Prolonged use of Swedish moist snuff increases risk of fatal cardiovascular disease and stroke

The use of snus has increased markedly in Sweden in the past few decades, so much so that it now accounts for half of all tobacco consumption in the country. Over 20 per cent of men between the ages of 18 and 79 are daily users. Consumers of snus absorb as much nicotine as smokers but are spared many of the toxic chemicals that are formed on smoking.

Although snus does not seem to increase the risk of myocardial infarction, one of the studies reported on in this doctoral thesis shows that its consumers run a 30 per cent (approximately) higher risk of fatal heart attack than people who have never used the product. This greater risk is even higher for those who take more than 50 grams of snus a day. Amongst those who suffer non-fatal heart attacks, users of snus have a higher fatality rate in general than non-users, and from cardiovascular diseases in particular.

The studies reveal no greater risk of stroke amongst users of snus; however, users were more likely to suffer a fatal stroke. Users also ran a higher risk of developing high blood pressure, which is a known factor of cardiovascular disease.

Two major population studies were used for the research now published. The first comprised Swedish men between the ages of 45 and 70, living in the counties of Stockholm or Västernorrland between 1992 and 1994. A total of 1,432 men diagnosed with first-episode myocardial infarction were compared in terms of tobacco habits and other factors with a coeval group of men from the same regions without heart problems.

The second was a study using data from health checks of all workers in the building industry between the years of 1978 and 93. Information recorded at these checks included tobacco habits and blood pressure. Episodes of non-fatal and fatal myocardial infarction and stroke as well as blood pressure readings for over 100,000 snus users and non-users were then plotted up to 2003/4 using national health records.

In both population studies, the analyses were confined to non-smokers, as smoking is strongly associated with the use of snus and cardiovascular disease.

Thesis: 'Swedish moist snuff and the risk of cardiovascular diseases'
by Maria-Pia Hergens, Department of Environmental Medicine, Karolinska Institutet 2007