Multiple sclerosis is still an enigma
Viruses as triggers?
Different disease agents, particularly viruses and bacteria (e.g. Epstein-Barr virus from the herpes virus group) are suspected of triggering MS. It is hypothesized that immune cells reacting to the disease agent are involved in a cross reaction with proteins in the brain and thus mistakenly attack brain tissue itself. Up till now, it has not been possible to clearly identify any specific virus or bacteria as an “MS agent”.
The risk of MS increases in 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 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. And although this connection 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 gender distribution
Lifestyle and nutrition also seem to play a role in the outbreak of the disease. For example, the risk of developing MS is 1.5 times higher in smokers than in non-smokers. Interestingly, more women than men suffer from relapsing-remitting MS – the ratio being approximately 3:1. The causes remain unknown.