January 14, 2004
Multiple Sclerosis Society
The cause of MS is currently unknown although it is widely thought that a combination of genetic and environmental factors act to increase a person's susceptibility to developing MS. Infectious agents, such as a viruses, have been implicated as triggers for MS onset, but there are likely to be a number of other factors that also play a role. This study used a questionnaire to determine whether tobacco smoking was associated with an increased risk of developing MS.
Information was obtained from 22,312 people, living in Norway. The questionnaire included questions on health and lifestyle, including whether the participant had MS, age of diagnosis, and whether they currently, or had ever smoked.
87 people (0.39%) from this sample reported having MS. All current smokers had started smoking before the onset of MS, as had the majority of 'previous' smokers. However, almost 25% of people with MS reported never having smoked.
This study reported that the risk of developing MS among people who smoked was nearly twice as high as in people who reported never smoking. However, no differentiation is made between the risk of developing MS, associated with current and past smokers. Based on these results, the study suggests tobacco smoking may be one of several risk factors for developing MS. The authors propose that smoking could influence the risk of developing MS by affecting the immune system directly, but suggest that further work to look at the effects of some specific components of tobacco smoke could be explored. A major limitation of this study is the very small number of people surveyed with MS, which makes the findings not significant.
This report was published in Neurology, 2003. Vol. 61, pages 1122-1124.
Copyright © 2004, Multiple Sclerosis Society