People who smoke and have multiple sclerosis (MS) may be at increased risk of brain shrinkage and increased brain lesions related to the disease, according to a study published in the August 18, 2009, print issue of Neurology, the medical journal of the American Academy of Neurology. Smoking has already been linked to an increased risk of developing MS.
Researchers studied 368 people in New York with an average age of 44 who had been diagnosed with MS for an average of 12 years. Participants underwent brain scans and were asked about their smoking history. Of the group, 240 were non-smokers, 96 were current smokers and 32 were past smokers. Current smokers were considered people who smoked more than 10 cigarettes per day in the three months leading up to the study and past smokers were those who smoked for at least six months sometime before the start of the study. The average current smoker in the study had been smoking for 18 years.
The study found that smokers with MS had a greater breakdown of the barrier between the brain and blood and had nearly 17 percent more brain lesions on their scans compared to non-smokers with MS. Smokers with MS had 13 percent larger ventricles and a smaller brain size compared to non-smokers with MS.