It was once believed that injecting shark cartilage into people would prevent them from contracting cancer.

The story behind the answer

True—this was a popular 1990s myth. After lab studies suggested shark cartilage contained compounds that might block angiogenesis (the growth of blood vessels that tumors need), a best-selling book, “Sharks Don’t Get Cancer,” fueled the belief that injections or supplements could prevent cancer. But sharks do get cancer, and rigorous clinical trials found no benefit from shark cartilage products (including extracts like AE-941/Neovastat). The idea was biologically appealing but medically unproven.

Remember it this way: “Ocean myths don’t make medicine.” A plausible mechanism isn’t enough—treatments must work in controlled human studies. Effective cancer prevention relies on evidence-based steps (like not smoking, vaccinations, and screening), not on unproven animal-derived