A Landmark study published today shows the longterm benefits of a food supplement in arresting the progression of osteoarthritis. Osteo arthritis, or wear and tear of the joints, affects 60 per cent of people over the age of 65.
It begins in the cartilage, an important component of a joint which caps the ends of bones. A rubbery gel-like tissue, it helps to reduce friction caused by one bone rubbing against another.
Dr Jean Reginster and his colleagues of the Bone and Cartilage Metabolism Unit, Liege, Belgium, assessed the effects of a natural substance called glucosamine sulphate on the longterm progression of joint structure changes and symptoms in arthritis.
In a random placebo-controlled trial, the researchers gave 1,500 mg of glucosamine sulphate once daily to 106 patients for three years, while an equal number were given a placebo (dummy) tablet. X-rays of the patients' knees were taken at the beginning and end of the trial.
The 106 patients taking a placebo had progressive joint space narrowing, one of the key diagnostic features of osteoarthritis, of 20 mm, after three years. Those taking glucosamine had no significant narrowing.
In addition, patients who completed the treatment with the compound had a 20-25 per cent improvement in their symptoms compared with a slight worsening in the placebo group. The good safety profile and low level of side-effects of glucosamine were also confirmed. Glucosamine is a major building block of a component of cartilage called proteoglycan. It jump-starts production of this building block, helping the body to repair damaged cartilage. Glucosamine is made up of glucose and an amino acid called glutamine.
This trial is the first to show the long-term benefits of glucosamine. The findings of the study were published in the Lancet. Previous research had shown its effectiveness in reducing the symptoms of osteoarthritis; now we have evidence of its ability to arrest disease progression.
Dr Robert Coughlan, consultant rheumatologist at Merlin Park Hospital, Galway, told The Irish Times the research was encouraging.
"I have seen some patients who have benefited symptomatically from taking glucosamine. However, I would like to await the outcome of a large trial which is currently being undertaken by the National Institute of Health in the US. Nonetheless, this is the only medicine with a suggestion of diseasemodifying effect in osteoarthritis."
Glucosamine is available as a food supplement as well as a prescribed medication. It is licensed by the Irish Medicines Board and can be prescribed as 1,500 mg-sachets of glucosamine sulphate. However, based on data supplied to the board in the licensing application in 1998, its prescription is restricted to three months at a time.