Previously, experts have linked low levels of sun exposure with the onset of conditions such as Parkinson’s, dementia, lupus, and Crohn’s disease. According to a new study from UC San Francisco, sunshine also has a protective effect against multiple sclerosis and other autoimmune diseases in children and young adults.
The analysis was focused on 332 individuals between the ages of three and 22 who had been recently diagnosed with multiple sclerosis. The researchers compared the participants’ locations and amount of sun exposure to 534 individuals without MS.
Among the participants who had been diagnosed with multiple sclerosis, 19 percent said they spent less than 30 minutes outdoors each day during the previous summer. At the same time, just six percent of individuals who did not have MS fell into this category of low sun exposure.
Ultimately, the researchers determined that participants who spent a daily average of 30 minutes to one hour outdoors had a 52 percent lower chance of multiple sclerosis compared to young people who went outside for less than 30 minutes per day.
Study co-senior author Dr. Emmanuelle Waubant, director of the UCSF Regional Pediatric Multiple Sclerosis Center, noted that sun exposure is known to boost vitamin D levels. “It also stimulates immune cells in the skin that have a protective role in diseases such as MS. Vitamin D may also change the biological function of the immune cells and, as such, play a role in protecting against autoimmune diseases.”
Multiple sclerosis usually emerges in adults between the ages of 20 to 50. However, up to five percent of the approximately one million MS patients in the United States begin experiencing symptoms in childhood.
Pediatric-onset multiple sclerosis takes longer than adults to advance, but debilitating symptoms that come along with disease progression – such as poor coordination and loss of bowel and bladder control – are reached approximately 10 years earlier.
The UCSF study also revealed that residents of Florida, who are exposed to a greater intensity of sunlight, are 21 percent less likely than residents of New York to develop multiple sclerosis.
According to the report, sun exposure is “dose-dependent,” (the longer the exposure the lower the risk). The researchers noted that even exposure in the first year of life seemed to protect against MS.
Fortunately, the use of sunscreen does not appear to lessen the therapeutic effects of sunlight in warding off MS, said Dr. Waubant. She added that clinical trials are needed to determine if increasing sun exposure or vitamin D supplementation can prevent the development of MS or alter disease course post-diagnosis.
“Advising regular time in the sun of at least 30 minutes daily especially during summer, using sun protection as needed, especially for first degree relatives of MS patients, may be a worthwhile intervention to reduce the incidence of MS.”
The study is published in Neurology, the journal of the American Academy of Neurology.