RESUMEN
PURPOSE: Knee osteoarthritis (OA) is the most common form of clinical arthritis in middle-aged and older individuals. Undenatured or native type II (TII) collagen derived from the chicken sternum has a good therapeutic effect on relieving severe pain of OA. Hence, the present study aimed to investigate the efficacy and safety of TII collagen (Native CT-II®) in individuals with knee OA. METHODS: We conducted a 12-week randomised, double-blind, placebo-controlled, parallel-group study on 101 participants aged 40-65 years with knee OA. The participants were randomised to receive either TII collagen, glucosamine hydrochloride + chondroitin sulfate (G + C) or a placebo. The primary outcome was an improvement in the joint health of the participants assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) compared to G + C and placebo. RESULTS: Compared with the placebo group (n = 27), the TII collagen group (n = 29) and G + C group (n = 29) significantly improved the overall joint health measured by the change in WOMAC total score (week 12: TII collagen = -32.47 ± 19.51 and G + C = -33.74 ± 24.64 vs. placebo = -13.84 ± 17.61; p < 0.05) and relieved knee joint pain (week 12: TII collagen = -5.69 ± 3.66 and G + C = -6.03 ± 4.72 vs. placebo = -2.71 ± 3.95; p < 0.05). The statistically significant effect was observed as early as 4 weeks after the investigational product administration. Additionally, the TII collagen was more effective in improving the quality of life than the G + C. CONCLUSION: TII collagen not only has a significantly better effect and high safety profile for OA but also improves the quality of life of patients. LEVEL OF EVIDENCE: Level 1 - Randomized Controlled Trial. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04470336 ; First submitted date: July 08, 2020; First posted date: July 14, 2020.
RESUMEN
Undenatured (native) type II collagen is a dietary supplement ingredient reported to support joint health in healthy individuals by providing relief from symptoms of stiffness and discomfort and improving mobility. This benefit is thought to occur through oral tolerance, a mechanism whereby the immune system distinguishes between innocuous material in the gut and potentially harmful foreign invaders. The presence of antigenic epitopes in undenatured type II collagen, but not in denatured (hydrolyzed) collagen, is thought to be the basis for the therapeutic benefits. The purpose of this study was to investigate the physicochemical and analytical characteristics of type II collagen supplements currently available on the market and to explore whether they might be sufficiently similar in their physical properties to yield similar benefits in promoting joint health. Collagen type II supplement powders (raw material) and capsules (products in the market) were examined for color, particle size, quality profiles, fatty acid profiles, electron microscopy, and were analyzed for amino acid content as well as antigenic potential via an ELISA assay. Powders labeled as undenatured type II collagen were found to have markedly different properties, including the size of collagen fibers as per electron microscopy and antigenic configuration as per the ELISA assay. As significant differences were found between products, it allows consumers and practitioners to not assume that products labeled as undenatured (native) type II collagen are interchangeable.