There's an herbal compound formulated by a Nobel Prize nominee that's clinically proven to reduce oxidative stress by up to 70% in 100% of the people who take it. Montel Williams is a big proponent. If you search for it (the name is Protandim) on PubMed, there are 7 peer-reviewed studies you can peruse.

Interesting part of the story is that the doc who helped to develop it is one of the two researchers who originally posited the idea of the "free radical theory of aging".