Possible Causes of Multiple Sclerosis

Despite decades of research, the exact cause of multiple sclerosis (MS) remains undetermined. However, a combination of factors appears to be involved, and researchers have identified a number of these factors. Popular theories are as follows:

• Epstein-Barr virus (EBV) is a common virus that can remain dormant for many years and possibly develop into MS in genetically susceptible people. Recent studies often show an increased risk of MS for individuals who have been exposed to EBV.
• Genes have some role in susceptibility to MS, but the exact mechanisms remain unclear. Genetic studies in MS have clearly shown that the increased frequency of MS seen within families is a result of relatives sharing DNA (the molecule that carries our genetic information) and not from living together as a family in the same environment.

Researchers are working to identify genes that may increase one’s susceptibility to MS, using a Karyotype (chart) to show the chromosomal makeup of an individual.
• Since the 1940s, Dr. Roy Swank and others have looked at diet and saturated fat intake for their possible involvement in developing MS. Benefits such as fewer symptoms, greater mobility, and greater longevity were reported, although incomplete follow-up and the lack of a control group to compare results prevent these claims from being considered as evidence-based medicine.
• Vitamin D deficiency has also been suspected in the development of MS. Vitamin D is primarily derived from sunlight, and fish oil is another good natural source of Vitamin D. These theories stem from the fact that areas close to the equator, with the most amount of sunlight, and areas near the North Pole and South Pole, with diets rich in oily fish, have the lowest rates of MS.
• While studies with high levels of Vitamin D supplementation have not seen any therapeutic effects on disease progression or relapses, some of these studies have seen a reduction in new lesions, as viewed on magnetic resonance imaging (MRI).
• Vitamin D is also being studied with certain symptoms of MS, including fatigue. Individuals interested in taking Vitamin D supplements as part of their treatment regimen should consult their physician. Continued high-dose Vitamin D supplementation can lead to life-threatening conditions, including kidney failure and heart arrythmias.
• Parasites, which can modulate the immune system and dampen its responses, are a possible risk-reduction factor in the development of MS. The parasites in this instance are “helminths,” which refer to a wide variety of worms. As conditions in different countries become cleaner – with fewer parasites – the number of individuals being diagnosed with MS is increasing in these parts of the world.
• Researchers have also found that interactions between a person’s microbiome and their immune cells may contribute to the development and severity of many diseases – including MS. The microbiome refers to the many millions of bacteria that reside in a person’s body, with current research focusing mainly on the bacteria that live in the intestines (referred to as “gut microbiota”).
• With regard to a person’s microbiome, researchers have hypothesized that imbalances in the number or types of different strains of bacteria could potentially cause the immune system to be inappropriately activated to develop an autoimmune disease.
• Another factor linked to MS is cigarette smoking. Women who smoke are 1.6 times more likely to develop MS than women who are non-smokers, and are also at a much greater risk of experiencing a more rapid progression of their disease.

MSAA’s Chief Medical Officer, Dr. Barry Hendin, provides this insightful overview: “Although we have not yet isolated the antibody/antigen responsible for causing MS, we have come a long way in clarifying this immune mediated disorder. Multiple genes act together to create varying degrees of risk in an individual; the balance between susceptibility and protective genes appears to determine the baseline risk for an individual.

“Triggers play an important role in changing the potential risk to the actual development of clinical MS. We don’t understand all of the triggers, but we have a clearer picture of a few. While Epstein-Barr virus (EBV) is commonplace and widespread, it appears to be nearly required for triggering MS. In addition, Vitamin D and lack of sunlight exposure create vulnerability. Other factors include cigarette smoking and potentially childhood obesity… and we are still learning.”