A controlled trial in Norway found that the popular dietary supplement glucosamine was no better than placebo at reducing pain-related disability in people with lower back pain with degenerative lumbar osteoarthritis (OA).

You can read about the trial in a report by lead investigator Dr Philip Wilkens of the Department of Orthopaedics at Oslo University Hospital in the 7 July online issue of JAMA.

Despite being one of the most common conditions seen in general practice, treatment for non-specific chronic low back pain is often expensive and ineffective, commented Dr Andrew L. Avins, in an editorial accompanying the report.

Avins explains how development of low back pain is somewhat of a clinical mystery: evidence on effective treatments is flimsy and dogged by badly designed studies, leaving doctors with very little reliable information to work with, making it nearly impossible to plan treatments in a rational way. The result is that many patients turn to complementary and alternative therapies.

Glucosamine is a precursor of a compound that makes up cartilage in joints (it is a precursor of glycosaminoglycans, unbranched chains of polysaccharides that when linked to proteins become proteoglycans that form part of the connective tissue in joints).

As a dietary oral supplement, mostly from animal or fish origin, glucosamine is widely used by patients with osteoarthritis (OA), possibly because they believe it will reverse or stop cartilage degeneration.

Wilkens and colleagues wrote in their background information that there is little evidence to support this belief, and so they set out to investigate the effect of glucosamine in patients with lower back pain and degenerative lumbar OA.

They set up a double-blind, randomized, placebo-controlled trial with 250 participants aged over 25 who were recruited from outpatients attending Oslo University Hospital Outpatient Clinic who had been experiencing lower back pain for more than six months, together with degenerative lumbar OA.

The participants were randomized to one of two groups (125 in each). One group took 1,500 mg of glucosamine supplement every day for 6 months, and the other group took the same, except in their case the “supplement” was a placebo (identical sugar pill without glycosamine). As a double blind trial, neither the patients nor the doctors who gave them the pills knew whether they were taking glycosamine or a placebo.

The patients underwent assessment at the start and then at fixed time points during and at the end of the 6 months, and then after another 6 months. In the assessments the patients completed questionnaires about their quality of life, level of disability and levels of pain experienced during rest and activity.

When they analyzed the results, Wilkens and colleagues found no difference between the two groups in quality of life, disability and lower back pain (LBP):

“No statistically significant difference in change between groups was found when assessed after the 6-month intervention period and at 1 year”, they wrote.

The researchers concluded that:

“Among patients with chronic LBP and degenerative lumbar OA, 6-month treatment with oral glucosamine compared with placebo did not result in reduced pain-related disability after the 6-month intervention and after 1-year follow-up.”

Mild side effects were reported by similar numbers in both groups.

Effect of Glucosamine on Pain-Related Disability in Patients With Chronic Low Back Pain and Degenerative Lumbar Osteoarthritis: A Randomized Controlled Trial.”
Philip Wilkens; Inger B. Scheel; Oliver Grundnes; Christian Hellum; Kjersti Storheim
JAMA, Vol. 304, No. 1, pp 45-52, Published online 7 July 2010.

Written by: Catharine Paddock, PhD