Participants who meet inclusion criteria will start placebo treatment by taking olive oil for 2 months. This period will include screening activities including 3 monthly MRIs. Those with 2 enhancing lesions on three placebo run-in period MRIs will continue in the study and receive omega-6 PUFA (linoleic acid) for 6 months. Brain MRIs will be repeated after 4,5, and 6 months after treatment.