A Myth Ends: Shark Cartilage Is Not Effective Against Cancer!

Many rumors circulate about marine life, but one attracts more attention than all the others: sharks do not get cancer as the "rumor" goes… This belief causes millions of sharks to be slaughtered for cartilage medicines sold to desperate cancer patients with claims of reducing or curing cancer…

What Is the History of Testing Shark Cartilage in Cancer?

The rumor began in the 1970s when Johns Hopkins researchers Henry Brem and Judah Folkman first found that cartilage prevents new blood vessels developing within tissueas a scientific observation. Angiogenesis , this formation of blood vessels, is a key feature of malignant tumors and a frequent target for potential cancer treatments.

Brem and Folkman investigated antiangiogenic cartilage compounds. Because cartilage lacks vessels, they reasoned it must signal molecules or enzymes preventing capillary formation. Placing young rabbit cartilage beside tumors in experimental animals inhibited growth. Later studies found similar effects in calf cartilage. A young researcher, Robert Langer, repeated the rabbit experiment using shark cartilage. Sharks' entirely cartilaginous skeletons seemed a more accessible treatment source. Shark cartilage indeed inhibited tumor-directed blood vessel growth, like calf and rabbit cartilage.

Meanwhile, Carl Luer at Sarasota's Mote Marine Laboratory studied sharks and cancer. Finding low disease rates, particularly cancer, he investigated why. He gave sharks large amounts of the known carcinogen aflatoxin B1, but observed no tumor development.

Dr. William Lane then entered the picture. Hearing Langer and Luer's findings, he immediately believed cartilage drugs could treat cancer. In 1992, he published “Sharks Don't Get Cancer: How Shark Cartilage Could Save Your Life”. It became a bestseller and Lane a media focus. An inadequate study he conducted in Mexico with Cuban physicians was described as extraordinary. In 1996, he published “Sharks Still Don't Get Cancer”, his second book.

Lane also established Lane Laboratories to hunt sharks and make cartilage pills, still sold today. Other companies followed with drugs and powders marketed as alternative treatments or supplements. In 1995, worldwide cartilage product sales exceeded 30 million dollars . More sharks are hunted for cartilage every day.

The consequences were terrible. North America's shark population fell over the past 10 years by %80. Companies catch nearly 200.000 sharks monthly in American waters. An American factory in Costa Rica planned to kill approximately 2.8 million annually. Sharks grow slowly compared with other fish and cannot live long enough to reproduce under this pressure. Unless global fishing rates fall, some species will sadly disappear before we realize it.

Does Shark Cartilage Actually Work Against Cancer?

Results of studies in 1998-2005 and 2007, also monitored by theFDA, were negative in at least 3 investigations. This ecological destruction for a useless product is tragic. Shark cartilage does not treat or cure cancer, and powders or pills have no positive effect in any cancer. Dr. Andrew Vickers likewise states it is not therapeutic. The United States Federal Trade Commission intervened in 2000 and imposed a 1 million dollar fine on Lane , prohibiting claims that his supplements or any cartilage derivatives could treat, cure or prevent cancer.

But the worst partis that this fraudulent enterprise, taking money from desperate people seeking the slightest hope, rests on a fairy tale. Whatever money-hungry people with agricultural biochemistry and nutrition doctorates say, sharks get cancer too!..

Cartilage not developing cancer does not mean sharks cannot. Moreover, human cartilage also very rarely develops cancer. The perception of low shark cancer rates comes from just one disease-incidence study. Nobody has systematically checked cancer or other diseases. A low-rate study does not mean resistance or immunity. Sharks are pelagic, deep-water fish; some live in relatively unpolluted areas, exposing them to fewer carcinogens than coastal species.

In 2004, University of Hawaii researcher Dr. Gary Ostrander and a colleague published a tumor-record investigation. Already, 42 tumors had been found in cartilaginous fishes, the group including sharks, rays and catfish. At least 12 were malignant and spreading. In 2 sharks, multiple tumors suggested genetic susceptibility or excessive carcinogen exposure. Tumors even occurred in cartilage! Ostrander hoped this would dispel the myth.

Despite this, cartilage pills remain on sale and many intelligent people still believe the tale. Worse, social media even includes tweets such as “There must be something in the water. Sharks are the only species known not to get cancer” and similar statements.

Conclusion

To summarize: sharks get cancer! There is insufficient evidence that cancer is uncommon in them, and nobody has systematically assessed rates. Claims of resistance are therefore misleading and completely wrong.

The most disappointing aspect is that sharks' immune system is fascinating and worth studying for cancer suppression. Sharks are the earliest evolutionary lineage with advanced adaptive immunity involving RAG proteins, T-cell receptors and immunoglobulins. They have two unique immune organs, Leydig's and Epigonal, whose functions are incompletely understood. Studying shark immunity is necessary to understand adaptive immunity's evolution in all vertebrates. If truly resistant to cancer, their immunity deserves even greater attention. Instead, we kill over 100 million sharks for ineffective treatment and mislead people by claiming they do not get cancer.