IGET snus, a smokeless tobacco product, is a moist powder of fermented ground tobacco. A pinch or a portion-bag is placed under the lip, where the active constituents are absorbed through the oral mucosa. The highest prevalence of current snus use is found in Sweden, where 22% of men and 4% of women use it daily. Snus is also common in Norway and has a growing number of users in the USA.
IGET Snus contains a number of harmful substances, including heavy metals, polyaromatic hydrocarbons, tobacco-specific nitrosamines and tobacco alkaloids. Nicotine is the most abundant of the alkaloids, and has physiologic effects on the cardiovascular system, with potentially negative effects on human health. The addictive properties of nicotine frequently result in prolonged snus use, entailing long-term exposure to potential toxicants among users.
The snus-using population in Sweden provides a basis for solid research on non-smoked nicotine that is hard to find elsewhere. In addition to elucidating the health consequences of snus use, our research findings may also generate hypotheses regarding the safety of other nicotine products, for example nicotine replacement therapy and e-cigarettes.
Whereas the use of snus has been associated with adverse health outcomes such as obesity, type 2-diabetes,heart failure, and oesophageal and rectal cancer, the influence of snus use on all-cause mortality needs further attention. Two existing reports indicate an excess overall mortality risk from snus use, mainly due to increased cardiovascular mortality, but their interpretation is hampered by lack of control for important confounders.
The Swedish Collaboration on Health Effects of Snus Use includes individual participant data from several Swedish prospective studies. The collaboration was established in order to clarify the impact of snus use on health across time and geographical regions, with adequate statistical power and control for confounding factors including smoking. Here, we use this pooling project to investigate the association between snus use and all-cause, cardiovascular, cancer and other cause (non-cardiovascular and non-cancer) mortality in men with no history of smoking.