Background & aims: Although many patients with multiple sclerosis (MS) use special diets, the data available at present are insufficient to assess any potential benefit of diet modification. Cuprizone induced demyelination is a commonly used animal model for demyelination in the central nervous system.
Methods: The present study was designed to analyse behaviour and activity due to demyelination in mice fed with 0.2% cuprizone on three different diets. The diets consisted of (1) salmon fillets rich in marine n-3 polyunsaturated fatty acids (PUFAs), (2) cod liver oil rich in marine n-3 PUFAs, or (3) a control diet containing soybean oil rich in n-6 PUFAs. After 5 weeks of continuous cuprizone treatment, animal activity was assessed with the elevated plus maze (EPM) test. After 6 weeks the brains were fixated in paraformaldehyde and stained with luxol fast blue (LFB).
Results: There was significantly less demyelination in the salmon-cuprizone group than in the two other cuprizone-treatment groups (P<0.0005). The salmon-cuprizone mice had less weight loss (P<0.001) and showed more visits in both open and closed arms of the elevated plus maze than the other cuprizone-treated groups (P<0.0001). In addition they had more entries in the open arms than both the cod liver oil-cuprizone (P<0.02) and the soybean oil-cuprizone-treated mice (P<0.0001).
Conclusions: A diet containing salmon seems to protect against behavioural changes induced by demyelination in the cuprizone model, indicating that a fish diet could have a protective effect in demyelinating diseases.