Photo: Crunched up cigarette

Smoking and low Vitamin D both worsen prognosis for people with CIS

Two new studies show that smoking and low vitamin D increase the risk of disability progression and declining cognitive function for people with clinically isolated syndrome (CIS).

CIS is often the first diagnosis of MS, although some people don’t go on to experience further symptoms.

Calculating the risks

The first study, led by Harvard University, looked at whether smoking and low vitamin D levels predict long term cognitive decline and nerve damage.

The second study, led by researchers in Spain, focused on whether they increase the risk of worsening disability (measured using EDSS). Both were presented at ECTRIMS 2018, the annual European MS research conference.

Researchers used statistical models to predict long term outcomes in people with CIS, and how lifestyle and environmental factors can affect this.

Changing habits can lower the risk of progression

People with CIS who smoked or had lower levels of vitamin D in their blood had a higher risk of their disability progressing more quickly. They were also more likely to experience greater cognitive decline compared with non-smokers and those who weren’t vitamin D deficient.

Importantly, researchers found that these risks could be improved. Increasing vitamin D levels by 50nmol/l over a two year period reduced the levels of nerve damage markers seen in the blood. And people were less likely to score below average on cognitive function tests.

Previous research has shown that quitting smoking can help everyday MS symptoms from getting worse, just a year after giving up.

A change for the better

Scientists aren’t sure why CIS turns into MS for some people and not others. Studies like these help us understand what increases the risk of disability progression and cognitive decline.

Although smoking and vitamin D levels are not the only factors that are important, they are ones that we can change.

If you’re currently a smoker, there are lots of free programmes to help you quit.

Read the abstract of the first smoking and vitamin D study on the ECTRIMS website

Read the abstract of the second smoking and vitamin D study on the ECTRIMS website