Shark Cartilage : Safety

by MedlinePlus

(Page 2 of 2)

Allergies

Allergic reactions to shark cartilage or to any of its ingredients are possible, although there is limited human information in this area. Caution should be used in patients with a sulfur allergy since products may be sulfated.

Side Effects and Warnings

A limited amount of published research suggests that shark cartilage is well tolerated in most people at recommended doses. An 18-month study in 330 people by the makers of the shark cartilage derivative Neovastat® did not report any major toxicities after being exposed to the product for more than 4 years. The most common adverse effects reported are mild-to-moderate stomach upset and nausea. In several studies, 5% to 10% of patients stopped taking shark cartilage due to gastrointestinal distress (nausea, vomiting, constipation, dyspepsia), while 20% to 40% experienced milder symptoms of cramping or bloating. Gastrointestinal upset may be due to the high calcium concentration in some shark cartilage preparations. There is one report of liver damage in an elderly male using shark cartilage, which resolved six-weeks after the supplement was stopped. One study reports taste alteration to be a frequent side effect, observed in up to 14% of patients.

Uncommon side effects reported in studies or historically include confusion, decreased muscle strength, decreased sensation, weakness, dizziness, fatigue, increased or decreased blood sugar levels, and low blood pressure. Shark cartilage products may contain high levels of calcium, which may be harmful to patients with kidney disease, abnormal heart rhythms, a tendency to form kidney stones, and those with cancers that raise calcium levels (breast, prostate, multiple myeloma, squamous cell lung cancer, and others). In theory, due to the blocking of new blood vessel growth, shark cartilage may be harmful in people with heart disease or narrowed blood vessels of the legs (peripheral vascular disease). In theory, wound healing and recovery from surgery or trauma may be reduced.

Limited evidence suggests that shark cartilage may lower blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Serum glucose levels may need to be monitored by a healthcare provider, and medication adjustments may be necessary.

One case report implicates inhaled shark cartilage dust in an asthma exacerbation and resulting death of a 38-year-old male.

Pregnancy and Breastfeeding

Shark cartilage is not recommended in pregnant or breastfeeding women. Shark cartilage may block the growth of new blood vessels, and drugs with similar properties, such as thalidomide, can cause birth defects. There is limited study of shark cartilage in these areas.

Interactions

Interactions with Drugs

Shark cartilage products may contain high doses of calcium, and may cause dangerously high blood calcium levels when taken with drugs known to increase blood calcium. Examples include long-term use of thiazide diuretics such as chlorothiazide (Diuril®). In theory, shark cartilage may add to the effects of drugs and experimental agents that block new blood vessel growth. Examples include: Ag3340, Bay12-9566, leflunomide (Arava®), Marimastat, Anti-VEGF antibody, carboxyaminotriazole, CGS 27023A, AGM-1470, SU5416, Vitaxin, EMD 121974, Interleukin-12, CM 101, Interferon α and β, and thalidomide. Based on one animal study, the cancer drug cisplatin and shark cartilage may act together against tumors, although there is no reliable human supporting evidence.

Limited evidence suggests that shark cartilage may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar. Patients taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare provider. Medication adjustments may be necessary.

Interactions with Herbs and Dietary Supplements

Shark cartilage products may contain high doses of calcium, and may cause dangerously high calcium levels in the blood when taken with calcium supplements or antacids such as Tums®. Chondroitin sulfate, a popular therapy for osteoarthritis, is a component of shark cartilage. In theory, use of shark cartilage with chondroitin may lead to higher than expected blood levels of chondroitin, with unknown effects.

Limited evidence suggests that shark cartilage may lower blood sugar levels. Caution is advised when using herbs or supplements that may also lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment. Possible examples include: Aloe vera, American ginseng, bilberry, bitter melon, burdock,fenugreek, fish oil, gymnema, horse chestnut seed extract (HCSE), marshmallow, milk thistle, Panax ginseng, rosemary, Siberian ginseng, stinging nettle and white horehound. Agents that may raise blood sugar levels include: Arginine, cocoa, and ephedra (when combined with caffeine).

Trace elements that are found in shark cartilage in higher amounts than those in other fish or animal bones include iron, zinc, selenium, manganese, copper, molybdenum, titanium and strontium.

Interactions with Foods

Acidic fruit juices, such as apple, grape, or cranberry, may reduce the absorption of shark cartilage taken by mouth.

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