Shark cartilage

Shark cartilage is a dietary supplement made from the dried and powdered cartilage of a shark; that is, from the tough material that composes a shark's skeleton. Shark cartilage is marketed under a variety of brand names, including Carticin, Cartilade, or BeneFin, and is marketed explicitly or implicitly as a treatment or preventive for various illnesses, including cancer.

There is no scientific evidence that shark cartilage is useful in treating or preventing cancer or other diseases.^[1][2] Controlled trials have shown no benefit to shark cartilage supplements,^[3] and shark cartilage contains potentially toxic compounds linked to Alzheimer's disease and amyotrophic lateral sclerosis.^[4][5] However, shark cartilage supplements are still marketed using the misconception that sharks do not get cancer, a myth that was as popularized by the 1992 book Sharks Don't Get Cancer. In the United States, the Federal Trade Commission has taken legal action against such fraudulent promoters.^[6][7]

Tumors of many kinds, some metastatic, have been found in numerous species of sharks.^[8] The first shark tumor was recorded in 1908. Scientists have since discovered 40 benign and cancerous tumors in 18 of the 1,168 species of sharks. Scarcity of studies on shark physiology has perhaps allowed the myth to be accepted as fact for so many years.^[9] Numerous cancers in sharks, including tumors in shark cartilage, were documented by Gary Ostrander and his colleagues from the University of Hawaii in research published in 2004.^[10]

The ongoing consumption of shark cartilage supplements has been linked to a significant decline in shark populations and the popularity of these supplements has been described as a triumph of pseudoscience and marketing over scientific evaluation.^[1]