“HNE is a well known, highly toxic compound that is easily absorbed from the diet,” said Csallany. “The toxicity arises because the compound is highly reactive with proteins, nucleic acids–DNA and RNA–and other biomolecules. HNE is formed from the oxidation of linoleic acid, and reports have related it to several diseases, including atherosclerosis, stroke, Parkinson’s, Alzheimer’s, Huntington’s and liver diseases.”

Csallany’s work underscores the risk of repeated heating, or reusing, highly unsaturated oils for frying because HNE accumulates with each heating cycle. In future studies, Csallany and her colleagues plan to determine how long polyunsaturated oil must be heated at lower temperatures in order to form HNE and its related compounds.

From a Press Release from the University of Minnesota