Your joint supplements may be made from powdered sharks

No one seems to know what percentage of chondroitin supplements are made from ground-up shark cartilage, perhaps because most chondroitin comes in bulk from mysterious sources in China. But the booming supplement poses enough of a threat to disappearing sharks that conservation groups, including Shark Trust, urge people to avoid it. Some groups urge people to buy only bovine chondroitin, which is made from cattle tracheas, if that’s a more comforting thought.
Chondroitin is usually combined with glucosamine, currently the most popular supplement in the United States with annual sales of more than $200 million, according to the University of Washington Department of Family Medicine (glucosamine pdf, chondroitin pdf). Glucosamine is usually made from shrimp and crab shells.
Both supplements contain the chemical building blocks of human cartilage, and we take them under the assumption that if we consume those building blocks, our body will have what it needs to make new cartilage. Studies have not borne out that assumption, although some patients have reported reduced pain from osteoarthritis. Many scientists believe the supplements pass through our bodies without doing much at all.
Except that they increase demand for shark, shrimp, and crab parts.
When the Journal of the American Medical Association or the Annals of Internal Medicine publish studies on glucosamine and chondroitin that fail to mention imperiled sea life, they sometimes hear from Dr. Martin Donohoe of Oregon Physicians for Social Responsibility. In 2007, Dr. D.T. Felson suggested in an editorial that there’s no harm in letting patients take chondroitin if they think it works, and Donohoe responded:
I disagree. In the midst of the largest global extinction since the demise of the dinosaurs 65 million years ago, when we are losing over 5,000 species per year (10,000 times the naturally-occurring rate of extinction), we must take special care to preserve all creatures and promote biodiversity.”
Fishermen kill 70 million sharks per year, according to the Pew Charitable Trusts, and 80 percent of sharks have vanished from some areas of the ocean. To add insult to injury, chondroitin is often used in arthritis supplements for pets, killing sharks so pet owners can believe they’re reducing arthritis pain in their dogs.
Booming sales in glucosamine and chondroitin can be traced, alas, to the media, which began reporting on the supplements in the mid-1990s. The positive coverage included popular books like “The Arthritis Cure” by Jason Theodosakis, and of course the New York Times is also at fault:
Sales boomed after New York Times health columnist Jane Brody wrote in a 1997 column that the combination helped her arthritic dog and relieved her own knee pain by about 30 percent. But Brody went on to have a double knee replacement, and recent studies have found little or no benefit from glucosamine and chondroitin, either separately or in combination, for treating osteoarthritis.
Related story: Meet a shark attack survivor who now works to save sharks.