Best-selling nutritional supplements, glucosamine and chondroitin sulfate do not offer treatment for people suffering from osteoarthritis, a two year published study reveals.
In this study, knee cartilage was measured, specifically the space between the knee joints. Patients were given the glucosamine/chondroitin supplement, a sugar pill or Celebrex.
After 18 months, the supplements did not appear to slow the loss of cartilage.
Some of the researchers participating in the study have taken funding from pharmaceutical companies, the disclosure following the published report in Arthritis & Rheumatism shows.
This study follows up on a large 2006 National Institutes of Health funded study called GAIT (glucosamine/chondroitin Arthritis Intervention Trial) and the original study was published in the New England Journal of Medicine in 2006.
Funded by the National Institutes of Health, National Center for Complementary and Alternative Medicine, GAIT found no pain relief over a placebo. But there was an exception - a subset of patients with severe osteoarthritis in the knee experienced a significant pain relief with the two supplements.
‘We don’t have good evidence that it slows progression, says rheumatologist Allen Sawitzke, professor of internal medicine at the University of Utah and head investigator.
More study is needed and that the methods of measuring the distance between the bones could be improved. Also confusing is why there was a slower loss of knee cartilage in people taking the placebos than predicted.
"While these results are of interest, we cannot draw definitive conclusions about the utility of glucosamine or chondroitin in reducing joint space width loss, in part because the placebo group fared better than anticipated based on prior research results," said Josephine P. Briggs, M.D., director of the National Center for Complementary and Alternative Medicine, at the National Institutes of Health (NIH), one of the study's funders.
"The results of the study provide interesting insights for future research."
Glucosamine and Chondroitin are top supplement sellers yielding $831 in annual sales, according to the Nutrition Business Journal.
While consumers swear on the combination, Dr. Sawitzke says he would neither discourage nor encourage use and that more study is needed.
Osteoarthritis or OA, affects 27 million Americans, is incurable, and may be due to a number of factors such as age, gender, genetics, obesity and joint injuries. It is a leading cause of disability in people over the age of 65.
After the age of 50, women suffer the effects of OA more often than men. OA generally affects certain joints such as the hip, knee, hands, lower back and neck.
About half of Americans are at risk for knee osteoarthritis over their lifetime. Cartilage in the knee breaks down allowing bones to rub against each other. Pain, stiffness and loss of movement result.
Dr. Mercola.com recommends other natural options to address arthritis are acupuncture and the herb, turmeric. The popular natural health newsletter suggests that the quality of the supplements must be considered.
The follow-up to the GAIT study appears in the October issue of Arthritis & Rheumatism which shows that among researchers from the 13 medical sites included in the study, some received consulting, speaking and honoraria from drug companies such as Merck, McNeil, Bristol-Myers Squibb, and Abbott Immunology among others. #