Cartilage is a tough connective tissue found in many parts of the body. Your ears and nose are made from cartilage, and so is the gliding surface in your joints.

One constituent of cartilage, chondroitin, is widely used in Europe to treat osteoarthritis. Cartilage itself has also been proposed as a treatment for osteoarthritis.

The most commonly used forms of cartilage come from cows (bovine cartilage) and sharks. Provocative evidence had suggested that shark cartilage might have some value in the treatment of cancer. However, properly designed studies have so far failed to find benefit.

Unless your uncle works at a slaughterhouse or you're brave enough to prepare your own cartilage from whole sharks, the preferred source of cartilage is your healthfood store or pharmacy, where you can purchase this supplement in pill or powdered form.