Accumulation of oxidative damage over time is thought to result in pathologies associated with aging, including arteriosclerosis, neoplasia, and cataracts. Overexpression of the antioxidant protein thioredoxin was reported to increase mean and maximum life span in a short-lived strain, but the specific agents that limited life span were not identified. The study published in the journal Science supports the free radical theory of aging and reinforce the importance of mitochondria as a source of these radicals and an important limiting factor in determining mammalian longevity.

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