According to WebMed, the shark cartilage (tough elastic tissue that provides support, much as bone does) used for medicine comes primarily from sharks caught in the Pacific Ocean. Several types of extracts are made from shark cartilage including squalamine lactate, AE-941, and U-995.
Shark cartilage is most famously used for cancer. Shark cartilage is also used for osteoarthritis, plaque psoriasis, age-related vision loss, wound healing, damage to the retina of the eye due to diabetes, and inflammation of the intestine (enteritis).
A more realistic picture is pained by this abstract:
The promotion of crude shark cartilage extracts as a cure for cancer has contributed to at least two significant negative outcomes: a dramatic decline in shark populations and a diversion of patients from effective cancer treatments. An alleged lack of cancer in sharks constitutes a key justification for its use. Herein, both malignant and benign neoplasms of sharks and their relatives are described, including previously unreported cases from the Registry of Tumors in Lower Animals, and two sharks with two cancers each. Additional justifications for using shark cartilage are illogical extensions of the finding of antiangiogenic and anti-invasive substances in cartilage. Scientific evidence to date supports neither the efficacy of crude cartilage extracts nor the ability of effective components to reach and eradicate cancer cells. The fact that people think shark cartilage consumption can cure cancer illustrates the serious potential impacts of pseudoscience. Although components of shark cartilage may work as a cancer retardant, crude extracts are ineffective. Efficiencies of technology (e.g., fish harvesting), the power of mass media to reach the lay public, and the susceptibility of the public to pseudoscience amplifies the negative impacts of shark cartilage use. To facilitate the use of reason as the basis of public and private decision-making, the evidence-based mechanisms of evaluation used daily by the scientific community should be added to the training of media and governmental professionals. Increased use of logical, collaborative discussion will be necessary to ensure a sustainable future for man and the biosphere.
To be clear: there is no good evidence that the supplements commercially available currently are effective for any condition.
Now, there is more news on this topic:
The objective of this study was to analyse labelling practices and compliance with regulatory standards for shark cartilage supplements sold in the United States. The product labels of 29 commercial shark cartilage supplements were assessed for compliance with U.S. regulations. Claims, including nutrient content, prohibited disease, and nutritional support statements, were examined for compliance and substantiation.
Overall, 48% of the samples had at least one instance of non-compliance with labelling regulations. The most common labelling violations observed were:
- missing a domestic address/phone number,
- non-compliant nutrient content claim,
- missing/incomplete disclaimer,
- missing statement of identity,
- prohibited disease claims,
- incomplete “Supplement Facts” label.
The use of prohibited disease claims and nutritional support statements without the required disclaimer is concerning from a public health standpoint because consumers may delay seeking professional treatment for a disease.
The authors concluded that the results of this study indicate a need for improved labelling compliance among shark cartilage supplements.
In summary, it seems that shark cartilage supplements are bad for all concerned:
- Patients who rely on them might hasten their death.
- Sharks are becoming an endangered species.
- Consumers are being mislead and misinformed.
There is just one party smiling: the supplement manufacturers who make a healthy profit destroying the health of gullible consumers and patients.