drug Administration released a health claim recognizing peanuts in helping maintain one's cholesterol.
Popular confections include salted peanuts, peanut butter (sandwiches, candy bars, and cups), peanut brittle, and shelled nuts (plain/roasted). Salted peanuts are usually roasted in oil and packed in retail size, plastic bags or hermetically sealed cans. Dry roasted, salted peanuts are also marketed in significant quantities. Peanuts are often a major ingredient in mixed nuts because of their inexpensiveness compared to Brazil nuts, cashews, walnuts, and so on. The primary use of peanut butter is in the home, but large quantities are also used in the commercial manufacture of sandwiches, candy, and bakery products. Boiled peanuts are a preparation of raw, unshelled green peanuts boiled in brine and typically eaten as a snack in the southern United States where most peanuts are grown. More recently, fried peanut recipes have emerged - allowing both shell and nut to be eaten. Peanuts are also used in cosmetics, nitroglycerin, plastics, dyes and paints.