Chondroitin is a molecule that occurs naturally in the body. It is a major component of cartilage -- the tough, connective tissue that cushions the joints. Chondroitin helps to keep cartilage healthy by absorbing fluid (particularly water) into the connective tissue. It may also block enzymes that break down cartilage, and it provides the building blocks for the body to produce new cartilage.
A number of scientific studies suggest that chondroitin may be an effective treatment for osteoarthritis (OA). OA is a type of arthritis characterized by the breakdown and eventual loss of cartilage, either due to injury or to normal wear and tear, and commonly occurs as people age. Chondroitin supplements have been shown to decrease the pain of OA. Some researchers think it may actually slow progression of the disease, unlike other current medical treatments for OA. (Many people take either acetaminophen or nonsteroidal anti-inflammatory drugs, such as ibuprofen and naproxen, for OA pain). However, so far studies have not shown conclusively that chondroitin helps repair or grow new cartilage, or stops cartilage from being further damaged. Chondroitin is often taken with glucosamine, another supplement thought to be effective in treating OA.
Results from several well-designed scientific studies indicate that chondroitin supplements may be an effective treatment for OA, particularly OA of the knee or hip. In general, findings from these studies suggest that chondroitin:
Reduces OA pain
Improves functional status of people with hip or knee OA
Reduces joint swelling and stiffness
Provides relief from OA symptoms for up to 3 months after treatment is stopped
However, the largest clinical trial so far, the 2006 Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT), sponsored by the National Institutes of Health, showed conflicting and somewhat confusing results. The study of about 1,600 people with OA of the knee found that glucosamine and chondroitin did not reduce pain in the overall group, although it did appear to lessen pain among those with moderate-to-severe OA of the knee. The study has raised questions for further research. Since glucosamine and chondroitin were combined in this study, it is not possible to determine the effect of chondroitin alone. In addition, researchers are now studying whether the glucosamine-chondroitin combination may in fact help those with more severe OA.
Most studies have shown that chondroitin needs to be taken for 2 - 4 months before it shows effectiveness, although some improvement may be experienced sooner. Glucosamine and chondroitin can be used along with NSAIDs to treat OA.
Other conditions for which chondroitin has been suggested include preterm labor, Alzheimer's disease, heart disease, and osteoporosis. However, no studies have yet evaluated these claims.
There are no significant dietary sources of chondroitin, so people who want to take it must take supplements.
Dosage and Administration
Chondroitin is commonly sold as chondroitin sulfate in capsule or tablet form. It is often combined with glucosamine and sometimes manganese as well. Manganese is a trace element necessary for normal bone health. While the total amount of manganese from foods and supplements should not exceed 11 mg per day, several combination supplements for arthritis (containing glucosamine, chondroitin, and manganese) contain more than that. Read labels carefully, and consider choosing a supplement without manganese.