Glucosamine and chondroitin are undoubtedly among the top-selling health products in South Africa. These ‘natural remedies’ are often sold under the pretext of being effective arthritis treatments with clinical trials to verify its efficacy. But just how true are these claims?

jointIndeed studies have indicated that both glucosamine and chondroitin may have some benefits in certain joint-related conditions. Some seemed to have conclusively supported the call for glucosamine and chondroitin to be part of the standard medical treatment for certain types of arthritis. However, many of the trials supporting these claims across the board for all joint conditions were in fact poorly designed and often raised more questions than it answered.

Extensive studies have also shown that despite some of these benefits, glucosamine and chondroitin should not discourage the use of pharmaceutical drugs known to be clinically effective in treating and managing different types of arthritis, nor delay surgery when and where necessary. In order to fully understand the issues relating to glucosamine and chondriotin use in treating arthritis, it is important to first have a greater understanding about these supplements and the condition.

Arthritis is a Broad Term

Most people do not realise that arthritis is not a specific disease. It is term that means joint inflammation, just as the word ‘arthralgia’ means joint pain. There are several types of arthritis, each with its own disease mechanism and features which differ significantly. These variations in the joint disease means that one treatment is not applicable for all types of arthritis. It also means that what works for one person with arthritis may not be useful for another person with arthritis.

There are two common types of arthritis that affects the general population – osteoarthritis and rheumatoid arthritis. Despite the common joint affliction and some similarity in symptoms, these two conditions are significantly different.

  • Osteoarthritis affects the cartilage of the joint (articular cartilage) whereas rheumatoid arthritis primarily involves the lining of the joint.
  • Osteoarthritis is condition where the articular cartilage becomes worn down and inflammation is not a major feature. In rheumatoid arthritis the joint lining becomes inflamed due to the immune system acting against it. Therefore osteoarthritis is considered as a degenerative condition whereas rheumatoid arthritis is an inflammatory joint condition.
  • Osteoarthritis typically involves the large joints of the body like the knees, hips and shoulders. Rheumatoid arthritis more commonly affects the small joints like that of the fingers.
  • Osteoarthritis tends to affect older people, generally starting after the age of 55 years. Rheumatoid arthritis commonly starts earlier in life, around the 20s and 30s.

Understanding these basic differences between osteoarthritis and rheumatoid arthritis is essential. The treatment will obviously differ significantly as a result of the variation in disease mechanism (pathophysiology) and part of the joint affected. There are also other types of arthritis like post-traumatic arthritis and septic arthritis. The latter can be extremely dangerous if prompt administration of antibiotics and surgical intervention is not conducted.

What are glucosamine and chondroitin?

Glucosamine and chondroitin are two natural substances found in the animal kingdom which can be synthetically produced.

  • Glucosamine is found in shellfish and is also known as chitosamine or glucosamine sulphate.
  • Chondroitin is present in shark cartilage and from cows (bovine). It is more correctly known as chondroitin sulphate.

Glucosamine and chondroitin are also naturally found in the human body. It plays an important role in the formation and maintenance of joint cartilage. Since it is the cartilage that is most affected in osteoarthritis, glucosamine and chondroitin are better indicated for this type of arthritis rather than other types like rheumatoid arthritis. However, in recent years studies have indicated that glucosamine has been shown to have some role to play in inflammatory conditions although the benefit is not as significant as non-steroidal anti-inflammatory drugs.

It is important to remember that these substances are considered to be dietary supplements and not medicines, be it pharmaceutical, herbal or homeopathic. As a dietary supplement glucosamine and chondroitin are manufactured without the stringent regulations that apply to medicines. Therefore the quantity of the active ingredients can vary greatly among different brands and sometimes even with different batches under the same brand.

Furthermore it has to be ascertained whether glucosamine and chondroitin are manufactured synthetically or acquired from natural sources. This is particularly important for people with shellfish allergies as these supplements may then be contraindicated. Once again the lack of standardised manufacturing procedures for dietary supplements may also raise the concern about other allergens within these products.

Benefit for Arthritis

Numerous studies have been conducted on the benefits of glucosamine and chondroitin for the treatment and management of arthritis, and specifically osteoarthritis. One of the largest such studies was GAIT (glucosamine/chondroitin arthritis intervention trial) that was done across 16 rheumatology research centres in the United States. However, many smaller trials were done across the globe for several years prior and even after GAIT. Collectively, these results are quite mixed.

Some of these studies verified that glucosamine and chondroitin helped with relieving joint pain and stiffness to some degree, although it was not as effective as non-steroidal anti-inflammatory drugs. Other studies however, have shown no significant pain relief from glucosamine and chondroitin when compared to placebos. These studies also noted that radiological evidence (like x-rays) did not show any improvement with using glucosamine and chondroitin supplements as assessed through the joint space narrowing.

Most studies while claiming that the benefits of using glucosamine and chondroitin for arthritis may not be notably significant, have indicated that these supplements are unlikely to be harmful provided that a person is not allergic to the ingredients. Conventional arthritis medication should not be stopped in favour of glucosamine and chondroitin as it can lead to poor outcomes in the long term. However, using these supplements alongside pharmaceutical drugs is not discouraged.

The bottom line for consumers: Use these supplements if you can afford it and only if you do not discontinue your current arthritis drug regimen, but do not expect your arthritis to resolve or reverse just due to these supplements.

References:

Glucosamine/Chondroitin Arthritis Intervention Trial Primary Study. NIH NCCAM

Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis. BMJ (former British Medical Journal)