Mussel lipid extract and rheumatoid arthritis symptoms in people
What it found
In 50 people with rheumatoid arthritis, those who took a mussel lipid extract for 6 months had greater improvements in disease activity scores than those who took a placebo.
The extract also changed some inflammatory markers in the blood.
What they found
Studies in people
Disease activity scores
After 6 months, the mussel extract group had a larger drop in DAS28 and CDAI scores than the placebo group. In the per-protocol analysis, the DAS28 fell by 0.47 more and the CDAI by 4.17 more in the mussel group.
Joint and stiffness symptoms
Tender joint count, swollen joint count and morning stiffness improved more in the mussel extract group than in the placebo group. Both groups improved over time, but the mussel group had a larger degree of improvement.
Inflammatory markers
Blood levels of TNF-α and PGE2 dropped more in the mussel extract group than in the placebo group after 6 months. IL-10, an anti-inflammatory cytokine, rose more in the mussel group. IL-1β fell in both groups with no difference between them, and IL-6 did not change significantly in either group.
Fatty acids in blood
The mussel extract group had a significant increase in omega-3 fatty acids (DHA and EPA) in red blood cell membranes. The placebo group had no significant change in these fatty acids.
Side effects and safety
No serious adverse events related to the oil supplements were seen in either group. Some patients reported mild nausea, vomiting or loss of appetite, but the frequency was similar between groups and it was not certain if these were related to the supplements. Liver enzyme elevations occurred in a few patients in both groups.
What the authors conclude
“In conclusion, present results suggest that HMLE supplementation was safe and had significant beneficial effects in improving clinical disease activity of patients with active rheumatoid arthritis.”
Also in their conclusions
- They conclude that HMLE supplementation was safe and had significant beneficial effects in improving clinical disease activity of patients with active rheumatoid arthritis.
- They suggest that the improvement in the balance between pro- and anti-inflammatory factors may serve as the mechanism.
- They advise that more multi-center and long-term studies with larger sample sizes are needed to confirm their observations.
How it was done
The authors wanted to see whether a lipid extract from hard-shelled mussel, which had shown anti-inflammatory effects in rat models of arthritis, could improve clinical conditions in people with rheumatoid arthritis.
Fifty rheumatoid arthritis patients aged 28 to 75 were randomly assigned to take either mussel lipid extract capsules or placebo capsules for 6 months. Forty-two patients completed the study. Disease activity was measured with DAS28 and CDAI scores, and blood inflammatory markers were tested.
What it can’t tell you
- This was a single-center trial with a small number of patients, so the results may not apply to everyone with rheumatoid arthritis.
- Patients continued their usual arthritis medications during the study, so the added benefit of the mussel extract alone cannot be separated from the effects of those medicines.
- The study lasted only 6 months, so longer-term effects or risks are not known.
Who paid
- Authors work at
- Zhejiang University, China; Zhejiang Sir Run Run Shaw Hospital, China; The General Hospital of Chinese People's Army Police Force, China
The paper
- Title
- Lipid extract from hard-shelled mussel (Mytilus coruscus) improves clinical conditions of patients with rheumatoid arthritis: a randomized controlled trial
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Fu Y, Li G, Zhang X, et al (2015). Lipid extract from hard-shelled mussel (Mytilus coruscus) improves clinical conditions of patients with rheumatoid arthritis: a randomized controlled trial. Nutrients. doi:10.3390/nu7010625Free full textPubMed 25602164DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error