The study, published in the April 2019 issue of the journalAddictive Behaviors, provides new research on what smokers think about snus, a Swedish style product that is popular in Scandinavia, but newer to the United States. Snus -- a Swedish word for "snuff" -- is a moist powder tobacco that can be sold in a loose form or in small prepacked pouches that users place under the top lip for about 30 minutes. It is typically spit free. About seven in 100 men use some form of smokeless tobacco in the United States, a figure the Centers for Disease Control and Prevention report is on the rise.

While smokeless tobacco products are addictive, contain cancer-causing chemicals and are linked with cardiovascular and certain cancer risks, products such as snus have comparatively fewer health risks than smoking when used exclusively -- not in tandem with smoking -- and may serve as harm-reduction alternatives for smokers unable or unwilling to completely quit tobacco. In Sweden, snus use has been linked to a decrease in tobacco smoking and smoking-related diseases.

The researchers reviewed how 256 smokers responded to questions about their perceived risk of developing lung cancer, heart disease and oral cancer from using snus versus cigarettes, and whether there were subgroups of smokers with similar patterns of beliefs. More than 75 percent of the participants smoked daily and about 20 percent had tried smokeless tobacco.

The researchers found that smokers fell into three subgroups based on their beliefs. About 45 percent perceived snus to be as harmful as smoking overall and for all three risks: lung cancer, heart disease and oral cancer. About 38 percent perceived that snus poses less risk for lung cancer and heart disease than cigarettes but had the same oral cancer risk as cigarettes, and another 17 percent accurately perceived snus to have lower risks for lung cancer but perceived risks for oral cancer and heart disease to be about the same as that from smoking. Almost 40 percent incorrectly perceived the risk of oral cancer to be higher from snus use than smoking.

"These findings continue to suggest that the public does not understand that combustion escalates the health risks in tobacco products that are smoked, making them more harmful than non-combusted smokeless tobacco on a continuum of risk," said lead researcher Olivia Wackowski, assistant professor of Health Behavior, Society and Policy at Rutgers School of Public Health and a member of the Rutgers Center for Tobacco Studies and Rutgers Cancer Institute of New Jersey. "They are also significant given that use of Scandinavian snus has not been clearly associated with oral cancer, unlike smoking, which poses a significant risk for oral cancer."

放弃所有烟草是最好的做法。However, smokers who have not been successful in quitting or who do not want to quit tobacco entirely may be able to reduce their risks by learning about and switching to a product like snus, Wackowski said. However, this information can be challenging to communicate and is a key area for research work. It's important for smokers to know that the reduced risks may come from completely switching over from smoking to snus use, and not using both products, she said. It's also important that such messaging does not unintentionally encourage product initiation among non-users, especially youth.

The study was co-authored by Anne Ray, an instructor of Health Behavior, Society and Policy at the Rutgers School of Public Health, and Jerod Stapleton, associate professor of medicine at Rutgers Robert Wood Johnson Medical School and faculty member at Rutgers Cancer Institute of New Jersey.