Peanuts start growing as a ground flower - but because the peanut flower is very heavy - it bends towards the ground and eventually pushes it's way underground where the peanut matures.
A University of Florida team says peanuts are rich in antioxidants which protect cells from damage linked to heart disease and cancer. Peanuts also contain high levels of protein and "good" monounsaturated fat.
The US researchers tested the antioxidant content of a dozen different varieties of peanuts. Antioxidants are the naturally occurring substances in plants that protect the body from free radicals - 'volatile' chemicals in the blood.
Although free radicals do play an important role in the immune system, they also alter cholesterol in a process known as oxidation, which is thought to speed up the hardening of the arteries.
Red and orange fruits and vegetables are already known to be particularly high in antioxidants. But the researchers found peanuts were also high in the beneficial chemicals. They found peanuts contain high levels of polyphenols, a family of chemicals commonly found in foods, which have strong antioxidant properties.
Steve Talcott of the University of Florida, who led the research, said: "When it comes to antioxidant content, peanuts are right up there with strawberries. We expected a fairly high antioxidant content in peanuts, but we were a bit shocked to find that they're as rich in antioxidants as many kinds of fruit."
Not everyone can eat peanuts, in fact some are highly allergic to them. There are various reasons why people develop or have allergies to things, some believe it is because of how frequently the item is used in foods. This may be why certain foods like corn (which is used in so many forms), peanuts and wheat are higher on the scale of allergy-forming foods.