Glucosamine sulphate shown to have long-term benefit
The food supplement glucosamine sulphate has been found to have a long-term benefit on osteoarthritis.
For the first time, glucosamine has been shown to slow down the progression of joint degeneration in osteoarthritis over a three-year period as well as reducing symptoms, according to a new study published in The Lancet.
More than 200 patients in Belgium took part in the randomised, placebo-controlled clinical trial run by scientists in Liege.
Previous, smaller studies have shown that the food supplement may have a mild pain-killing effect in the short to medium term, while others have shown it is no more effective than placebo.
In the Belgian study, patients with osteoarthritis received a daily 1,500mg dose of glucosamine, or a placebo, for three years. X-rays were taken of their knees at the start and end of the trial.
The 106 patients on placebo had progressive joint-space narrowing, with an average loss of 20mm after three years; there was no significant loss in the 106 patients taking the supplement.
And those who completed the course of treatment had a 20-25 per cent improvement in symptoms, compared to slight worsening of symptoms in the placebo group. There were no differences in safety, or reasons for early withdrawal between the treatment and placebo groups.
Glucosamine has traditionally been regarded with scepticism by the medical profession, who have pointed to a lack of proper evidence. Nevertheless, some GPs and rheumatologists recommend it to their patients, and it is very popular with osteoarthritis patients who have had to come off NSAIDs because of side effects.
ARC Scientific Officer Dr Madeleine Devey, said: " Many people with osteoarthritis take glucosamine sulphate, but until now the evidence that it does any good has been very inconclusive. These latest results are very encouraging."
Dr Peter Glennon, a GP in Stafford, and a member of the ARC Education Sub-Committee, welcomed the new research, although he said he still had some reservations about the supplement, and called for further studies confirming the results, particularly the radiological evidence.
"I'm not sure whether all sources of the supplement are the same; the compound used in this study was approved as a prescription drug and likely to have tight quality in manufacture," he added. "The dose of 1500mg daily would be expensive for many patients - often people on meagre pensions. If glucosamine was more tightly regulated and became a prescribable drug it would obviously be of benefit to some patient groups, especially the elderly, who could get it free."
Tim McAlindon, of the Arthritis Centre at Boston University Medical Center, quoted in The Lancet, said that the findings were a "landmark in OA research."
"Although inestimable resources have been poured into the development of a panoply of NSAIDs, scarce currency has been given to the notion that progression of OA could be retarded pharmacologically, let alone by a nutritional product," he added.
