Glucosamine and chondroitin, two supplements commonly used to combat joint pain, do not relieve symptoms, researchers wrote in an article published in the BMJ (British Medical Journal). The two supplements are typically taken in combination or on their own in order to reduce pain in patients with osteoarthritis in the knees and hips.
The authors add that taking the supplements does not harm patients either; they are not dangerous for human health.
Professor Peter Jüni at the University of Bern in Switzerland, said:
We see no harm in having patients continue these preparations as long as they perceive a benefit and cover the cost of treatment themselves.
(However) Health authorities and health insurers should not cover the costs for these preparations, and new prescriptions to patients who have not received treatment should be discouraged.
Osteoarthritis of the knee or hip is a long-term (chronic) condition. Patients are usually prescribed anti-inflammatory drugs and painkillers - they can cause heart and stomach problems if taken for long periods.
The authors say that ideally, treatments should not only reduce pain, but also slow down the disease's evolution.
Over the last ten years GPs (general practitioners, primary care physicians) and rheumatologists have been prescribing glucosamine and chondroit into patients with osteoarthritis of the hip or knee increasingly. A significant number of patients buy the supplements over-the-counter (without a prescription).
In 2008, $2bn dollars' worth of glucosamine supplements were sold worldwide; 60% more than in 2003.
The authors found that previous trials on glucosamine and chondroitin had contradictory findings. So, they decided to carry out a large scale review of studies in order to find out whether the supplements were effective.
Professor Jüni and team examined the results of ten published trials with 3,803 patients - all of them diagnosed with osteoarthritis of the knee or hip. The investigators assessed changes in levels of pain after taking the chondroitin, glucosamine or their combination with a placebo or head to head.
No clinically relevant effect of glucosamine, chondroitin or their combination on joint pain or on joint space narrowing was found. Put simply - they did not work.
Some patients are certain these supplements help their symptoms, the authors explain. The researchers believe this is probably due to the natural course of osteoarthritis or a placebo effect.
The authors concluded:
Compared with placebo, glucosamine, chondroitin, and their combination do not reduce joint pain or have an impact on narrowing of joint space. Health authorities and health insurers should be discouraged from funding glucosamine and chondroitin treatment.
What is osteoarthritis?Osteoarthritis, also known as degenerative arthritis, degenerative joint disease, OA, or osteoarthrosis, is a form of arthritis caused by inflammation, breakdown, and the eventual loss of cartilage in the joints - the cartilage wears down over time.
Osteoarthritis is the most common type of arthritis. According to the National Health Service, UK, approximately 8.5 million people are affected by the condition. The Arthritis Foundation, USA, says that about 27 million Americans are affected.
Osteoarthritis is a progressive disease; signs and symptoms gradually worsen over time. There is no cure. However, available therapies may help with pain and swelling (inflammation), as well as keeping the patient mobile and active. Experts say that patients who take steps to actively manage their osteoarthritis are more likely to gain control over their symptoms.
Any joint in the body may be affected. However, the disease is most likely to affects the patient's hips, knees, hands, lower back, or neck.
Osteoarthritis has three characteristics:
- Bony growths develop around the edge of joints.
- It damages cartilage - Cartilage is the part of the joint that cushions the ends of the bones and allows easy movement of joints.
- Synovitis - there is mild inflammation of the tissues around the joints.
Click here to read about osteoarthritis in more detail.
"Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis"
Simon Wandel, Peter Jüni, Britta Tendal, Eveline Nüesch, Peter M Villiger, Nicky J Welton, Stephan Reichenbach, Sven Trelle
BMJ 2010; 341:c4675 doi: 10.1136/bmj.c4675 (Published 16 September 2010)
Written by Christian Nordqvist