“Sharks can't get cancer.”

It's a common misunderstanding that sharks are immune to cancer, a notion that gained significant traction from a 1992 book titled "Sharks Don't Get Cancer" by I. William Lane and Linda Comac. While the book itself suggested sharks rarely get cancer, it controversially promoted shark cartilage as a miraculous cure for human cancer, a claim that was amplified by media attention, including a segment on 60 Minutes. This sparked a widespread belief that these ancient predators held a secret to disease resistance.

However, scientific evidence clearly busts this myth. Sharks, like virtually all other animals, can and do develop cancer. The first documented malignancy in a shark specimen dates back to 1908, and since then, scientists have recorded various types of tumors in over 40 different shark species and their relatives. Cases include a great white shark found with a substantial tumor and a blue shark diagnosed with a malignant growth in its gums. While cancer may be observed less frequently in sharks compared to some other species, this could be partly due to their vast oceanic habitats making observation difficult, rather than a true immunity.

The enduring appeal of this myth lies in a combination of factors. The captivating image of sharks as powerful, ancient creatures naturally leads some to believe they possess extraordinary biological defenses. Furthermore, the desperate hope for a cancer cure fueled the commercial market for shark cartilage supplements, despite a complete lack of scientific backing for their effectiveness. It is crucial to understand that consuming shark cartilage does not prevent or cure cancer and can even be detrimental to health due to high mercury content, while also posing a threat to shark populations through overfishing. Scientists continue to study shark immune systems and genetics for insights into disease resistance, but this research does not support the myth of cancer immunity or the use of shark cartilage as a remedy.