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Smoking and MS Choices booklet

Everyone is aware smoking is bad for your health – one in two smokers will die from a smoking-related illness. Smoking can also exacerbate asthma, increases the risk of stroke by at least 50%, heart attack, pneumonia, emphysema, and contribute to sexual dysfunction as well as reducing fertility (1).

For people with multiple sclerosis (MS) there are even more compelling reasons to quit. There is evidence that demonstrates smoking is an environmental risk factor that contributes both to MS onset and disability progression (2).

Smoking is associated with a reduction in brain volume, it can lead to a higher relapse rate and also more cognitive problems (3).

Risk of developing MS for smokers

Research published in October 2003 in the journal Neurology, looked at the increased risk of developing MS in people who smoked within the general population. The study followed 22,312 people in Norway, who completed a detailed questionnaire about past and current smoking habits and were given a physical examination. In this group, 87 people were reported to have MS at the beginning of the study, some of whom smoked, or had smoked in the past (4).

The study concluded that there was an increased risk in developing MS associated with smoking – for men the risk was three times greater than for a male non-smoker, and for women the risk was one and a half times greater. The theory behind these results was smoking may damage the cells which line blood vessels and these damaged cells cause the vessels to leak, allowing the toxic chemicals in cigarette smoke to damage the brain (4).

Risk of disability progression for smokers

In 2005 the Harvard School of Public Health published research in Brain - A Journal of Neurology, suggesting smoking contributes to the progression of MS (5). The researchers examined the medical records of more than 2,000 people, including 179 people with relapsing remitting MS (RRMS).

Researchers found current or former smokers with RRMS were over three times more likely to develop secondary progressive MS, another phase of MS marked by a steady increase in MS symptoms and disability, compared to non- or past smokers (5).

The study was interesting because, amongst other viral and genetic factors potentially involved in either the development of MS, or disability progression in MS, quitting smoking is something which can slow disability progression. This was the first time a modifiable risk factor for MS was identified. The theory behind these results was that nitrous oxide - a chemical in cigarette smoke - may be responsible for damage to the cells that create myelin, the protective coating around a nerve cell.

Risk of passive smoking of developing MS in children

In 2007, research from France was published in Brain – A Journal of Neurology, linking children’s exposure to passive smoking and an increase in development of MS in later life (6). In the study, 62 per cent of the people diagnosed with MS had been exposed to parental smoking as children, compared to 45 per cent of people diagnosed with MS, whose parents did not smoke.

The research also pointed to a time-related correlation between the increase in risk of developing MS as an adult and the length of time a child had been exposed to passive smoking (6).

Smoking and Tysabri

For people taking the disease modifying drug Tysabri (natalizumab), there is evidence that smoking increases the risk of the body developing neutralising antibodies to the therapy, causing the drug to have little or no therapeutic effect.

A study published in July 2014 looked at 1,338 people on at treatment programme of Tysabri in Sweden (7). The risk for developing neutralising antibodies was over twice as high in smokers, compared to non-smokers.

Advice given at the 2014 conference ACTRIMS/ECTRIMS following the results of the study was that a person should not be prevented from starting Tysabri if they smoked. If the treatment proved ineffective due to the presence of antibodies, other therapies should then be considered (8).

For more detailed information about Tysabri, see MS-UK’s Choices leaflet Disease modifying therapies.

Stopping smoking 

Although it may be difficult to stop smoking, this lifestyle change could prevent you from increasing your, and your children’s risk, of developing MS. If already diagnosed, stopping smoking could help to decrease your risk of disability progression.

Researchers at University College London published a report in 2017, which states that success rates for giving up smoking are at their highest for over a decade. In the first half of 2017, nearly 1 in 5 attempts at quitting smoking were successful (9).

It is suggested that some of this success has come from the use of e-cigarettes. According to the Government stop smoking campaign ‘Stoptober’, 53% of those taking part in the campaign in 2016 used e-cigarettes to help them quit (9).
If you smoke and want to quit, there are numerous ways to get support including the NHS’ ‘Smokefree’ website at

Further support can be found from the National Centre for Smoking Cessation and Training (NCSCT). You can find out about the support service on their website

Your GP, hospital and local pharmacy will also be happy to advise you on what may be the best course of action for you, to help you stop smoking.

This content is taken from the MS-UK Choices booklet. 

Visit the Choices booklet web page