Cartilage is a type of dense connective tissue found in humans and other animals. Bluish-white or gray in color, the semi-opaque tissue has no nerve or blood supply of its own. Cartilage supplements come from such animal sources as cattle, sheep, sharks, and chickens, with cows and sharks being the predominant sources. Bovine cartilage supplements are derived from the wind-pipes of cows, while the cartilage from the heads and fins of sharks is used for shark supplements.
Both shark and bovine cartilage supplements have been proposed as treatments for cancer. In addition, a compound derived from cartilage called chondroitin has been publicized as a useful treatment for osteoarthritis. Cartilage preparations are available as pills, powders, or liquids for oral dosage. They can also be given as enemas, topical applications, or intravenous or intramuscular injections.
Bovine cartilage supplements
Beginning in the 1950s, a physician named John F. Prudden noticed that bovine cartilage could enhance wound healing in animals. Dr. Prudden then injected an extract of bovine cartilage into a breast cancer patient whose tumor had ulcerated her skin. The patient's tumor ultimately disappeared, and she lived for 12 years before dying of other causes. In 1985, Prudden published the first of several scientific papers on the subject.
Dr. Prudden believes that the anticancer ingredients in bovine cartilage are mucopolysaccharides, which are complex sugar molecules that help fight cancer by stimulating the patient's immune system. Prudden also states
Shark cartilage supplements
The use of shark cartilage to treat cancer is based on the claim that it blocks angiogenesis, or the development of new blood vessels that tumors need to survive. A researcher at Harvard Medical School in the 1970s, Judah Folkman, M.D., developed the theory of angiogenesis. Dr. Folkman's proposal that tumors, much like a normal organ or mass of cells, require a supply of blood to deliver nutrients for growth, has since become closely linked to the treatment of cancer with shark cartilage.
In 1983, William Lane, Ph.D., motivated by Folkman's research, began investigating the possible link between shark cartilage and its ability to starve tumors with an antiangiogenetic mechanism. In 1993, Lane published his book Sharks Don't Get Cancer, making shark cartilage one of the leading alternative cancer therapies, with 99% of the cartilage market in 1997 comprised of shark cartilage.
The use of shark cartilage as an alternative treatment has been opposed by wildlife experts who say that use of the substance threatens the shark population. According to figures for 1997, more than one hundred thousand sharks are killed each year to produce cartilage products. Further research has also shattered the myth that sharks do not get cancer. A study discussed at a cancer research meeting in 2000 documented about a dozen cases of apparent cancer in sharks, including cancer of the cartilage.
Both shark and bovine cartilage have been used to treat a wide variety of cancers, including tumors of the breast, ovary, cervix, prostate, rectum, colon, stomach, kidney, and brain. The U.S. Food and Drug Administration (FDA) maintains that both types of cartilage can be tested as potential cancer therapy in clinical trials, but must be sold strictly as dietary supplements. Dietary supplement manufacturers are also prohibited from making specific claims that the supplements can cure disease.
While some studies have shown positive results from both bovine and shark supplements as a treatment for cancer, continued research is being conducted to determine their effectiveness. Some studies indicate that the proposed antiangiogenetic effects of shark cartilage are ultimately destroyed by digestion, and the substance therefore is unlikely to be effective when taken orally. The results from the phase II Cancer Treatment Centers of America (CTCA) shark cartilage study were published in November 1998. The report concluded that oral shark cartilage given as a single agent was ineffective in 47 patients with advanced cancer.
Chondroitin is best known to the general public as a remedy for osteoarthritis, which is a form of arthritis caused by wearing away or degeneration of the cartilage that cushions the ends of bones. It is thought that the drying out of cartilage tissue in osteoarthritis is a major cause of tissue destruction. Chondroitin sulfate is given together with glucosamine, a compound that is a building block of cartilage. The chondroitin helps to attract and hold fluid within cartilage tissue. Tissue fluid keeps cartilage healthy in two ways: it acts as a shock absorber within the joints of the body, thus protecting cartilage from being worn away by the bones; and it carries nutrients to the cartilage.
Several randomized double-blind studies of chondroitin in osteoarthritis patients were conducted in France and Italy in 1998. The European studies demonstrated that oral, as well as injected, chondroitin helps to increase joint mobility and reduce pain. A landmark 2001 study showed that combining glucosamine and chondroitin worked better than either alone in preventing cartilage damage and that both supplements worked well when taken orally.
Shark and bovine cartilage supplements are available in capsule form, while shark is also sold as a powder and liquid. Shark supplements are made from ground-up shark skeletons (mainly the fins and head), while bovine supplements are prepared from the cartilage taken from cow bones. Chondroitin sulfate can be taken orally as a pill, powder, or liquid. It can also be administered by injection. Oral preparations of chondroitin, by itself or in combination with glucosamine, are available in the United States as over-the-counter (OTC) dietary supplements. They can be purchased over the Internet, at pharmacies, health food stores, or even some grocery stores.
The recommended dosage of shark and bovine cartilage varies per person and individual need. General guidelines indicate that the effective dose of shark cartilage is 1 g daily per kilogram of body weight—the equivalent to almost 70 g per day for a 150-pound individual. With observed shrinkage of the tumor, the dosage may be
While cartilage supplements do not appear to be harmful, persons who are considering them as a cancer treatment should not use them as their sole form of therapy and should consult their doctor before taking them. Persons who are considering chondroitin as a treatment for joint pain should be careful not to diagnose themselves. They should check with their physician to be sure that the pain is caused by osteoarthritis. Some conditions, including Lyme disease, gout, bursitis, and rheumatoid arthritis, can also cause pain in the joints. Although chondroitin appears to be helpful in treating osteoarthritis, it is not useful for these other conditions. Chondroitin has not been studied in children or in pregnant or nursing women.
Both shark and bovine cartilage supplements show little or no side effects when taken at the appropriate dosage levels. Some patients have reported an allergic reaction to traces of bovine protein or other side effects that include a bad taste in the mouth, fatigue, and nausea. Shark cartilage can cause hypercalcemia (excessive amounts of calcium in the body) when taken at the recommended daily dose of 70 g per day. This dosage results in 14 times the amount of calcium recommended by the United States Recommended Daily Allowance (USRDA). Some patients taking chondroitin have been known to experience nausea and gas or bloating.
Chondroitin sulfate is not known to cause any significant interactions with other medications. One researcher, however, has suggested that chondroitin might increase the effect of anticoagulant drugs and should probably not be used in combination with them.
Theodosakis, Jason, MD, MS, MPH, Brenda Adderley, MHA, and Barry Fox, PhD. The Arthritis Cure. New York: St. Martin's Press, 1997.
Theodosakis, Jason. "Relief for your Painful Joints (Wellness)." Better Nutrition (May 2002):32.
National Cancer Institute Cancer Information Service (CIS). (800) 4-CANCER or TTY: (800) 332-8615. http://www.cancernet.nci.nih.gov.
NIH National Center for Complementary and Alternative Medicine (NCCAM). NCCAM Clearinghouse. Post Office Box 8218. Silver Spring, MD 20907-8218. TTY/TDY: (888) 644-6226.
Center for Alternative Medicine Research in Cancer Home Page. http://www.sph.uth.tmc.edu/utcam/therapies/crtlg.htm (January 17, 2001).
Teresa G. Odle