A gene carried by up to 20 percent of white Americans raises heavy drinkers' risk of developing colon cancer, according to new research out of Heidelberg University in Germany.

The Washington Post reported Dec. 19 that individuals with the gene ADH1C*1 metabolize ethanol to acetaldehyde more rapidly than those who don't carry the gene mutation. Genetic testing of patients with and without colon cancer led researchers to conclude that those who carry the ADH1C*1 gene and are chronic drinkers (consuming more than two drinks daily) are at higher risk of developing the disease.

"Acetaldehyde is a very toxic compound which changes and damages our DNA. And the speed of the change from ethanol to acetaldehyde is different in different individuals," said study co-author Helmut Seitz. "So the idea is that if people have that gene which is responsible for a faster metabolism to acetaldehyde, then more of it would be produced in a shorter period of time, and more of would bind to our DNA. And that could increase colon cancer risk."

Seitz said that the overall genetic risk of colon cancer is low, but, "to be on the safe side, if you don't know your genetic background, be moderate in your alcohol consumption."

The findings were published online Dec. 19, 2008 in the journal Alcoholism: Clinical and Experimental Research.