Do antioxidants impair signaling by reactive oxygen species and lipid oxidation products?

► Reactive oxygen/nitrogen species, ROS/RNS, have dual functions. ► Lipid oxidation products exert both harmful and beneficial effects. ► Lipid peroxidaton (LPO) products may induce adaptive response. ► Radical scavenging antioxidants do not impair physiological signaling. ► Inhibition of LPO by antioxidants should be beneficial for human health.