Lipidomics and Metabolomics of Dietary Lipid Peroxidation
Dietary fats containing polyunsaturated fatty acids are readily peroxidized during isolation, storage and food preparation. The unsaturated acids serve also as substrates for endogenous peroxidation. Both exogenous and endogenous peroxidation proceed through free radical intermediates. The present review summarizes recent lipidomic and metabolomic evidence for the formation and absorption of bioactive dietary lipid oxidation products, and for the isolation and identification of their lipid, protein and nucleic acid adducts, which accumulate in tissues during chronic disease and ageing. The use of chromatographic and mass spectrometric methods to identify and quantify the entire spectrum of lipid oxidation products, along with the loss of substrate, has greatly advanced these investigations, which have now progressed from a hypothesis–driven approaches to a holistic and systematic collection of sound analytical evidence at large scale. The review identifies overloading with dietary polyunsaturates and exhaustion of endogenous antioxidants and other protective mechanisms as the main facilitators of the aldehyde attack on proteins and nucleic acids, which eventually contributes to cell death, disease and shortening of life span.