Busting Marine Myths: Sharks DO Get Cancer!

There are a lot of myths out there about the marine world, but by far the one that bothers me the most is the notion that sharks don't get cancer. This simply untrue statement has led to the slaughter of millions of sharks via the industry for shark cartilage pills, which are sold to desperate cancer patients under the false pretense that they can help reduce or cure their illness. A young researcher by the name of Robert Langer decided to repeat the initial rabbit cartilage experiments, except this time using shark cartilage. Since sharks skeletons are entirely composed of cartilage, Langer reasoned that they would be a far more accessible source for potential therapeutics. And indeed, shark cartilage, like calf and rabbit cartilage, inhibited blood vessels from growing toward tumors . He'd noticed that sharks seem to have relatively low rates of disease, especially cancer, and wanted to test their susceptibility experimentally. So he exposed nurse sharks to high levels of aflatoxin B , a known carcinogen, and found no evidence that they developed tumors . He'd heard about the studies done by Langer and Luer, and become immediately entrenched with the idea that oral shark cartilage could be a treatment for cancer. He then co-authored a second book, Sharks Still Don't Get Cancer , in 1996. But Lane was not alone - many companies began selling shark cartilage pills and powders as alternative therapies or nutritional supplements. The world market for shark cartilage products was estimated to have exceeded $30 million in 1995, prompting more and more harvesting of sharks for their cartilage. decreased by up to 80% in the past decade, as cartilage companies harvest up to 200,000 sharks every month in US waters to create their products. One American-owned shark cartilage plant in Costa Rica is estimated to destroy 2.8 million sharks per year . Shark cartilage does not cure or treat cancer in any way, even in mouse models . These are also the results of at least three randomized, FDA-approved clinical trials - one in 1998 , another in 2005 , and a final one presented in 2007 . Ingestion of shark cartilage powders or extracts had absolutely no positive effects on cancers that varied in type and severity. To paraphrase Dr. Andrew Vickers, shark cartilage as a cancer cure isn't untested or unproven, it's disproven . Indeed, the Federal Trade Commission stepped in by 2000, fining Lane $1 million as well as banning him from claiming that his supplements, or any shark cartilage derivatives, could prevent, treat or cure cancer. No matter what a money-grubbing man with a PhD in Agricultural Biochemistry and Nutrition tries to tell you, sharks do get cancer . A shark whose function is compromised by tumors would likely end up the meal of other, hungry sharks long before they'd end up on a hook cast by researchers. There were even tumors found in shark's cartilage ! Sharks are the only known species to never suffer from cancer." So any statement that even suggests that sharks are cancer resistant is misleading at best, and down right wrong at worst. Sharks are the earliest evolutionary lineage to have developed an adaptive immune system complete with immunoglobin, T-cell receptors, MHCs and RAG proteins , and they do it without bone marrow, the source of almost all of our immune system cells. But instead, we mindlessly kill over 100 million of them a year to make Asian delicacies and ineffective cancer treatments, and we keep brainwashing our kids into believing that shark's don't get cancer. Shark cartilage contains inhibitors of tumor angiogenesis. Evaluation of shark cartilage in patients with advanced cancer: a North Central Cancer Treatment Group trial. Shark cartilage, cancer and the growing threat of pseudoscience.