Multiple sclerosis is still an enigma
The cause (etiology) of MS is still unknown. Many findings indicate that MS is an autoimmune disease in which the body’s own immune cells attack the brain and spinal cord. Up to now research has shown that genetic factors play a role in the cause of the disease (pathogenesis), but also environmental factors such as viruses or other agents can trigger it as well. Although MS is not a classic hereditary disorder, most of the genetic risk factors which have been found to be associated with the disease have one thing in common: they are genes of the immune system.
Viruses as triggers?
Different disease agents, particularly viruses and bacteria (i.e. Epstein-Barr virus from the herpes virus group) are suspected of triggering multiple sclerosis. It is hypothesized that immune cells reacting to the disease agent are involved in a cross reaction with proteins from the brain and thus mistakenly attack the brain tissue itself. It still has not been possible to clearly identify any virus or bacteria as an “MS agent”.
The risk of MS increases in the northern latitudes
Multiple sclerosis is most common in central and northern Europe, North America as well as in the southern parts of Australia, while countries with higher exposure to sun, such as in Africa and most parts of Asia, are less affected. Researchers suspect a link to vitamin D metabolism: vitamin D is formed by sunlight on the skin. The more exposure to sun an individual has had as a child, the lower the risk of MS. Although this has been demonstrated in some scientific studies, it is not yet proven that a deficiency of vitamin D really does play a role in the development of MS.
Lifestyle and nutrition also seem to play a role in the outbreak of the disease. For example, smokers’ risk of developing MS is 1.5 times higher than in non-smokers.