• A recent study found that sun exposure in childhood and young adulthood may have a protective effect against multiple sclerosis (MS).
• Researchers found that participants who spent an average of 30 to 60 minutes outdoors daily had a 52 percent lower chance of developing MS.
• The study authors suggest that individuals who spend at least 30 minutes in the sun daily, particularly those who have a parent, sibling, or child with MS, may have a reduced risk of developing MS.

Children and young adults who spend more time in the sun may have extra protection against developing MS, according to a recent study.

Researchers reviewed questionnaires from 332 people with MS between the ages of 3 and 22 to evaluate their levels of sun exposure. Their responses were then compared against the questionnaire answers from 534 people who did not have MS. After adjusting for typical MS risk factors, such as smoking and being female, the researchers found that participants who spent an average of 30 to 60 minutes outdoors daily had a 52 percent lower chance of developing MS.

“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,” said Dr. Emanuelle Waubant, director of the UCSF Regional Pediatric Multiple Sclerosis Center, in a statement.

The study authors also found a link between the intensity of sunlight exposure and the likelihood of developing MS. They concluded that residents of Florida would be 21 percent less likely to have MS compared to those living in New York, for instance.

The boost in vitamin D levels, the direct result of sun exposure, may be the key to this discovery. Vitamin D is known to stimulate immune cells in the skin, which may have a role in protecting against diseases such as MS.

Dr. Waubant noted that using sunscreen does not appear to reduce sunlight’s effectiveness in preventing MS. Importantly, however, overexposure to ultraviolet (UV) rays can increase skin cancer risk. The Centers for Disease Control and Prevention (CDC) recommends that, when spending time in the sun, people use broad spectrum sunscreen with an SPF of 15 or higher. The CDC also suggests wearing clothing and accessories to limit direct sunlight exposure, including a brimmed hat, sunglasses, and clothing that fully covers arms and legs.