Swedish "snus"- an oral, smoke free tobacco - has proven much less harmful to health than conventional smoking tobacco. Snus causes no increased risk for lung or mouth cancer for never-smokers and could produce a net health benefit to the population if smokers switched to using it. But users of Snus are twice as likely to contract pancreatic cancer than never-smokers. The findings are revealed in two Articles published early Online and in an upcoming edition of the Lancet.
In the first Article, Dr Coral Gartner, School of Population Health, University of Queensland, Australia and colleagues assessed the potential population health effects of snus in Australia to estimate the difference in life expectancy between never-smokers and those with varying scales of tobacco use, including switching from tobacco to snus.
They found little difference in health adjusted life expectancy between smokers who quit all tobacco and smokers who switch to snus.
The authors conclude: "Current smokers who switch to snus rather than continuing to smoke can realise substantial health gains. Snus could produce a net benefit to health at the population level if it is adopted in sufficient numbers by inveterate smokers.
"Relaxing current restrictions on the sale of snus is more likely to produce a net benefit than harm, with the size of the benefit dependent on how many inveterate smokers switch to snus."
In the second Article, Dr Olof Nyrén, Clinical Epidemiology Unit, Karolinska Institutet, Stockholm, Sweden and colleagues studied around 280,000 Swedish construction workers tobacco consumption habits from 1978 to 1992, and then followed them up until 2004.
They found no increased risk of lung or oral cancer in snus users compared to never-smokers, but did find that snus users were around twice as likely to contract pancreatic cancer than never-smokers. But smokers were still more likely to contract pancreatic cancer than snus users.
The authors say: "Our finding is at odds with the perception that use of Swedish moist snus has no demonstrable carcinogenic risk.
"If valid, it will have important public health implications, since snus has been proposed as a way to reduce harm in nicotine addicts."
In an accompanying comment, Dr Jonathan Foulds, Tobacco Dependence Program, University of Medicine and Dentistry, New Jersey School of Public Health, USA, says: "The papers in the Lancet, when added to mounting epidemiological evidence, indicate that we should not delay in allowing snus to compete with cigarettes for market share, and we should be prepared to accurately inform smokers about the relative risks of cigarettes, snus, and approved smoking-cessation medications.
"In light of all the available evidence, the banning or exaggerated opposition to snus in cigarette-rife environments is not sound public health policy."