Glucosamine is a naturally occurring substance that may alleviate symptoms associated with osteoarthritis.
Glucosamine is found in chitin, the fibrous material that makes up the exoskeleton of crustaceans and insects. It is also found in mucoproteins and mucopolysaccharides produced by many animals.
Medically valid uses
A long-term clinical trial funded by the National Center for Complementary and Alternative Medicine and the National Institute of Arthritis and Musculoskeletal and Skin Diseases found that glucosamine, taken in combination with chondroitin, decreased knee pain in people with moderate to severe osteoarthritis. The combination was no better than placebo (sugar "dummy" pill) in treating mild arthritis pain. Glucosamine alone was not significantly helpful in those with either mild or moderate to severe knee pain.
Smaller, prior studies showed that using glucosamine long-term (three years) was effective for slowing progression of knee osteoarthritis, and that it was superior to placebo and ibuprofen for osteoarthritis pain relief.
Please note that this section reports on claims that have NOT yet been substantiated through scientific studies.
Glucosamine is claimed to possibly help prevent joint overuse symptoms. It also may reduce symptoms of temporal mandibular joint (TMJ) disease.
The recommended dose of glucosamine is 400–500 mg three times a day. Higher doses are sometimes used to relieve symptoms of osteoarthritis in some individuals.
Significant concentrations of glucosamine are not available through normal food sources and must be obtained as dietary supplements.
Glucosamine sulfate is often supplied in combination with other materials such as chondroitin sulfate or manganese ascorbate.
Women who are pregnant or breastfeeding should consult a physician before taking any dietary supplements.
Side effects, toxicity, and interactions
Unlike other osteoarthritis medications, the side effects of glucosamine are minimal. Mild gastrointestinal problems, as well as drowsiness and skin reactions have been reported.
People with diabetes should consult a physician before taking high doses of glucosamine. Glucosamine has been shown to increase insulin resistance in several studies.
Several theories suggest how glucosamine provides symptomatic relief for osteoarthritis.
Some studies suggest that glucosamine is an essential substrate for the biosynthesis of glycosaminoglycans and hyaluronic acid. Enhanced synovial production of hyaluronic acid may explain rapid clinical response to high-dose glucosamine in osteoarthritis. By supplying the body with large amounts of glucosamine, it is possible to increase the production of both glycosaminoglycans and hyaluronic acid. These materials are critical in maintaining the structure and integrity of the cartilage and synovium in the joint.
Another theory holds that glucosamine stimulates the synovial production of hyaluronic acid. Hyaluronic acid is the component that is thought to lubricate the joint cartilage and absorb shock.
When given orally, glucosamine concentrates in the articular cartilage of the joints.
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