Oxidative modification of biologically essential molecules by reactive oxygen and nitrogen species (ROS/RNS) has been implicated in the pathogenesis of various diseases. At the same time, roles of ROS/RNS as physiological signaling messenger have been established. Lipid oxidation products also have two faces. It is argued that the radical scavenging antioxidants taken from diet or supplement may impair such beneficial effects of ROS/RNS and lipid oxidation products. However, it is unlikely that antioxidants impair physiologically important signaling, since the antioxidants do not scavenge signaling ROS/RNS nor do they inhibit the formation of signaling molecules. Lipid peroxidation products are not produced on purpose and inhibition of lipid peroxidation by antioxidants should be beneficial for maintenance of health and reducing disease risk. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
