A naturally occurring amino sugar synthesized in the body from L-glutamine and glucose, glucosamine stimulates the manufacture of glycosaminoglycans, important components of the cartilage needed for healthy joints.59, 60 Aging people seem to lose their ability to produce a sufficient amount of glucosamine, and no food sources are available. Commercial sources of glucosamine from the exoskeleton of certain shellfish are available as glucosamine sulfate, glucosamine hydrochloride, and N-acetyl-glucosamine. The sulfated form may most effectively incorporate sulfur into the cartilage.61,62

Glycosaminoglycans and glycoproteins allow cells in tissues to hold together. They are necessary for the construction and maintenance of virtually all connective tissues and lubricating fluids in the body.63, 64 In particular, a combination of N-acetyl-glucosamine bound to glucuronic acid, is polymerized to make the joint lubricant, hyaluronic acid.

Chondroitin sulfates provide the structural components of joint cartilage and facilitate the entry of glucosamine into joints. Chondroitin sulfates also inhibit free radical enzymes. Chondroitin sulfate attracts water into the cartilage matrix and helps stimulate the production of cartilage.

Recent research suggests that chondroitin in combination with glucosamine sulfate has a positive effect on subchondral bone structural changes and may help augment repair processes following accessory joint tissue injury.65-67 These important joint health agents may help maintain healthy joint structure and function, and reduce joint discomfort and stiffness.65-69