I found these latest updates from Medcram really interesting. Most people know that MS incidence correlates with latitude and that low levels of Vitamin D may be a risk factor. The UV element in daylight is what helps us build up Vit D levels.
New evidence is showing that the Near Infrared element of daylight may be very important in reducing inflammation and oxidative stress in cells generally and in the brain in particular, and that daylight exposure levels appear to correlate with brain volume - ie. people with higher levels of daylight exposure with MS and in controls have larger brain volumes.
The updates carefully go through the science of it (and he is a master at explaining complex ideas in clear simple terms). I won’t try to do a simplified version here - you need to view his videos.
Infrared light actually penetrates the brain a few inches and bathes the cerebrospinal fluid, and can get deep into the grey matter. You don’t need to be in direct sunlight to get the benefit as infrared radiation is reflected off vegetation, and you can be clothed - it is why you feel warm in the sun.
The levels of infrared radiation people get nowadays are greatly reduced because most people spend a great deal of time indoors, where most window glass has Low E coating which stops it coming through the glazing. Also most of our light bulbs are LED or fluorescent rather than incandescent, and don’t emit much infrared. We also have central heating rather than fires. We get a tiny fraction of what even our grandparents got.
He did a long explanation first - it is almost 2 hours so probably listen in sections. I’m putting the link that jumps to where he talks about MS in particular.
He’s done a shorter version (25 mins) which covers the salient facts of the first but misses out the bit where daylight may relate to and be beneficial for people with MS. So if you are time or attention poor due to fatigue, then listen to that one.
I listened to part of the long version first, but ran out of time! I then listened to the whole of the shorter version, found it fascinating, and then went to listen to the whole of the longer version, and there came across the bit that is particularly relevant to MS.
I came across his channel through his coverage of Covid 19, which has included looking for simple things we can do to optimise our immune systems to fight off Covid better, but much is relevant to chronic illness and disease more widely. He has videos explaining oxidative stress, which I have found particularly enlightening. No politics, just pure medical science.