Note: Separate PDQ summaries on Lung Cancer Screening; Small Cell Lung Cancer Treatment; Non-Small Cell LungCancer Treatment; and Cigarette Smoking: Health Risks and How to Quit are also available.
Who is at Risk?
Lung cancer risk is largely a function of older age combined with extensive cigarette smoking history. Lung cancer is more common in men than women and in those of lower socioeconomic status. Patterns of lung cancer according to demographic characteristics tend to be strongly correlated...
Even its critics admit that snus is less harmful than other forms of smokeless tobacco. And it is far less harmful than cigarette smoking.
So is snus a good thing?
It would be a good thing if everyone who smoked cigarettes or dipped snuff switched to snus instead. It would be a good thing if snus were a way station on the road to quitting all forms of tobacco. It would even be a good thing if kids who would have become smokers became snus users instead.
But despite all of that, mounting evidence suggests snus isn't a good thing -- and may be far worse than they appear.
Snus: Less Harmful, But Not Safe
Cigarettes are the world's most efficient nicotine delivery device. They are also the most deadly. Many of the most dangerous byproducts of cigarettes are created during the burning process.
Smokeless tobacco products obviously don't burn. But smokeless tobacco is a major cause of oral cancer, pancreatic cancer, and esophageal cancer.
Much of this risk comes from cancer-causing chemicals called nitrosamines and polycyclic aromatic hydrocarbons (PAH). And snuff products actually deliver more cancer-causing nitrosamines than cigarettes do.
But nitrosamine content is far lower in snus than in snuff, says Stephen S. Hecht, PhD, professor of cancer prevention at the University of Minnesota.
"Snus are made with a special process to help control nitrosamine levels," Hecht tells WebMD.
There's a catch, of course. Carcinogen levels in snus may be lower -- but they are not low.
"Nitrosamine levels in snus are still 100 times greater than levels of nitrosamines in foods like nitrite-preserved meats," Hecht says. "This is not a harmless product."
And there's evidence that these nitrosamines -- or something else in snus -- are causing cancer. In Sweden and Norway, where snus originated, snus users have a significantly higher risk of pancreatic cancer.
Snus are also linked to mouth sores, dental cavities, heart attack, stroke, and diabetes risk. And they do deliver nicotine -- an addictive drug.
Snus: Harm Reduction or Multiplication?
OK, so snus isn't without harm. But if it's so much safer than cigarettes, wouldn't it be good for smokers to switch to snus?
In Scandinavia, there's some evidence that snus contributed to a decline in smoking. Whether that happens in the U.S. depends on young people, says Michael Eriksen, ScD, director of the Institute of Public Health at Georgia State University and former director of the CDC Office on Smoking and Health.
"If we see that existing smokers are the primary users of snus and go from smoking to snus, that would be a public health success story," Eriksen tells WebMD. "But if kids start out on snus and then grow into smoking, that is going to be a disaster."