Oral cancer mouthwash, increased cancer risk mouthwash, Listerine cancer

Study Linking Mouthwash to Cancer Has Skeptics

January 13, 2009 11:04 AM
by Josh Katz
A new study from Australia associates the use of certain mouthwash with a higher risk of oral cancer. However, other researchers have doubted the study’s conclusions.

Study Connects Mouthwash With Oral Cancer

A study headed by Professor Michael McCulloch, chairman of the Australian Dental Association’s therapeutics committee and associate professor of oral medicine at Melbourne University, indicates that there is “sufficient evidence” linking mouthwashes containing alcohol with an increased risk of oral cancer. The study says that such mouthwashes should be removed from store shelve or they should have health warnings, according to the Sunday Telegraph.

The ethanol in the mouthwash permits carcinogens to penetrate the mouth’s lining more easily, the scientists claim in the study, which was published in the Dental Journal of Australia. McCulloch said that the mouthwash “increases the permeability of the mucosa” to cancer-causing substances like nicotine. The professor also noted that acetaldehyde, a toxic product from the breakdown of alcohol, is a carcinogen as well and could build up in the oral cavity.

“We believe there should be warnings,” he said. “If it was a facial cream that had the effect of reducing acne but had a four-to-five-fold increased risk of skin cancer, no one would be recommending it.”

Although the research suggests that simply drinking alcohol could also be a cancer risk, such consumption “usually did not involve swishing it around the mouth,” the Telegraph writes.

However, the study has many detractors. Dr. Neil Hewson, of the Australian Dental Association, is one. Hewson says that the recent study is “very interesting,” but indicated that more research needed to be done on the issue. “It hasn’t actually been established there is a direct relationship between mouthwashes with alcohol and oral cancer,” he said.

Also, a study that appeared in an American dental journal in 2003 had a different conclusion. That research said “it was unlikely that using mouthwashes containing alcohol would increase the risk of oral cancer,” according to The New Zealand Herald.

Thousands of people each year are affected by oral cancer, and half of those afflicted die within five years of the initial diagnosis, the Telegraph reports.

Reactions: Professors, companies quarrel over mouthwash study

Laurence Walsh, the head of the University of Queensland’s School of Dentistry, questioned the results of the study, contending that mouthwash could actually prevent cancer. “There is a whole range of reasons why some mouth rinses would actually reduce the chance of the cancer because they impair the production of molecules that do have cancer-causing effects like acetaldehyde,” he said, according to The Australian in a Jan. 12 article. Walsh also said that, “There is literature which is now recommending that mouth rinses be used to reduce bacteria which produce acetaldehyde and there is a fairly strong consensus internationally that mouth rinses containing alcohol aren’t linked to cancer.”

But The Australian published a follow-up article in which Professor Walsh conceded that he has received funding from Listerine producer Johnson & Johnson. Professor McCullough of the mouthwash study had first pointed out Walsh’s possible conflict of interest: Johnson & Johnson paid for some of his expenses but did not directly fund any of his research. McCullough also urged the Australian Dental Association to reconsider its endorsement of Listerine.

Johnson & Johnson has denied that its product could increase the threat of cancer, claiming that the study used a “selective group of clinical data.” The company’s statement also said that, “All reviewers came to a similar conclusion: that evidence from at least 10 epidemiological studies published over the last three decades strongly suggests that use of alcohol-containing rinses does not increase the risk of oral cancer.”

Reference: Mouthwash study; cancer guide


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