This randomised study evaluates the efficacy of an oral dietary supplement of Hydrolyzed Collagen in reducing pain and improving physical function in subjects with osteoarthritis.

In recent years, research efforts have focused on interventions such as collagen supplementation as an alternative treatment for pain and physical function in patients with osteoarthritis. Hydrolyzed collagen (HC) is a mixture of collagen peptides with a molecular weight of less than 5,000 Da. It is obtained from the gelatinization and subsequent enzymatic hydrolysis of native collagen from animal tissues rich in this protein. In this line, several studies show that HC is more easily absorbed enzymatically, has a higher bioavailability, is distributed to joint tissues, and has analgesic and anti-inflammatory properties, consistently showing symptom-relieving effects, thus improving joint function and reducing joint pain, as well as optimizing the patient's quality of life. In this randomized pilot study, the investigators aimed to evaluate the effect on pain and other parameters related to physical function of an oral dietary HC supplement composed of lemon flavoring, anhydrous citric acid (acidifier), calcium ascorbate (vitamin C), sucralose (sweetener) and stevia (sweetener). A 10.728 g dose provides 10 g of HC and 80 mg of vitamin C. Each placebo packet contained sucralose (sweetener) and stevia (sweetener) in identical proportions to the active preparation. Both the active and the placebo were manufactured by NutraResearch© SL (Barcelona, Spain) under Good Manufacturing Practices (GMPs).

Inclusion Criteria:

• Diagnosis of osteoarthritis according to the clinical and radiographic criteria of the American College of Rheumatology.
• Pain score of at a minimum of 50 mm on a VAS scale of 0-100 mm

Exclusion Criteria:

• Presence of a previous cardiovascular event in the last 6 months.
• History of liver or kidney disease.
• Presence of medical condition requiring chronic treatment with drugs or other substances.
• Excessive alcohol consumption (> 20 g/day) or substance abuse.
• Presence of intolerance or hypersensitivity to the food supplement or to any of its components in isolation.
• Use of any intra-articular injection in the anatomical area under study in the last 6 months.
• Treatment with symptomatic slow-acting osteoarthritis drugs (SYSADOA) in the last 3 months.
• Criteria listed in the Clinical Investigation Guideline for medicinal products used in the treatment of osteoarthritis published by the European Medicines Agency of the European Union in 2010 and radiographic osteoarthritis grade 4 according to the Kellgren-Lawrence classification system.
• Any condition that, in the opinion of the investigators, would disqualify the subject from participation in the study.