Chondroitin sulfate is widely known as a food supplement used to help those with joint pain and osteoarthritis.  You may be unaware that chondroitin sulfate (CS) is also an important structural component of cartilage.  Many countries have approved CS is a “slow-acting drug for osteoarthritis” (SYSADOA).  This is because of studies showing that chondroitin sulfate can 1) decrease pain, 2) improve functional disability, and 3) reduce non-steroidal anti-inflammatory drug use.  Chondroitin is usually well tolerated with few side effects.

In Europe, the publication of the EULAR Recommendations for the Treatment of Knee Osteoarthritis in 2003 has listed oral chondroitin sulfate (CS) as evidence 1A and strength of recommendation A.  This recommendation represents the highest level for a “therapeutic strategy.”  Some of the reasons chondroitin sulfate has received such high ratings are summarized below:

• CS shows carry-over effects of about 3 months after cessation of use
• CS can reduce the use of anti-inflammatory drugs and, therefore, limit gastrointestinal side effects, such as ulcers and bleeding.
• CS is effective in knee and finger OA. Some data shows it is helpful in hip OA as well. 
• Oral CS supported the comparison with NSAIDs, such as diclofenac sodium in a medium/long-term clinical study in patients with knee OA. 
• CS is has a very good safety and tolerability profile.

According to the authors of a review of CS studies, “We definitively have enough clinical data available supporting the view that oral CS is a valuable and safe symptomatic treatment for OA disease. More recent data based on a couple of previous trials and two pivotal studies do provide further evidence that oral CS does also have structure-modifying effects in knee OA patients.”

This latter point is vital to understand.  There are few “disease-modifying” treatments available for OA—that is, treatments that actually repair components of joint tissue, as opposed to merely relieving symptoms.  This makes CS a tremendously valuable tool in the effort to restore joint health and mobility.

[Uebelhart, D. Clinical review of chondroitin sulfate in osteoarthritis. Osteoarthritis Cartilage 2008.]

A 2008 review of 20 studies found that pain relief after CS treatment steadily increased between 4 and 12 weeks of treatment.  This was compared to NSAIDs (non-steroidal anti-inflammatory drugs) where pain relief actually decreased during the same period.  Two meta-analyses (studies that assess other studies) found “consistently higher frequencies of side effects in the placebo group than in patients treated with CS.”  The authors wrote, “Data provided by these meta-analyses indicate that chondroitin sulfate has a slight to moderate efficacy in the symptomatic treatment of OA, with an excellent safety profile.”

[Monfort, J, Martel-Pelletier, J, Pelletier, JP. Chondroitin sulphate for symptomatic osteoarthritis: critical appraisal of meta-analyses. Curr Med Res Opin. 2008;24(5):1303-8.]
Uebelhart, D. Clinical review of chondroitin sulfate in osteoarthritis. Osteoarthritis Cartilage 2008

Chicken combs are known to contain a high concentration of hyaluronic acid.  A recent study published in the Nutrition Journal examined a product made from chicken combs that claims 60 percent hyaluronic acid.  Pain and quality of life in 20 people with osteoarthritis of the knee were measured before and 8 weeks after taking this oral form of hyaluronic acid.  Those taking the hyaluronic acid supplement demonstrated improved quality of life based on the WOMAC scale, a well-validated test for determining outcomes in osteoarthritis.  Though the study was small, it offers further promise that these supplements could helpful in OA.

Kalman, DS, Heimer, M, Valdeon, A, et al. Effect of a natural extract of chicken combs with a high content of hyaluronic acid (Hyal-Joint) on pain relief and quality of life in subjects with knee osteoarthritis: a pilot randomized double-blind placebo-controlled trial. Nutr J. 2008 Jan 21;7:3.

The extracellular matrix of cartilage is composed of proteoglycans attached to a backbone of hyaluronic acid that is intertwined among collagen fibrils. Proteoglycans have both chondroitin-sulfate- and keratin-sulfate-rich regions, and link proteins facilitate binding of aggrecan to hyaluronic acid.

Moreland Arthritis Res Ther 2003 5:54   doi:10.1186/ar623

The Importance of Sulfur

You will notice that chondrotin sulfate provides sulfate in addition to the chondroitin molecule.  The human body has a strong daily need for sulfur.  One benefit to supplementation by chondroitin sulfate may be through this delivery of extra sulfur that is needed by all the body's connective tissues.  This needs for sulfur is explored in more depth on our page The Importance of Sulfur.