Migration, age, and MS . . . and other stories

Migrants and multiple sclerosis

Studies of migrants show that people who move from countries where multiple sclerosis is rare to places where the prevalence is high tend to retain the low risk of their country of origin. A nationwide study from Denmark, where multiple sclerosis is common, finds that age at migration has an important effect (Brain doi:10.1093/brain/awz088). Migrants who arrived in Denmark before the age of 15 had a risk of multiple sclerosis that was higher than that in their country of birth, although lower than that among ethnic Danes. In contrast, risk in people who were older when they …