Half-hour walk a day can halve risk of developing this

By Mark Waghorn via SWNS

A half-hour walk every day can halve the risk of developing multiple sclerosis, according to new research.

Young people who spend most time outdoors are less prone, say scientists.

It adds to evidence vitamin D - produced during exposure to sunlight - has a protective effect.

The devastating neurological condition is more common in cloudier countries further from the equator.

Lead author Dr. Emmanuelle Waubant, of California University in San Francisco, said: "Providing guidance on the best amounts of sunlight exposure to get while weighing the benefits against the risks is challenging.

"We found spending between one and two hours outdoors daily provided the most benefit.

"But spending as little as 30 minutes outside daily may cut risk of MS roughly in half."

The UK government recommends all over fives take a daily Vitamin D supplement during autumn and winter.

Around a fifth of Britons are deficient in the nutrient. Between October and early March the strength of the sun's rays are too weak.

The study in Neurology was based on 332 children, teens and young adults in the US who had the disease for an average of seven months.

They were matched with 534 healthy peers of similar age and sex. Participants ranged in age from three to 22.

Those who spent an average of 30 minutes to an hour outside daily in the previous summer had a 52 percent lower chance of MS.

Those who averaged between one and two hours a day had an 81 percent reduced risk.

This was compared to peers who managed less than half an hour.

Smoking exposure, gender and other potential factors were taken into account. MS is more common in women - and smokers.

Dr. Waubant said: "It's important to note too much sun exposure without protection also has risks.

"Our study found that spending two hours or more outside daily did not further reduce the risk of MS compared to one to two hours."

The study also found those who lived in sunnier areas of the country - or had more sun exposure in their first year of life - also had lower odds of MS.

For example, someone living in Florida was 21% less likely to have MS compared to someone living in New York.

While rare, MS can develop in children. Most patients' symptoms start between the ages of 20 and 50

Sun exposure was measured as time spent outdoors and use of sun protection like a hat, clothing and sunscreen.

The amount of ultraviolet light was also calculated based on where participants lived at birth and at the time of the study.

The children or their parents or guardians answered a questionnaire about how much time they spent outdoors daily at various ages and in the past year.

In the summer before the study, 19% of the patients said they spent less than 30 minutes outdoors - compared to 6% of those who did not have MS.

And 18% of the patients spent one to two hours outdoors - compared to 25% of those without it.

Dr. Waubant and colleagues said the study does not prove sun exposure prevents MS - but shows an association.

Multiple sclerosis is an unpredictable, disabling disease of the central nervous system.

Symptoms range from numbness and tingling to blindness and paralysis. There is currently no cure. It affects women three times more than men.

It's estimated that about 1 million people in the US have MS.

Vitamin D is also found in small amounts in oily fish, eggs, meat, milk and margarine. Some cereals and yogurts are also 'fortified' with the nutrient.

The Multiple Sclerosis Society says: "We know MS is more common in countries further away from the equator.

"There are many possible reasons for this pattern. But researchers are particularly interested in the role that sunlight (and therefore vitamin D) could play in MS.

"In 2015 scientists demonstrated a clear link between low vitamin D and MS.

"They found people who naturally had lower levels of vitamin D (because of their genetics) were more likely to develop MS.

"Researchers in Oxford have also discovered vitamin D could affect the way a gene linked to MS behaves.

"They showed when vitamin D was present, the gene was more active. This groundbreaking research could help us understand more about the role vitamin D plays in developing MS."

It adds: "There is currently no evidence high vitamin D levels reduce the risk of developing MS."