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Multiple Sclerosis Health Center

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Smoking Tied to Multiple Sclerosis Progression

Harvard Study Links Smoking With Greater Risk of More Rapid Increase in MS Symptoms

Smoking Hastens MS Progression continued...

In an extension of the study comparing multiple sclerosis patients to people without the disease, cigarette smoking was associated with a 30% increase in the likelihood of getting MS. However, the finding was not significant and the researchers could not rule out the possibility of this being a chance finding.

The findings identify smoking as possibly the first modifiable risk factor for multiple sclerosis progression. But Hernan tells WebMD that the study does not address the question of whether patients who stop smoking can really alter the course of their disease.

"Our data can't tell us if quitting makes a difference," he says. "It may be that by the time MS is diagnosed the damage has been done."

LaRocca agrees, although he says multiple sclerosis patients, like everyone else, should not smoke.

"I would like to see everyone who is smoking stop," he says. "But I think it is premature to tell patients that they can slow their MS course by stopping."

Explaining the MS, Smoking Link

The researchers offered several theories about the mechanism that could be driving the smoking-MS connection. A number of recent studies have suggested a link between nitric oxide, one of many chemicals present in cigarette smoke, and MS.

Nitric oxide and other chemicals that smokers breathe in could also damage the cells that protect myelin, a protective nerve coating that is eventually destroyed by multiple sclerosis.

"At this stage, this is all speculation," Hernan says. "More study is needed to answer these questions."

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