Junkfood Science: Sharks do too get cancer!

June 04, 2007

Sharks do too get cancer!

Millions of people have purchased shark cartilage supplements, believing it could help cure their cancers. Despite well-designed clinical trials showing it to be worthless, the biological implausibility that these supplements could ever even work, and that government agencies have been taking actions against shark cartilage marketers for years — beliefs in shark cartilage have continued for decades. This sadly demonstrates how people see only what they want to believe and will reject all amounts of evidence to the contrary.

Another clinical trial just released at the annual meeting of the American Society for Clinical Oncology found shark cartilage to be worthless as a cancer treatment. What may be most unsettling for medical professionals is not the findings, but that our government diverted limited cancer research resources — which includes cancer patients — to conduct another study on a treatment with such little likelihood of proving of any value.

According to the National Cancer Institute:

Cartilage from cows (bovine cartilage) and sharks has been studied as a treatment for cancer and other medical conditions for more than 30 years. Studies to date have not proven cartilage to be an effective treatment for cancer in people...Since the 1970s, there have been more than a dozen clinical studies of cartilage as a treatment for cancer....

On their website, the NCI reviews the randomized clinical trials that have been conducted and published to date, all of which have shown shark cartilage to have no effect on the quality of life or survival rates as compared to a placebo.

Dr. Victor Herbert, M.D., J.D., who had been a professor of medicine at Mount Sinai School of Medicine and chief of the Hematology and Nutrition Research Laboratory at the Bronx Veterans Affairs Medical Center, along with Dr. Stephen Barrett, M.D. of Quackwatch, wrote an overview of the research behind questionable cancer therapies, with some helpful tips for consumers on typical misrepresentations, noting:

Misinformation about questionable cancer therapies is spread through books, articles, audiotapes, videotapes, talk shows, news reports, lectures, health expositions, “alternative" practitioners, information and referral services, and word of mouth. Promoters typically explain their approach in commonsense terms and appear to offer patients an active role in their care: (a) cancer is a symptom, not a disease; (b) symptoms are caused by diet, stress, or environment; (c) proper fitness, nutrition, and mental attitude allow biologic and mental defense against cancer; and (d) conventional therapy weakens the body's reserves, treats the symptoms rather than the disease. Questionable therapies are portrayed as natural and nontoxic, while standard (responsible) therapies are portrayed as highly dangerous.

They remind us that what sounds natural, helpful and intuitive, isn't necessarily true. Nor can "healthy" diets, exercise and positive mental attitude prevent cancer, as much as it is natural to want to believe cancer is something we can control. Along with reviewing the research and expert reviews in which even scientists at the Cancer Treatment Research Foundation and Cancer Treatment Centers of America concluded shark cartilage had no action on cancer, including those of the breast, colon, lung and prostate, what may be surprising to learn is how many actions have been taken against companies marketing shark cartilage. Yet these alternative modalities are still being marketed and they continue to have a following.

This concerns many doctors, including doctors Barrett and Herbert, because: “The dangers of using questionable treatments include delay in getting appropriate treatment, decreased quality of life, direct physical harm, interference with proven treatment, waste of valuable time, financial harm, and psychological damage.”

Perhaps most frustrating is the difficulty in helping people recognize science that can credibly support clinical claims and those tactics used by junk science. One unsound idea is mistakenly believing that an effect seen in the lab means anything in real life. Not only are we not rats, but our bodies are certainly not test tubes. Concerning shark cartilage, they explained: “Although a modest anti-angiogenic effect has been observed in laboratory experiments, it has not been demonstrated... [human] in patients with cancer. Even if direct applications were effective, oral administration would not work because the protein would be digested rather than absorbed intact into the body.”

Once a pseudoscientific belief gets out there it never dies, but keeps going and going. Dr. Steven Novella, M.D., at Neurologica wrote a terrific article today entitled “Shark Cartilage, Cancer, and the Ethics of Research.”

To those who may remember the rumor (that sharks don’t get cancer) that began the whole shark cartilage pseudoscience, Dr. Novella explains:

This dubious observation was followed by the even more dubious logic that it must be their cartilage that has magical anti-cancer properties. A liberal dose of wishful thinking, biased observation, and exploitive marketing then led to the belief that consuming shark cartilage could treat or cure cancer in humans. In fact, sharks do get cancer.

But it’s too late, the belief is out there. The need for hope at all costs and the relative absence of critical thinking skills has proven most effective in sustaining beliefs, even when the core claims have been utterly shattered. Such is human nature, and the need for science and the nurturing of the critical thinking that does not seem to come naturally to our species.

The real tragedy is that our scientific and healthcare institutions have become distorted and compromised by social forces of ignorance and irrationality coming in the guise of openness, freedom, and multiculturalism. These institutions should be serving and protecting society by following a mature and thoughtful system of ethics and scientific methods. They should be rocks that can weather the storms of fads and fashionable nonsense. Instead they are now largely promoting them by offering an undeserved imprimatur of scientific legitimacy.

He is, of course, referring to the NIH which funds all too many studies of questionable merit, and specifically the National Center for Complementary and Alternative Medicine, which has spent nearly $965 million since 1992 on alternative modalities and not discovered one new breakthrough treatment or been able to find scientific support for a single life-saving therapy.

As he laments, “resources of time, effort, appropriate subjects, and money were diverted from more promising cancer research in order to deal with a popular but worthless treatment. This is an inefficiency in biomedical research that we would all be better off without.”

He goes on to explain and caution that one can take any biological product and find something that has an effect in the lab and make all sorts of speculations and claims for some clinical effect. But, this kind of research “often becomes a hunt for post-hoc rationalization — almost a data-mining exercise.” For consumers, this highlights the need to:

Always be suspicious of clinical claims of benefit based solely on Petri-dish evidence. Most of this type of information does not pan out as we expect. Second, the fact that someone can find a putative mechanism for an alleged clinical effect does not, in and of itself, provide much support for the clinical claim. The bottom line is that clinical claims must be plausible and must also be supported by solid clinical research. Also, science works by connecting all the dots very carefully.

I won’t spoil the end, but critical thinkers will be eager to see if the CAM community takes him up on his challenge.

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