The most important antioxidants are vitamens C, E, Bioflavenoids, and Betacarotene. Anitoxidents can be found in fruits, vegetable, oils(olive oil, or sesame seed is the best), seeds, and nuts. In the majority of articles read although meat has some antioxidant properties, most of those properties can be found in other foods....that's why a mostly vegetarian diet is highly recommended. More about what meat does during digestion later(its not good). Antioxidants are said to be free radical scavengers in that they go around completing those outer shell electrons and in the process they have the ability to stay stable themselves, thus reducing the amount of free floating radicals in our bodies. Tissue saved!
Another important factor about free radicals is that free radicals are a natural part of our immune system. Free radicals attack viruses and illnesses, its when there are too many that our tissues and organs are damaged.