What the Study Showed
In this 1999 Canadian study published in the Journal of Rheumatology, researchers found that glucosamine helped relieve knee pain in people suffering from osteoarthritis.

How It Was Done
Researchers at the University of Toronto studied 98 people who had moderate pain from knee osteoarthritis. They gave glucosamine hydrochloride (550 mg capsules, taken three times a day) to part of the group and a Placebo to the other.

During the eight-week study, men and women, 40 to 85 years of age, answered questionnaires about pain, stiffness, and knee function. They also kept daily pain diaries, and were given X-ray examinations. If more help was needed for pain, participants were allowed to take 500 mg of acetaminophen.

Why It's Important
With an estimated 20 million Americans suffering from osteoarthritis, the supplement glucosamine has been extensively used to relieve pain and reduce the degeneration of arthritic joints. To date, however, no credible study has proved the effectiveness of glucosamine.

In this particular trial, the patient questionnaires revealed no significant improvement in symptoms among glucosamine takers. However, the pain diaries indicated that the glucosamine group did experience more improvement each week, but that the placebo group did not. And beginning at week four, knee examination data showed substantial improvement for the glucosamine group. There was no significant difference in acetaminophen use between or within either group.

In addition, both the glucosamine and placebo groups agreed to take glucosamine for a second eight-week, open-label trial. A remarkable 77% of all participants continued to take the glucosamine even after this trial ended. No significant side effects were reported by the participants taking glucosamine.

The clinicians concluded that certain people with knee osteoarthritis could benefit from glucosamine use but that larger studies need to be done.