New research published in Multiple Sclerosis Journal (abstract here) and authored by Anna Hedström of Stockholm’s Karolinska Institute of Environmental Medicine confirms that snus users have a significantly lower risk for multiple sclerosis (MS) than nonusers of tobacco. I discussed the researchers’ earlier findings on this subject five years ago in this blog (here).
Hedström’s study is based on some 7,900 Swedes with MS and 9,400 controls. Compared with never users of tobacco, snus users had a lower risk for MS (odds ratio OR = 0.75, 95% confidence interval, CI= 0.63 – 0.90). Hedström also showed an increased effect at higher duration-dose levels of snus. For example, users with greater than ten packet-years (the number of snus doses per day and years of use) had an OR of 0.45 (CI= 028 – 0.68). Smokers had modestly increased risk (OR= 1.49, CI= 1.40 – 1.59), a finding that is similar to that reported in Hedström’s previous study.
Scientific research is methodically unveiling the benefits of nicotine and smoke-free tobacco use with respect to degenerative brain diseases. A finding that nicotine may improve performance in people with mild cognitive impairment (discussed here), has resulted in calls for more research on nicotine’s effect on dementia (reference here).
The impact of nicotine/tobacco use on Parkinson’s disease is well documented. An American Cancer Society study (here) provides clear evidence that smokeless tobacco use may be protective for Parkinson’s disease (RR = 0.22, CI = 0.07 – 0.67). In fact, nicotine is being discussed as therapy for this disorder (here, here and here).
Alzheimer’s disease is the sixth leading cause of death in the United States, and Parkinson’s disease is the fourteenth. The role of nicotine and smoke-free tobacco in reducing risk of or treating these disorders is of significant import.