Shark Cartilage

Cartilage is a tough, somewhat elastic tissue found mainly in the joints of many animals, including humans. The skeleton of a shark, however, is made entirely of cartilage, rather than bone.

It is true that shark cartilage possesses a compound that, in the laboratory at least, has anticancer effects. The growth of any tumor requires the creation of new blood vessels to feed it-a biological process called angiogenesis. Anything that blocks the blood supply to the tumor stops the tumor from growing and eventually kills it. It's believed that shark cartilage contains glycoprotein compounds that have an anti-angiogenesis effect.

Shark cartilage is purported to ease the pain and inflammation of arthritis, but it is best known as an alternative treatment for cancer. It is said to slow the growth of existing tumors and prevent new cancers from developing.

Chondroitin sulfate, a compound that has shown promise on its own as an arthritis remedy, is found in significant amounts in shark cartilage, and may explain its role in easing the pain and inflammation of arthritis. A group of Canadian researchers found that a preparation of shark cartilage, used on the skin, had an anti-inflammatory effect. An animal study conducted in Brazil found that shark cartilage had a pain-relieving effect.

In the 1970s, laboratory studies found shark cartilage to have anticancer properties. But human studies have not shown much promise. Most of the evidence of its effectiveness is based on testimonials, rather than scientific research. The most highly publicized study was of sixty patients with several types of advanced cancer who were given daily doses of powdered shark cartilage for twelve weeks. Five patients died during the study and none showed any reduction in the size of their tumors.

Claims that shark cartilage is effective against viral diseases, especially HIV and herpes infections, have not been scientifically proved. Many researchers maintain that shark cartilage, when taken orally, is digested by stomach acids and unlikely to be of much benefit.

Shark cartilage comes from sharks that are caught for food or from nonendangered species such as the spiny dogfish shark. However, some ecologists are concerned that widespread killing of sharks is depleting their numbers worldwide.

Most shark cartilage is taken from the fins and head. It is dried and ground into a powder that is made into capsules and tablets in doses of 250 to 800 mg each. It is also available as a powder and a liquid, and in some countries, it has also been given as an injection. Because shark cartilage is not standardized, the amount of glycoprotein compounds likely varies greatly from product to product. In fact, some products have been found not to contain any shark cartilage at all or have been diluted with bovine (cow) cartilage, which is also being investigated as a possible anticancer agent. To get the dosage used in the research studies, it would take forty or more capsules a day of products available over the counter. Some experts say that the active compounds in shark cartilage may not even be effective when taken by mouth.

Side effects are not common with shark cartilage, though some people have experienced a bad taste in the mouth, gastrointestinal upset, fatigue, and nausea. Because it is supposed to act by preventing the growth of new blood vessels, it could be harmful if it is taken during pregnancy or by children, surgery patients, or anyone who has sustained a recent injury that has not fully healed.

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