Q. My face turns red when I drink alcoholic beverages. Is this harmful?

A. A red face after drinking alcohol may be more that just embarrassing. According to a recent report published in the Public Library of Science journal, this red glow might be a warning sign of increased risk for a deadly form of cancer of the esophagus. The esophagus is the muscular tube that connects your throat to your stomach.

Facial flushing that turns the face red when drinking alcohol is common in about one-third of Japanese, Chinese and Korean people. It is often accompanied by nausea and a rapid heartbeat. A genetic deficiency in an enzyme called aldehyde dehydrogenase 2 (ALDH2) is the culprit. As little as half a bottle of beer can trigger the reaction.

ALDH2 deficiency makes it difficult to break down alcohol completely, causing a toxin called acetaldehyde to accumulate in the body. People with two copies of the gene responsible for this reaction have such unpleasant side effects that they are unable to drink large amounts of alcohol. This actually protects them from the increased risk for cancer. However, those with only one copy of the gene can develop a tolerance to acetaldehyde and become heavy drinkers.

This type of esophageal cancer can be treated with surgery, but survival rates are low. It is considered one of the world's deadliest cancers. Even moderate drinking increases the risk, but risk increases dramatically in heavy drinkers. An ALDH2-deficient person who has two beers a day has six to 10 times the risk of developing esophageal cancer as a person who is not deficient in this enzyme.

Reducing drinking can decrease the incidence of this cancer among Asian adults. However, researchers say it is important to point out that the increased risk of esophageal cancer among ALDH2-deficient people is only in those who drink alcohol. Non-drinkers do not appear to have a higher risk of esophageal cancer.

Some young people treat flushing by taking antihistamines while continuing to drink. Ignoring the symptoms and continuing to drink is likely to increase the incidence of esophageal cancer.

If you drink alcohol regularly and have experienced the flushing response, you may want to ask your doctor to test you for esophageal cancer.