Study: Glucosamine and Chondroitin Sulfate Fail to Relieve Arthritis Pain

The media was all abuzz last week over the new study suggesting that glucosamine and chondroitin sulfate do not relieve arthritis pain. It makes a great news story, but the study was deeply flawed.

First the obvious problems that even the media reported:

In a journal editorial, Dr. Marc Hochberg of the University of Maryland noted the study's limitations: a high dropout rate (20 percent) and a whopping 60 percent who said the dummy pills made them feel better — double the usual placebo effect. Hochberg has received consulting fees from Pfizer Inc., which makes Celebrex, and Merck & Co., which made Vioxx.

Clegg and 10 other researchers in the study reported receiving fees or grant support from Pfizer or McNeil Consumer & Specialty Pharmaceuticals, which makes Tylenol.

So, biggest issue: possible ulterior motives for those that receive funding from pharmaceutical companies who would have a financial interest in the study's failure to confirm positive benefits for supplements. Second biggest issue: self-reporting that allows 60 percent of respondents to experience the placebo effect--soemthing is very wrong here. Third issue: 20 percent drop-out rate is very high.

However, the number one, throw-this-study-out-the-window problem: it is not clear that they used glucosamine sulfate rather than the cheaper and more widely available glucosamine hcl. Only the sulfate form of glucosamine has ever been shown to be effective.

This is from an article available on this site about supplements for joing health (emphasis added):

GLUCOSAMINE is an amino-sugar that is a key component of mucopolysaccharides (a complex polysaccharide group [sugar] with an amino acid group attached, occurring primarily in joints) that diminishes as we age. Some studies show new connective tissue in as little as 30 days after taking the supplement. Only the sulfate form of glucosamine has been shown to increase the rate of cartilage repair and the reduction of tissue loss in joint diseases. Glucosamine hydrochloride, by itself, has not produced sustained benefits in multiple studies. Until more is known, the sulfate variation is the best choice.

There has been some concern that glucosamine impairs blood sugar metabolism, but according to a review of two three-year studies, glucosamine does not reduce insulin sensitivity or produce any other abnormalities in glucose metabolism. There is also no evidence that glucosamine increases cholesterol levels. However, acetaminophen use seems to inhibit the benefits of glucoasmine sulfate.

1. Current Opinion in Rheumatology. 2003 Sep; 15(5): 651-5.
2. Journal of Family Practice. 2003 Aug: 52(8); 645-7.
3. Archives of Internal Medicine. 2003 Jul 14; 163(13): 1514-22.
4. Journal of Arthroplasty. 2003 Apr; 18(3 Suppl 1): 5-9.
5. Metabolism. 2001 Jul; 50(7): 767-70.

There is no reason to stop taking a glucosamine sulfate/chondroitin sulfate supplement at this point. This study has too many flaws to be taken seriously.

UPDATE: Here is a doctor's take on the arthritis study. More reason to ignore it and move on with our lives as though it never happened.