14 Research
The sunshine puzzle Sunshine and MS are definitely linked but, says Ian Cook, that’s the only thing we can know for certain
W
ith the days getting longer and the sun a little higher in the sky I have found myself reflecting more and more on the complicated and unresolved puzzle of sunshine and multiple sclerosis (MS). Since my diagnosis, 30 years ago in 1993, I have seen many theories about the causes of MS come and go. The lack of sunshine/vitamin D theory is one of them. In fact, the theory never goes away or gets disproved or proved. One might say the sun never sets on this theory.
In 2003, 10 years after I was diagnosed, I heard a Canadian neurologist, Prof. George Ebers, talk at a conference about a “latitude gradient” in MS. Basically, he was saying that the further away from the equator you go and the less sunshine you get, the more cases of MS you find. This is accepted as being as true today as it was in 2003, although no one really knows the reason why.
Sunshine mystery It was clear to Ebers that something in sunlight either
stopped MS developing or perhaps eased its symptoms. The question was, what was this thing? There were two possibilities. The first was vitamin D which is produced when the sun hits your skin. The other was sunlight itself, or to be more exact ultraviolet (UV) light, perhaps strong sunlight in the UVB band. It was argued this might be doing something to your body in addition to darkening or tanning your skin. For the past 20 years there has been an ongoing debate about which of these is responsible for the latitude
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17/03/2023 14:12