Note: I am not a medical professional, the following information is my opinion based off of my own research and experiences. Always consult with a doctor before making drastic dieting choices.
Dieting can play a huge role in battling Multiple Sclerosis in fact, for some people, a good diet is all they need to beat most their symptoms and prevent further flare ups. But right off the bat I want to mention something I have said many times before: Everyone is different - MS effects everyone differently - Medications effect everyone differently. What works for one person might not work for you. What works for you might not work for someone else.
When I relapsed a second time I really started looking into dieting more closely as at the time I was simply avoiding junk foods and other unhealthy items that no one should really be eating to stay healthy. I wanted to take it to the next level, learn about dieting, and put myself back into remission. At the time all I really knew is that I wanted to avoid foods with high inflamatory properties but I didnt really have a clear idea of what exactly I should be eating and avoiding. So I started looking up specific diets that people with Multiple Sclerosis tend to follow. Here are the main ones:
The Best Bet Diet
The Paleo Diet
The Swank Diet
If you are just starting your quest to find yourself a proper diet this is where you want to start. All three diets are very similar and very popular but they do have some minor differences in opinion of what is "good" or "bad". I went through each diet and created a list of "goods" and "bads" and then created a separate list of "goods" and "bads" that were in all three diets and I chose to eat and avoid those foods for a while.
Here is where the "everyone is different" concept comes into the picture. Though a healthy diet is good for you regardless of your current health condition I have come to the realization that food is not a "trigger" for everyone. A lot of people claim that when they eat certain foods with certain properties they can feel negative effects kick in almost immediately. After doing much "self-testing" and experimenting" it is starting to look like food doesn't really effect me at all. I have been keeping a daily journal of what I eat and what symptoms I experience and looking back I can see that my symptoms havn't really changed at all when comparing a week of strict dieting to a week of Red Robins, steak, and a few sweets. I have tried eating large amounts of everything your not supposed to eat when on these diets and have seen no flare ups in my symptoms and when I am strict about my diet I also see no improvements.
So again, everyone is different and for me dieting does not seem to be the secret to concurring an exacerbation. I am still going to continue eating healthy but I probably am not going to be as strict on certain things like potatoes or gluten. My obvious triggers seem to be limited to heat and stress at the moment: when I am in a hot area or stressfull situaton my symptoms flare up almost immediately which is something I have yet to experiance with food.
So how will you know what works for you? Trial and error. Look at the three diets mentioned above and try them out for a few weeks. See if you feel any different. Do what I did and keep a daily journal of everything you ate and the symptoms you experienced day by day. After a few weeks see if there has been any noticeable changes or patterns in you eating and symptoms. You can also go to the doctors and get a food allergen test done to see if you have any obvious allergies to different foods.
Either way you go, you won't know till you try something and when it comes to dieting it might take you a while to find the right one in fact, you might find that certain aspects of certain diets apply to you and others don't. In the end you will probably end up creating your own, personalized, diet as you slowly learn which foods are good for you and which foods cause you problems.
Trial and Error, Good Luck!