Shark cartilage cures cancer?

any proof, studies on this? sharks don't get cancer?

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Results From The Foundation's Shark Cartilage-Cancer Survey

The benefits of shark cartilage in treating cancer have been touted in almost every health newsletter in the United States. When the CBS News documentary "60 Minutes" reported on a study that appeared to show that shark cartilage was effective in shrinking tumors and restoring weight and vitality to cancer patients, shark cartilage became the hottest selling cancer therapy in the country.

The most compelling part of the "60 Minutes" broadcast was when an eminent oncologist, independently contacted by CBS News, verified the results of the study and stated that: "Whatever these people were taking was producing tumor shrinkage", and "that is about the best you can hope for in this business". These patients had been taking high doses of shark cartilage, and it looked as if alternative medicine had discovered a real cancer breakthrough.

After this show, The Foundation was besieged by cancer patients seeking a low cost alternative to the high cost shark cartilage products sold in health food stores. While reports of tumor shrinkage and apparent long-term remissions were being reported by some cancer patients, too many people using shark cartilage did not appear to derive any benefit and many of them, eventually, died.

The Foundation Conducts A Survey

In early 1995, The Life Extension Foundation decided to conduct a survey of the people who had purchased shark cartilage products over the last year. A total of 587 questionnaires were sent to people who had purchased shark cartilage products by mail.

These questionnaires asked for detailed information about the type and stage of cancer these people had, the conventional and alternative therapies that had been used, the dose and brand-name of the shark cartilage product used, and the success or failure of shark cartilage therapy as perceived by the patient, their family and/or their doctors.

Results Of Survey

The overall results were disappointing with regard to shark cartilage as a treatment for cancer. Surprisingly, more people reported benefits in using shark cartilage for arthritis than for cancer. What makes this finding remarkable is that this was a SHARK CARTILAGE CANCER SURVEY, not an arthritis survey. The report of successful use of shark cartilage for arthritis came in spontaneously.

When reviewing the results of the survey, it appears that shark cartilage is an effective cancer therapy for some people, and indeed, there are cancer patients who are certain that shark cartilage saved their life.

Out of 587 questionnaires sent to people who had purchased shark cartilage by mail, we received only 74 (12.61%) responses. This poor response rate suggests the possible failure of shark cartilage as a treatment for cancer. Our experience is that people like to report their successes and that only living people are capable of filling out questionnaires.

It's also possible that some patients benefited from other innovative cancer therapies, rather than from shark cartilage. Clearly, the results of our survey are only suggestive, but we believe they are of value. Controlled studies to determine the value of shark cartilage for cancer and arthritis will eventually be conducted, but such studies are expensive and take years to complete. Cancer and arthritis patients simply cannot wait for the the results of such studies. They are suffering and dying in the present and must determine what treatment to use right now!

We conducted our Shark Cartilage Cancer Survey to develop information for use in advising cancer patients. We will continue to evaluate the effectiveness of all cancer therapies in order to provide our members with the best information in the world. It is crucial for everyone following our recommendations to report both their successes and their failures to us, so that we can help others. Please communicate with us in writing about the results you obtain with our disease treatment protocols.

Article copyright Life Extension Foundation.

Sharks and cancer

Scientists at Johns Hopkins University and George Washington University have discovered that sharks may be susceptible to cancer, according to an April 5, 2000, news release from The Johns Hopkins University. For years, businesses have sold shark cartilage as a cancer cure or preventive.

At the annual meeting of the American Association for Cancer Research, scientists presented findings that indicate sharks can get chondromas. In surveying data in the National Cancer Institute's Registry of Tumors in Lower Animals, scientists found 40 cases of tumors in sharks and other related fishes. They do note, however, that this discovery does not rule out the possibility that one day a useful cancer treatment may be found in shark cartilage.

Currently, scientists have not studied cancer rates in sharks, and information currently is not available to allow them to determine the cause of cancer in these animals. Sharks' isolation from humans, and therefore their reduced exposure to carcinogenic pollutants, is one reason for the myth that sharks are not susceptible to cancer.

No proof currently exists that shark cartilage can have positive effects on cancer. Issues, such as the cost of cartilage pills, potential interference with proven cancer treatments, and the potentially devastating impact on the Earth's ecosystem, have scientists deeply concerned about people using shark cartilage.

"People are out there slaughtering sharks and taking shark cartilage pills based on very faulty data, and no preventative studies to show that it works," says Gary Ostrnader, Hopkins professor of biology and comparative medicine. "That is not only giving desperate patients false hope based on misinterpreted data, it is also taking a top level predator out of an ecosystem, which could cause major disruptions in the ecosystem."

Shark Cancers Cast More Doubt on Cartilage Pills (news release, Baltimore: Johns Hopkins University, April 5, 2000) 1-3. Available from http:/ news/home00/apr00/sharks.html. Accessed 9 June 2000.

Shark cartilage and cancer research

So much public interest has been focused on the alleged efficacy of the oral ingestion of shark cartilage as a means to prevent cancer or reduce the size of cancerous tumors. The shark cartilage might be a cancer cure is an idea based on sound scientific research initially done in the early 1970s at Harvard University and MIT. However, an evaluation of the research done in Cuba and Mexico in the 1990s and touted by Lane Laboratories and its founder Dr. William Lane indicates that the therapy is not successful as they claim it to be.

Full Text :COPYRIGHT 1997 Committee for the Scientific Investigation of Claims of the Paranormal

A tremendous amount of marketing has accompanied the sale of shark cartilage as a preventive and cure for cancer. Do the claims far outstrip the evidence?

A Tale of Two Wills

Recently I heard a fascinating story about a man we will call Wilhelm, a German POW imprisoned in the Arizona desert during World War II. He stole a local map and was elated to find that there was a river close to the prison camp. Armed with this knowledge, Wilhelm eagerly recruited several other prisoners with the promise of freedom. They invested a great deal of time and energy digging a tunnel and constructing a small boat that would carry them down the river to Mexico. There was some reason to believe that the plan might succeed. The river was only a few minutes from the tunnel opening, and Mexico was only a few miles away. Finally, they finished their tunnel and escaped into the desert night with Wilhelm leading them toward the river.

The saga of Dr. William Lane and the shark-cartilage cure for cancer parallels this story to a large extent. Lane stumbled onto an interesting idea that held out the promise of freedom from the pain and suffering of cancer. The plan was not without some merit, for it was based on sound scientific research. Studies done at Harvard, MIT, and elsewhere had shown that under certain conditions cartilage sometimes prevented cancer from spreading in laboratory animals (Brem and Folkman 1975). Just as Wilhelm had little trouble convincing hopeless prisoners that his plan was workable, so Lane was able to convince cancer victims that shark cartilage offered them some hope.

Both men found success early on. Wilhelm was able to conceal both the tunnel and the boat from his captors. Lane proclaimed the news of studies in Mexico and Cuba that suggested the ingestion of shark cartilage might reduce the size of cancerous tumors (Lane and Comac 1992; McSweeney 1994). Wilhelm actually escaped with his followers and made it all the way to the river without being detected or pursued. William's book, Sharks Don't Get Cancer (Lane and Comac 1992), sold so well that it led to a sequel, Sharks Still Don't Get Cancer (Lane and Comac 1996). He generated so much interest in shark cartilage that funding was given to researchers to study its effects on human cancer patients under controlled conditions.

But here things take a dramatic turn for the worse for both Wills. When Wilhelm and his compatriots got to the riverbank, they were shocked to find that there was no water. Their seemingly wonderful plan had a serious flaw, and they were recaptured within days. The many critics of William Lane believe that there are serious flaws in his reasoning. They are doubtful that shark cartilage taken orally will ever prove to be a major weapon in the war on cancer. To understand why they are skeptical, let us go back to the beginning of the shark cartilage story.

The Background

Beginning in the early 1970s, Judah Folkman and several colleagues at Harvard and MIT published a series of research papers detailing the use of cartilage as a means of slowing the growth of cancerous tumors. See Folkman and Klagsbrun (1987) for an overview of this research. In some of these studies, the cartilage source was rabbits. In others, it was cattle (bovine); later, sharks. They demonstrated that the growth of a tumor is dependent on a "process through which tumors . . . encourage blood vessel growth in order to supply themselves with nutrients so that they can expand" (Shark cartilage/angiogenesis 1992). This process is called angiogenesis. In other words, solid tumors need a blood supply in order to grow large. Since cartilage usually contains no blood vessels, it was reasoned that something in the cartilage might prevent angiogenesis.

The basic strategy was to implant tumors in laboratory animals and then determine if cartilage delayed angiogenesis. In the Brem and Folkman (1975) study, for example, cartilage was placed between the tumor and a blood supply, and observations were made over a period of time in order to determine if the cartilage slowed or stopped the growth of blood vessels needed to "feed" the tumor. Some control groups received no cartilage, while others received boiled (inactivated) cartilage. The purpose of the latter was to show that the effect was not due to cartilage, per se, but some active chemicals (proteins) in the cartilage. They were able to show that some proteins found in cartilage either halted or (in most cases) delayed angiogenesis slightly.

Langer and colleagues (1976) carried this a step further when they extracted chemicals from bovine cartilage and used the extract alone to inhibit the growth of tumors in rabbits. Injecting the extract into the bloodstreams of rabbits and mice with cancerous tumors greatly inhibited angiogenesis (Langer et al. 1980).

I have read several of the papers authored by Folkman and his colleagues - papers that have appeared in research journals with reputations for publishing top-quality work. In my opinion, their work is quite good, and those experts on cancer research to whom I have talked agree.

Lane Seizes the Shark by the Cartilage

William Lane read a paper by two of Folkman's associates (Lee and Langer 1983) and envisioned a great financial opportunity. What these researchers showed was that shark cartilage produced much the same effect as bovine cartilage. According to cancer researcher John Prudden, Lane came to him in 1983 seeking advice on how to extract shark cartilage (Prudden 1996). In 1990 Lane became the consultant for a company that initiated the commercial production of shark cartilage, and Lane began looking for opportunities to test it on human subjects suffering from cancer. He didn't have to wait long.

At the Ernesto Contreras Hospital in Tijuana, Mexico, in 1991, eight cancer patients were given large doses of Cartilade, the brand name of the shark cartilage that the company produced. A year or so later Cartilade was being given to twenty-nine cancer patients in Cuba. Lane proclaimed both the studies and the product to be highly successful, describing them in glowing terms in his books.

Then something went wrong. According to Prudden (1996), the company filed suit against Lane in 1994. The suit was settled out of court. At approximately the same time, according to Prudden, Lane Laboratories was founded. William Lane was a consultant and his son, Andy, was president of the company.

Since then, William Lane has been eager to demonstrate that his new brand, BeneFin, is even more effective than Cartilade. This eagerness has led to sponsorship by Lane Laboratories of at least two studies. The first is unpublished, although Lane Laboratories has summarized its results in its advertising and in a newsletter (Lane 1996). Dr. James Lott implanted tumors in three groups of mice. Then either bovine cartilage, Cartilade, or BeneFin was administered orally. When the animals died, the tumors were removed and magnified slides were made. The slides appeared to be quite different from each other, a fact interpreted by Lane to mean that BeneFin is a superior product.

In the other study sponsored by Lane Laboratories, Martin Milner (1996) interviewed twenty-one cancer patients by telephone. Each had used shark cartilage and had voluntarily contacted Lane Laboratories to express their satisfaction with it. In the telephone interviews, several reported a reduction in tumor size, and most reported a significant improvement in the quality of their lives. Lane (1996) interpreted this as evidence that the human body can absorb the protein molecules found in shark cartilage when taken orally.

The Numbers Game

Why are some critics skeptical about the claims made for shark cartilage? We can get some idea by looking at a few numbers. Eight Tijuana cancer clinics were cited by Dr James Lowell in a report on Mexican cancer clinics (Lowell 1901) as having used dubious cancer treatments. One of those eight was the Ernesto Contreras Hospital, where a number of questionable treatments were employed, including laetrile, Bible study, and sing-alongs. Because the first printing of the book containing Lowell's article appeared in late 1990, and because it was published by the American Cancer Society, it seems possible that Lane might have been aware of the hospital's reputation before he hooked up with Contreras in 1991.

Eight is also the number of patients who received shark cartilage at the Contreras Hospital. It is very difficult to draw firm conclusions from such a small sample - a problem compounded by the fact that one of the eight quit the treatment and two others had emergency operations while still taking shark cartilage.

Then we have the number of living patients from the Cuban study. An unpublished paper given to me by someone from Lane Laboratories states on page 209 that out of twenty-nine patients, sixteen improved or at least didn't worsen during treatment. An additional six showed "at least short-term improvement during treatment." Twenty-nine minus twenty-two equals seven patients who died. However, further down the page, we find that "eight patients died during the study." In an address Lane gave in late 1993, he was quoted as saying that "of the original twenty-nine patients, nine died during the study" (Lane 1994, 26).

How have the surviving patients fared since the completion of the study? The June 3, 1996, Orange County Register (Dold 1996) ran a story in which Lane was reported as claiming that, as of then, three and a half years after the study was completed, fourteen of the patients were cancer-free. But in April of 1996, another individual close to the shark-cartilage controversy claimed that all of the patients in the Cuban study were now dead (Prudden 1996). I suppose it could be argued that dead patients are cancer-free, so maybe both statements are correct.

There are other numbers too, like the ones that appeared on page 210 of the aforementioned unpublished paper from Lane Laboratories. On that page are six columns of ten numbers - data from a subset of the patients in the Cuban study. When I crunched those same numbers on my computer's statistical program, I found that five of the twelve values reported at the bottom were wrong (two means and three standard deviations). Most of the errors were small, but one of the standard deviations was way off the mark.

Landmark Literary Lane-isms

I have a number of favorite curious statements made by Lane or his associates. Here are some of my favorites.

According to Lane, they have had "countless positive reports of tumor reductions from patients using only BeneFin shark cartilage" (Lane 1996, 1). Maybe so, but where are they? In the Mexican, Cuban, and Milner studies, virtually all of the patients previously received either chemotherapy, surgery, radiation, or some combination thereof. In some cases, these other treatments were given only a few weeks before shark cartilage therapy was initiated. This makes it difficult to tell whether the "success" of these studies was due to shark cartilage.

"They have followed my research, however, and it has even been written up in the July 1992 Journal of the National Cancer Institute" (Passwater 1993, 79). Actually, Lane's name was not mentioned in one of the two articles on shark cartilage that appeared in that issue (Shark cartilage/angiogenesis 1992). The research cited was that of Langer and Folkman, both of whom are unhappy about the way Lane has interpreted their research (Kirchhof and Kirchhof 1995). In the other article (Mathews 1992), Lane was mentioned, but the author's major purpose was to highlight the research of Langer and of Carl Luer, who also opposes what Lane has done. The article concludes by mentioning the skepticism expressed by scientists "about Lane's use of shark cartilage pills" (1002), and by emphasizing the need to understand how something works before we use it on humans.

"I'm a scientist," Lane has said. "If I can't do it the right way, I'm not going to do it" (Snyder 1996). Scientists have been among the most vocal critics of Lane's work (Mathews I993; Prudden 1996). Most scientists agree that the right way to conduct the Mexican and Cuban studies would have been to randomly assign half of the subjects to the shark cartilage group and the other half to a placebo group. The placebo should have been made to look, smell, and taste as much like the shark cartilage as possible. The treatments should have been given to patients who did not know which treatment they were getting by research assistants who did not know which treatment they were administering. Inferential statistics should have been used to determine if any differences between the two groups were reliable. None of these things were done in the Mexican, Cuban, or Milner studies.

"The data have been presented to some of the more critical organizations, including some of the best known cancer research centers, and to date, not one has expressed anything but major interest" (Lane n.d., 7). The "Sixteen Questions" brochure from which this quote was taken probably originated in 1995, because it also refers to BeneFin as a new product. At that time Lane's ideas had already been criticized by representatives of the National Cancer Institute and the American Cancer Society (Mathews 1993). More recently, spokespersons for the Foundation for Cartilage and Immunology Research have been sharply critical of Lane's ideas as well as his practices (Kirchhof and Kirchhof 1985; Prudden 1996). Despite these criticisms, the above quote from Lane, along with the rest of the "Sixteen Questions" brochure, was still available on the Internet at least as recently as March of this year.

Here's a gem from Martin Milner, an associate of Lane's: "This study was funded by Lane Labs . . . with the understanding in advance that the results would be published regardless of the findings" (Milner 1996, 99). I appreciate the need for an understanding of this sort when a sponsor is financially supporting a research project that evaluates the sponsor's product. I had a similar agreement with a supplement manufacturer when I did a double-blind study evaluating one of its products (McCutcheon 1996), and the sponsor honored that agreement in spite of a mostly negative outcome. The problem with Milner s statement is that, because of the way his subjects were chosen (all had previously reported beneficial effects to Lane Laboratories), there was no way the study could have yielded anything other than a positive outcome.

Referring to the unpublished study by Lott in which mice with cancerous tumors received BeneFin, Cartilade, or bovine cartilage, Lane had this to say: "BeneFin performed far better than all other products tested - showing no toxicity and incredible efficacy against solid tumors" (Lane 1996, 2). However, Lott told me that his work showed only that the three products yielded slides of the magnified tumors that looked noticeably different from each other (Lott 1997). He was not willing to conclude that BeneFin was necessarily a better product. Furthermore, he told me that he had found no significant difference in longevity among the three groups. If human cancer patients had a choice between living a long period of time or a shorter time but having their tumors look different on a slide, which do you think they would choose?

In commenting on the need to follow the progress of cancer patients, Lane said: "Many treatments provide an excellent initial response. They shock the tumor and stop its growth, but only temporarily" (Lane and Comac 1996, 174). In other words, we need to track subjects who participate in cancer treatment studies for a long time, to make sure that the effect was more than just a blip on the radar screen. With that thought in mind, we might ask why there was no long-term followup in the Mexican study?

What Lies over the Horizon?

One of the principle objections to Lane's marketing of shark cartilage is that it is worthless when taken orally (Shark cartilage/angiogenesis 1992). Some experts believe that none of the protein molecules that fight angiogenesis can survive the digestive process (Mathews 1992), but others disagree (Blackadar 1993; Gardner 1988; Simone 1997). What percentage of these molecules survive digestion intact and eventually get to the site of the tumor? It isn't clear, yet, but my reading of Gardner's paper suggests that it is likely to be small. If the percentage is near zero then the oral use of shark cartilage should decline, and we can hope that the ongoing attempt to synthesize the antiangiogenic molecules found in cartilage is successful.

At this point, it is fair to say that shark cartilage taken orally is unproven as a cancer remedy for humans. That, combined with its high cost, would discourage me from taking it as a preventative measure. For those who already have cancer, I would discourage its use by anyone who is pregnant or trying to become so, and anyone who is recovering from wounds, just in case it does have some small effect. The growth of new blood vessels is vital for these people. It is also unlikely to work on the several kinds of cancers that do not rely on the process of angiogenesis. I would also recommend against its use by anyone who is not psychologically prepared to deal with the possibility that it might not work at all. Finally, and most important, it should never be used alone as a substitute for the more conventional forms of cancer treatment.

One point on which I agree with Lane is the need for top-quality, double-blind research in which human cancer patients are orally given shark cartilage or a placebo and carefully studied for a long time. Fortunately, a few such studies have been approved and funded in the mid-1990s. I know that some of them are nearing completion (Simone 1997).

William Lane has worked tirelessly to convince others that shark cartilage is the tunnel that leads to freedom from cancer. Many people have risked their lives and a significant portion of their income to buy a seat on his boat. I believe that the river bed is just over the horizon. Will there be any water in it?


Blackadar, C. B. 1993. Skeptics of oral administration of shark cartilage. Journal of the National Cancer Institute (December): 1961-2.

Brem, H., and J. Folkman. 1975. Inhibition of rumor angiogenesis mediated by cartilage. Journal of Experimental Medicine 141: 427-39.

Dold, C. 1996. Controversy surrounds the sale of shark-cartilage pills as a cure for cancer. Orange County Register, June 3.

Folkman, J., and M. Klagsbrun. 1987. Angiogenic factors. Science 235: 442-7.

Gardner, M. L. 1988. Gastrointestinal absorption of intact proteins. Annual Review of Nutrition 8: 329-50.

Kirchhof, D., and E. Kirchhof. 1995. The Successful Use of Bovine Tracheal Cartilage in the Treatment of Cancer. Belgrade, Mont.: Kriegel & Associates.

Lane, I. W. 1994. Shark cartilage modulates angiogenesis. Vitamin Retailer (March): 25-7.

-----. 1996. Shark Cartilage Update 3(2).

-----. n.d. Sixteen Questions Most Often Asked of Dr. I. William Lane. Kerrville, Tex.: Information Services.

Lane, I. W., and L. Comac 1992. Sharks Don't Get Cancer. New York: Avery.

-----. 1996. Sharks Still Don't Get Cancer. New York: Avery.

Langer, R., H. Brem, K. Falterman, M. Klein, and J. Folkman. 1976. Isolation of a cartilage factor that inhibits tumor neovascularization. Science 193: 70-2.

Langer, R., H. Conn, J. Vacanti, C. Haudenschild, and J. Folkman. 1980. Control of tumor growth in animals by infusion of an angiogenesis inhibitor. Proceedings of the National Academy of Sciences 77: 4331-3.

Lee, A., and R. Langer. 1983. Shark cartilage contains inhibitors of tumor angiogenesis. Science 221: 1185-7.

Lott, J. 1997. Personal communication.

Lowell, J. A. 1991. Mexican cancer clinics In Dubious Cancer Treatment, edited by S. Barrett and B. Cassileth. Tampa, Fla.: American Cancer Society.

Mathews, J. 1992. Sharks still intriguing cancer researchers. Journal of the National Cancer Institute (July): 1000-2.

-----. 1993. Media feeds frenzy over shark cartilage as cancer treatment. Journal of the National Cancer Institute (August): 1190-1.

McCutcheon, L. E. 1996. Treatment of anxiety with a homeopathic remedy. Journal of Applied Nutrition 48: 2-6.

McSweeney, D. 1994. Shark cartilage attacks illness. Vitamin Retailer (March): 22-5.

Milner, M. 1996. Follow-up of cancer patients using shark cartilage. Alternative Complimentary Therapies 2: 99-109.

Passwater, R. A. 1993. Shark cartilage and cancer. Whole Foods, pp. 42, 44, 76, 79.

Prudden, J. F. 1996. Position paper on cartilage therapy history and comparison of bovine and shark cartilage. Townsend Letter for Doctors and Patients (April): 44-7.

Shark cartilage/angiogenesis. 1992. Journal of the National Cancer Institute (July), news section.

Simone, C. 1997. Personal communication.

Snyder, B. 1996. FDA OKs shark cartilage for tests on cancer patients. Nashville Banner, July 10.

Lynn McCutcheon, a longtime psychology professor, is a health food store owner who would like to see the industry make a concerted effort to stop the promotion of bogus products. Previously he wrote articles in the SKEPTICAL INQUIRER on the Bach Flower Remedies (July/August 1995) and aromatherapy (May/June 1996). He can be reached at 240 Harbor Drive, Winter Garden, FL 34787.

 Answer by prokopton

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