" In scientific circles, the phenomenon by which oxygen molecules grab stray electrons and go crazy is called oxidant, or oxidative, stress. According to the theory, the resulting cellular damage is what essentially causes aging. Aging and disease have been thought of as the oxidation of the body. Those brown age spots on the back of your hands? They’re just oxidized fat under the skin. Oxidant stress is thought to be why we all get wrinkles, why we lose some of our memory, why our organ systems break down as we get older. Basically, the theory goes, we’re rusting. You can slow down this oxidant process by eating foods containing lots of antioxidants. You can tell whether a food is rich in antioxidants by slicing it open, exposing it to air (oxygen), and then seeing what happens. If it turns brown, it’s oxidizing. "
― Michael Greger , How Not to Die: Discover the Foods Scientifically Proven to Prevent and Reverse Disease