, 10:773 | Cite as

Origin and evolution of the free radical theory of aging: a brief personal history, 1954–2009

  • Denham HarmanEmail author


Aging is the progressive accumulation in an organism of diverse, deleterious changes with time that increase the chance of disease and death. The basic chemical process underlying aging was first advanced by the free radical theory of aging (FRTA) in 1954: the reaction of active free radicals, normally produced in the organisms, with cellular constituents initiates the changes associated with aging. The involvement of free radicals in aging is related to their key role in the origin and evolution of life. The initial low acceptance of the FRTA by the scientific community, its slow growth, manifested by meetings and occasional papers based on the theory, prompted this account of the intermittent growth of acceptance of the theory over the past nearly 55 years.


Aging Free radicals Mutations Mitochondria Origin of life Evolution Functional life span Clinical gerontology 

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  1. 1.University of Nebraska Medical Center College of MedicineOmahaUSA

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