What role does acetaldehyde play in hangovers

The hangover and its biochemistry

Ethanol and its breakdown products are poisonous and damage the body - not only when you drink it, but also for some time later.

Ethanol is a cell toxin: the molecule is absorbed into the body in the stomach and small intestine and is distributed via the bloodstream to all body cells, where it impairs the synthesis, metabolism and detoxification performance. The cells respond with an inflammatory reaction - which is different depending on the organ. Chronic alcohol consumption leads, among other things, to liver and pancreatic diseases, to neurological damage, contributes to high blood pressure and is considered a trigger for some types of cancer.

Alcohol begins to break down soon after drinking: it is first oxidized in the liver to acetaldehyde and then to acetic acid - the latter is finally “breathed in” by the body, ie converted into water, CO2 and energy. Acetaldehyde is a poison, it is mainly responsible for the symptoms of the hangover ("Veisalgia"), explains the nutritionist Marika Miklautsch (MedUni Vienna).

The alcohol metabolism has numerous consequences: There is an accumulation of lactic acid ("acidosis"), the liver produces less glucose - the result is hypoglycaemia - the excretion of fluids and minerals is increased, acute gastritis occurs, and more cells spill Histamine (which may play a role in headache) and sleep becomes less deep. It all adds up to a hangover.

But not only ethanol itself is responsible, other substances that are produced during fermentation are even worse - above all methanol and "lint" (multi-chain or cyclic alcohols). That means: the purer a drink is, the weaker the hangover is. The most important factor is and remains the dose.

("Die Presse", print edition, June 13, 2010)