CLA antioxidant or prooxidant?

Abstract

The conjugated linoleic acid (CLA) is a term referred to a mixture of positional and geometrical isomers of linoleic acid with double conjugated bonds in carbon atoms 10 and 12 or 9 and 11 with all of the possible cis and trans combinations. CLA is a naturally occurring substance in food. The major dietary sources of CLA are foods derived from ruminants, e.g. beef and cheese and its content increases when meals are processed. There is ample evidence showing that free radicals and oxidation processes mediated by free radicals play an important role in many pathological situations including cancer and atherosclerosis. Natural and synthetic antioxidants, tolerated by humans, are employed in order to avoid or treat these pathologies. In the present paper, articles evaluating the antioxidant or prooxidant activity of CLA have been revised. Preliminary in vivo and in vitro studies suggested the antioxidant role for CLA, however recent researches have not shown any evidence related to it. New studies have to be carried out in order to get more information on the antioxidant and protective role of CLA in free radical-related degenerative diseases.