TOC  |    Herbal Medicine    

Herbal Medicine                                            
REF:  http://www.intelihealth.com/IH/ihtIH/WSIHW000/8513/31402.html    

Be aware that the U.S. Food and Drug Administration does not strictly regulate herbs and dietary supplements. There is no guarantee of strength, purity or safety of products containing or claiming to contain shark cartilage. Decisions to use herbs or supplements should be carefully considered. Individuals using prescription drugs should discuss taking herbs or supplements with their pharmacists or health care providers before starting.

Evidence   

Scientists have studied shark cartilage for the following health problems:

Cancer

Historically, it was thought that sharks did not get cancer (we know now that this is not true). Therefore, it was thought that taking shark cartilage supplements may work against cancer. There have been several studies using shark cartilage in humans with various types of cancer, and most of the current evidence shows shark cartilage may have some efficacy in preventing angiogenesis (formation of new blood vessels by the tumor that supports growth and spread of cancer to other parts of the body). A randomized, controlled, multicenter trial reported a significantly longer survival time in patients receiving shark cartilage at a higher dose than at a lower dose. The shark cartilage was in the form of Neovastat, an orally active extract from shark cartilage tissue, but the amount of shark cartilage provided in the doses given in the study was not indicated. This study included only 22 patients in the analysis, even though 144 were given the drug. Currently, many animal studies and studies done in test tubes suggest shark cartilage would be effective in preventing angiogenesis. However, larger studies need to be done in humans before recommendations can be made. Possible forms of cancer that may respond to treatment with shark cartilage include kidney cancer, lung cancer and multiple myeloma (cancer of the bone marrow), but safety and efficacy have not been confirmed. Check with your doctor and pharmacist before taking shark cartilage.

Psoriasis

Researchers have tested shark cartilage for psoriasis, both by mouth and on the skin as a cream. These studies have been small and low quality. At this time, there is no reliable evidence to recommend shark cartilage for psoriasis.

Macular degeneration

One small study using shark cartilage in patients with macular degeneration suggested good results. More studies are needed before a recommendation can be made.

Pain

Animal studies suggest that shark cartilage may decrease inflammation and pain, but there are no reliable studies in humans.

Unproven Uses    

Shark cartilage has been suggested for many other uses, based on tradition or on scientific theories. However, these uses have not been thoroughly studied in humans, and there is limited scientific evidence about safety or effectiveness. Some of these suggested uses are for conditions that are potentially very serious and even life-threatening. You should consult a health care provider before using shark cartilage for any unproven use.

Atherosclerosis (clogged arteries) Bacterial infections Diabetic retinopathy Diarrhea Fungal infections Glaucoma Immune system stimulant Kaposi's sarcoma Kidney disease Lupus

Osteoarthritis Osteoporosis Reiter's syndrome Rheumatoid arthritis Sarcoidosis Scarring Sjogren's syndrome Skin rash Wounds Wrinkles

Potential Dangers    

Allergies

• People with a history of allergies to shark cartilage or any of its ingredients (including chondroitin sulfate and glucosamine) should avoid taking products containing shark cartilage. Patients with sulfur allergy should use caution because products may be sulfated.

Side Effects

• Shark cartilage is well tolerated by most people for up to 18 months. Some patients receiving a shark cartilage product called Neovastat reported few side effects, even after being exposed to the product for more than four years. Mild stomach discomfort, dizziness and fatigue may occur. There are rare cases of high blood sugar (hyperglycemia) and high levels of calcium in the blood (hypercalcemia). In theory, slower wound healing and irregular heartbeats could occur when taking shark cartilage. One study reports taste alteration to be the most frequent side effect, seen in 13.6 percent of patients. An existing case report blames inhaled shark cartilage dust for the death of a 38-year-old male, with an autopsy confirming asthma as cause of death. Shark cartilage should be considered an occupational safety hazard in facilities that may use it.

Pregnancy And Breast-Feeding

• Shark cartilage should be avoided by pregnant or breast-feeding women because of theoretical concerns that it may affect the growth of developing blood vessels and cause birth defects.

Interactions    

Interactions with drugs, herbs and other supplements have not been thoroughly studied. The interactions listed below have been reported in scientific publications. If you are taking prescription drugs, speak with your health care provider or pharmacist before using herbs or dietary supplements.

Interactions With Drugs

• Shark cartilage products are rich in calcium. If used with calcium supplements or drugs that raise calcium levels in the blood, such as hydrochlorothiazide (Hydrodiuril), shark cartilage may cause serious problems (for example, irregular heartbeats). In theory, shark cartilage may add to the effects of drugs that decrease the growth of blood vessels or healing of wounds. Examples are thalidomide and interferon. Shark cartilage may lower blood sugar levels. Caution is advised if you also are taking drugs that may lower blood sugar levels. Patients taking oral drugs for diabetes or using insulin should be monitored closely by their health care provider while using shark cartilage. Dosing adjustments may be necessary. In theory, very large doses of shark cartilage may actually increase blood sugar levels.

Interactions With Herbs And Dietary Supplements

Shark cartilage may lower blood sugar levels. People using other herbs or supplements that may alter blood sugar levels, such as bitter melon (Momordica charantia), should be monitored closely by their health care provider while using shark cartilage. Dosing adjustments may be necessary. In theory, shark cartilage may raise blood sugars levels if taken with glucosamine. Shark cartilage is rich in calcium and should not be combined with calcium supplements. Other trace elements that are found in higher amounts in shark cartilage than in other fishes and in other animal bones include iron, zinc, selenium, copper, manganese, molybdenum, titanium and strontium.

Dosing    

The doses listed below are based on scientific research, publications or traditional use. Because most herbs and supplements have not been thoroughly studied or monitored, safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients even within the same brand. Combination products often contain small amounts of each ingredient and may not be effective. Appropriate dosing should be discussed with your health care provider before starting therapy; always read the recommendations on a product's label. The dosing for unproven uses should be approached cautiously, because scientific information is limited in these areas.

To increase absorption, shark cartilage should be taken on an empty stomach. Acidic fruit juices, such as apple, grape, orange, tomato or cranberry juice, should be avoided for 15 to 30 minutes before and after taking shark cartilage.

Adults (Aged 18 Or Older)

Ground cartilage extract: A dose of 80 to 100 grams per day or one to 1.3 grams per kilogram of weight per day, divided into two to four doses, has been taken by mouth.

Children (Younger Than 18):  Shark cartilage should be avoided in children because of concerns that it may interfere with normal growth.

For Psoriasis

Adults (Aged 18 Or Older)

• Ground cartilage extract: A dose of 0.4 to 0.5 grams per kilogram of weight per day for four weeks has been taken by mouth. If symptoms improve, reduce the dose to 0.2 to 0.3 grams per kilogram of weight per day.
• Skin cream: A dose of 5 percent to 30 percent cream has been applied to the skin daily for four to six weeks.

For Arthritis

Adults (Aged 18 Or Older)

• Ground cartilage extract: A dose of 0.2 to two grams per kilogram of weight per day, divided into two to three doses, has been taken by mouth.

Summary    

• Although shark cartilage has been suggested for many diseases, there is no scientific evidence to support its use for any medical condition. It should be avoided by pregnant or breast-feeding women, by children and by patients with a history of diabetes or high calcium blood levels. Shark cartilage may increase the risk of bleeding or high calcium blood levels caused by other drugs. Consult your health care provider immediately if you have side effects.

The information in this monograph was prepared by the professional staff at Natural Standard, based on thorough systematic review of scientific evidence. The material was reviewed by the Faculty of the Harvard Medical School with final editing approved by Natural Standard.

Resources    

Selected Scientific Studies: Shark Cartilage

• Natural Standard reviewed more than 145 articles to prepare the professional monograph from which this version was created.

Some of the more recent studies are listed below:

Last updated June 21, 2005