Smoking and early menarche may increase the risk of multiple sclerosis in Japanese people

Takeaway

  • Smoking, earlier age of menarche, and limited exposure to sunlight may increase the risk of multiple sclerosis in Japanese people.

Why this matters

    This is the first comprehensive survey of environmental risks for multiple sclerosis in East Asia. The identified environmental factors could account for the increasing prevalence of multiple sclerosis in Japanese females.