Osteoarthritis is a condition which is prevalent, mainly among people over the age of 50, in many parts of the world. In some countries, up to 10% of the population suffers with this disease, to some extent.

The effect of osteoarthritis can vary from being a mild inconvenience to serious disability. There are about 27 million people in the USA and 7 to 8 million in the UK who are affected by this condition.

Glucosamine and Chondroitin, taken singly or in combination, are supplements used by a huge number of sufferers and constitute a billion dollar market. A recent report, in the British Medical Journal, of a clinical trial conducted in Switzerland, casts serious doubt on the beneficial effect of these products.

This is disturbing news, because it appears to be a direct contradiction of conclusions made by a previous study, carried out in the USA in 2008. Both trials examined people with osteoarthritis of the hip or knee.

The more recent trial was carried out by Professor Peter Juni and his team, at the University of Bern. 3,803 patients took part in the trial and the opinion of the team was that there was “no clinically relevant effect” from Glucosamine and Chondroitin on perceived joint pain, whether taken singly or together.

Claims are very often made that Glucosamine helps to repair and sustain damaged cartilage, which is particularly important in the knee. Professor Juni was of the opinion that there was no evidence of any impact on narrowing of the joint space.

Because there is a strong public acceptance that glucosamine is beneficial in the treatment of arthritis, there is possibly a strong placebo effect and for this reason Professor Juni does not advocate that people should stop taking it, only that it should not be paid for out of the public purse. In addition, these products are not dangerous or harmful, unlike some other arthritis painkillers, such as non-steroidal anti-inflammatory drugs.

The earlier clinical trial, in the USA, was carried out by 16 universities and hospitals and was co-ordinated by the School of Medicine at the University of Utah. This survey was in a smaller group of 1,583 patients with osteoarthritis of the knee.

For the purposes of this exercise, they were examined as two separate subgroups. The majority of the patients (1,229) had only mild joint pain, while the much smaller group, of 354, were sufferers with moderate-to-severe pain.

The patients with moderate-to-severe pain exhibited “statistically significant pain relief compared with placebo”, at least 79% of them did. For the people with mild pain, glucosamine and chondroitin sulfate, whether together or alone, did not provide statistically significant pain relief.

This means that only 280 patients out of the 1583 who participated (18%) showed sustainable evidence of benefit from these supplements, other than any relief which may be attributable to a placebo effect. However, the conclusions drawn by the researchers do indicate strongly that the patients with the more severe pain did get relief from the treatment.

The overall message would seem to be “if you think they’re doing you some good, keep taking them, because they certainly won’t do you any harm”.

Find full details of both trials and their conclusions, at Glucosamine and Chondroitin