Collagen supplementation and pain in knee osteoarthritis: a systematic review

Abstract

Abstract Background: Knee osteoarthritis is the most common type of arthritis and one of the leading causes of global disability. Pain is the most prominent symptom of the disease and the most disabling. The safety and efficacy of drugs that have traditionally been at the first line of treatment for pain in osteoarthritis have been questioned. Object: The purpose of this study was to review the evidence of oral collagen supplement’s impact on pain in patients with knee osteoarthritis. Method: The study was conducted as a systematic review following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. The databases of Pubmed, Epistemonikos, EMBASE and Web of Sciences were systematically searched for Randomized Controlled Trials that used oral collagen supplements as intervention in patients with knee osteoarthritis with measures of pain as outcome. The quality of the included trials was assessed with Helsebiblioteket`s checklist for Randomized Controlled Trials. Results: A total of 13 trials with 1367 participants were included. Only four of the trials were assessed to be of high methodological strength. The results revealed that 12 out of 13 trials reported significant reduction in pain outcomes when collagen supplements were compared against placebo. Conclusion: The findings from this study demonstrate that different types of oral collagen supplements can improve pain outcomes with significant effect compared to most placebos and control groups. The evidence is limited because of potential biases and few of the trials were conducted with optimal methodological strength. Further well designed Randomized Controlled Trials of robust methodology are needed to confirm our findings. Key words: Osteoarthritis, knee osteoarthritis, collagen, collagen supplements, pain