Multiple sclerosis (MS) is apparently common at higher latitudes, farther away from the equator. This ailment may be associated with environmental factors such as low levels of sun exposure and a history of infectious mononucleosis. According to a recent study, people who are exposed to low levels of sunlight and with a history of having a common virus known as mononucleosis face greater threat of developing MS than those without the virus.
During the study, investigators looked at all hospital admissions to National Health Service hospitals in England over seven years. Around 56,681 cases of MS and 14,621 cases of infectious mononucleosis were thoroughly scrutinized. NASA data on ultraviolet intensity in England was also evaluated.
“Lower levels of UVB in the spring season correspond with peak risk of MS by birth month. More research should be done on whether increasing UVB exposure or using vitamin D supplements and possible treatments or vaccines for the Epstein-Barr virus could lead to fewer cases of MS,” said George C. Ebers, MD, with the University of Oxford in the United Kingdom and a member of the American Academy of Neurology.
The effects of sunlight exposure and mononucleosis together were probably found attributable to 72 percent of the variance in the occurrence of MS across the United Kingdom. Sunlight exposure alone reportedly accounted for 61 percent of the variance. However, low sunlight exposure in the spring may be significantly linked with MS risk. It is predicted that vitamin D deficiency causes an abnormal response to the Epstein-Barr virus.
The study is published in the April 19, 2011, print issue of Neurology, the medical journal of the American Academy of Neurology.