Are all sharks immune to cancer

Sharks get cancer!

Cartilage blocks new blood vessels from forming. Therefore, cartilage can also inhibit tumor formation. Sharks, on the other hand, have a lot of cartilage and apparently do not develop tumors. Ergo: If I swallow ground shark cartilage, I protect myself against cancer. Humbug! Mainly because sharks are very likely to get cancer.

(September 9, 2010) Bayer 04 Leverkusen is not one of the most popular clubs among German football fans. There are multiple reasons for that. What hardly counts, however: About three years ago the factory club of the pharmaceutical (!) Giant Bayer advertised on its homepage for shark cartilage preparations as anti-cancer drugs.

Such nonsense should actually stand for forced relegation to the association league. Because not least because of such actions, quite a few people still believe the fairy tale about the sharks who don't get cancer. A misconception that has led, among other things, to the fact that the shark populations in North American waters have decreased by about 80% in recent years. No wonder that certain companies there kill up to 200,000 sharks per month to produce dubious shark cartilage products with names like 'Country Life', 'Now' or 'Puritan's Pride'.

To make it immediately and unmistakably clear: Sharks get cancer! In 2004, for example, researchers from the University of Hawaii combed the 'Smithsonian Registry for Tumors in Lower Animals' - and found 42 listed cartilaginous fish tumors. Twelve of them were malignant tumors that had spread throughout the body; two sharks had multiple ulcers, and even tumors in shark cartilage have been reported multiple times.

So how did the myth that sharks get cancer come about - including the even bigger misconception that shark cartilage can protect humans from tumors? It began with none other than the “Pope of Angiogenesis”, Judah Folkman, who passed away in 2008. In the 1970s, he and his colleague Henry Brem made the simple observation that cartilage inhibits the formation of new blood vessels, i.e. angiogenesis. And since a functioning angiogenesis is known to be one of the absolute key requirements for the formation of malignant tumors, Brem and Folkman subsequently looked for substances in cartilage that inhibit the formation of blood vessels. Because, according to the general logic, whoever inhibits the formation of new capillary blood vessels may also inhibit tumor formation.

Indeed, when Brem and Folkman planted pieces of rabbit cartilage right next to tumors, they inhibited capillary formation - whereupon the tumors stopped growing due to a lack of vascularization (J Exp Med (141), 427-439). Around the same time, a Florida team found that the carcinogen aflatoxin B1 did not cause tumors in sharks. Whereupon some clever minds immediately concluded that this must be due to the large amount of cartilage in the shark.


One of them was William Lane, a doctor of nutrition and biochemistry, who immediately fell into the idea that simply swallowing shark cartilage powder could protect yourself from cancer. He wrote two books on the subject: Sharks Don't Get Cancer: How Shark Cartilage Could Save Your Life (1992)and Sharks Still Don't Get Cancer (1996). And of course he also started a company called LaneLabswho manufactures and sells shark cartilage pills to this day.

But he wasn't the only one. Dozens of companies got on board - and hunted sharks. With the results mentioned above. In 1995 alone, global sales of shark cartilage products exceeded 23 million euros

In this country, the Starnberg-based company Medisana Medizinische Vertriebsgesellschaft is part of the crew. It has been producing and selling the shark cartilage preparation 'Haifit' since the mid-1990s. In 1996 the controversial pharmacist Gregor Huesman from Marburg put Haifit in his shop window as 'Shit of the Month'. Some lawsuits followed. However, after a brief ban, Haifit has been back on the market as a dietary supplement since 1997. Til today. A judgment to which the Skeptics Portal Esowatch writes: “This means that an ineffective miracle drug is legally on the market again. As long as the provider only secretly advertises his miracle drug, he can do so without any trouble with the German judiciary. A typical example of the actual value of the legal system and a measure of the low level of consumer protection in the FRG. "

Ineffective mainly because the cartilage preparation is completely digested in the stomach - and therefore no active ingredients, if any, can reach the tumors via the bloodstream.

Bayer 04 Leverkusen quickly removed its advertising for shark cartilage preparations from its homepage. Apparently a competent employee of the pharmaceutical company immediately told his colleagues from the sport what everyone should understand: Sharks do get cancer, and swallowing shark cartilage for cancer is nonsense.

What remains is the phenomenon that under certain circumstances shark cartilage extracts can actually inhibit angiogenesis. However, it has not been possible to identify a real inhibitor in thirty years of research.


Ralf Neumann


Further sources:


- shark cartilage for cancer (
- Erich Eder (2002) Are sharks immune to cancer? Alternative medicine versus species protection (
- Ocean of Pseudoscience: Sharks DO get cancer! (
- Do Sharks Hold Secret to Human Cancer Fight? (

Last changes: 03/04/2013