A recent study looked at whether exposure to paint and other organic solvents are among the causes of multiple sclerosis in people who are genetically susceptible to the disease.
Multiple sclerosis is a debilitating autoimmune disease of the central nervous system, which includes the brain and spinal cord. Symptoms of multiple sclerosis differ from person to person. They can include numbness or weakness in one or more limbs, partial or complete blindness, fatigue, slurred speech and tingling or pain in parts of the body. As there is currently no cure, treatments for multiple sclerosis aim at modifying the course of the disease and managing its symptoms.
Multiple sclerosis causes include environmental and genetic factors
Several different factors are responsible for multiple sclerosis causes, including both environmental and genetic factors. Recent studies have suggested that although genes for multiple sclerosis can be passed onto children from their parents predisposing them to the disease, this only plays a part of the role in an individual developing the disease.
Instead, research is suggesting environmental factors may play a greater role in increasing the risk of developing multiple sclerosis. Environmental factors include infection with Epstein-Barr virus, vitamin D levels and sun exposure habits, adolescent obesity and smoking. Of these environmental factors, studies have recently shown a strong link between smoking and an increased risk of multiple sclerosis in people carrying the genes.
Another environmental factor that causes irritation and damage to the lungs is exposure to organic solvents such as paint and varnish. Therefore, a recent study by Swedish researchers investigated whether there is a relationship between lung irritation and the development of multiple sclerosis. They looked at how exposure to organic solvents could potentially increase an individual’s risk of multiple sclerosis, especially in people carrying genes for the disease. Their findings were recently published in Neurology.
The study included 2,042 participants who were reported to have multiple sclerosis and 2,947 control participants. The Swedish researchers compared the participants in terms of the occurrence of multiple sclerosis with those carrying the genes for multiple sclerosis, smoking habits and exposure to organic solvents.
Exposure to organic solvents increases the risk of multiple sclerosis
The results showed that exposure to organic solvents did indeed increase the risk of developing multiple sclerosis. Participants who carried the genes for multiple sclerosis and were exposed to both smoking and organic solvents were also found to have a 30-fold increased risk of developing multiple sclerosis compared to those who did not carry the genes or were not exposed.
It was reported that the combination of exposure to solvents and carrying the multiple sclerosis genes was responsible for approximately 60% of the risk of developing multiple sclerosis. This finding highlights that exposure to more than one factor has a much greater effect than just one factor on its own.
One limitation is that participants were asked to remember any exposure to solvents they may have had. Therefore, it is possible they may not have remembered correctly.
More research needed to understand how these factors interact to increase an individual’s risk
In conclusion, this study showed exposure to both smoking and paint or other organic solvents is significantly linked to the risk of multiple sclerosis. People who are exposed to these environmental factors are 50% more likely to develop multiple sclerosis.
The researchers proposed that the way in which the exposure increases the risk is possibly by causing inflammation and irritation in the lungs leading to an immune reaction in the lungs. However, more research is required to understand how exactly these factors interact to cause such an increase in risk.
Written by Lacey Hizartzidis, PhD
- Hedström AK, Hössjer O, Katsoulis M, Kockum I, Olsson T, Alfredsson L. Organic solvents and MS susceptibility: Interaction with MS risk HLA genes. Neurology. 2018 Jul pii: 10.1212/WNL.0000000000005906. doi: 10.1212/WNL.0000000000005906.
- Exposure to paint, varnish, other solvents linked to increased risk of MS. American Academy of Neurology Website, https://www.aan.com/PressRoom/Home/PressRelease/1658. Accessed July 14th, 2018.