The meaning of flushing
Alcohol (CH3CH2OH) is absorbed into the blood stream through the stomach. Blood is sent through the liver, where the liver breaks down the alcohol in 2 stages:
1. In the first stage the enzyme alcohol dehydrogenase (ADH) converts alcohol into acetaldehyde. Acetaldehyde is toxic to humans.
2. In the second stage the enzyme aldehyde dehydrogenase (ALDH) converts acetaldehyde into acetic acid. Acetic acid is harmless to humans. Acetic acid is further metabolised and leaves the body as carbon dioxide and water.
If the liver cannot convert acetaldehyde into acetic acid quickly enough, the acetaldehyde accumulates in the bloodstream. The accumulation of acetaldehyde in the blood is the reason for flushing when drinking (turning red in the face or neck). It is recommended to a person who flushes that he or she slow down or stop drinking alcohol.