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Shark Cartilage for Osteoarthritis Introduction The use of shark cartilage initially focused on its potential use as an anti-neoplastic agent. However, some individuals have begun to wonder about any potential effects it may have as an anti-inflammatory treatment for osteoarthritis. This potential action is due to the fact that shark cartilage is primarily composed of chondroitin sulfate, which is further metabolized into glucosamine. Both of these products have been widely used as an alternative therapy for treatment of individuals suffering from osteoarthritis. While no studies have currently been performed investigating the use of shark cartilage as an anti-inflammatory, numerous clinical trials have been conducted to determine the efficacy of both glucosamine and chondroitin in treating osteoarthritis. These results could be applied to indirectly investigate the ability of shark cartilage, mainly composed of chondroitin sulfate, to successfully treat pain symptoms in patients suffering from osteoarthritis. Glucosamine and Chondroitin Glucosamine is an amino sugar that serves as a precursor for the formation of glycosaminoglycans, proteoglycans, and glycolipids. One specific glycosaminoglycan is chondroitin sulfate. These glycosaminoglycans, in turn, are a major component of joint cartilage, which becomes eroded and deficient in individuals suffering from osteoarthritis. Due to their structural importance in cartilage, it was hypothesized that oral replacement of glucosamine and chondroitin sulfate, either alone or in combination, could help alleviate pain in arthritis sufferers. A clinical trial was recently published in the February 23, 2006 edition of the New England Journal of Medicine focusing on the efficacy of glucosamine and chondroitin sulfate in treating the pain symptoms of osteoarthritis. This Glucosamine/chondroitin Arthritis Intervention Trial (GAIT) was a multi-center, double-blind study involving 1583 patients with symptomatic knee osteoarthritis. These individuals were randomly assigned to groups receiving either 1500 mg glucosamine daily, 1200 mg chondroitin sulfate daily, both glucosamine and chondroitin sulfate, 200 mg celecoxib daily, or placebo for a period of 24 weeks. The groups were further stratified according to the severity of their pain, either mild (1229 people) or moderate-to-severe (354 people). The primary outcome measure was a 20% decrease in their pain from the beginning to end of the 24 week time period. Results were collected using an intention-to-treat principle. When viewing the results for the patient group as a whole, glucosamine and chondroitin sulfate were not found to significantly reduce knee pain by 20% when compared to placebo. The response rate to placebo was determined to be 60.1%, while glucosamine alone yielded a response of 64.0%, chondroitin sulfate alone one of 65.4%, and the combination of the two a response of 66.6%. None of these values were found to be a statistically significant difference. Analysis of the moderate-to-severe baseline pain group only, however, did yield a significant difference in the rate of response. While placebo yielded a response of 54.3%, combination therapy with both glucosamine and chondroitin sulfate had a response of 79.2%. The authors of this study concluded that glucosamine and chondroitin sulfate alone or in combination did not reduce knee pain in the patient group overall. Combination therapy may, however, provide symptomatic relief in patients with moderate-to-severe arthritis pain. Applications to the Use of Shark Cartilage for Osteoarthritis Treatment This data can be used to indirectly assess the efficacy of shark cartilage in the treatment of symptomatic osteoarthritis. Commercial preparations of shark cartilage, available at stores like General Nutrition Companies (GNC) and No Name Nutrition, typically come in tablets of 750-800 mg. In addition to chondroitin sulfate, these preparations additionally contain cellulose, chlorophyll, vegetable acetoglycerides, and titanium dioxide. It is instructed to take one to five tablets daily. Shark cartilage, along with both glucosamine and chondroitin, are considered dietary supplements in the United States, and are thus held to less stringent standards when compared to either over-the-counter of prescription drugs. Dietary supplements also do not need the approval of the Food and Drug Administration (FDA) before being marketed. According to the Dietary Supplement Health and Education Act of 1994, the manufacturer of dietary supplements is responsible for determining the safety of the product and that any claims made about it are adequately substantiated. As a result, the exact composition of glucosamine and chondroitin sulfate in these preparations is unknown. Application of the GAIT study results indicate that 1500 mg glucosamine and 1200 mg chondroitin sulfate (2700 mg total) would need to be ingested daily for relief of moderate-to-severe arthritis pain. While this may potentially be achieved with the recommended dosages of shark cartilage (750 mg tablets one to five times a day) it is unknown the exact amount of either substance that is being obtained. Given the unknown amount of either glucosamine and chondroitin sulfate in preparations of shark cartilage and the lack of any clinical trials directly assessing the efficacy, it seems that ingestion of shark cartilage alone may not be as effective or efficient an anti-inflammatory treatment for osteoarthritis as individual preparations of glucosamine and chondroitin sulfate. Further research into its usage is needed for more definitive results. Resources Clegg, DO, Reda, DJ, Harris, CL, et al. "Glucosamine, Chondroitin Sulfate, and the Two in Combination for Painful Knee Osteoarthritis" The New England Journal of Medicine. 23 Feb 2006; 354, 8: 795-808. Hochberg, MC. "Nutritional Supplements for Knee Osteoarthritis - Still No Resolution" The New England Journal of Medicine. 23 Feb 2006; 354, 8: 858-860. |
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