Can environmental factors increase the risk of multiple sclerosis? A narrative review

Multiple sclerosis (MS) is one of the most common neurological disorders, which causes non-trauma in young adults in many countries. An important symptom of a disease is the presence of plaque in the brain or the spinal cord, which includes a demyelination region along with relative preservation of axons that may vary in acute and chronic stages. This review was conducted using related keywords through searching in scientific databases. Assessing the related papers showed that in general, MS is recognized as an autoimmune disease with genetic background caused by uncertain environmental factors. Epidemiological effects based on race, sex, geographical location are strongly linked to the frequency, types and severity of the disease. Vitamin D, infection, smoking and diet have been reported to be potential factors associated with MS. Due to the importance of these factors in MS disease, the control of them is potentially useful to prevent the disease and the rapid progression and exacerbation of its symptoms.