By Charles H. Weaver, MD
August 27, 2007
Smokeless tobacco refers to chewing tobacco and snuff. Both these types of smokeless tobacco contain cancer-causing agents, and users of smokeless tobacco have an increased risk of oral cancer. Oral cancer includes cancers of the lip, tongue, cheeks, gums, and the floor and roof of the mouth.
Because smokeless tobacco does not involve exposure to the harmful components of tobacco smoke, some have suggested that it may be less harmful than cigarettes.
To evaluate this claim, researchers assessed levels of a strong carcinogen (cancer-causing agent)—known as NNK—in 420 cigarette smokers and 182 users of smokeless tobacco. All study participants were seeking treatment for tobacco dependence.
NNK exposure was assessed by measuring NNK metabolites (total NNAL) in urine. The researchers also assessed levels of cotinine—a marker of nicotine exposure.
Urine NNAL and cotinine levels were higher in users of smokeless tobacco than in cigarette smokers.
While the processing of NNK by the body may differ between users of smokeless tobacco and cigarette smokers, the researchers state that these results “indicate that exposure to NNK is at least comparable in smokeless tobacco users and smokers.”
The researchers conclude: “These findings do not support the use of smokeless tobacco as a safe substitute for smoking.”
Reference: Hecht SS, Carmella SG, Murphy SE et al. Similar exposure to a tobacco-specific carcinogen in smokeless tobacco users and cigarette smokers. Cancer Epidemiology Biomarkers & Prevention. 2007;16:1567-72.Smoking NewsSmoking News