The polymorphisms of alcohol and aldehyde dehydrogenase and their significance for acetaldehyde toxicity.

Evidence is growing that acetaldehyde is responsible for some toxic effects after ethanol intake. Large individual and racial differences in blood and breath acetaldehyde concentrations are observed after alcohol consumption. In many Orientals but few Caucasians extremely high blood acetaldehyde levels occur leading to an acute aldehyde syndrome also observed after treatment with aldehyde dehydrogenase inhibitors. Individuals suffering from the aversive symptoms of that syndrome will be protected from excessive drinking and the related problems. In chronic aldehydism slightly elevated aldehyde concentrations are observed possibly leading to organic injury due to the cytotoxic action of acetaldehyde. Sites exhibiting high alcohol dehydrogenase activity may specifically be affected in alcoholics.