Several recent studies have found an association between level of education and MS-risk. These findings are important as they could help to identify new environmental risk factors for the disease. However, it has not been clear whether these findings could be explained by some of the established risk factors for MS, including vitamin D, smoking, body size and infectious mononucleosis. This study included measures of several of these exposures and could therefore adjust for them in the analyses.
The current study is a part of the EnvIMS study, a large international case-control study with participants from Norway, Sweden, Italy, Serbia and Canada. Detailed information on prior exposure to a range of environmental factors relevant to MS was collected through a validated questionnaire. Among the Norwegian participants, a higher level of education was associated with a lower MS risk. This association could not be fully explained by any of the established risk factors, including prior sun exposure, smoking, infectious mononucleosis, body size or intake of cod liver oil and fatty fish. This suggests the presence of additional environmental risk factors for MS and that these currently unknown exposures could be associated with education or socioeconomic status.
Bjørnevik K, Riise T, Cortese M, Holmøy T, Kampman MT, Magalhaes S, Myhr KM, Wolfson C, Pugliatti M. Level of education and multiple sclerosis risk after adjustment for known risk factors: The EnvIMS study. Mult Scler 2015.