FEB/MAR 2005
Volume 11 - No. 1
Research Activities at a Featured Program
SRNT Newsletter
February/March 2005, Volume 11, Number 1
Is Smokeless Tobacco Effective in Reducing Cigarette
Smoking and Tobacco-Related Harms?
Member Commentary on The Smokeless Tobacco Debate
In late November, the SRNT listserv hosted an interesting online discussion about the pros and cons of pursuing research on smokeless tobacco, particularly with respect to whether or not such efforts might yield reduced tobacco-related harms. Drs. Brad Rodu and Scott Tomar were important contributors to this discussion. They have agreed to summarize their positions for this issue of the SRNT newsletter. Please note that Drs. Rodu and Tomar worked independently to prepare their contributions to this newsletter. As such, the commentaries presented below should not be regarded as reactions to one another.
Dr. Rodu's commentary: Tobacco harm reduction is based on two straightforward propositions:
- Smokeless tobacco (SLT) use is vastly safer than smoking.
- Smokers have a fundamental right to information about safer tobacco products, and health professionals have an ethical mandate to provide it.
It is clear from recent SRNT listserv debates that some members dismiss any research that is even remotely supported by the tobacco industry. (In my case recent support apparently even taints my earlier unfunded studies as well). But many are open to independent research. That exists, in the form of three recent publications _ entirely untarnished by tobacco industry funding.
The first is a review of the cardiovascular effects of SLT by Dr. Kjell Asplund (2003), now the Director-General of Sweden's National Board of Health and Welfare and an international cardiovascular disease expert. Funded entirely by Swedish research foundations, Dr. Asplund conducted an extensive review of epidemiologic and laboratory studies relevant to SLT use and cardiovascular disease risk. He concluded that, "In all, the use of SLT (with snuff being the most studied variant) involves a much lower risk for adverse cardiovascular events than smoking does."
The second article (Waterbor et al., 2004) reviewed the scientific evidence for the adverse health effects of SLT as claimed in brochures from prominent health organizations such as the American Lung Association, the American Cancer Society, the American Academy of Otolaryngology, the American Dental Association, and the National Cancer Institute. The study — funded by the National Cancer Institute — was conducted by investigators from epidemiology, dentistry, psychology and the Comprehensive Cancer Center at the University of Alabama at Birmingham. The investigators asked a simple question: Are the claims regarding adverse health effects of SLT use supported by scientific evidence?
Here are some of the claims regarding SLT, followed by the researchers' assessments:
Claims | Scientific Evidence |
|---|---|
Pharnyx and lary nx cancer |
No relationship |
Lung cancer |
Inadequate |
Stomach cancer |
Not persuasive |
Kidney cancer |
No association |
Esophageal cancer |
Not persuasive |
Pancreatic cancer |
Inconclusive |
Breast cancer |
None |
Bladder cancer |
None |
Bad breath |
None |
What is the study's most surprising finding? Virtually all of the four dozen brochures examined by the UAB researchers claimed unequivocally that smokeless tobacco use causes oral cancer. The scientific evidence: not decisive. The investigators concluded that "Many brochures overemphasize the risk of oral cavity cancer, reaching beyond the scientific data."
Finally, a new study, also funded by the National Cancer Institute and co-written by prominent tobacco researchers (Levy et al., 2004), emphasizes the differential risks of SLT use versus smoking. The authors recruited an international panel of eight epidemiology experts (from institutions such as University College London, University of Vienna [Austria], Johns Hopkins University, Georgetown University, Columbia University, the American Cancer Society and the National Cancer Institute). The panel concluded that modern smokeless tobacco products have only 5-9% of the health risks of smoking.
The report's concluding sentence comments on the inappropriate campaign of misinformation by anti-tobacco extremists:
"This finding [substantially lower risks of smokeless products] raises ethical questions concerning whether it is inappropriate and misleading for government officials or public health experts to characterize smokeless tobacco products as comparably dangerous with cigarette smoking."
Dr. Brad Rodu is a Professor in the Department of Pathology and a Senior Scientist in the Comprehensive Cancer Center at the University of Alabama at Birmingham. Disclosure: www.uab.edu/smokersonly
References:
Asplund K. (2003). Smokeless tobacco and cardiovascular disease.
Progr Cardiovasc Dis, 45, 383-394
Waterbor JW, Adams RM, Robinson JM, et al. (2004). Disparities between public health educational materials and the scientific evidence that smokeless tobacco use causes cancer. J Cancer Educ, 19, 17-28.
Levy DT, Mumford EA, Cummings KM, et al. (2004). The relative risks of a low-nitrosamine smokeless tobacco product compared with smoking cigarettes: estimates of a panel of experts. Cancer Epidemiol Biomarkers Prev, 13, 2035-2042.
Dr. Tomar's commentary: Moist snuff use has been proposed as a harm reduction strategy for smoking, with suggestions that snuff might even prevent smoking initiation by young people. Prima facie, it makes sense: exclusive use of oral snuff undoubtedly carries much lower health risks than exclusive cigarette smoking, and both products provide substantial nicotine dosing. But, is that sufficient evidence that this approach could work?
Sweden has been cited as the one example in which snuff use apparently replaced smoking for a proportion of males, although that occurred against a backdrop of Sweden's progressive anti-smoking efforts. Did snuff use "prevent" smoking initiation? Smoking prevalence dropped by 50% between 1980 and 2001 among 16_24 year-old males while their snuff use increased, but the same rate of decline in smoking was seen for young women with almost no snuff use (http://www.statveca.com/english/index.html). Economic analysis of consumption data from 1964_1997 suggests two addictive products whose consumptions were each negatively related to their prices but behaved independently (Bask & Melkersson 2003). There are few published reports on use of snuff for smoking cessation; the most recent is from a cross-sectional study in which 29% of male former smokers and 5% of female former smokers used snuff on their last quit attempt, compared to 23% of men and 5% of women who used snuff at their last quit attempt but still smoked (Gilljam et al. 2003). Snuff certainly helped some Swedish smokers to quit, but the apparent effectiveness was small in men and nonexistent in women. With more than 70% of men and 95% of women who smoked having no history of snuff use, clearly other factors were responsible for most smoking cessation in Sweden.
What has been the experience with snuff in other western countries? Although 19% of US male ever-smokers aged 34_47 in 2000 had a history of regular smokeless tobacco use, just 1% of former smokers in that group reported using smokeless tobacco to quit smoking; most apparently used it for other reasons and dual product use was more common than complete switching from cigarettes to smokeless tobacco (Tomar 2005). Daily smoking and daily smokeless tobacco use both declined among US male high school seniors between 1997 and 2003 (Johnston et al., 2004), suggesting that product substitution is not necessary to reduce youth smoking. There is a significant positive association between the age-adjusted prevalence of daily smoking and daily snuff use among men in the 50 US states — the opposite of what might be expected if snuff substantially prevented or replaced smoking (Tomar 2005). Smokeless tobacco use also is fairly prevalent among some groups at low risk for initiating smoking, such as high school and college athletes (Walsh et al. 2002; Castrucci et al. 2004). In Norway, the prevalence of snuff use among 16_24-year-old males climbed from 9% in 1985 to 21% in 2002, while the prevalence of smoking among males and females in that age group remained relatively constant during that period at 25_32% (Statistics Norway website: http://www.ssb.no/english/subjects/03/01/royk_en/ ). Neither the USA nor Norway demonstrated a net positive effect from snuff use.
I share the concerns of Dr. Rodu and others that the current carnage from tobacco use is unacceptable. Unfortunately, the existing evidence base for promoting snuff as an effective or feasible approach to reducing smoking is weak. All forms of snuff contain levels of carcinogens that are several magnitudes of order higher than any other consumer products, most initiators are adolescent boys, and moist snuff is designed to foster dependence. Shouldn't meaningful regulation for all tobacco products and adequate funding for comprehensive tobacco control be prerequisites for allowing US Smokeless Tobacco Co. and Swedish Match to conduct experiments on human populations?
References:
Bask M, Melkersson M (2003). Should one use smokeless tobacco in smoking cessation programs? A rational
addiction approach. Eur J Health Econ, 4, 263_70.
Castrucci BC, Gerlach KK, Kaufman NJ, Orleans CT (2004). Tobacco use and cessation behavior among adolescents participating in organized sports. Am J Health Behav, 28, 63_71.
Gilljam H, Galanti MR (2003). Role of snus (oral moist snuff) in smoking cessation and smoking reduction in Sweden. Addiction, 98, 1183_9.
Johnston LD, O'Malley PM, Bachman JG, Schulenberg JE (2004). Monitoring the Future national survey results on drug use, 1975-2003. Volume I: Secondary school students (NIH Publication No. 04-5507). Bethesda, MD: National Institute on Drug Abuse. Available at: http://monitoringthefuture.org/pubs/monographs/vol1_2003.pdf
Tomar SL (2005). Smokeless tobacco products in the United States and Sweden. In: National Cancer Institute. Background papers from the WHO Study Group on Tobacco Product Regulation. Smoking and Tobacco Control Monograph (in press).
Walsh MM, Ellison J, Hilton JF, Chesney M, Ernster VL (2000). Spit (smokeless) tobacco use by high school baseball athletes in California. Tobacco Control, 9 (Suppl 2), II32_9.
Scott L. Tomar, DMD, MPH, DrPH, is an Associate Professor in the University of Florida College of Dentistry, Division of Public Health Services and Research