Australian Study Links Alcohol-Containing Mouthwash to Cancer

Scientists at the University of Melbourne are recommending that Australian supermarkets stop selling mouthwash that contains alcohol after a research review found that users may face an increased risk of developing oral cancer, the Daily Telegraph reported Jan. 11.

The researchers found that using mouthwash that includes alcohol increased the risk of developing oral cancers by four to five times among people who didn’t smoke or drink alcohol. Smokers had a nine-fold increased risk of developing oral cancers, and those who consumed alcohol were at five times greater risk.

Scientists are concerned that the ethanol in some mouthwashes enables carcinogens to filter through the lining of the mouth more easily. Researchers believe that acetaldehyde, which is formed as a byproduct of alcohol, also is carcinogenic, and may build up in the oral cavity when mouthwash is swished around the mouth.

“We see people with oral cancer who have no other risk factors than the use of alcohol-containing mouthwash, so what we’ve done in this study is review all the evidence that’s out there,’’ said lead study author Michael McCullough, who chairs the Australian Dental Association’s therapeutics committee and is an associate professor of oral medicine at the University of Melbourne. “Since this article came out, further evidence has come out, too. We believe there should be warnings.”

McCullough and co-author Camile Farah, director of research at the University of Queensland’s School of Dentistry, are calling on the Australian Dental Association to reconsider endorsing Listerine and other alcohol-containing mouthwashes. They recommend that consumers restrict use of such mouthwashes to “short-term” medical use or switch to alcohol-free versions.

The review was published online Nov. 27, 2008 in the Australian Dental Journal.