Could the wide-mouthed creature that sometimes lunches on terrorized swimmers provide a dandy cancer treatment? Some researchers and doctors think so, claiming that there’s something in shark cartilage that can inhibit the growth of tumors in human beings.
Tumor growth involves a process known as angiogenesis, in which the body creates new blood vessels to feed a tumor with oxygen and nutrients as well as remove waste. If the blood supply is removed, the tumor dies. It’s believed that shark cartilage does just that, stopping the development of new blood vessels and thereby starving the tumor.
"Sharks are unique in that they rarely get cancer," says I. William Lane, Ph.D., a biochemist and independent consultant at Cartilage Consultants, Inc. in Short Hills, New Jersey and author of Sharks Don’t Get Cancer and Sharks Still Don’t Get Cancer. "Only roughly one in a million has any signs of cancer, whereas fish get cancer at a rate of about three or four per hundred," he says.
Diving Deeper into Research
While promoters suggest that cancer can be cured with shark cartilage treatments, other doctors are frankly skeptical. "There are no cures. If there were, it would put me and every other cancer doctor out of work," says Charles Simone, M.D., founder of the Simone Protective Cancer Center in Lawrenceville, New Jersey, and author of several books, including Cancer and Nutrition.
Since 1994, Dr. Simone has been conducting one of the few shark cartilage studies approved by the Food and Drug Administration (FDA). The study combines shark cartilage with his own 10-point lifestyle plan that emphasizes proper nutrition, certain vitamin supplements, no smoking, no alcohol, exercise, stress reduction, and other lifestyle changes. The patients he treats are terminally ill, with cancer that has already spread to various parts of their bodies. All have failed to respond to chemotherapy or radiation therapy. In other words, their cancers are widespread and can’t be cured with any conventional treatments.
Using shark cartilage and lifestyle modification, Dr. Simone has seen a response rate of about 15 percent in his patients, defined as a "reduction in tumor mass of at least 50 percent or more for at least four weeks." Not all types of cancers have responded, however. Cancers that occur in the upper part of the body—particularly those of the lungs, head, and neck—don’t seem to be influenced by this treatment.
"We’ll probably never see a lengthening of life span with any treatment," says Dr. Simone. "What we’re looking for in this study is simply response: Can we shrink the tumor or not? The answer is yes, but in a limited number of patients."
Dr. Simone says that he can’t be sure whether the shark cartilage, the 10-point lifestyle plan, or both have caused the reduction in tumors. "I wrote the study the way I did because I think it is unethical to withhold lifestyle changes from cancer patients," he notes.
Improving the quality of life for these terminally ill patients is an important component of Dr. Simone’s study. He defines quality of life as whether the patient, not the doctor, indicates an improvement or not. By this definition, quality of life is enhanced in more than 75 percent of patients, he says. Dr. Simone emphasizes, however, that these are patients who are no longer getting chemotherapy or radiation treatments, so they aren’t experiencing the painful or uncomfortable side effects of those treatments, either. That in itself could account for their temporary improvement in quality of life, he points out.
SUPPLEMENTSNAPSHOT
| Shark Cartilage May help: Inhibit tumor growth. Cautions and possible side effects: Do not take if you are pregnant or have recently had a heart attack or surgery. Do not give to children. May cause gastrointestinal distress in doses of 10,000 milligrams or more. |
Taking a Bite Out of Shark Claims
Robert Langer, Ph.D., professor of chemical and biomedical engineering at the Massachusetts Institute of Technology in Boston, who was one of the early trailblazers in the study of shark cartilage and tumor growth, has been involved in research to isolate the cause of biological activity in cartilage. The goal is to find the active component, purify it, clone it, and ultimately use it on cancer patients.
Oral supplements are created by grinding up shark cartilage. According to Dr. Langer, people who say that this ground-up cartilage can provide a cure for cancer are making some illogical leaps. "I make the following analogy: If somebody is diabetic, he gets pig insulin. Insulin is a large molecule that you can’t swallow. You have to inject it. It took an enormous amount of work by a lot of people to purify that molecule. But just grinding up a pig and injecting it into a diabetic would do nothing." Similarly, chopping up shark cartilage and processing it into supplements that are taken orally isn’t likely to produce results either, he says.
An Ocean of Uses
Dr. Lane has added fuel to the fire of controversy by claiming that cancer is not the only disease that may benefit from shark cartilage. "Cancer is the headline grabber, but shark cartilage will work on any growing mass, such as fibroids," he says.
A number of eye-damaging diseases, such as diabetic retinopathy, macular degeneration, and neurovascular glaucoma, may benefit from shark cartilage, says Dr. Lane, because, like tumors, their growth depends on the formation of new blood vessels.
Dr. Simone strongly disagrees. "There have been no studies, nor have there been any anecdotes to suggest that cartilage can benefit these medical disorders. It is not appropriate to make such speculation," he says.
Connecting with Arthritis
You may also see advertising claims linking shark cartilage to a treatment for rheumatoid arthritis and osteoarthritis. There’s no solid evidence of animal or human studies published in medical journals to support this use, says Luke Bucci, Ph.D., vice president of research for Weider Nutrition International in Salt Lake City and author of several books on arthritis and nutrition, including Healing Arthritis the Natural Way. Besides, he adds, dosages are impractical and high, and the supplement itself is very costly. "I do not advocate shark cartilage supplements to anyone for anything," he explains. "We have so many better choices that we have good data on."
Similarly, bovine cartilage, another supplement used to treat arthritis, has been ineffective. Once researchers began to uncover the active components in cartilage, however, they came up with glucosamine and chondroitin sulfate, Dr. Bucci says. These components, both of which have been used effectively to treat osteoarthritis, are available as separate supplements.
"Thus, the components of shark or bovine cartilage, but not the actual cartilage powder itself, work on arthritis," says Dr. Bucci. "Cartilage powders are much cheaper than purified components. Some manufacturers use cartilage powders and claim that their products have chondroitin."
Land Sharks
You’ll see shark cartilage powders and capsules in the natural foods aisle and in some mail-order catalogs. By Dr. Lane’s estimation, as many as 95 percent of these supplements may be worthless because they have been denatured—that is, their molecular form has been altered during processing, making them largely ineffective against cancer and other illnesses.
"My best advice is to deal with clinical-quality, 100 percent shark cartilage brands from companies that specialize in the shark cartilage business," Dr. Lane says. This poses a dilemma for the average consumer. According to Dr. Lane, off-the-shelf products labeled "shark cartilage" may not be effective.
Meanwhile, research continues. To test the effectiveness of shark cartilage, Dr. Lane has initiated four FDA-approved research studies for a number of different kinds of cancer that have not responded to conventional medical treatments. To participate, patients must have failed to respond to at least two therapies, such as chemotherapy and radiation. The studies are designed to find out whether tumors respond to treatment with shark cartilage and also whether pain can be reduced, improving the patient’s quality of life.
"The main thing we hope to achieve is tumor reduction and extension of life. If we can extend life in a quality manner by four or five years, that will be quite a victory," he says.
