Cartilage is elastic, translucent connective tissue in people and animals. Most cartilage turns into bone as animals mature, but some remains in its original form in places such as the nose, ears, knees, and other joints. Two kinds of cartilage are used as nutritional supplements. Bovine cartilage (also called cow cartilage) comes from cattle, and shark cartilage comes from sharks. (Interestingly, sharks do not have any bones in their bodies, only cartilage.) Cartilage supplements started to be used to treat cancerous tumors when researchers observed that a protein in shark cartilage stopped the growth of new blood vessels. Since tumors get their nourishment from blood, they need to make new networks of blood vessels in order to grow. If shark cartilage could stop the blood vessels from being developed, researchers reasoned, then the cancer couldn't grow and might even shrink. However, studies to prove that the process works in humans have not yet been published. Bovine cartilage has been shown to speed up wound healing and reduce inflammation.

Here is a partial list of the health problems cartilage helps to relieve:

• Psoriasis, a skin disease that is also worsened by overgrowth of blood vessels
• Bone diseases, such as osteoporosis
• Rheumatoid arthritis
• Osteoarthritis
• Inflammation and pain, especially in joints
• Intestinal inflammation

Not available; use commercially prepared cartilage for safety.

Cartilage is sold in powdered form or in capsules that contain the powder.

New anticancer drugs are being developed to take advantage of the effective elements in cartilage supplements.

When using shark or bovine cartilage as a dietary supplement, 3 to 4,750 mg capsules per day.

• Whether you're using shark or bovine cartilage, buy from reputable manufacturers.
• Check labels carefully and choose only supplements that contain 100% pure shark cartilage.
• Check the color of the cartilage supplements before you take them. Any color other than white means the product is not pure and you should not consume it.
• Never give cartilage supplements to children.
• Pregnant women should not take cartilage.
• People who recently had surgery or recently survived a heart attack should not take cartilage supplements.

Cartilage can be used in addition to conventional treatments for cancer and arthritis, but it should not be a substitute for conventional treatments. Check with your health care provider, and if you're taking cartilage on your own, be sure to let your health care provider know what type and how much you're taking.

Cartilage supplements are expensive. Bovine cartilage costs about $160 for a month's supply, while shark cartilage is about $700 for a month's supply.

No noteworthy interactions (positive or negative) between cartilage and conventional medications are known to have been reported in the literature to date.

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