Effect of Agar/Collagen-based Compounds on Osteoarticular Pain: Randomized Triple-blind Clinical Trial

Inclusion Criteria: * Men and women between 40 and 70 years of age. * Submit a score of 6 to 10 out of 20 on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) knee pain questionnaire. * Sign the informed consent form. * Know how to read, write, and speak Spanish and/or Catalan. Exclusion Criteria: * Present body mass index (BMI) values \<18.5 kg/m\^2 or ≥30 kg/m\^2. * Present intolerances or allergies related to Agar-Agar, or any of the components of the products being evaluated, such as collagen or maltodextrin. * Take or have taken medications that may affect the study results. This is especially true for those who have been treated with oral or intra-articular corticosteroids within the 4 and 12 weeks prior to screening, respectively, or medications for osteoarthritis at the time of screening. * Patients who depend on prescription medications for pain control. * Take multivitamin or mineral supplements, collagen derivatives, or supplements containing bioactive compounds that may exert an anti-inflammatory effect, such as turmeric, ginger, omega-3, or polyphenol supplements. (Individuals who consume multivitamin, mineral, or collagen-derived supplements or supplements will be eligible to participate in the study, provided they are willing to discontinue their intake for at least two weeks prior to the start of the study and throughout the entire study period). * Be an active smoker or have been one for less than 6 months. * Alcohol consumption: * Men: Consume 4 or more Standard Drink Units (SDU) daily or SDUs weekly. * Women: Consume 2 or more Standard Drink Units (SDU)\* daily or SDUs weekly. * Have a diagnosis of osteoarthritis, active rheumatoid arthritis, and any inflammatory arthritic condition such as secondary inflammatory arthritis, gout, pseudogout, knee infection, marked angular deformities, or significant injury to the target joint within the 6 months prior to the start of the trial; arthroplasty and joint surgery of the target knee within the 2 years prior to the start of the study. * Have any gastrointestinal disease that affects the absorption of the compound and/or the study results, such as celiac disease, Crohn's disease, active cancer of any organ of the digestive or renal system, or hepatitis. * Be ineligible to participate in the study, according to the pre-screening evaluator's criteria. * Have lost 3 kg or more in the last 3 months. * Be pregnant or intend to become pregnant. * Be breastfeeding. * Be unable to follow the study guidelines. * Be participating or have participated in a clinical trial involving drug intervention or nutritional intervention within the last 30 days prior to inclusion in the study.