Environmental Risk Factors for Multiple Sclerosis: A Review with a Focus on Molecular Mechanisms

Abstract

Multiple sclerosis (MS) is a chronic disabling disease of the central nervous system commonly affecting young adults. Pathologically, there are patches of inflammation (plaques) with demyelination of axons and oligodendrocyte loss. There is a global latitude gradient in MS prevalence, and incidence of MS is increasing (particularly in females). These changes suggest a major role for environmental factors in causation of disease. We have reviewed the evidence and potential mechanisms of action for three exposures: vitamin D, Epstein Barr virus and cigarette smoking. Recent advances supporting gene-environment interactions are reviewed. Further research is needed to establish mechanisms of causality in humans and to explore preventative strategies.

The immunogenetics of multiple sclerosis. The frequency of HLA-alleles class 1 and 2 is lower in Southern Brazil than in the European population

“…We believe that the mainly factor to our different results was the different ethnic backgrounds into Brazil which can really results in many possible genetic combinations in the Brazilian population. Furthermore, beside the type of HLA and ethnic diversity, probably climate with less sunlight, different environmental conditions and dietary habits could play a role in the triggering and incidence of MS in southern Brazil different from other countries 8,32,33,34,35 .…”

Effects of green tea epigallocatechin-3-gallate on the proteolipid protein and oligodendrocyte transcription factor 1 messenger RNA gene expression in a mouse model of multiple sclerosis

“…Recent studies suggest that vitamin B 12 , in addition to its known role as a co-factor in myelin formation, has important immunomodulatory and neurotrophic effects [19]. It has been shown that low vitamin D intake or serum vitamin D status is associated with increased risk of developing MS [22]. It has been documented that EGCG given to patients with MS over 12 weeks improves muscle metabolism during moderate exercise to a greater extent in men than in women, possibly because of sex-specific effects on autonomic and endocrine control [18].…”

Original article Effect of oral administration of pig spinal cord hydrolysate on clinical and histopathological symptoms of experimental allergic encephalomyelitis in rats

“…It is diagnosed in so-called "young adults", people between 20 and 40 years old, but also it affects both older people and children. The etiology of the disease still remains unknown, but there are some hypotheses proposing the involvement of genetic, environmental and infectious agents [28,33]. The unknown etiology is the main reason for the difficulty in developing an effective MS treatment.…”