Many people have never heard of annatto, also called achiote. The closest most of us in North America have come to this tiny seed that grows in Central America, South America, and the Caribbean is cheddar cheese. Annatto is used to color the naturally white cheddar a pleasant shade of orange. Stunning new research shows that this often overlooked spice from the rainforest is very good for us. For centuries, folk healers have used annatto to treat infections topically and orally.