Recent study showed that smoking before age 17 increases the risk of developing multiple sclerosis. Research team led by Joseph Finkelstein, MD, PhD, at Johns Hopkins University School of Medicine in Baltimore studied data collected from 87 patients with multiple sclerosis (MS).

The study subjects were divided into three categories: nonsmokers, early smokers who started before age 17, and late smokers who started at 17 or later. Research team also studied factors like sex, race, age, marital status, education, income level, and region.

Data analysis revealed that 32% of the MS patients were early smokers as compared to 19% of the people who didn't develop the disease. This means the people who started smoking before age 17 have 2.7 times increased risk multiple sclerosis than nonsmokers.

However people who started smoking at 17 or later have no increased risk of developing multiple sclerosis as compared to nonsmokers.