The Surprising Risk Factors for Multiple Sclerosis

Multiple sclerosis (MS) is a disease in which your immune system attacks myelin, the covering that protects your nerves. This causes the nerves to deteriorate and disrupts information flow both within your brain and between your brain and the rest of your body.

While the cause of MS is unknown, there are environmental and genetic factors that are believed to be associated with this disease.

Environmental Risk Factors for MS

Known environmental associations for MS include Epstein-Barr virus (EBV), vitamin D deficiency, smoking and childhood obesity.

“It’s important to note that these factors are associations, not causations of MS,” emphasizes Amin Sanei Moghaddam, MD, MPH, a neurologist with ProMedica Physicians Neurology – Toledo.

This means that just because you have or had one or more of these risk factors, doesn’t necessarily mean that you will get MS, it just may put you at a higher risk for the disease.

Epstein-Barr Virus (EBV)

Epstein-Barr virus (EBV) is a virus in the herpes virus family and is one of the most common human viruses in the world. In fact, about 9 in 10 adults have antibodies that indicate that at some point they were exposed to EBV. It’s most commonly spread through saliva by kissing or sharing drinks, food or utensils.

While most people who get EBV won’t experience any symptoms from the infection, EBV is the highest-known risk association for MS. “If you are EBV-positive, your risk of developing MS is 32-fold higher than someone without EBV,” shares Dr. Sanei Moghaddam.

In a recent study that examined the medical records of 10 million active-duty United States military personnel, 955 of them developed MS. Of the MS-diagnosed individuals with sufficient blood samples (total of 801), all except one were or became EBV-positive.

“Because of this strong association, efforts are currently being made to develop an effective EBV vaccine” shares Dr. Sanei Moghaddam.

Vitamin D Deficiency

Individuals who are vitamin D deficient are diagnosed with MS at a higher rate than those without a deficiency. Also, individuals who are diagnosed with MS and were vitamin D deficient at the time of their diagnosis tend to have worse symptoms, or flare-ups, than those who had adequate levels of vitamin D.

“We don’t know if there is a genetic component to this correlation,” Dr. Sanei Moghaddam shares. Vitamin D and inflammatory genes are also closely related, so the tie between the two could lie there.

The correlation is strong enough that there’s a higher incidence of MS the further away you move from the equator. 

“I periodically measure vitamin D levels among my patients who have MS. For someone with MS, we want to aim for a level of 40-70 ng/ml, compared to about 30 ng/ml for someone without MS,” Dr. Sanei Moghaddam shares.

These levels can be achieved through prioritizing sun exposure as well as vitamin D supplementation.

Smoking

Smoking can both increase your risk of developing MS as well as increase the risk of regression among individuals with the disease.

“Interestingly, studies have not shown an increased risk of MS among people who use chewing tobacco. So it’s thought that it might not be the tobacco itself, but other ingredients found in cigarettes that cause the increased risk,” shares Dr. Sanei Moghaddam.

Childhood Obesity

“Increased abdominal fat is associated with MS,” shares Dr. Sanei Moghaddam. “Because fat is biologically active, it produces inflammatory materials that can increase inflammation in your body, therefore increasing your risk of inflammatory diseases such as MS.”

When obesity begins in childhood, your body is in a prolonged state of inflammation, which puts you at a greater risk.

Genetic Risk Factors for MS

There is not a single gene responsible for MS. In fact, there are more than 200 genes that are believed to be associated with MS and MS risk. Unfortunately, this rules out genetic testing as an option to assess your risk of developing the disease.

However, familial risk is demonstrated. For the general population who have no known family members with MS, their risk of developing MS is about 0.5% in the United States. If you have a first-degree relative with MS, such as a parent or sibling, your risk of developing MS increases to 2-3%.

Risk Calculated by a Combination of Genetic and Environmental Factors

The impact of both genetic and environmental factors on MS risk is demonstrated among observational studies of identical twins. “If one identical twin has MS, the other twin actually only has a 20-30% chance of also having MS,” shares Dr. Sanei Moghaddam. “This is interesting because even though the twins have the same genetics, and likely grew up in a similar environment, their risk is not the same. This shows that there are other factors beyond genetics at play.”

Lowering Your Risk for MS

While it has not been proven that MS can be prevented, you can take steps to better your health to decrease your risk of developing the disease. Lifestyle modifications such as exercising more, eating healthy and quitting smoking will help you in the long run.

“If it’s good for your heart, it’s good for your brain,” shares Dr. Sanei Moghaddam. He recommends eating a diet high in fruits and vegetables and low in processed, high-salt and inflammatory foods. Exercising, getting good quality sleep, staying hydrated and prioritizing mental health are also important to overall health and decreasing risk of MS.

Supplementing vitamins and minerals that you may be lacking in your diet can also be beneficial. Dr. Sanei Moghaddam recommends considering vitamin D, vitamin B12 and folic acid, as these all play a role in your nervous system. Deficiencies of these vitamins are associated with cognitive problems and muscle weakness.

When To See a Doctor

Because there is no way to prevent MS or test your risk, Dr. Sanei Moghaddam suggests prioritizing lifestyle changes if you’re worried about your risk. However, it’s time to make an appointment with your primary care provider or neurologist if you experience any of these symptoms for 24 hours or more:

• Numbness or weakness of one limb or one side of your body.
• Blurry or double vision, complete vision loss or painful eye movement.
• Loss of feeling from a certain part of your torso down.
• Loss of bladder or bowel control.
• Lack of coordination or “feeling drunk”.

Your provider will work with you to rule out other potential causes before jumping to the conclusion of MS. This process is important so that the correct treatment and follow-up care can be provided to help address current and future symptoms of the disease.