What is Shark Cartilage?
Shark cartilage is extracted from the heads and fins of sharks. Cartilage is a type of connective tissue that is found in the skeletal systems of many animals, including humans. Sharks’ skeletons are made up almost entirely of cartilage. The major compounds in shark cartilage are proteoglycans and glycoproteins (large molecules with protein and carbohydrate components), as well as protein and calcium salts. Shark cartilage is promoted mainly as an alternative to conventional cancer treatment, but some forms are being studied for use along with standard therapies.
Although some laboratory and animal studies have shown that some components in shark cartilage have the ability to slow the growth of new blood vessels, these effects have not been proven in humans. The few small clinical studies of shark cartilage products published to date have not shown any benefit against cancer. Further clinical trials of the supplements and of a purified cartilage extract are currently under way.
How is it promoted for use?
Supporters believe that shark cartilage supplements or cartilage from other animals, such as cows, can slow or stop the growth of cancer (see also Bovine Cartilage). According to its supporters, shark cartilage contains proteins that stop angiogenesis, the process of blood vessel development. Tumors need a network of blood vessels to survive and grow, so cutting off the tumor’s blood supply starves it of nutrients, causing it to shrink or disappear. Some supporters also claim that shark cartilage can help against other diseases such as osteoporosis, arthritis, psoriasis, macular degeneration, and inflammation of the intestinal tract.
In what form it is taken?
Most shark cartilage products are sold as dietary supplements in the form of pills or powders. Most have not been tested for effectiveness, safety, or to verify the purity of ingredients. Available scientific evidence does not support claims that shark cartilage supplements sold as food supplements are an effective treatment for cancer, osteoporosis, or any other disease. One shark cartilage product, called AE-941, is in the early phases of development as an investigational new drug.
Shark cartilage, the tough material that a sharks’ skeleton is composed of, is dried and powdered to create this popular dietary supplement.
Shark cartilage is usually taken by mouth as a capsule, powder, or liquid extract, but some people have trouble taking it by mouth because of the strong fishy smell and taste. It is sometimes used as an enema. The dose and length of treatment varies widely. Manufacturers often recommend large doses (up to 1 cup a day). Chondroitin, a supplement often used with glucosamine to help arthritis, is also made from cartilage. Either bovine or shark cartilage may be used to produce chondroitin.
Shark cartilage dietary supplements are different from AE-941, a liquid shark extract known as Neovastat. This extract is regulated by the U. S. Food and Drug Administration (FDA) as an investigational new drug. AE-941 is being used in carefully controlled clinical trials for people who have agreed to be part of the study.
A New York surgeon named John Prudden began investigating the use of animal cartilage as a medical treatment in the early 1950s. He used powdered cow cartilage to help heal the wounds of surgical patients and later used it to treat cancer. He reported that tumors shrank in more than half of the patients he treated, but the results have not been repeated in other studies.
Since then, many kinds of cartilage, from animals such as pigs, sheep, chickens, cows, and sharks, have been studied. After the 1992 publication of a popular book titled Sharks Don’t Get Cancer, written by I. William Lane, PhD, shark cartilage supplements became very popular among people interested in alternative medicine. The idea was that since cancer does not seem to develop in sharks as much as in humans, there may be something in the sharks’ systems that protects them from the disease.
Interest in shark cartilage increased after a television news magazine aired a segment in 1993 showing a study of patients with advanced cancer in Cuba who had gone into remission after being treated with shark cartilage. The results, however, have not been published in a peer-reviewed medical journal. The National Cancer Institute (NCI) later concluded that the results of the Cuban study were “incomplete and unimpressive.”
According to the FDA and the Federal Trade Commission, some manufacturers of shark cartilage supplements have been fined and/or forced to remove their products from the market for making unproven claims that they have cancer-fighting abilities. Such claims can only be made for drugs with proven effects.
Finding drugs that halt the spread of cancer by stopping the growth of blood vessels has been the subject of many conventional research studies in recent years. Some researchers believe that this therapy, called anti-angiogenesis therapy, holds a great deal of promise for certain types of cancer. A number of anti-angiogenesis drugs are currently being studied, and one is already approved to treat certain types of cancer. In addition, several drugs that were approved for other uses, including cancer treatment, have anti-angiogenic effects. These are now being studied more carefully for their role in anti-angiogenesis. Some researchers are trying to purify compounds in cartilage that stop the growth of blood vessels. But the most promising anti-angiogenic substances now in existence are those that have been purified from sources other than cartilage or have been made in laboratories.
Actual Evidence :
Shark cartilage is claimed to combat and/or prevent a variety of illnesses, most notably cancer. It is often marketed under the names Carticin, Cartilade, or BeneFin. A derivative of it named Neovastat was tested by AEterna Zentaris as an angiogenesis inhibitor and showed promising results in animals. Two clinical trials of Neovastat were completed in 2007, showing negative results
The consensus of available scientific evidence does not support claims that whole shark cartilage supplements are an effective treatment for cancer in humans. Although studies using cow and shark cartilage in people with cancer began in the early 1980s, few have been published. The scientific truth of many of these studies is open to question because they do not describe how treatment was given, how patients were assessed, long-term survival outcomes, or information about the cartilage used and its components.
Some experiments have shown that some forms of shark cartilage possess a modest ability to slow the growth of new blood vessels in laboratory cell cultures and in animals, but the effects on humans are not known. According to one review, results from 9 clinical series of patients receiving shark cartilage were mixed. None of the series were done under strict scientific controls.
In one clinical trial involving about 50 patients, researchers concluded that shark cartilage supplements had no effect on patients with advanced-stage cancers. When a more recent placebo-controlled clinical trial tested shark cartilage in more than 80 patients with advanced cancer, no benefit was found. “It wasn’t well tolerated, there wasn’t any suggestion of benefit in terms of quality of life, there wasn’t any suggestion of benefit in terms of survival,” commented Charles L. Loprinzi, the physician who authored the study report.
Researchers generally agree that the protein molecules in shark cartilage may be too large to be absorbed by the digestive tract and are simply excreted without ever reaching tumors in the body. However, some scientists have suggested that these substances may be more readily absorbed when taken in a liquid form. One study concluded that the liquid shark cartilage extract AE-941 (Neovastat) taken by mouth effectively slowed the growth of new blood vessels in healthy men, suggesting to the study authors that the active ingredients in liquid shark cartilage were available for use by the body’s healing systems.
A small study of the extract found that larger doses were better than smaller doses at prolonging survival in patients with advanced kidney cancer. A larger study was then done. While the results of this study have not been published, the manufacturer has stopped testing it against kidney cancer, suggesting that the results may not have been positive. The NCI sponsored a large, placebo-controlled randomized clinical trial using the extract with conventional chemotherapy and radiation therapy for the treatment of advanced (stage III) lung cancer. Preliminary results in this study were reported at the 2007 meeting of the American Society of Clinical Oncology. Based on analysis of outcomes from 379 patients, the researchers concluded that AE-941 did not improve overall survival.
This product is sold as a dietary supplement in the United States. Unlike drugs (which must be tested before being allowed to be sold), the companies that make supplements are not required to prove to the Food and Drug Administration that their supplements are safe or effective, as long as they don’t claim the supplements can prevent, treat, or cure any specific disease.
Some such products may not contain the amount of the herb or substance that is written on the label, and some may include other substances (contaminants). Actual amounts per dose may vary between brands or even between different batches of the same brand.
Most such supplements have not been tested to find out if they interact with medicines, foods, or other herbs and supplements. Even though some reports of interactions and harmful effects may be published, full studies of interactions and effects are not often available. Because of these limitations, any information on ill effects and interactions below should be considered incomplete.
Shark cartilage is not thought to be toxic, although it has been known to cause nausea, indigestion, fatigue, fever, and dizziness in some people. It may affect liver function, so ask your doctor before taking it if you have any kind of liver disease. It may also slow down the healing process for people recovering from surgery. People with a low white blood cell count should not take shark cartilage enemas, because there is a risk of life-threatening infection. Children should not take it because it could interfere with body growth and development.
Allergic reactions are possible. People with seafood allergies should avoid shark cartilage and chondroitin that is made from it. Women who are pregnant or breast-feeding should also avoid these supplements.
It is not known whether shark cartilage could cause any problems from interactions with other medicines. Relying on this type of treatment alone and avoiding or delaying conventional medical care for cancer, may have serious health consequences.
Criticism and controversy
Proponents of shark cartilage are encouraged by anecdotal evidence from users as to its efficacy. The proponents also cite studies that show that shark cartilage has had some success in preventing angiogenesis, the growth of new blood vessels from pre-existing vessels. While angiogenesis is often a normal function, it is also consistent with the growth of malignant tumors. They argue too, that very little research (in the quantity and quality of studies) has been conducted, and thus the benefits cannot be scientifically disputed.
Opponents cite existing studies of shark cartilage on a variety of cancers that produced negligible to non-existent results in the prevention or treatment of cancer. Most notably was the breast-cancer trial conducted by the Mayo Clinic that stated that the trial “was unable to demonstrate any suggestion of efficacy for this shark cartilage product in patients with advanced cancer.”  The results of another clinical trial were presented at the 43rd annual meeting of the American Society for Clinical Oncology. In that study (sponsored by the National Cancer Institute), “researchers did not find a statistical difference in survival” between patients receiving shark cartilage and those taking a placebo.
Detractors also purport that previous beliefs in regards to sharks and cancer have been overturned, as forty-two varieties of cancer have now been discovered in sharks and related species. Also, many opponents feel that non-existent (or even limited) results do not justify the rampant over-fishing of many endangered species of sharks, further threatening their extinction.
The protein involved in inhibiting angiogenesis would have to be injected into the bloodstream to have any effect on the cancer in the body. When a patient takes shark cartilage orally the protein is digested before it reaches the area of the tumor. Not all cancers rely on angiogenesis for energy.
In the summer of 2004, Lane Labs, the manufacturers of BeneFin, was ordered to cease the promotion BeneFin as a treatment or cure for cancer, as they had not conducted any research as to their claims for the product, much less reported any potential side effects. Thus, the FDA ordered Lane Labs to “pay restitution to all of its customers from September of 1999 to the present