I have a friend that has had non-diabetic neuropathy for several years and it seems to be getting worse as he can barely walk more than 100 yards or so. He is an older fellow (in his mid-70s) and is not about to radically change his diet at this stage of life. Are there any supplements that have a proven significant benefit for neuropathy and hopefully not just in relieving the pain, but more significantly the nerve damage that seems to be the proximate cause of the pain? Many thanks.