Does dietary supplementation of cod liver oil mitigate musculoskeletal pain?

Objective: To investigate the relationship between dietary supplementation of cod liver oil and the intensity of pain in people with musculoskeletal pain. Design: Cross-sectional study. Setting: Data from the Norwegian Health Survey 1985. Subjects: All adult respondents who had reported musculoskeletal pain (n=4490). Main outcome measures: intensity of musculoskeletal pain as assessed by self reports during an interview. Results: in logistic regression analyses (adjusting for age, gender, socioeconomic status, civil status, smoking habits, physical exercise, mental distress, and use of medicines), there was a negative association between regular intake of cod liver oil during the previous week and intense pain (OR=0.75; 95% CI: 0.56-1.00; P=0.048) and considerable-intense pain (OR=0.81; 95% CI: 0.67-1.00; P=0.045). The association was stronger in the 33% of the respondents who reported a musculoskeletal disease, as expressed by the relationship of cod liver oil to intense pain (OR=0.64; 95% CI: 0.43-0.95; P=0.028) and considerable/intense pain (OR = 0.74; 95% CI: 0.54-1.03; P=0.076). The association varied between diagnostic groups, and was not seen in people who did not report a musculoskeletal disease. Conclusion: The study suggests that people with musculoskeletal pain experience less pain if they take cod liver oil.