Metabolism of alcohol
Ingested by drinking ethanol, acetaldehyde is converted, and then is metabolized into harmless acetic acid. And the reaction proceeds by two enzymes(alcohol dehydrogenase and acetaldehyde dehydrogenase).
Acetaldehyde cause a hangover
The acetaldehyde that cannot be metabolized by drinking a large amount of alcohol influences the body harmfully, and causes symptoms such as headache and nausea (hangover). Also there is carcinogenic acetaldehyde, which causes cancer. (Ethanol is not carcinogenic). By accelerating the metabolism of acetaldehyde, reduce hangover, you can prevent cancer.