Multiple sclerosis is an autoimmune disease The central nervous system When the immune system rushes away and attacks myelin, a protective sheath of nerve fibers that plays an important role in spreading nerve impulses from the brain to the body. It is considered a disease that affects young people because it often Their ages range from 25 to 35 years. Among the risk factors mentioned by the scientific community, in addition to genetic predisposition, most are environmental. Thus, viral infection can play a reinforcing role in the same way Vitamin D deficiency, as suggested by the frequency of MS in northern countries.
This is the hypothesis that researchers at the University of California, San Francisco, wanted to explore in a study published in the Journal of Neuroscience. This indicates that Children and teenagers Young people who spend more time outdoors during the summer months and live in areas that have more UV radiation from the sun have a lower risk of developing MS. These results also reveal that Exposing people to sunlight During their first year of life, they also had a lower risk of childhood MS, although childhood MS is rare.
At least 30 minutes outdoors a day
The study included 332 participants between the ages of 3 and 22 years, Who Suffered From Multiple Sclerosis For an average of seven months. Sun exposure was measured by time spent outdoors, use of sun protection, participants’ place of residence at birth and time of the study. After modification by Tobacco exposure And other factors that may influence the risk of developing multiple sclerosis, researchers found that people who spent an average of 30 minutes to an hour a day outdoors in the summer prior to the study had a 52% lower risk of developing MS than those who passed. Less than 30 minutes outside Daily.
In addition, people who have passed between one and 2 hours out of the day They were 81% less likely to have MS than those who spent less than 30 minutes on average. “It is important to note that excessive unprotected sun exposure also carries risks, and our study found that spending two hours or more in outside in the day It did not reduce the risk of developing MS compared to one to two hours. », identifies the American College of Cardiology’s lead author, Emmanuel Wupant. The location of the living place was also important because More intense than sunlight It was associated with a lower risk of developing MS.
Vitamin D plays a role in protecting against autoimmune diseases
For example, researchers estimate that a person who lives in Florida, one of the sunny From the United States, they are 21% less likely to have MS than someone who lives in New York City. How do we explain this useful link? The answer is simple: exposure to sunlight is known to increase vitamin D levels. It also stimulates the immune cells in the skin that have a protective role against diseases such as Multiple sclerosis. Vitamin D can also alter the biological function of immune cells and thus play a role in protecting against autoimmune diseases. Professor Emmanuel Wupant adds.
The use of sunscreen reduces the therapeutic effects Sun light In the prevention of MS, this does not appear to be the case, according to the scientific team. However, she wants to do more clinical trials to determine whether increased exposure to sunlight or vitamin D supplementation can prevent MS development or change its course after diagnosis. Meanwhile, “advising at least 30 minutes of sunshine per day to use sunscreen as needed, especially for first-degree relatives of patients with multiple sclerosis, may be a beneficial intervention. reduce its occurrence. ‘, she concludes.