Scientists from the University of Newcastle in New South Wales, Australia report that 16 weeks of supplementation with fish oil (2.4 grams per day of EPA+DHA) led to significant improvements in osteoarthritis-specific pain and burden, compared with no fish oil treatment.
The positive effects were correlated with improvements in microvascular function and well-being, wrote the scientists in the journal Rheumatology Advances in Practice.
However, when curcumin was used, either alone or in combination with the fish oil, pain measures were unaffected.
This study was sponsored by the Blackmores Institute, which also supplied the supplements used in the study: Blackmores Omega Brain (fish oil) Blackmores Brain Active (curcumin)
“Cautiously optimistic”
Commenting independently on the study’s findings, Harry Rice, PhD, VP of regulatory & scientific affairs for the Global Organization for EPA and DHA Omega-3s (GOED), told us: “I remain cautiously optimistic that further research will demonstrate a benefit of fish oil for reducing osteoarthritis-specific pain in the population studied.
“This was an exploratory analysis, so you don't want to jump to conclusions. Given the qualification of the results and discussion of the limitations, the authors and I appear aligned. I look forward to the investigators' follow up research in this area,” added Dr Rice.
Study details
Julia Kuszewski, Rachel Wong, and Peter Howe recruited 152 sedentary older adults (aged between 50 and 80) to participate in their randomized, double-blind, 2 × 2 factorial, placebo-controlled intervention. Participants were randomly assigned to one of four groups: placebo, fish oil (2,000 mg/day DHA + 400 mg/day EPA), curcumin (160 mg/day), or a combination of fish oil plus curcumin for 16 weeks.
Results showed that, for the 134 participants who completed the study, those receiving fish oil reported a significant reduction in osteoarthritis-specific pain and burden, compared to no fish oil. Osteoarthritis-specific burden relates to physical distress, sleep disturbance, psychological distress, loss of productivity, physical limitations, and financial hardship.
Kuszewski, Wong, and Howe found that fish oil supplementation was associated with increases in the small artery elasticity index (which they used as a surrogate marker for microvascular function).
“Clinical trials have shown that fish oil supplementation can enhance flow-mediated dilatation, a marker of endothelial function,” they wrote. “The improved endothelium-dependent vasodilatation after fish oil supplementation might improve perfusion to previously hypoxic tissues, restoring the oxygen and nutrient supply in affected joints, thereby reducing ischaemic pain.”
Curcumin, alone or combined with fish oil, had no effect on pain measures, said the researchers.
“Further studies are warranted to evaluate the benefits of DHA-rich fish oil, alone or as an adjunct to pharmacotherapy, in patients diagnosed with [osteoarthritis] who suffer moderate-to-severe pain, to investigate the mechanisms underlying the potential pain-reducing effects of DHA-rich fish oil and to identify [osteoarthritis] patients who might benefit from curcumin supplementation,” they concluded.
Source: Rheumatology Advances in Practice
Volume 4, Issue 2, rkaa036, doi: 10.1093/rap/rkaa036
“Fish oil supplementation reduces osteoarthritis-specific pain in older adults with overweight/obesity”
Authors: J.C. Kuszewski, et al.