• Annualized relapse rate [ Time Frame: 9 months ] [ Designated as safety issue: No ]
• Changes in depression and fatigue symptoms on standardized questionnaires (Beck Depression Scale and Modified Fatigue Impact Scale). [ Time Frame: 9 months ] [ Designated as safety issue: No ]
• Changes in T2 lesion counts/volume, change in T1 hypointense lesion counts/volume, white matter volume and gray matter volume [ Time Frame: 9 months ] [ Designated as safety issue: No ]

Several investigations have suggested that polyunsaturated fatty acids may promote therapeutic effects in MS. This pilot study will determine whether omega-6 polyunsaturated fatty acids (PUFAs),in the form of linoleic acid,can reduce disease activity and prevent disability progression in patients with relapsing MS.This study will seek to measure disease activity as seen on MRI scans in addition to measuring relapse rates.

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.

Inclusion Criteria:

1. Relapsing MS
2. treated with FDA-approved dosage of interferon-beta (Avonex,Betaseron,Rebif), glatiramer acetate for at least 6 months OR no immunotherapy for at least 3 months
3. at least one clinical exacerbation or at least one gadolinium enhancing lesion on brain MRI in the past 12 months
4. at least two gadolinium enhancing lesions on three brain MRIs obtained during the placebo run-in period
5. women of childbearing potential may participate provided that they are using adequate birth control methods for the duration of the study. Women of childbearing potential must have a negative pregnancy test at baseline and be non-lactating.
6. willing and able to provide informed consent

Exclusion Criteria:

1. corticosteroids within 1 month prior to screening
2. treatment with other immunotherapies (other than interferon-beta, glatiramer acetate or sporadic corticosteroids) within 3 months prior to screening
3. any significant medical condition or laboratory abnormality which may interfere with the subject's ability to participate in the study, including peptic ulcer disease, avascular necrosis and hepatic insufficiency
4. history of hypersensitivity or intolerability to vegetable oils or their constituents
5. unable to perform any of the required study procedures