Approximately 9 million people in the U.S. use chewing tobacco, snuff or other related products. Now researchers have identified a strong oral carcinogen substance in smokeless tobacco. The teams findings are reported at the 244th National Meeting & Exposition of the American Chemical Society.

Stephen Hecht, Ph.D., of the University of Minnesota, who led the study, explained:

“This is the first example of a strong oral cavity carcinogen that’s in smokeless tobacco. Our results are very important in regard to the growing use of smokeless tobacco in the world, especially among younger people who think it is a safer form of tobacco than cigarettes. We now have the identify of the only known strong oral carcinogen in these products.”

For years, evidence that individuals who use smokeless tobacco have an increased risk of developing cancer of the mouth, esophagus and pancreas has been rising. In addition, researchers were also aware that people who use smokeless tobacco products are exposed to carcinogens and experience some damage to their genetic material impairing its normal function. However until now, said Hecht, no substance in these products was clearly implicated as a cause of mouth cancer.

The researchers identified (S)-NNN as the culprit. (S)-NNN belongs to a family of hundreds of compounds called nitrosamines, the majority of which are carcinogenic. Although nitrosamine levels are significantly high in smokeless tobacco, they can also occur in a variety of foods and form naturally in the stomach when individuals consume foods with high levels of nitrite.

For the study the researchers gave rats two forms of NNN at low doses for around 17 months – roughly the equivalent to a human consuming smokeless tobacco for 30 years. The team found that (S)-NNN caused oral and esophageal tumors in the rats.

Hecht said:

“The most popular brands of smokeless tobacco that are sold in the U.S. have unacceptably high levels of this particular carcinogen. And smokeless tobacco is a known cause of oral cancer. Obviously, we need to decrease the levels of this material in all smokeless tobacco products – or eliminate it altogether.”

The U.S. Food and Drug Administration is able to regulate tobacco products, although at present, no regulations on the levels of specific carcinogens exist. Hecht said: “My suggestion is that levels of (S)-NNN in smokeless tobacco be decreased to below 10 parts per billion. That would make it more consistent with the levels of nitrosamines in food products.”

In addition, he explained that (S)-NNN in cigarettes and other smoked tobacco items should be regulated as well.

Written by Grace Rattue