HNE (4-hydroxynonenal), a toxic aldehyde found in french fries cooked in high linoleic acid fryer oil, is linked to pathological conditions.

“so basically if you want to make Henny you break a linoleic acid molecule in half and you add an oxygen molecule to one side so uh it's you know half the number of carbons half the number of hydrogens and an extra oxygen and it's made a variety of different ways in the body either enzymatically as we discussed or it can be made non-enzymatically by linoleic acid self Auto oxidizing which can happen in the mitochondria catalyzed by Iron and cytochrome C which is part of the mitochondrial complexes that produce energy”