Osteoarthritis is one of the main health concerns of middle-aged and elderly populations due to its high prevalence. Osteoarthritis is the most common form of arthritis in the world. It causes moderate-to-severe disability in approximately 43 million people, making osteoarthritis the 11th most debilitating disease globally. The pathological changes of osteoarthritis can result in pain, joint contracture, malalignment, muscle weakness, and declining mobility. Research in the last decade has examined the potential clinical benefit of glucosamine and chondroitin, two structural components of cartilage, in the setting of osteoarthritis.  

Glucosamine may support joint function and cartilage health by being a substrate in the biosynthesis of proteoglycans in chondrocytes. Glucosamine may also help to decrease the synthesis of connective tissue proteolytic enzymes, support hyaluronic production in the synovial membrane, and promote a healthy inflammatory response. Chondroitin may help to promote cartilage repair, maintain the viscosity of the joint synovial fluid, and potentially stimulate chondrocytes to synthesize hydroxyapatite, proteoglycans, and collagen.  

A systematic review and meta-analysis examined the effects of glucosamine supplementation alone or in combination with other bioactive compounds (including chondroitin sulfate) on various pain scores for individuals with knee osteoarthritis. Eighteen randomized controlled trials were included. They varied between 18 to 630 subjects, ranged from 6 weeks to 2 years of observation time (with 12 weeks being the most common), and most studies administered 1,500 mg per day of glucosamine. The researchers concluded that the groups who received glucosamine supplementation showed a generally favorable effect on pain scores compared to a placebo. Moreover, the researchers highlighted that since chondroitin may also assist in healthy inflammatory responses and joint health, there may be a synergistic effect between glucosamine and chondroitin. The six studies that used a combination method of glucosamine and chondroitin exhibited a larger effect on pain scores compared to studies examining glucosamine alone.  

The potential clinical relevance of combined glucosamine and chondroitin in the presence of osteoarthritis has been further researched. One systematic review and meta-analysis (n = 1,067) concluded that individuals supplemented with a combination of the two showed a statistically significant impact on Western Ontario and McMaster Arthritis Index (WOMAC) pain scores for those with knee osteoarthritis, whereas the other groups showed no significance. Another systematic review and meta-analysis (n = 764) stated the combination of glucosamine and chondroitin is more effective in lowering joint pain, tenderness, swelling, and dysfunction in patients with knee osteoarthritis than chondroitin or glucosamine alone. However, other clinical trials have concluded mixed results.  

Further research is needed to elucidate the clinical benefits of combining glucosamine and chondroitin for those with osteoarthritis. Together, the two compounds may play a synergistic role in supporting overall joint and cartilage health.  

By Danielle Moyer, MS, CNS, LDN