Supplementation with omega-3 fish oil has no effect on bone mineral density in adults with knee osteoarthritis: a 2-year randomized controlled trial

Chen JS, Hill CL, Lester S, Ruediger CD, Battersby R, Jones G, Cleland LG, March LM · Osteoporosis International

The bone-density arm of the two-year high-versus-low-dose fish oil trial, and it is null: no difference in lumbar spine (3.7 mg/cm², 95% CI −7.9 to 15.3) or femoral neck BMD (−5.5, 95% CI −14.9 to 3.9) after adjusting for baseline, and the null held across every sensitivity analysis (all p ≥ 0.25). Mild headache and GI intolerance were common in both arms and no more frequent in either.

Population

202 Australians aged 40+ with knee osteoarthritis, mean age 61, 49% female

Intervention

High-dose fish oil, 4.5 g/day EPA + DHA, for 2 years

Comparator

Low-dose fish oil, 0.45 g/day

Limitations

The comparison is high dose against low dose, not against placebo, so a shared effect would be invisible. Bone density is not a cartilage endpoint. Registered ACTRN12607000415404.