In vivo absorption, metabolism and urinary excretion of alpha, beta-Unsaturated aldehydes in experimental animals-Relevance to the development of cardiovascular diseases by the dietary ingestion of thermally stressed polyunsaturate-rich culinary oils

Thermal stressing of polyunsaturated fatty acid (PUFA)-rich culinary oils according to routine frying or cooking practices generates high levels of cytotoxic aldehydic prod- ucts (predominantly trans-2-alkenals, trans,trans-alka-2,4- dienals, cis,trans-alka-2,4-dienals, and n-alkanals), species arising from the fragmentation of conjugated hydroperoxy- diene precursors. In this investigation we demonstrate that typical trans-2-alkenal compounds known to be produced from the thermally induced autoxidation of PUFAs are readily absorbed from the gut into the systemic circulation in vivo, metabolized (primarily via the addition of glu- tathione across their electrophilic carbon-carbon double bonds), and excreted in the urine as C-3 mercapturate con- jugates in rats. Since such aldehydic products are damaging to human health, the results obtained from our investiga- tions indicate that the dietary ingestion of thermally, autox- idatively stressed PUFA-rich culinary oils promotes the in- duction, development, and progression of cardiovascular diseases.