The bones of sharks as medicine
“How easy it is to make people believe a lie, and how hard it is to undo that work again!”
- Mark Twain
I worked with Fusion’s Project Earth team to unearthed a trove of troubling evidence about the shark cartilage industry. Shark cartilage pills, which are taken as health supplements, have no known health benefits and research has shown that they may contain toxins and chemical properties that could be harmful to humans; and now, DNA testing has revealed that various brands of shark cartilage pills contained cartilage from an endangered species of shark, while other brands didn’t have shark cartilage at all, but rather DNA from other marine animals. After Fusion’s team shared their DNA evidence with the manufactures and retailers of shark cartilage products, two leading health stores in the U.S. announced that they had removed the product from their shelves and website.
Nope, cartilage doesn't cure cancer.
Shark cartilage pills first became popular in the 1990’s, when William Lane a biochemist
turned cancer researcher, published a book called “Sharks Don't Get Cancer. How Shark Cartilage Could Save Your Life.” In the book, Lane argued that as cartilage doesn’t have any blood vessels (tumors need blood vessels to grow) and sharks are made almost entirely out of cartilage, a concoction of shark cartilage could help human patients battle various forms of cancer. In 1993 Lane’s work got a publicity boost when 60 Minutes devoted an entire segment to his ideas, and by 1996 Lane decided to follow his first book with a similarly titled sequel: “Sharks Still Don't Get Cancer: The Continuing Story of Shark Cartilage Therapy.” Conveniently, the cartilage concoction that Lane promoted as cancer cure was manufactured by Lane Labs, a company run by his son.
There was only one problem to Lane’s theory: there wasn’t any solid evidence that cartilage actually helped with cancer. In the years that followed, the National Cancer Institute called for research to investigate whether Lane’s cancer cure was as fishy as it sounded; a number of scientists conducted their own trials, but found no reliable evidence that shark cartilage cures cancer. Following these studies, the FDA pushed several injunctions against Lane Labs, and, in 2000, a number of cartilage manufacturers were made to pay restitution to customers because they had falsely claimed their product could help fight cancer.
It’s also been shown that sharks do in fact get cancer.
Cartilage pills are still sold in health stores across the country. Their labels now claim that cartilage can help treat joint pain and arthritis, among other things. But, just like the claim that shark cartilage cures cancer, researchers say there isn’t any medical backing here either. Moreover, recent research into cartilage products has found that at shark cartilage could be harmful to humans if consumed. All the while, shark numbers across the planet are plummeting at unsustainable levels.
The potential health hazards of shark cartilage pills.
“Shark, shark products, shark cartilage, it's not medicine, no proven health benefits,” explained Deborah Mash, professor of Neurology and Pharmacology at the University of Miami. In 2014, Mash co-authored a study which examined shark products, including shark cartilage, for traces of toxic chemicals. Nearly all of the samples that Mash used in her study tested positive for both methylmercury and BMAA, a neurotoxin with links to degenerative diseases such as Parkinson's and Alzheimer's. “We already know that methylmercury is very bad, that's why the EPA tells pregnant women and children not to eat shark, “explained Mash. “But [with BMAA] it gets worse.”
Both BMAA and methylmercury are toxins that biomagnify, which means that they get more concentrated the higher up the food chain you go. And so sharks, as apex predators, tend to have higher concentrations of both toxins then the little critters of the ocean. Mash explains that the presence of both toxins in cartilage products is especially troubling given that they have “synergistic toxicities.”
“Why would you ever supplement your diet with a purported health product that's gonna potentially even a small risk, expose your brain to methylmercury and this neurotoxin BMAA?” said Mash. “I don’t get it.”
The year after Mash published her paper, researchers from the University of Miami released a study suggesting that shark cartilage supplements wouldn’t be helpful in treating the symptoms of arthritis and joint pain. In fact, by exposing human cells to shark cartilage, researchers found that shark cartilage might actually be harmful for those suffering from joint pain.
“Those [human] cells responded by producing a whole list of pro-inflammatory mediators, and our conclusion was that those would be exactly the kinds of mediators you would not want for most of the kinds of conditions for which shark cartilage is marketed,” explained Liza Merly, the study’s co-author and a senior lecturer at the University of Miami, where she focuses on Marine Immunology and Shark Conservation. “I think in a large part the scientific community has thought that the worst case scenario with these kinds of pills is that they have no effect and people are wasting their money, but the worst case scenario could in fact be that they're sort of counter indicated for the kinds of things that people are taking them for.”
Merly pointed out that even though there is mounting evidence against the health benefits of cartilage pills, their status as supplements means that they lie outside the oversight of the FDA; “So there is no governmental body that oversees the production of these products… we don't have a way of checking what the company is putting in the product.”
Even though demand for cartilage pills may be quite small (in 2011, the total U.S. market was about $3 million, according to the Nutrition Business Journal), it’s still another stressor for global shark populations. Merly explained that the cartilage industry adds value to shark carcasses, which, no matter how small the market may be, further incentives shark fishermen to increase their catch.
Moreover, Merly believed that because the manufacturers of cartilage pills have little oversight and provide almost no information about the sharks used for their products, it’s possible that sharks are being sourced unsustainable. “When you call these companies to find out what the geographic location [of the shark] is, what species they use, what age the sharks were, how they were harvested, they do not provide any information,” said Merly. “It could absolutely be any species of shark.”