On Monday, September 29, the journal Arthritis & Rheumatism released findings from the second part of the Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT II). The researchers concluded that supplements of chondroitin sulphate and glucosamine, alone or in combination, may not positively affect joint health. The research was conducted at the University of Utah, School of Medicine in Salt Lake City, funded by the National Institutes of Health (NIH).
The researchers admit in their conclusion that “the validity and mechanisms of this novel observation are uncertain but could be related to altered absorption of glucosamine,” and the combination of the ingredients may be less effective than the glucosamine or chondroitin sulphate individually.
These results are contradictory to previous research reported in the first NIH GAIT study in 2006, a six-month study of 1,500 osteoarthritis patients who were given a placebo or daily doses of 1,500 milligrams of glucosamine hydrochloride and/or 1,200 milligrams of chondroitin sulfate or 200 milligrams of the common prescription pain medication celecoxib.
The first GAIT study concluded that glucosamine and chondroitin were statistically more effective than COX-2 inhibitors in the subgroup of people who suffer the most from osteoarthritis, those who experience moderate to extreme pain.
In 2007, The Annals of Internal Medicine (AIM) published a meta-analysis questioning the efficacy of chondroitin for pain in osteoarthritis. The Natural Products Association reviewed the analysis and found that, among other things, no distinction was made between mild, moderate, and severe osteoarthritis, which all involve very different treatment regimens, also major factors in the conclusions of the 2006 study.
The Natural Products Association reviewed the results of GAIT II and observed:
The research in the GAIT II study did not use a “gold standard” as they did in the first study; a necessary factor to establish any comparison.
The researchers admit in the study that their results were affected by several limitations including a smaller number of participants, large variations in measurements, and slower decline in the knee joints as measured by joint space width (JSW).
The researchers acknowledge they cannot draw any definitive conclusions from their observations, and suggest significant changes that should be incorporated into the next trials.
Daniel Fabricant, Ph.D., vice president of scientific and regulatory affairs for the Natural Products Association, says, “Bottom line: this is one study -- it doesn't represent the totality of the research on glucosamine/chondroitin, which is very positive overall. Especially when compared to the few other options for osteoarthritis, it’s one of the few options without dangerous side effects.”