In April 2020 researchers from Sweden published the results of their study to assess the effect of fish consumption on the risk of multiple sclerosis and also to what extent vitamin D may be able to reduce any risk. A total of 6,914 individuals with multiple sclerosis were involved in the study, plus 6,590 individuals with no history of multiple sclerosis, matched by age, sex and residential area, who acted as a control group. Information regarding environmental exposures and lifestyle factors were collected via questionnaire. Results showed that a low consumption of both lean and fatty fish was significantly associated with an increased risk of multiple sclerosis. There was also a significant trend showing increasing multiple sclerosis risk with a decreasing consumption of fatty fish. No significant sex differences were seen. A further analysis revealed that whilst fatty fish consumption resulted in higher vitamin D levels, there was only a borderline significant association between consumption of lean fish and vitamin D levels. However, no interaction was noted between vitamin D and fish consumption on the risk of multiple sclerosis. Individuals who had a low sun exposure appeared to have a higher incidence of multiple sclerosis, but again no interaction was observed between sun exposure and fish consumption with regard to risk of multiple sclerosis.
Hedström AK et al. Low fish consumption is associated with a small increased risk of MS. Neurol Neuroimmunol Neuroinflamm. 2020 Apr 10;7(3). pii: e717