Glucosamine chondroitin sulphate

 To answer that question, let's think about your knee joint for a moment. The ends of the two key bones which meet at the knee - the femur and tibia - are covered with a material called hyaline cartilage. Hyaline cartilage contains living cells called chondrocytes which are surrounded by a tough yet somewhat flexible 'matrix'. The matrix itself contains a mixture of important things, including collagen fibres (the same steel-like strands of connective tissue which toughen tendons and ligaments), elastic fibres to promote flexibility, and chemical compounds called proteoglycans. These proteoglycans have a protein 'trunk' to which are attached 'branches' of sulphated mucopolysaccharides (mucopolysaccharides are merely complex carbohydrates which bind with water to form a somewhat jelly-like substance). One of the most important mucopolysaccharides in the human body is chondroitin sulphate.

As it turns out, chondroitin sulphate is a highly 'electronegative' structure, which means that it has an extremely powerful capacity to attract and retain water molecules. The resulting ample presence of water within chondroitin-sulphate-rich cartilage guarantees that it will be elastic and yet highly resistant to friction and impact forces. In fact, that's why cartilage is so good at protecting bony tissue from damage during movement. Ultra-hard bones can not grind away at each other when they are 'capped' properly with cartilage, and the cartilage itself is usually not damaged because of its flexibility and resiliency.

Unfortunately, in osteoarthritis the cartilage matrix is disturbed, and those key molecules of chondroitin sulphate begin to break down, causing the cartilage to lose its water-retaining properties and overall protective function. Of course, that's why many doctors, researchers, and arthritis patients are attracted to CS supplementation, believing that dietary CS might replace what is being lost in the joints as part of the disease process. Scientists are also encouraged by the fact that there is experimental evidence that CS actually increases the activity of the living cartilage cells, stimulating them to manufacture more matrix. Finally, several studies indicate that CS can also reduce the activity of elastase, an enzymereleased by white blood cells in inflamed joints which breaks down elastic fibres and thus reduces the resiliency of cartilage.

The 64 dollar question
But does chondroitin-sulphate supplementation actually work? Sceptics contend that the compound - when taken orally - is actually chemically degraded in the digestive system long before it can reach any inflamed joints. At first glance, that seems to be a fairly likely scenario, but research has actually shown that CS can in fact be absorbed intact from the small intestine into the bloodstream ('Biochemical and Pharmacokinetic Aspects of Oral Treatment with Chondroitin Sulphate,' Arzneim Forsch/Drug Res., vol. 45, pp. 918-925, 1995).

But once CS cascades through the blood to the joints, can it do any good? In a recent, randomized, double-blind, 'double-dummy' study carried out at the Clinical Institute of Orthopaedics and Traumatology at the University of Siena in Italy, 146 patients with osteoarthritis of the knee were divided into two groups. During the first month, patients in one group were treated with three 50-mg tablets of diclofenac per day (diclofenac is a non-steroidal anti-inflammatory medication which is often used to treat arthritis), along with three 400-mg tabs of placebo. For five follow-up months, the subjects received only the placebo.

A second collection of subjects (the chondroitin-sulphate group), ingested three 400-mg tabs of chondroitin sulphate per day for the first month, along with three 50-mg tabs of placebo. For the next two months, members of this group received only chondroitin sulphate. Finally, for the last three months of the study, these individuals took in only placebo.

The effectiveness of the two compounds (the popular non-steroidal anti-inflammatory diclofenac v. the upstart, chondroitin sulphate) was evaluated by assessing the 'Lequesne Index' in both groups, as well as daily discomfort, pain when the knee joints were 'loaded' with weight, and total consumption of pain-killer medications ('Comparison of the Anti-Inflammatory Efficacy of Chondroitin Sulfate and Diclofenac Sodium in Patients with Knee Osteoarthritis, Journal of Rheumatology, vol. 23(8), pp. 1385-1391, 1996).

How did chondroitin sulphate do? Well, those patients who were treated with diclofenac experienced prompt and effective relief from their symptoms. However, their pain and discomfort returned rather quickly when they shifted from diclofenac to a placebo. Meanwhile, the chondroitin-sulphate people got relief from their symptoms considerably later than the diclofenac poppers, but their therapeutic response lasted for up to three months after they stopped taking the chondroitin. The Italian researchers wisely concluded that chondroitin sulphate seems to have a slow but gradually increasing clinical activity in patients suffering from osteoarthritis, with the benefits lasting for a relatively long period after supplementation is discontinued.

A noteworthy aspect of this study was that the osteoarthritic symptoms of the CS-group members were not significantly relieved until they had been taking CS for at least 30 days. Thus, if you decide to give CS supplementation a try, you shouldn't quit in disgust after three weeks simply because you haven't noticed any improvement. It makes sense to give the stuff at least a two-month trial (probably in a quantity of 1200 mg per day, divided into three different doses).

No French side-effects
Many other studies have also been chondroitin-sulphate supportive. In an investigation carried out at the University Hospital in Toulouse, France, 122 patients with osteoarthritis of the knees and hips participated in a prospective, randomized, placebo-controlled, double-blind trial designed to evaluate the effectiveness of CS. This investigation lasted for five months, with three months of treatment with CS (or a placebo) followed by two months in which all patients went 'cold turkey' ('Chondroitin Sulfate in the Treatment of Gonarthrosis and Coxarthrosis: 5-Months Result of a Multicenter Double-Blind Controlled Prospective Study Using Placebo,' Rev Rhum Mal Osteoartic, vol. 59 (7-8), pp. 466-472, 1992).

At the end of three months, patients in the CS group required significantly fewer doses of non-steroidal anti-inflammatory medication to control pain and inflammation, compared to the placebo group; this drop-off in the use of medication continued through the two months of follow-up, even though daily ingestion of CS had been discontinued.

 Pain and overall joint function also improved in the CS group, compared to placebo. An outstanding feature of the CS therapy was that it was well tolerated by the patients (none of the CS subjects had to withdraw from the study because of problems associated with taking CS). In contrast, traditional non-steroidal anti-inflammatory drugs are fairly frequently associated with a variety of side-effects, including ulcers and other digestive-system maladies.

The French researchers concluded that chondroitin sulphate is useful for the treatment of osteoarthritis, both as an agent which progressively becomes more effective against symptoms and as a compound which reduces the need for less-well-tolerated medications. Furthermore, the 'carry-over capacity' of CS (its ability to keep working even after oral supplementation is discontinued) suggests that those who use CS don't have to take it all the time, which certainly will help ease wallet-related pain at the same time that the discomforts of arthritis are allayed.

In a third study carried out in Austria with 61 patients plagued by osteoarthritis of the finger, knee, and hip joints, individuals who took chondroitin sulphate for a period of three months were able to reduce their intakes of non-steroidal anti-inflammatory drugs by 72 per cent ('Results of a Multi-Center Study of Chondroitin Sulfate (Condrosulf) Use in Arthroses of the Finger, Knee and Hip Joints,' Wien Med Wochenschr, vol. 146(24), pp. 609-614, 1996). Pain dropped dramatically in these patients (in fact, the researchers reported that CS was just as effective in controlling pain as the traditionally used, powerful non-steroidal anti-inflammatories), and - as in most of the studies carried out with CS - the compound was well tolerated, with very few side effects.

A further plus for CS
The attractiveness of CS becomes even greater when one realizes that the anti-inflammatory drugs which are often prescribed for osteoarthritis - although they do control pain - may actually accelerate the disease process and lead to a more rapid 'closing' of joints (as a joint closes, the cartilage covering bones gradually disappears, and the bones edge ever closer together, leading to a progressive loss in flexibility and function ('Effects of Anti-Inflammatory Drugs on the Progression of Osteoarthritis of the Knee,' Journal of Rheumatology, vol. 22(10), pp. 1941-1946, 1995). CS does not appear to have this gap-closing effect.

Interestingly enough, there is also evidence that CS might be useful in the treatment of malaria. One of the key problems associated with malarial infections is that parasitized red blood cells tend to 'stick' to the inner surfaces of tiny blood vessels, blocking the normal flow of blood and producing life-threatening complications. This adhesion of infected cells to the linings of blood vessels is one reason why 'cerebral malaria' is so deadly.

In a study carried out at Monash University in Australia, researchers found that CS could block this attachment of infected red blood cells, suggesting that CS might have therapeutic value for malaria patients ('Adhesion of Malaria-Infected Red Blood Cells to Chondroitin Sulfate A under Flow Conditions,' Blood, vol. 88(10), pp. 4040-4044, 1996).

Kenyan runners with sore knees should take notice (many of the Kenyans have periodic bouts of malaria).

And athletes?
Of course, the results of these studies don't necessarily mean that CS is the best treatment for osteoarthritis; they merely indicate that CS does indeed have therapeutic value for arthritis sufferers.

But are there also benefits for athletes? It's intriguing to think that CS might be beneficial for endurance athletes engaged in strenuous training. The rationale for such supplementation would simply be that the constant stresses of training could irritate the cartilaginous surfaces in the knees for example, requiring nearly constant remediation.

Could a higher CS intake make it easier for athletes to keep their joint cartilage in tip-top shape? We simply don't know at this point; the research has not been done. If you are an athlete who has suffered from knee-cartilage damage in the past, CS supplementation is certainly appealing. But - to date - the only studies which have linked oral intakes of CS with improved function have been carried out with osteoarthritis patients, not athletes who may have joint pain but don't truly have osteoarthritis.

Of course, the other problem associated with CS supplementation is that you can never be sure about exactly what you're getting when you pop a CS tablet in your mouth. The supplement industry is poorly regulated, so CS pills might contain a variety of contaminants and - indeed - less CS than is advertised on the label.

What about a somewhat related supplement - shark cartilage? Based on the myth that sharks never get cancer (they do), shark-cartilage sales have soared among those gullible folk who think that the stuff is a tumour prophylactic. Shark-cartilage marketeers also claim their product is good for the joints, but shark cartilage of course contains lots of other ingredients besides CS. If you do decide to supplement your diet in hopes of helping your joints, you're probably better off taking pure CS rather than ground-up cartilage.

Owen Anderson