A new study has found evidence that smoking negatively impacts people with relapsing-remitting multiple sclerosis (RRMS) who are receiving interferon treatment.

Smoking and interferons

The study, published in the journal Neurology, looked at the effect of smoking on people with RRMS who are being treated with beta interferons, comparing the risk of relapse in smokers versus non-smokers.

Researchers took blood samples of 2,723 people with MS from the Danish MS Biobank. 834 of them were chosen, and their DNA records covering a two year period up until the end of the treatment were analyzed. Information relating to smoking habits came from patients filling out a questionnaire. 

The findings revealed that smokers are 20% more likely to have a relapse than non-smokers and that this risk increases for each pack of cigarettes smoked per day. The research team, led by Eva R. Peterson, MD, from the Department of Neurology at the Danish Multiple Sclerosis Center, said:

"The results should encourage physicians to inform patients with MS about the harmful effect of smoking and increase focus on smoking cessation."

In conclusion

However, they also acknowledged that the study had its limitations, such as being unable to analyse the effects of passive smoking. Also, the study did not explore the risk in occasional smokers.

Furthermore, location-specific factors such as environment, genetics and smoking habits were not accounted for. Nevertheless, the findings are consistent with previous research into smoking and MS.

The evidence shows that smoking not only increases the risk of developing MS, but also increases the risk of disease progression. For these reasons, the OMS Program recommends immediate cessation. You can read the abstract here.

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