Influence of Blue Mussel ( Mytilus edulis) Intake on Disease Activity in Female Patients with Rheumatoid Arthritis: The MIRA Randomized Cross-Over Dietary Intervention

Nutrients. 2018 Apr 13;10(4):481. doi: 10.3390/nu10040481.


Rheumatoid Arthritis (RA) is a chronic inflammatory disease. This study evaluates the effect of blue mussel intake on disease activity and quality of life in women with RA. Thirty-nine women with established RA and a disease activity score 28 (DAS28) >3.0 were recruited to a randomized 2 × 11-week cross-over dietary intervention. The participants continued with their medication and habitual diet and exchanged one cooked meal a day, five days a week, with a meal including 75 g blue mussels or 75 g meat. Diets were switched after an eight week washout period. Data regarding quality of life (SF-36), blood lipids, erythrocyte sediment rate (ESR), C-reactive protein (CRP) and tender and swollen joints were examined at the start and end of each dietary period. Thirty women completed one period, and twenty-three completed both. Intake of the blue mussel diet led to a significant reduction of DAS28-CRP (p = 0.048), but not DAS28. The number of EULAR (European League Against Rheumatism) criteria moderate and good responders were higher when consuming blue mussel diet (p = 0.036). Blood lipids did not change. To conclude, blue mussel intake reduced disease symptoms in women with RA and improved perceived health. The reported effects need to be confirmed by non-patient reported outcomes, such as inflammation markers.

Keywords: DAS28; Mytilus edulis; diet; intervention; patient global health; quality of life (SF-36); rheumatoid arthritis; seafood.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Animals
  • Arthritis, Rheumatoid / diet therapy*
  • Biomarkers / blood
  • Cross-Over Studies
  • Female
  • Humans
  • Inflammation / diet therapy
  • Middle Aged
  • Mytilus edulis*
  • Quality of Life
  • Severity of Illness Index


  • Biomarkers