Multiple sclerosis is a debilitating neurological disease that affects the central nervous system.

This auto-immune disorder attacks myelin, a protective layer coating nerve fibers, causing a range of symptoms like muscle weakness, coordination loss, and trouble with vision, speech, or bladder control. The disease usually starts between the ages of 20 and 40 and is more common in women than men.

While the cause of multiple sclerosis is still unknown, a combination of genetic, environmental, and lifestyle factors is believed to contribute to its development. Here are ten factors that can influence the risk of developing multiple sclerosis.

1. Genetics

Genetics plays an important role in the development of multiple sclerosis. Studies show that people with a family history of multiple sclerosis are more likely to develop the disease.

The risk of developing multiple sclerosis is higher in people who have a first-degree relative (parent, sibling, or child) with the condition.

According to the National Multiple Sclerosis Society (NMSS), the risk of developing multiple sclerosis is around 2.5 to 5% for people who have a first-degree relative with the condition, compared to a risk of 0.1 to 0.2% for people without a family history.

2. Gender

Multiple sclerosis is more common in women than men. According to the NMSS, the ratio of women to men with multiple sclerosis is 3:1. This gender difference has been observed worldwide and is believed to be related to hormonal and/or genetic factors.

Women may be more susceptible to immune dysfunction due to the effects of estrogen and progesterone on the immune system.

3. Age

Multiple sclerosis usually starts between the ages of 20 and 40, although it can affect people of any age. The risk of developing multiple sclerosis decreases with age, and the disease is relatively rare in individuals over 65 years old.

However, some people develop multiple sclerosis at an earlier age, such as children or adolescents, which is known as pediatric multiple sclerosis.

4. Ethnicity

Multiple sclerosis is more common in people of northern European descent, including those of Scottish, Irish, and Scandinavian ancestry.

However, the disease can also occur in people of other ethnicities, including African Americans, Hispanics, Asians, and Native Americans. The prevalence and severity of multiple sclerosis may vary among different ethnic groups.

5. Geographic location

Multiple sclerosis is more common in temperate regions of the world, such as Europe, North America, and Australia, and less common in tropical regions.

This geographic distribution suggests that environmental factors, such as sunlight exposure and vitamin D levels, may play a role in the development of multiple sclerosis. The further away from the equator a person lives, the higher the risk of developing multiple sclerosis.

6. Vitamin D

Vitamin D is a nutrient that is essential for bone health and immune function. Studies have shown that low levels of vitamin D are associated with an increased risk of developing multiple sclerosis.

This may be related to the role of vitamin D in regulating the immune system and suppressing inflammation. Sunlight exposure is the main source of vitamin D, and people who live in areas with less sunlight or have limited exposure to sunlight may be at higher risk of vitamin D deficiency.

7. Smoking

Smoking is a well-established risk factor for multiple sclerosis.

Studies have shown that smokers are at higher risk of developing multiple sclerosis than non-smokers, and that people who quit smoking may reduce their risk of multiple sclerosis over time. The exact mechanisms by which smoking increases the risk of multiple sclerosis are not fully understood, but it is believed to involve immune dysfunction and oxidative stress.

8. Infections

Infections, particularly viral infections such as Epstein-Barr virus (EBV), may play a role in the development of multiple sclerosis.

Studies have shown that people who have had a history of infectious mononucleosis, which is caused by EBV, are at higher risk of developing multiple sclerosis. Other viruses that have been linked to multiple sclerosis include human herpesvirus 6 (HHV-6), varicella-zoster virus (VZV), and hepatitis A virus (HAV).

9. Obesity

Obesity, which is defined as having a body mass index (BMI) greater than 30, has been associated with an increased risk of multiple sclerosis.

The exact mechanisms by which obesity increases the risk of multiple sclerosis are not fully understood, but it is believed to involve chronic, low-grade inflammation and insulin resistance. Weight loss and physical activity have been shown to have beneficial effects on multiple sclerosis outcomes.

10. Stress

Stressful life events, such as illness, bereavement, or divorce, may trigger the onset of multiple sclerosis or exacerbate its symptoms.

Stress can affect the immune system and increase inflammation, which may contribute to the development of auto-immune disorders like multiple sclerosis. Managing stress through relaxation techniques, exercise, and psychological interventions may help improve multiple sclerosis outcomes.