Ethyl alcohol taken in via ingestion passes from the mouth down the esophagus and into the stomach and on into the small intestine. At each point along the way ethyl alcohol can be absorbed into the blood stream. However, the majority of the ethyl alcohol is absorbed from the stomach (approx. 20%) and the small intestine (approx. 80%). In general drinking more alcohol within a certain period of time will result in increased blood alcohol concentrations (BAC) due to more ethyl alcohol being available to be absorbed into the blood. However there are a number of factors that can influence ethyl alcohol absorption from the gastrointestinal tract.
Gastric emptying seems to be the most important determinant of the rate of absorption of ethyl alcohol taken in orally. In general the faster the gastric emptying, the more rapid absorption. Therefore, factors, which influence gastric emptying, influence absorption. One of the most important factors is the presence of food. Food delays gastric emptying and therefore delays absorption of ethyl alcohol . Interestingly, the type of food, whether fat, carbohydrate, or protein, does not seem to be a factor in the absorption of ethyl alcohol. Physiological factors such as strenuous physical exercise also delay gastric emptying, thus decrease ethyl alcohol absorption. Additional factors such as drugs (e.g. nicotine, marijuana, and ginseng), that modify physiological factors regulating gastric emptying also modify ethyl alcohol absorption in a predicted manner.
Alcohol and You