Sammanfattning
Snus is a smokeless, ground tobacco product, which is most commonly placed in the mouth
between the gum and lip. Like other tobacco products, snus contains the biologically active and
addictive substance, nicotine. Snus also contains carcinogenic tobacco-specific nitrosamines (TSNA)
and small amounts of other carcinogenic substances. Snus consumption in the Norwegian population
is rising with the greatest increase in the youngest age groups (16–24 years).
The exposure to nicotine and TSNA can be similar or slightly higher in users of snus compared with
smokers. However, the exposure will vary considerably with the type of snus and usage patterns.
Nicotine acts primarily via the nicotinic acetylcholine receptors, causing the release of different
signaling molecules that are present in a wide range of organs and tissues. Nicotine has a significant
addictive potential as well as effects on the cardiovascular system. Animal experiments also show
effects on lung and brain development.
Animal experiments have convincingly documented tobacco-specific nitrosamines (NNK and NNN) to
be carcinogenic. The risk of developing cancer increases with increasing exposure. Since NNK and
NNN are both carcinogenic and genotoxic, it should be assumed that any exposure is associated
with some cancer risk.
The most comprehensive assessments of the carcinogenic properties of snus and other smokeless
tobacco have previously concluded that snus is carcinogenic. Evidence is based on epidemiological
studies, experimental studies and the presence of carcinogenic tobacco-specific nitrosamines (TSNA)
as well as other substances that may impact cancer development. Overall, there is evidence that
snus consumption increases the risk of cancer in the pancreas, esophagus and oral cavity. However,
the increased risk is still lower than the high cancer risk associated with smoking, since smoking
provides additional exposure to combustion products that could contribute to the development of
cancer.
Use of snus causes changes in the oral cavity, most of which is seen as white and/or red mucosal
lesions (spots). These are called snus-induced lesions. Some of these injuries have been classified
as possibly pre-cancerous, but most of these lesions heal when snus consumption ceases.
Permanent gingival retractions may occur on teeth in the area where the snus is placed, leading to
exposure of the tooth cervix and subsequent tooth sensitivity. From cross sectional studies
performed in Sweden, there is not identified any increased risk for caries, gingivitis and periodontitis
development associated with the use of snus. However, maternal use of snus early in pregnancy has
been associated with increased risk of oral cleft malformation.