Multiple sclerosis is a chronic, autoimmune and inflammatory disease of the central nervous system (brain and spinal cord). Twice as many women as men suffer from it, and, in total, it affects more than 2.5 million people worldwide. In Spain, there are 47,000 people who suffer from it, and 1,800 new cases are diagnosed each year, according to the Spanish Society of Neurology (SEN); in fact, the number of patients has doubled in the last two decades. As the SEN explains in a press release, “smoking, vitamin D deficiency, low exposure to sunlight and a change in diet” could be involved in this increase in cases.
With all these data in hand, it is obvious that it is very necessary to carry out studies to find new drugs for its treatment, to delay its progression. In addition, specialists believe that precision medicine should be targeted, since, as each patient presents a different disease activity profile, with symptoms that differ from one person to another, the personalization of therapies is essential. And, within this framework of finding new treatments, it is also important to study the possible triggers of this degenerative pathology.
Thus, a recent study, carried out by the Karolinska Institute in Stockholm (Sweden), has concluded that exposure to solvents such as those found in paints and varnishes can increase the risk of suffering from multiple sclerosis , and this risk is even greater if this factor is combined with others. Previously, it had already been observed that smoking has a negative influence on the risk of developing this chronic disease in those genetically predisposed to suffer it, and for this reason they wanted to analyze another source of lung irritation – such as organic solvents – as another possible factor of risk.
The Swedish study, published in the scientific journal Neurology, was carried out evaluating a total of 2,042 patients diagnosed with the disease and 2,947 subjects who do not suffer from it . All of them were asked if they were smokers or not and also if they had been exposed to solvents. Blood tests were also performed in order to detect a genetic variant that has been related to a greater predisposition to the appearance of multiple sclerosis and that 30% of the population carry – the presence of this genetic mutation does not imply that the person go to develop the disease far from it; in fact, most carriers will not.
A cocktail of factors
The results of this research confirmed the relationship between exposure to organic solvents and a greater risk of suffering from the disease, as well as that the combination of genetic and environmental factors – as happened with smoking – increased this risk much more. And among those study participants who carried the indicated genetic variant, there was also a synergistic effect – that is, their combined effect was greater than the sum of each agent individually – between organic solvents and smoking. In fact, Swedish scientists were surprised that the interaction of the three factors increased the risk so much: those who had the three analyzed – genetic mutation, smoking and exposure to solvents – were 30 times more likely to develop the disease than the people who did not present any of them.
Scientists also explain that, of course, the risk of suffering from the disease increases the higher the dose of exposure to solvents, so that a professional painter would be more exposed than a private person who has occasionally painted their house. , as explained, in an interview with the scientific social network ResearchGate, one of the authors of the study, Anna Hedström.
What can be done to, as far as possible, minimize the risks when you suffer from a greater genetic susceptibility to developing the disease – people with the genetic variant and also a family history of the disease? According to Heström, “ avoid tobacco and unnecessary exposure to organic solvents, and, especially, the combination of both factors”.
As for whether these findings could have an application in new treatments for this pathology, the researcher explains that more studies are needed to understand the mechanisms behind them, but that a greater knowledge of them “will increase the opportunity to develop new treatments in the future ”, highlights in ResearchGate.
