Dr. C. Joseph Bennett, Navigating Cancer, 09/11/12

If I have written about the dangers of tobacco in my weekly column hundreds of times, it is for a reason. The use of tobacco products is the leading cause of death that could be prevented by simply not using the tobacco products.

Many people, especially the younger generation, think dipping and chewing tobaccos are safe to use, and not associated with a risk of cancer. The use of these products is huge, with approximately 9 million people in the U.S. using chewing tobacco, snuff or other related products.

We have plenty of users here in Citrus County, and it worries me to see all of the Levis and Wranglers on our younger population with that familiar ring in the back pocket. Maybe a new finding will enlighten the younger generation and their parents of the dangers of dipping and chewing.

New research has identified a strong oral carcinogen substance in smokeless tobacco, that is a chemical that causes cancer, and it is very potent. This research was recently reported at the 244th National Meeting & Exposition of the American Chemical Society.

While we have known for years that those who used smokeless tobacco products were at an increased risk of getting cancer, we were not sure what caused it. This is the first example of a strong oral cavity carcinogen that is in smokeless tobacco.

These 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. With this research, we now have the identity 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, we have also been aware of the fact 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, no substance in these products was clearly implicated as a cause of cancers that develop in the mouth.

The researchers identified a compound named (S)-NNN as the culprit. (S)-NNN belongs to a family of hundreds of compounds called nitrosamines, the majority of which are carcinogenic, or cancer causing.

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.

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

The most popular brands of smokeless tobacco 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 better yet, eliminate it altogether, and eliminate it in our food supply as well.

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. The levels in food products are regulated, but they are still present.

It would be a good start to limit the amount in tobacco to the same level required for food, and, eventually, eliminate it altogether. These chemicals are also found in cigarettes and other smoking-related tobacco products, and should be eliminated from them as well.

Dr. C. Joseph Bennett is a board-certified radiation oncologist and a member of the Citrus County Unit of the American Cancer Society. Watch “Navigating Cancer” on WYKE TV at 7:30 p.m. Tuesdays and at 10 a.m. Thursdays. If you have any suggestions for topics, or have any questions, contact him at 522 N. Lecanto Highway, Lecanto, FL 34461, or email cjbennett@rboi.com. ­