Trans-fatty acids and radical stress: what are the real culprits?

Free radical-catalysed cis-trans isomerization of unsaturated lipids in biomimetic models and their significance in eukaryotic cells have been explored in the last few years, an integrating hypothesis being that trans-fatty acids have their origins in both dietary sources and from isomerization of natural isomers by an endogenous radical stress. In this perspective, a summary of the achievements and a discussion of the possible biological sources of isomerizing radical species are given, indicating a need for further research on thiyl radical generation in biological systems. In this context, crucial questions remain to be answered by free radical research involving membrane lipids, thus contributing to lipidomics and embracing biology and medicine.