Antioxidants are a group of chemical compounds that protect against free radicals. Free radicals are highly reactive molecules produced naturally or induced by exposure to things like radiation, certain chemical pollutants, or other sources. When free radicals come in contact with healthy cell membranes, they cause damage to the membrane and may ultimately cause the cell to die. Antioxidants prevent this damage by "quenching" the free radical and thus helping maintain health and proper function of the cell. Antioxidants are often the substances that give foods their color or strong flavor. This is why choosing a naturally "colorful" diet can be a very healthy idea!