CLIMATE, LATITUDE, AND MULTIPLE SCLEROSIS

Incidence of multiple sclerosis have long been understood to increase amongst populations furthest from the equator. Indeed the rate of multiple sclerosis diagnosis in equatorial latitudes is generally accepted as zero. Significantly, people from these communities if they emigrate to other climates, particularly early in life, tend to adopt the multiple sclerosis rate of the host community.

Where this epidemiological link can be seen most clearly is in studies that look at Australia. Most of us would not be surprised by the statistic that tells us incidence of malignant melanoma increases with every degree higher in latitude from the southeren tip of Tasmania to the northern point of Queensland. However, the incidence of multiple sclerosis increases to a greater extent in the opposite direction.