Smoking and multiple sclerosis


We aimed to study the influence of smoking habits, exposure to passive smoking and snuff use on disease progression, cognitive performance and quality of life in patients with multiple sclerosis (MS).

Patients from two population-based case–control studies were categorised based on tobacco exposure at diagnosis and were followed up to 15 years post diagnosis through the Swedish MS registry (n=9089) regarding changes in Expanded Disability Status Scale (EDSS), Multiple Sclerosis Impact Scale 29 and Symbol Digit Modalities Test.

Compared with non-smokers, current smokers had a faster EDSS progression (βcurrent smoking×time=0.03, 95% CI 0.02 to 0.04).
A faster EDSS progression was also associated with passive smoking (βcurrent passive smoking×time=0.04, 95% CI 0.03 to 0.06).

Smoke exposure negatively impacted all secondary outcomes. Those who continued smoking had worse outcomes than those who stopped smoking post diagnosis. Snuff users had a more favourable EDSS progression, compared with never users.

These findings indicate that both smoking and passive smoking have a negative influence on MS and that smoking cessation post diagnosis may be an important secondary preventive measure.

Snuff use was associated with slower disease progression, suggesting that nicotine replacement therapy could be an attractive way to increase the chance of quitting smoking among patients with MS.

Source: Journal of Neurology, Neurosurgery & Psychiatry 2023;94:589-596