Shark Cartilage

by MedlinePlus

Shark cartilage is one of the most popular supplements in the United States, with over 40 brand name products sold in 1995 alone. Primarily used for cancer, its use became popular in the 1980s after several poor-quality studies reported "miracle" cancer cures.

Laboratory research and animal studies of shark cartilage or the shark cartilage derivative product AE-941 (Neovastat®) have demonstrated some anti-cancer (anti-angiogenic) and anti-inflammatory properties. However, there is currently not enough reliable human evidence to recommend for or against shark cartilage for any condition. There are several ongoing cancer studies. Many trials are supported by manufacturers of shark cartilage products, raising questions about impartiality.

Commercial shark cartilage is primarily composed of chondroitin sulfate (a type of glycosaminoglycan), which is further broken down in the body intoglucosamineand other end products. Although chondroitin andglucosaminehave been extensively studied for osteoarthritis, there is no evidence supporting the use of unprocessed shark cartilage preparations for this condition. Shark cartilage also contains calcium (up to 600-780mg of elemental calcium/daily dose). Manufacturers sometimes promote its use for calcium supplementation.

Shark cartilage supplements at common doses can cost as much as $700-1000 per month.

Synonyms

AE-941, Arthrovas, cartilage, Haifischknorpel (German), Houtsmuller Diet, Neoretna, Neovastat®, Psovascar, shark, shark fin soup, Sphyrna lewini (hammerhead shark), Squalus acanthias (spiny dogfish shark), squalamine, U-955.

Note: The product Catrix® is made from cow cartilage, not from shark cartilage.

Evidence

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Uses based on scientific evidence

Cancer

For several decades, shark cartilage has been proposed as a cancer treatment. Studies have shown shark cartilage or the shark cartilage product AE-941 (Neovastat®) to block the growth of new blood vessels, a process called "anti-angiogenesis," which is believed to play a role in controlling growth of some tumors. There have also been several reports of successful treatments of end-stage cancer patients with shark cartilage, but these have not been well designed or included reliable comparisons to accepted treatments.Many studies have been supported by shark cartilage product manufacturers, which may influence the results. In the United States, shark cartilage products cannot claim to cure cancer, and the Food and Drug Administration (FDA) has sent warning letters to companies not to promote products in this way. Without further evidence from well-designed human trials, it remains unclear if shark cartilage is of any benefit in cancer and patients are advised to check with their doctor and pharmacist before taking shark cartilage.

Arthritis

Chondroitin sulfate, a component of shark cartilage, has been shown to benefit patients with osteoarthritis. However, the concentrations of chondroitin in shark cartilage products may be too small to be helpful. The ability of shark cartilage to block new blood vessel growth or reduce inflammation is proposed to be helpful in rheumatoid arthritis. However, there is limited research in these areas, and more studies are needed before a recommendation can be made.

Macular degeneration

It is proposed that shark cartilage or the shark cartilage product AE-941 (Neovastat®) may be helpful in patients with macular degeneration. A small amount of research suggests possible benefits, but more study is needed before a recommendation can be made.

Psoriasis

Shark cartilage products have been tested by mouth or on the skin in people with psoriasis. However, no clear benefits have been shown. More research is needed before a conclusion can be drawn.

Pain

Based on laboratory studies, shark cartilage may reduce inflammation. However, it is unclear if shark cartilage is a safe or helpful treatment for pain in humans.

Uses based on tradition or theory

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Allergic skin rashes, ankylosing spondylitis, atherosclerosis (clogged arteries), bacterial infections, diabetic retinopathy, diarrhea, immune system stimulant, intestinal disorders and inflammation, fungal infections, glaucoma, Kaposi's sarcoma, kidney disease, kidney stones, lupus, osteoarthritis, osteoporosis, Reiter's syndrome, rheumatoid arthritis, sarcoidosis, scar healing, Sjogren's syndrome, skin rash, systemic lupus erythematosus (SLE), wound healing, wrinkle prevention.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Standardization

Standardization involves measuring the amount of certain chemicals in products to try to make different preparations similar to each other. It is not always known if the chemicals being measured are the "active" ingredients. There is no well-accepted method of preparing or purifying shark cartilage products, although manufacturers may use specific procedures to control their own processes. Shark cartilage products are often made by sterilizing and grinding dried shark cartilage (hammerhead or spiny dogfish shark) into a powder form. Some manufacturing processes can destroy the proteins that are believed to slow cancer growth. Analysis of one shark cartilage product found it to contain more than 99% water.

Adults (18 years and older)

Cancer: 80 to 100 grams, or 1.0 to 1.3 grams per kilogram of body weight, of ground shark cartilage extract has been taken by mouth daily, divided into 2 to 4 doses. Doses of the shark cartilage derivative AE-941 (Neovastat®), available in clinical trials, have ranged from 30 to 240 milliliters per day taken by mouth, or 20 milligrams per kilogram taken twice daily. Rectal doses of 15 grams per day or 0.5 to 1.0 grams per kilogram of body weight per day in 2 to 3 divided doses (prepared as an enema) have also been studied.

Arthritis: Doses of 0.2 to 2.0 grams per kilogram of body weight per day, taken by mouth in 2 to 3 divided doses, have been studied.

Psoriasis: Doses of 0.4 to 0.5 grams per kilogram of body weight per day, taken by mouth for four weeks, have been used. If skin lesions improve, doses have been reduced to 0.2 to 0.3 grams per kilogram per day for four additional weeks. Creams applied to the skin with 5% to 30% shark cartilage are available, and have been recommended by some practitioners for treatment of psoriasis alone or with shark cartilage by mouth, for 4 to 6 weeks. Studies have used 5% to 10% preparations applied daily.

Children (younger than 18 years)

Shark cartilage is not recommended in children due to lack of scientific study and a theoretical risk of blocking blood vessel growth. There is one report of a nine year-old child with a brain tumor treated with shark cartilage who died four months later.

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