Alcohol Flush Signals Cancer Risk For East Asians
Alcohol is a known risk factor for a variety of cancers, including esophageal, and heavier drinking is considered riskier than light drinking.
Lots of people turn slightly red if they imbibe too much. At issue here is facial flushing from a small amount of alcohol. Its due to a deficiency in an enzyme that helps metabolize alcohol, called ALDH2.
People with a severe deficiency of the enzyme usually dont drink because it makes them feel too bad; in addition to flushing they feel nausea and a rapid heartbeat.
But people with a partial deficiency – they inherited one bad copy of the enzyme-producing gene instead of two – may put up with the flushing. A series of studies by Dr. Akira Yokoyama of Japans Kurihama Alcohol Center found that those people are six to 10 times more likely to develop esophageal cancer than people who drink a comparable amount but arent enzyme-deficient.
“Somehow the message just hadnt gotten out,” said Dr. Philip J. Brooks, who researches alcohol and cancer at the U.S. National Institutes of Health.
So he paired with Yokoyama and others to review the link for PLoS Medicine, a journal published by the Public Library of Science.
Without enough of that enzyme, alcohol breaks down into a DNA-damaging chemical similar to formaldehyde but it doesnt go the next step and turn into yet another chemical thats non-toxic, said Brooks. Dont drink, and the flushers arent at increased risk.
Esophageal cancer is fairly rare, but its also hard to treat. Worldwide, anywhere from 12 percent to a third of people who develop it survive five years.
Up to 8 percent of the worlds population has the enzyme deficiency, meaning if even a small number of the at-risk avoided alcohol, esophageal cancer deaths could drop substantially, the review concluded.
In the U.S., most esophageal cancer is a type called adenocarcinoma that is linked to chronic, severe heartburn. The flushing-linked type is squamous cell carcinoma, less common here than abroad.