How does lifestyle change the risk of developing MS?
Raghda is an MS researcher based at the University of Cambridge. She shares an insight into how lifestyle differences might be linked to MS prevalence in the UK and the Middle East.
Research shows MS is more common in the UK than in the Middle East. In the UK, around one in every 400 people has MS. And around one in every 2000 people in the Middle East live with MS. My PhD research focuses on how genetics could play a role in why MS clinical course progresses differently for each person. But genetics alone is unable to explain why MS is more common in some countries than others.
As an MS researcher who's lived in the Middle East and is now studying in the UK, I'm very interested in why there's such a difference in the prevalence of MS between different nations. Interestingly, studies have shown that the risk of MS for children of immigrants in the UK is similar to that seen in the general UK population. This suggests that environmental factors in the UK, rather than genetic factors alone, play a significant role in the development of MS.
Here, I discuss what I found the main two environmental and lifestyle differences between the UK and the Middle East that may influence MS prevalence.
Number of people living with MS in different countries
Sun exposure and Vitamin D
One of the biggest differences is the amount of sun exposure. In the Middle East, people are exposed to plenty of sunshine throughout the year from their childhood. The sun helps our bodies generate vitamin D, which is essential for healthy organs development and functions including the brain and the immune system.
In the UK, I think we can all agree there is less sun! So people may not have enough sun exposure to meet the daily requirement of vitamin D. As a result, many people in the UK have low levels of vitamin D.
Indeed, the NHS advises that everyone should consider taking a daily vitamin D dietary supplement during the autumn and winter based on their age and their vitamin D level. Before taking vitamin D dietary supplements, you should discuss this with your GP.
Studies have shown that low levels of vitamin D may increase the risk of developing MS, and many other conditions. Additionally, I can't emphasise enough the importance of vitamin D for organ development, including the brain during childhood. In my opinion, childhood brain development is an understudied factor for developing MS later in adulthood.
Read our information about MS and Vitamin D
Find out more about the NHS recommendations for Vitamin D
Childhood viral infections
Another important factor is the exposure to viral infections during childhood. There is a theory called the “hygiene hypothesis”. This suggests that living in cleaner environments with fewer viral infections can alter the immune system. And increase the risk of conditions like MS where the immune system mistakenly attacks the body.
In the Middle East, children are often exposed to various viruses early in life through their environment. This exposure can help their immune system.
In the UK, better hygiene could result in fewer childhood viral infections. I’ve noticed in the UK that it’s more common for children with flu-like symptoms not to attend school or nursery to prevent the spread of infection to other children. While it's obviously beneficial to avoid illness, it might mean that the immune system doesn't get as much of a workout. This might potentially increase the risk of MS in adulthood.
One example is the Epstein-Barr Virus (EBV). Most people (more than 95%) are infected with EBV at some point in their lives. This leads to life-long immunity against future EBV infections.
EBV infection doesn’t usually cause symptoms when it’s caught as a child. However, people who get the infection as teenagers are at a greater risk of developing the condition called infectious mononucleosis, also known as glandular fever.
In countries like those in the Middle East, most children acquire EBV by the age of 4 years old. But in the UK, EBV infection tends to occur later in life, and between 25–75% of people with EBV infection develop glandular fever.
Research has shown experiencing symptoms of infectious mononucleosis is linked with an increased risk of developing MS later in life.
Presenting my work at the international MS conference ECTRIMS in 2023
Studying genetics and environmental factors in the lab
I’m using cells in a dish to study the genetic factors which influence MS progression. I hope to ultimately find new drug targets which can have an impact on MS progression.
In my PhD, I’m focusing on a particular version of a particular part of DNA. This tiny part of DNA has been directly linked with MS progression. If someone has a certain version, they're more likely to experience greater disability. This section of DNA sits next to a gene called “ZNF638”. Interestingly, this gene has roles in controlling viruses and is linked to brain development. As I mentioned earlier, viral infections are linked to MS. So, I think by understanding this gene better we can understand the causes of MS progression better too.
Stem cells under the microscope, with special dyes to show them... sending their love!
Understanding genetics and environmental factors together
Although genetics are essential in understanding MS, environmental factors also play a crucial role in the likelihood of developing MS. Even if someone has genetic variants that make them more likely to develop MS, they may not actually get MS unless they're exposed to certain environmental risk factors. This could explain why there can be multiple people living with MS in one family. They share not only genes but also similar environments.
Understanding the differences in lifestyle and environment between the Middle East and the UK can provide valuable insights into the prevention and management of MS.
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