Journal of Bioenergetics and Biomembranes

, Volume 38, Issue 5, pp 327–333

Carbohydrate restriction does not change mitochondrial free radical generation and oxidative DNA damage

Original Paper

DOI: 10.1007/s10863-006-9051-0

Cite this article as:
Sanz, A., Gómez, J., Caro, P. et al. J Bioenerg Biomembr (2006) 38: 327. doi:10.1007/s10863-006-9051-0

Abstract

Many previous investigations have consistently reported that caloric restriction (40%), which increases maximum longevity, decreases mitochondrial reactive species (ROS) generation and oxidative damage to mitochondrial DNA (mtDNA) in laboratory rodents. These decreases take place in rat liver after only seven weeks of caloric restriction. Moreover, it has been found that seven weeks of 40% protein restriction, independently of caloric restriction, also decrease these two parameters, whereas they are not changed after seven weeks of 40% lipid restriction. This is interesting since it is known that protein restriction can extend longevity in rodents, whereas lipid restriction does not have such effect. However, before concluding that the ameliorating effects of caloric restriction on mitochondrial oxidative stress are due to restriction in protein intake, studies on the third energetic component of the diet, carbohydrates, are needed. In the present study, using semipurified diets, the carbohydrate ingestion of male Wistar rats was decreased by 40% below controls without changing the level of intake of the other dietary components. After seven weeks of treatment the liver mitochondria of the carbohydrate restricted animals did not show changes in the rate of mitochondrial ROS production, mitochondrial oxygen consumption or percent free radical leak with any substrate (complex I- or complex II-linked) studied. In agreement with this, the levels of oxidative damage in hepatic mtDNA and nuclear DNA were not modified in carbohydrate restricted animals. Oxidative damage in mtDNA was one order of magnitude higher than that in nuclear DNA in both dietary groups. These results, together with previous ones, discard lipids and carbohydrates, and indicate that the lowered ingestion of dietary proteins is responsible for the decrease in mitochondrial ROS production and oxidative damage in mtDNA that occurs during caloric restriction.

Keywords

CarbohydratesDietary restrictionFree radicalsMitochondriaDNA damageAgingOxidative stress

Abbreviations

8-oxodG:

8-oxo-7,8-dihydro-2’-deoxyguanosine

CR:

caloric restriction

mtDNA:

mitochondrial DNA

nDNA:

nuclear DNA

ROS:

reactive oxygen species

Copyright information

© Springer Science + Business Media, Inc. 2006

Authors and Affiliations

  1. 1.Department of Animal Physiology-II, Faculty of Biological SciencesComplutense UniversityMadridSpain
  2. 2.Departamento de Fisiología Animal-II, Facultad de Ciencias BiológicasUniversidad ComplutenseMadridSpain