High Sun Exposure During Childhood May Lower Risk of MS, Study Finds

High Sun Exposure During Childhood May Lower Risk of MS, Study Finds

People who live in areas with medium to high levels of ultraviolet-B (UV-B) radiation from sunlight during their childhood and early adolescence, or in the years preceding the age of onset of multiple sclerosis (MS), have a lower risk of developing the disease, according to researchers.

The study’s findings were reported in an article titled “Sun exposure over the life course and associations with multiple sclerosis,” published in the journal Neurology.

Researchers examined data from the Nurses’ Health Study, an international study with thousands of participating nurses intended to provide insights into women’s health. There were 151 women with MS included in the study, and 235 healthy women were selected as age-matched controls.

All participants completed questionnaires about their summer, winter, and lifetime sun exposure history.

Participants were divided into three groups according to their level of exposure to ambient UV-B from sunlight before the age of MS onset — low, medium, and high levels of exposure. The level of UV-B exposure was associated with the place where participants lived during different periods of their lives because latitude, altitude, and cloud cover can affect the amount of UV radiation people are exposed to in a given region.

Seasonal sun exposure was defined as low, with nine hours per week or less in summer, and three hours a week or less in winter; or high, with more than 10 hours per week in summer, and more than four hours a week in winter.

The vast majority of participants were Caucasian, at 98 percent, with a mean age of 39.5 years at MS onset.

Living in medium or high UV-B areas in the years before MS onset was generally associated with a 45 percent lower risk of developing the disease.

The risk was also lower, by 51-52 percent, for people living in regions of medium or high exposure from ages 5 to 15 and at five to 15 years before MS onset.

Living in a high UV-B area and also having high sun exposure in the summer was associated with a lower MS risk.

The team pointed out that once people develop MS, they tend to spend less time outdoors, which may have an impact on their health.

“Reduced sun exposure was evident in later life for patients with MS, which may have health consequences,” the researchers wrote.

“Living in high ambient UV-B areas during childhood and the years leading up to MS onset was associated with a lower MS risk. High summer sun exposure in high ambient UV-B areas was also associated with a reduced risk,” the team concluded.


  1. Mike says:

    Well I was always outside as a kid playing baseball in spring n summer among other things. 1st diagnose with M.S. at age 15 loss sensation in right hand. M

  2. Marc says:

    High vitamin D levels are profoundly associated with a reduced risk of MS. However, there is little indication that intake of vitamin D from foods or supplements lessens MS risk. However, there is little doubt that sun exposure is also profoundly associated with reduced MS risk. Too many scientists have stated that the reason for the obvious inverse relationship between sun exposure, vitamin D levels and MS risk, is the production of vitamin D caused by the sun exposure. It is likely that that high vitamin D levels are really acting as a surrogate measure for sun exposure, and that sun exposure reduces the risk of MS by some other photoproduct. Vitamin D is simply along for the ride.
    For example, sun exposure also produces serotonin, endorphin, dopamine, nitric oxide and BDNF. BDNF is a vitally important photoproduct of sun that is essential for health of the nervous system. It could be that the sun’s protective effect is due to BDNF production. More research needs to be done on that subject. In the meanwhile, be sure to obtain your share of safe, non-burning sunlight, and drop the sunscreens.
    For more information visit the Sunlight Institute at sunlightinstitute.org

  3. Janice says:

    what a joke I had more sun than most and still Diagnosed with MS by age 40. I lived outside Riding horse, working dogs and working with many outside animals so the findings are wrong!!!!!!!!!!!!!!!!!

  4. Kathleen Larson says:

    I’m one that falls in this category as far as sun exposure & I have Secondary Progressive MS. I sure wish this was true for me 🙂

  5. Sarah Doganieri says:

    I lived on the beach during the summers. I have other ideas as to what caused my MS. Somebody ought to to take a complete history of people with MS.

    I had Black measles aka Rocky Mountain Spotted Fever as a child. Serious hormone imbalance after birth of a child st 21. Hysterectomy at age 31. Disgnosed with MS at age 42 while in menopause.

    Always wondered if these might have contributed.

  6. Rodger Ashton-Smith says:

    I have had a good summer time as a young person and now can’t stand a high temperature as it causes my fatigue to get worse. It seems to be like related by having an accident that cause MS so I don’t see a connection to get MS for any extermers causes or any inner damage that has be done. My wife has had a lot of problems from abuse from her father and friends from an early age to 22 years and lots of operations and she has not got MS, I have, so previous problems do not bring on MS. It comes from a genetic system as been found if you have any links back to the French/German area you may get it, but if you don’t you won’t get it.

  7. Lynda - says:

    In which countries was this research conducted? Living in Cape Town, I was exposed to ultra high sun exposure all my life for 8 – 9 months of the year. First MS attack in 1981 and then nothing until 1992. Even now I am outside in the spring and autumn (fall) before it gets too hot with temperatures hitting over 30C

  8. Debra Apple says:

    It seems to be like related by having an accident that cause MS so I don’t see a connection to get MS for any extermers causes or any inner damage that has be done.

  9. Mary Ann Cincinnati says:

    I was mostly outdoors when I was a kid and I also drank plenty of milk because I hated water. I have PPMS and in a wheelchair.

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