Yeti, I'm one person who succeeded with the Swank MS Diet. I know i succeed with it because of the bad things that happen (symptom wise) when I get off it, which I occasionally do for various reasons. Now does the Swank diet help me for another reason than MS? I don't know, but Dr. Swank's idea was that MS was an attack on fat cells, including myelin, an autoimmune attack on them. Now in my case it is possible that I react to fat from other reasons (with neuro symptoms). I have no way to tell and no one to ask. I don't know any neurologists whom I could ask as they would not know.
You may ask, do I have myelin damage shown on MRI? Yes, many years ago when I first got a dx. Also Visual Evoked Response and Visual Fields tests, also abnormal, eye symptoms later normal on next tests, although Myelin remained damaged (and spots moved) over the several years I was going to MS neurologists. I finally quit going to them because I got another dx which can produce neuro symptoms although it can produce other ones as well. But I didn't quit because I lost my MS dx--no doctors still varied on whether I had MS or not. No one was sure. But I did have the typical brain spots we all have heard about and which most of us have. I'm old now, but when I got my dx it was a LONG time ago, almost 30 years. And all that time I've been on the Swank. And all that time I got worse if I got off it.
Now I have a rare blood disease called Polycythemia Vera, so all diagnostic bets are off as to what is causing what. But I am still on the Swank diet.
Dr. Swank also thought that "something is missing in MS blood" but he was never able to finish research on that. He was, after all, very old, and underfunded. The underfunding of Dr. Swank is not my idea of intelligence.