Polyunsaturated fatty acids in multiple sclerosis therapy

Results from epidemiological and uncontrolled intervention studies in multiple sclerosis (MS) suggest a beneficial disease-modifying effect of increased intake of polyunsaturated fatty acids (PUFAs).

To review the current evidence from animal studies and randomised controlled trials on the therapeutic effect of PUFAs in MS.

We searched PubMed and Medline for articles using the terms 'polyunsaturated fatty acids', 'eicosapentaenoic acid', 'docosahexaenoic acid', 'linoleic acid', 'linolenic acid', 'omega-3' and 'omega-6' combined with 'multiple sclerosis', 'randomised controlled trials', 'animal models', 'experimental autoimmune encephalomyelitis' and 'cuprizone'. The abstracts of retrieved citations were reviewed and checked for relevant content.

There was some evidence from animal model studies indicating an effect of ω-6 PUFAs, while the results from randomised controlled trials (RCTs) indicated that the ω-6 PUFAs linoleic acid or γ-linolenic acid have no beneficial effects on clinical disease activity in MS. However, the identified studies had several limitations in design with a mixture of relapsing-remitting and progressive MS patients. No studies investigated ω-6 efficacy on MRI disease activity. For ω-3 PUFAs, there was conflicting results from animal studies. RCTs show no beneficial treatment effect of the ω-3 PUFAs eicosapentaenoic acid and docosahexaenoic acid on MRI or clinical disease activity in MS.

Randomised controlled trials of PUFA intervention provide no evidence of beneficial effects from ω-3 or ω-6 PUFAs on relapse rate, disability progression or MRI disease activity in MS.