While it is present in the walls of blood vessels, chondroitin sulfate's main role is in keeping cartilage fluid and elastic. It is found naturally in the body where it is one of the critical compounds that makes up connective tissue. Connective tissue is responsible for building and supporting cartilage found in the joints and elsewhere.
Glucosamine is an amino-sugar that is naturally produced in humans. It is the key building block in the synthesis of glycosaminoglycans, hyaluronic acid and proteoglycans. These substances are the foundation of many of the body's tissues including tendons, ligaments, cartilage, collagen, basement membranes, mucous membranes of the digestive system, membranes in the respiratory tract, and synovial fluid in the joints. Proteoglycans are proteins that make up the connective tissue of cartilage giving joints their elasticity, strength, and resilience.
A recent study has found that supplementation with glucosamine and chondroitin lowered the overall risk of death. The study included 77,719 participants who completed questionnaires to determine supplement usage and were then followed for an average of five years. Researchers evaluated the health impact of 13 vitamins and minerals. During the five year follow-up, a total of 3,577 deaths occurred. It was found that none of the supplements increased mortality, but glucosamine and chondroitin were found to reduce the risk of death. Glucosamine use that was categorized as low was associated with an eight percent decreased risk of death, while high use was associated with a 17 percent lower risk. Chondroitin was associated with a 12 percent reduced risk in people with low use and a 17 percent lower risk in participants categorized as high usage. The researchers suggest that glucosamine and chondroitin may have anti-inflammatory properties that contribute to lower mortality, but further research is needed to evaluate the potential benefits of glucosamine and chondroitin supplementation.1
1 Pocobelli G, Kristal AR, Patterson RE, et al. Total mortality risk in relation to use of less-common dietary supplements. Am J Clin Nutr. Jun2010;91(6):1791-800.