Is the mitochondrial free radical theory of aging intact?

Sanz, A., Pamplona, R. and Barja, G. (2006) Is the mitochondrial free radical theory of aging intact? Antioxidants and Redox Signaling, 8(3-4), pp. 582-599. (doi: 10.1089/ars.2006.8.582) (PMID:16677102)

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The present state of the mitochondrial free radical theory of aging is reviewed. Available studies do not support the hypothesis that antioxidants control the rate of aging because: (a) they correlate inversely with maximum longevity in vertebrates, and (b) increasing their concentration by different methods does not increase maximum lifespan. On the other hand, comparative studies consistently show that long-lived mammals and birds have low rates of mitochondrial reactive oxygen species (ROS) production and low levels of oxidative damage in their mitochondrial DNA. Furthermore, caloric restriction, which extends longevity, also decreases mitochondrial ROS production at complex I and lowers mtDNA oxidative damage. Recent data show that these changes can also be obtained with protein restriction without strong caloric restriction. Another trait of long-lived mammals and birds is the possession of low degrees of unsaturation in their cellular membranes. This is mainly due to minimizing the presence of highly unsaturated fatty acids such as 22:6n-3 and emphasizing the presence of less unsaturated fatty acids such as 18:2n-6 in long-lived animals, without changing the total amount of polyunsaturated fatty acids. This leads to lower levels of lipid peroxidation and lipoxidationderived protein modification in long-lived species. Taken together, available information is consistent with the predictions of the mitochondrial free radical theory of aging, although definitive proof and many mechanistic details are still lacking.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Sanz Montero, Professor Alberto
Authors: Sanz, A., Pamplona, R., and Barja, G.
College/School:College of Medical Veterinary and Life Sciences > Institute of Molecular Cell and Systems Biology
Journal Name:Antioxidants and Redox Signaling
Publisher:Mary Ann Liebert, Inc. Publishers
ISSN (Online):1557-7716
Published Online:05 May 2006

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