Summary

Oral collagen-based supplements have been proposed as candidates for treating symptomatic osteoarthritis. However, as part of the nutraceuticals family and the lack of a standardized treatment of this relatively novel approach to treat osteoarthritis, suspicion about its real therapeutic effectiveness is imminent.

Abstract

Background. Osteoarthritis (OA) is one of the most common causes of disability and a prevalent chronic disease. Oral collagen-based supplements have been proposed as candidates for treating symptomatic OA.
Objective. The aim of the present meta-analysis was to evaluate the effect of collagen-based supplements on OA symptoms.
Methods. PubMed-Medline, Scopus, and Google Scholar databases were searched for randomized placebo-controlled trials evaluating the effect of orally administered collagen on OA symptoms using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scale and/or the Visual Analog Scale (VAS). Meta-analysis was conducted using a random-effects model and generic inverse variance method. Heterogeneity was tested using the I2 statistic index.
Results. Collagen treatment showed a significant reduction in the score of total WOMAC index (WMD: -8.00, 95% CI: -13.04, -2.95, p=0.002). After subgroup analysis of the WOMAC subscores, the collagen supplementation revealed a significant decrease in the stiffness subscore (WMD: -0.41, 95% CI: -0.74, -0.08, p=0.01), whereas the pain (WMD: -0.22, 95% CI: -1.58, 1.13, p=0.75) and functional limitation (WMD: -0.62, 95% CI: -5.77, 4.52, p=0.81) subscores did not have significant differences. Finally, a significant reduction was found in the VAS score after collagen administration (WMD: -16.57, 95% CI: -26.24, -6.89, p<0.001).
Conclusion. The results of this meta-analysis showed that collagen is effective in improving OA symptoms by the decrease of both total WOMAC index and VAS score.