The aim of this study was to determine the effect of omega-3 on the painful symptomatology of osteoarthritis (OA) in synovial joints.
An electronic/manual search was conducted (2004-2019). Using pain as a primary outcome and stiffness/function and swelling as secondary outcomes, based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria, Consolidated Standards of Reporting Trials (CONSORT) reporting quality, and Cochrane/RoB-2 risk of bias assessment. Data were processed using RevMan v5.2 (Cochrane Collaboration).
Six randomized controlled trials were selected. The study population included 454 patients with OA. In 4 studies the pain in the intervention group presented significant pain reduction compared with the control group (mean difference = 22.89; 95% confidence interval, 3.37-42.42). Studies did not stablish the effective anti-inflammatory dose. The number of studies on stiffness/function and inflammation was low (n = 2). The evidence and degree of recommendation was 2B. The randomized controlled trials presented high clinical and methodological variability.
Omega-3 can significantly reduce painful symptoms in patients suffering from OA in synovial joints. However, the limited number of studies, range of doses, intervention periods, baseline characteristics of patients, and asymmetry in reporting bias, combined with the heterogeneity in the combined effect of the studies, offer low-quality evidence on which clinical guidance cannot be based.