Chondroprotective Effects of Avocado/Soybean Unsaponifiables Versus Glucosamine–Chondroitin Sulfate: A Comprehensive Review of Preclinical and Clinical Evidence.

Background: Osteoarthritis (OA) is the most prevalent degenerative joint disorder, characterized by progressive loss of articular cartilage, subchondral bone remodeling, synovial inflammation, and chronic pain. Conventional pharmacological options, including nonsteroidal antiinflammatory drugs (NSAIDs) and corticosteroids, primarily target symptoms but fail to halt or reverse cartilage degradation, often resulting in adverse effects with long-term use. Nutraceuticals such as glucosamine and chondroitin sulfate have been widely investigated as diseasemodifying osteoarthritis drugs (DMOADs), with evidence suggesting moderate symptomatic relief and potential structural benefits. More recently, avocado/soybean unsaponifiables (ASU), a natural extract comprising one-third avocado and two-thirds soybean oil, have emerged as a promising chondroprotective agent with anti-inflammatory, anabolic, and anticatabolic properties. Preclinical studies and clinical trials have indicated that ASU may modulate cartilage metabolism, reduce pro-inflammatory mediators, and enhance extracellular matrix synthesis, providing a complementary or alternative therapeutic strategy for OA management. This review aims to critically evaluate and compare the chondroprotective efficacy of avocado/soybean unsaponifiables with that of the established glucosamine–chondroitin sulfate combination. By synthesizing evidence from preclinical models and clinical trials, we explore their mechanisms of action, therapeutic outcomes on cartilage integrity, pain reduction, functional improvement, and safety profiles. Particular emphasis is placed on the differential modulation of inflammatory pathways, matrix metalloproteinase activity, and structural progression of OA. Conclusion: Evidence suggests that both ASU and glucosamine–chondroitin exert beneficial effects in the management of OA, with potential disease-modifying properties beyond symptom control. Glucosamine–chondroitin remains the most extensively studied nutraceutical combination, with documented clinical efficacy in reducing pain and improving joint function, though variability in study quality and patient response limits universal recommendations. ASU, by contrast, has demonstrated robust chondroprotective and anti-inflammatory activity in preclinical research and encouraging clinical trial outcomes, particularly in slowing joint space narrowing and reducing NSAID dependence. While comparative head-to-head trials remain limited, emerging data suggest that ASU may offer equivalent or even superior benefits in terms of structural preservation and long-term safety. Further large-scale, standardized clinical studies are warranted to establish optimal dosing regimens, long-term efficacy, and potential synergistic use of these nutraceuticals. [ABSTRACT FROM AUTHOR]