While this deviates from the subject I have read that if you have metal fillings from dental work they can be bad for MS. Myth says that they should be replaced with non metalic the fillings they use now. I have also heard sleeping on a magnetic matress can help reduce frequency???
You already answered your own question... "Myth". Let's think about
it...if it were true that the mercury used in fillings would be bad for MS (or cause MS...the more common "myth"), wouldn't every dentist and certainly every dental technician HAVE MS? After all, they're poking and prodding and dislodging bits of the stuff every time they dig around in someone's mouth!
The truth is -- you end up getting exposed to a lot more mercury by having all your fillings removed and replaced, than if you left them alone (assuming they're in good condition and not breaking apart .. which your dentist should be telling you, when you get your annual or semi-annual exam, and they'd need replacing for good oral health).
There's no truth to either of these. If you go to snopes (the link I provided above) and search for them, you'll find them debunked as well.
...I am not a doctor, nor health professional, and don't pretend to be one, here.....