In the past few decades there has been an increase in the number of people in Europe and North America using smokeless tobacco, particularly among people younger than 40. Given that these products are being promoted as 'safer' alternatives to smoking cigarettes, the number of individuals using them is set to increase, says the study.
The research team, led by Dr Paolo Boffetta at International Agency for Research on Cancer in France, analysed the results of 11 studies carried out in Sweden and North America on the use of smokeless tobacco products and the risk of developing or dying from a heart attack or stroke.
Differences in study design and quality were taken into account to minimise bias.
They found a small increased risk of death from a heart attack or stroke among users of smokeless tobacco products compared with non-users. Smokeless tobacco caused 0.5% of all heart attacks in the United States and 5.6% in Sweden. The products were also the cause of 1.7% of stroke deaths in the United States and 5.4% in Sweden.
The authors conclude that, although the magnitude of the excess risk, particularly for fatal myocardial infarction, was small, the consistency of the results among studies and their robustness with respect to study design and quality added to their credibility.
If the association is real, the authors believe that its public health and clinical implications might be substantial and they call for more research in this area.
