Functions
CS, when taken orally, theoretically stimulates chondrocytes to produce more glycosaminoglycans and proteoglycans in the connective tissues. When this occurs in arthritic joints, the symptoms of pain and dysfunction decrease. Culture studies in the laboratory have shown that when CS was added to cartilage and chondrocyte cell cultures, production and secretion of proteoglycans was enhanced.1,2
Absorption
Oral absorption of CS has been a controversial topic within the nutritional community. Many researchers feel that due to the size of the CS molecule (which is many times larger than the glucosamine molecule), intact absorption is impossible. They further feel that the fragments that are absorbed do not have significant biologic effects. When compared to the glucosamine molecule, the percentage of CS that is absorbed is considerably less. Glucosamine, when taken in the sulfate or hydrochloride form, has an absorption profile of 90-98% in humans.3 In contrast, Murray cites three European studies, the best of which showed that purified, pharmaceutical grade CS had only a 13% absorption rate when ingested orally by humans.
Morrison, a cardiovascular researcher in Loma Linda, California, worked extensively with CS in the treatment of heart disease. In one study, 120 patients were divided into two groups of 60 subjects each. Each group received traditional allopathic care, but one group also took 1500 mg a day of CS for 4 (?) years, and then 750 mg for another 18 months. After six years, four people in the CS group had died, compared to 13 in the nontreated group. Most impressive was the finding that only six people in the chondroitin-treated group had acute cardiac incidents over the six-year period, while 42 patients in the group that did not receive CS had acute events. Although this was not a direct absorption study, it was obvious (in this study) that moderate amounts of oral CSs had significant biological effects in humans. Bucci4 is convinced that, when in their purified form, CS are absorbed by humans in various chain links. He notes that the human gut contains specific enzymes (known as chondroitinases) which are able to digest glycosaminoglycans.
Human Studies
The vast majority of positive studies using CS for patients suffering from arthritis and connective tissue dysfunction have been done with injectable forms. Theodosakis et al5 describe a study performed in Europe in the mid 1980s, when 50 patients were given 800-1200 mg of CS orally or 500 mg of a pain medication for three months. The study compared cartilage tissue samples at the beginning and the end of the three-month period and found that the chondroitin group showed marked cartilage regeneration when the pre- and post-study samples were compared. No such improvement was found in the pain medication group.6
Recommendations
When comparing the scientific literature on absorption and positive human trials of CS to glucosamine, glucosamine is far and away superior to CS. Remember that glucosamine is a precursor to chondroitin, so by taking glucosamine, the production of CS will be increased. However, the interest in CS has begun to climb with Luke Bucci's 1995 book, Pain-Free,7 and really took off with Dr. Theodosakis's 1997 book, Arthritis Cure.7 Both authors felt that purified CS could benefit connective tissue when taken orally in adequate amounts. Hopefully, the publicity garnered from these books will stimulate more research on CS, both alone and in concert with glucosamine. For patients with limited funds, the choice between using CS and glucosamine is a no-brainer. Go for the glucosamine. However, if funds are available, oral CS is certainly nontoxic to humans and may be of benefit. Dosing for CSs is approximately 8 mg per pound of body weight for four to six weeks. If the patient feels no subjective difference, discontinue. If the patient has benefitted, gradually reduce the dose to the minimum amount required to control symptoms.
There is one final problem with CS, and that is quality control. There are very few companies that market a purified product that patients can purchase over the counter. There is currently ongoing research being conducted out of the University of Maryland School of Pharmacy analyzing the purity of many brands of CS and glucosamine. At this time the only health-food store brand I recommend is from Twin Labs. However, there are brands of purified CS available from nutrition companies that service healthcare professionals. Hopefully, these companies will donate product (and look-alike placebos) to the chiropractic and naturopathic colleges for research purposes, which will be enthusiastically reported in this column. I also encourage these companies to submit samples to the University of Maryland for independent purity certification.
Resources
- Bollet, A.J. Stimulation of protein chondroitin sulfate synthesis by normal and osteoarthritic articular cartilage. Arthritis and Rheumatism, 1968, 11:663.
- Schwartz and Dorfman. Stimulation of chondroitin sulfate proteoglycan production by chondrocytes in monolayer. Connective Tissue Research, 1975, 3:115.
- Murray, Michael T. Glucosamine sulfate versus chondroitin sulfate. American Journal of Natural Medicine, 4(4):7, May 1997.
- Bucci, L. Nutrition Applied to Injury Rehabilitation in Sports Medicine. CRC Press. 1995.
- Theodosakis, Adderly, and Fox. The Arthritis Cure. New York: St. Martin's Press. 1997.
- Pipitone. Chondroprotection with chondroitin sulfate. Drugs in Experimental and Clinical Research, 17(1):3-7. 1991.
- Bucci, Luke R. Pain-Free. Ft. Worth, Texas: The Summit Group. 1995.
G. Douglas Andersen, DC, DACBSP, CCN, DACBN
Brea, California
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