Glucosamine and Chondroitin Supplements for Arthritis Symptoms

Glucosamine is a raw material that your body uses to build cartilage; chondroitin is a component of that cartilage. Your body makes both substances, and you also get a bit from food. These substances can be taken in high doses as over-the counter nutritional supplements, and this has been done in Europe and Asia for many years to help arthritis pain, swelling, and loss of motion. They have also been used in the United States, but were mostly used by veterinarians until a book, The Arthritis Cure, by Jason Theodosakis, was published in 1992. Since then the use of glucosamine sulfate (GS) and chondroitin sulfate (CS) for arthritis pain has gained much popularity.

The most scientific data to support the use of these supplements is based on studies of GS. Studies have shown that GS can stimulate the synthesis of joint cartilage building blocks, providing some rational for its use in osteoarthritis. The best evidence of that possible benefit comes from a Belgian study of patients with knee arthritis. It was published in the respected  British medical journal, The Lancet, and demonstrated that GS may decrease serious progression of arthritis by 50%. Smaller studies have demonstrated cartilage repair on microscopic evaluation after GS treatment. GS reduces joint pain in a high percentage of patients with arthritis (50-80%, compared with 20-30% who responded to placebo), and rarely causes side effects. In some instances heartburn and nausea are reported. Since GS is derived from shellfish shells (chitin), those with allergies should be cautious, although there have been no reports of allergic reactions. Patients with diabetes mellitus should monitor their blood glucose when using GS. GS was shown in animal studies to affect blood-insulin response; but recent human studies do not confirm this relationship. 

There is little data on CS and even less data on the combination of GS and CS in the treatment of arthritis. Chondroitin may keep in check and enzyme that breaks down cartilage as well as fight inflammation. CS may cause bleeding in people with bleeding disorders or who take blood-thinning medications. A small risk exists for bovine spongiform encephalopathy (BSE) from CS prepared from cow cartilage originating in countries affected by the disease. Two brands, Cosamin DS and Nutramax, have done research to prevent any contamination with BSE. Unlike GS, CS is poorly absorbed from the GI tract. The long-term safety of CS and GS is unclear.

The FDA does not consider GS or CS to be drugs, so these agents do not currently undergo the same scrupulous standards for production, purity, testing and labeling. Because supplements are unregulated, consumers may not get the amount listed on the labels. Supplement cost is not defrayed by medical insurance because it is not considered a drug. No dose response studies have been published to date, so the optimal dose of these supplements for the management of OA is not known. Many companies recommend 500mg of GS and 400 mg of CS three times each day. Many patients have a satisfactory response to 1000 mg of GS and 800 mg of CS in the AM and 500 mg of GS and 400 mg of CS in the PM. It is not known how long this dosage should be continued for. Some companies add other cofactors to their brand of supplement. Cosamin DS, for example, adds manganese ascorbate and states that this is better for the efficacy of the supplement.

These supplements may be "chondroprotective" in patients at risk for arthritis. Although never tested in this way, supplements may protect "joints at risk" for arthritis from getting arthritis. Examples include patients with early signs or symptoms of arthritis, patients with a strong family history of arthritis, arthritis in another joint or joints, patients with a deformity of a joint, or previous trauma to a joint.

Improvement in symptoms may not be seen for at least two months, but prolonged relief can be obtained. Other treatment methods should be sought if no results are seen in a reasonable amount of time.

Note that two other supplements may possibly help ease the symptoms of osteoarthritis, although evidence is quite preliminary. A few human studies suggested that a compound called SAM-e might help relieve the pain and inflammation. And two observational studies suggest that vitamin D (which is needed for healthy cartilage and bone) may slow the progression of osteoarthritis.

The Arthritis Foundation, the leading non-profit information and advocacy group for people with arthritis, issued a statement last June calling GS "an appropriate treatment" for osteoarthritis. Many physicians continue to reserve judgment, and await a pivotal $14 million study by the NIH's Nation Center for Complementary and Alternative Medicine and the National Institute of Arthritis and Musculoskeletal and Skin Diseases. Final results of this study are due in March 2005. In January of 2002, Consumer Reports looked at supplements for arthritis and concluded that because no one knows which formulation works best, it makes sense to try one of the least expensive combination products (see below).