Tobacco harm reduction aims to reduce tobacco-related diseases by encouraging smokers to use much less harmful forms of non-smoked tobacco, such as low nitrosamine smokeless tobacco known in Sweden as snus . Such policies are controversial for at least two reasons: (1) that increased use of smokeless tobacco products will increase population tobacco use if substantial proportions of snus users go on to become smokers; and (2) that any health benefits from using snus will be nullified if users continue to smoke tobacco, i.e. engage in ‘dual use’ of smoked and smokeless tobacco, as they are being encouraged to do by US tobacco companies .
Stenbeck et al.'s report in this issue presents evidence bearing on both concerns . They report analyses of longitudinal data from the Swedish Survey of Living Conditions on patterns of snus use and smoking in Swedish men, a population with one of the world's highest rates of snus use. Their results confirm the inverse relationship found between snus use and smoking in cross-sectional studies in Swedish men [4–6], and suggest that snus use promotes smoking cessation in older men and deters smoking initiation in younger males. While some snus users do become smokers, many more use snus for smoking cessation, thereby producing a net reduction in smoking prevalence and tobacco-related harm. Their findings on the dual use of cigarettes and snus tobacco are also reassuring: the dual use of smoked cigarettes and snus was rare and its prevalence decreased over time, patterns also reported in a US study by Zhu et al.. These results are consistent with the marked decline in smoking prevalence and lung cancer rates among Swedish men that have coincided with increasing snus use among men .
Something that some tobacco control advocates may find more troubling was the finding that younger non-smoking men were more likely than older men to initiate snus use. Increased uptake of smokeless tobacco among young non-smoking men raises important questions for advocates of tobacco harm reduction policies in other countries: should we encourage the uptake of snus among young men either directly (e.g. allowing industry promotions) or indirectly (e.g. by imposing lower taxes on these products than on cigarettes) in order to deter them from smoking?
Our answer to this question will depend critically upon the way in which the tobacco industry is allowed to promote snus. The current marketing of snus products in the United States with the same brand names as cigarettes provides strong reasons for advertising and marketing bans on promoting the dual use of cigarettes and snus. It also indicates the need for public health messages that this practice undermines any health gains from using snus.
We have argued elsewhere that the Swedish experience with snus is sufficiently positive to encourage cautious trials of tobacco harm reduction strategies in countries that have in place public health policies that discourage smoking [1,9]. Stenbeck et al.'s results (in combination with the results of epidemiological modelling) add to the case for cautious trials of promoting snus as a smoking cessation aid for smokers who are unable or unwilling to quit .