The free-radical damage theory: Accumulating evidence against a simple link of oxidative stress to ageing and lifespan

John R. Speakman* (Corresponding Author), Colin Selman

*Corresponding author for this work

Research output: Contribution to journalReview article

165 Citations (Scopus)


Recent work on a small European cave salamander (Proteus anguinus) has revealed that it has exceptional longevity, yet it appears to have unexceptional defences against oxidative damage. This paper comes at the end of a string of other studies that are calling into question the free-radical damage theory of ageing. This theory rose to prominence in the 1990s as the dominant theory for why we age and die. Despite substantial correlative evidence to support it, studies in the last five years have raised doubts over its importance. In particular, these include studies of mice with the major antioxidant genes knocked out (both singly and in combination), which show the expected elevation in oxidative damage but no impact on lifespan. Combined, these findings raise fundamental questions over whether the free-radical damage theory remains useful for understanding the ageing process, and variation in lifespan and life histories. Editor's suggested further reading in BioEssays Blind cave salamanders age very slowly:

Original languageEnglish
Pages (from-to)255-259
Number of pages5
Issue number4
Early online date2 Feb 2011
Publication statusPublished - Apr 2011



  • Ageing
  • Free radicals
  • Life histories
  • Lifespan
  • Oxidative stress

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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