MS used to be very rare in the Middle East, but rates are rapidly rising. Why? One theory: as residents adapt a more "western" diet and lifestyle, obesity and inactivity rates have risen, while UV exposure has decreased. Lifestyle matters, as all of these "western" measures decrease cerebral perfusion and increase endothelial dysfunction. Environmental factors really do affect MS progression. Here's more from Julie Stachowiak

We know a great deal about the epidemiology of MS in the populations of the United States, Canada and Europe. However, we don’t hear much about what is going on with MS outside of these...