Why has antioxidant therapy not significantly extended the life spans of mammalian species?

While the free-radical theory of aging suggests that antioxidants might repair damage caused by reactive oxygen species and thereby slow the aging process, this hypothesis has not been scientifically established.1

The primary reason antioxidant therapy has failed to significantly extend the life spans of mammalian species is that the theory remains a subject of ongoing research rather than a proven mechanism for longevity. Although antioxidants can neutralize free radicals in laboratory settings, clinical evidence has not demonstrated that supplemental antioxidant therapy effectively translates into a longer life span in mammals.12

Furthermore, aging is a complex, multifactorial process influenced by genetics, environmental factors, and various biological mechanisms—such as telomere shortening and mitochondrial dysfunction—that cannot be addressed by antioxidants alone. While some antioxidants may help manage specific age-related conditions, such as macular degeneration, they do not appear to fundamentally alter the biological rate of aging.341