Glucosamine and Chondroitin Safe, But No Proven Benefit for Arthritis Relief
The dietary supplements glucosamine and chondroitin have been promoted and used as a treatment for osteoarthritis by many because they are natural substances made by the body to support healthy cartilage. However, clinical studies often fail to find scientific evidence that either substance can relieve the pain of osteoarthritis, a condition that affects more than 20 million people.
Analysis of Previous Studies Confirm No Benefit to Arthritis Supplements
An analysis of 10 studies, which included over 3,800 people, published in the recent edition of BMJ, reinforces the negative findings of other large studies that show that glucosamine, chondroitin or a combination of the two are no better than a placebo when it comes to relieving joint pain or reducing the loss of cartilage that occurs in osteoarthritis of the knee.
When studied alone, glucosamine monotherapy had a slight edge over chondroitin monotherapy. Glucosamine had a small effect on joint space narrowing, while chondroitin alone had no effect.
However, the supplements do appear to be safe to try. “We see no harm in having patients continue these preparations as long as they perceive a benefit and cover the cost of treatment themselves,” said lead author Peter Juni of the University of Bern in Switzerland.
But be sure to tell your doctor, says David Pisetsky MD, chief of rheumatology at Duke University Medical Center in North Carolina. Animal research has raised the possibility that glucosamine may worsen insulin resistance, a major cause of diabetes, although the finding has not been substantiated in humans. Chondroitin can cause bleeding in people who have a bleeding disorder or who take a blood-thinning drug, such as Coumadin.
Glucosamine, an amino sugar, is thought to promote the formation and repair of cartilage and supplements are usually derived from shellfish shells. Therefore, those with a shellfish allergy should not take glucosamine supplements.
Chondroitin, a carbohydrate, is a component thought to promote elasticity and inhibit the enzymes that break down cartilage. It is usually derived from cow cartilage.
Global sales of glucosamine reached almost $2 billion in 2008, according to Juni, an increase of almost 60% compared to 2003.
Wandel S, et al "Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis" BMJ 2010; DOI: 10.1136/bmj.c467