Researchers have examined the association between fish consumption and the risk of multiple sclerosis (MS) using data from the MS Sunshine Study. The multi-ethnic matched case-control study of incident MS or its precursor, clinically isolated syndrome (CIS), was conducted in a Southern Californian population.
Oily fish is the best dietary source of vitamin D and omega-3 polyunsaturated fatty acids (PUFAs), both of which may play a protective role in MS.
Information on fish consumption over the 12 months prior to symptom onset (567 cases and 618 controls) were collected using two questions in a structured questionnaire. The research team used logistic regression models to test associations between fish consumption and MS or CIS, adjusting for age, sex, race or ethnicity, history of infectious mononucleosis, education, smoking and deseasonalised vitamin D levels, as monitored using the serum 25-hydroxyvitamin D test.
Researchers found that compared with fresh fish consumption once per month, consuming fresh fish 1-3 times per month, or once per week or more was associated with a 29% reduced risk of MS or CIS. However, they did not find any statistically significant association between consuming shrimp, canned or dried fish and the risk of MS or CIS. No multiplicative interaction of fish consumption with race or ethnicity on risk of MS or CIS was detected.
Researchers concluded that these results support a protective effect of fresh fish consumption and decreases the risk of MS independent of vitamin D status and race or ethnicity. They said: “Future studies should elucidate whether specific components of fish (namely omega-3 PUFAs) are protective or whether the replacement of other potentially detrimental foods are factors in reducing the risk of MS.”