Glucosamine and Chondroitin Supplements Found Ineffective for OA

January 31st, 2009

Two studies of Glucosamine and Chondroitin (G/C) used to treat osteoarthritis (OA) have yielded similar conclusions: the popular supplements do not effectively treat OA.
Although the pills, separately or in combination, contain compounds found in cartilage, it is doubtful that these substances can build new cartilage. Osteoarthritis involves wear and tear on the joints. Cartilage cushions and protects joints such as knees. When this cushion wears away, joint pain and disability result.

The first Glucosamine/Chondrodroitin Intervention Trial (GAIT) included 1,600 participants who had knees affected by osteoarthritis. One group of patients was given G/C supplements for pain relief, while others received the proven pain reliever celecoxib (Celebrex), and a placebo group got sugar pills. Those taking Celebrex noted the greatest improvement. A tiny segment of patients taking the combination supplement reported more pain relief than the placebo group, but they were statistically insignificant. Also, in the small group, placebo users claimed as much pain relief as those taking Celebrex, which casts further doubt on the supposed benefits of G/C.

In the second GAIT study, researchers used x-rays to measure physical effects of G/C supplements and other treatments on knee joints. They analyzed knee images from 357 persons with OA to determine if the supplements prevented loss of joint space. (Bones get closer together as the cartilage erodes.) They found no meaningful differences among people taking G/C, Celebrex, or placebo. Glucosamine and Chondroitin users had worse results when taking combination pills than when each was taken alone, but differences were again insignificant and no better than a placebo.

Despite the most recent confirmation that these supplements are ineffective, many will continue to take them. OA is painful, and it is difficult to get relief. Those who believe they are being helped could try about 1,500 mg a day of glucosamine alone – the most promising dosage. Well-designed studies which are independent of supplement manufacturers have not been able to prove G/C works. Pills can cost $30 or more a month – a lot of money for what could be a placebo effect.
Source: Johns Hopkins Medical Letter: Health After 50; February 2009; blog article by Anna Dabney

Entry Filed under: pharmaceuticals