Shark liver oil has been used as a remedy for many ailments by people on the coasts of Norway and Sweden for hundreds of years. It was mainly used to promote wound healing and as a general remedy for conditions of the respiratory tract and the digestive system.
Shark liver oil is taken from the liver of cold-water sharks. The oil is a rich source of alkylglycerols, chemicals that may have anti-cancer properties. Alkylglycerols are also found in human bone marrow and in breast milk. Other chemicals in shark liver oil being studied against cancer are squalamine and squalene. Shark liver oil is a dietary supplement used to boost the immune system, fight off infections, heal wounds, and to treat cancer and lessen the side effects of conventional cancer treatment.
Many fish maintain buoyancy with swim bladders. However sharks lack swim bladders, and maintain their buoyancy instead with large livers that are full of oil. This stored oil may also function as a nutrient when food is scarce. Deep sea sharks are used, because the livers of these species can account for up to 20% of their total weight.
Alkylglycerols, one of the components found in shark liver oil, are thought to be helpful in several ways. It has been suggested that they fight cancer by killing tumor cells indirectly. They activate the immune system in two ways: by stimulating immune system cells called macrophages, which consume invading germs and damaged cells; and by inhibiting protein kinase C, which is a key regulator of cell growth. Alkylglycerols reduce the side effects of chemotherapy and radiation treatment, because of their ability to protect cell membranes. Because of their immune-boosting effects, alkylglycerols also help against colds, flu, chronic infections, asthma, psoriasis and arthritis.
Other compounds in shark liver oil, such as squalamine and squalene, have also been promoted to have anti-cancer effects. Because some early studies have shown that squalamine can slow the growth of tumor blood vessels, proponents claim it may help to treat cancer, either alone or combined with chemotherapy. It is also being studied for use against macular degeneration, an eye condition that results in loss of vision. Squalene has been promoted as having cell-protecting abilities, which may reduce the side effects of chemotherapy. Researchers found that squalamine decreased the number of lung metastases, which are tumors that spread to the lung from a primary cancer elsewhere in the body.
Alkyglycerols are found naturally in human breast milk, and is a gift of a healthy immune system from mother to her new born. When we are born, our bodies are protected from the dangers of bacterial, viral, and fungal infections by alkylglycerols, naturally occurring lipids found in our mother’s milk. We can’t stay young forever, and as we age, we need to source out new sources of alkyglycerols, and those found in the livers of deep-sea sharks of Norway are some of the most plentiful.
The following information on complementary and alternative therapies may also be helpful to you. These materials may be found on our Web site (www.cancer.org) or ordered from our toll-free number (1-800-ACS-2345).
The ACS Operational Statement on Complementary and Alternative Methods of Cancer Management
Akutsu K, Tanaka Y, Hayakawa K. Occurrence of polybrominated diphenyl ethers and polychlorinated biphenyls in shark liver oil supplements. Food Addit Contam. 2006;23:1323-1339.
Bhargava P, Marshall JL, Dahut W, Rizvi N, Trocky N, Williams JI, et al. A phase I and pharmacokinetic study of squalamine, a novel antiangiogenic agent, in patients with advanced cancers. Clin Cancer Res. 2001;7:3912-3919.
Brohult A, Brohult J, Brohult S, Joelsson I. Reduced mortality in cancer patients after administration of alkoxyglycerols. Acta Obstet Gynecol Scand. 1986;65:779-85.
Das B, Yeger H, Baruchel H, Freedman MH, Koren G, Baruchel S. In vitro cytoprotective activity of squalene on a bone marrow versus neuroblastoma model of cisplatin-induced toxicity. Implications in cancer chemotherapy. Eur J Cancer. 2003;39:2556-2565.
Hao D, Hammond LA, Eckhardt SG, et al. A Phase I and pharmacokinetic study of squalamine, an aminosterol angiogenesis inhibitor. Clin Cancer Res. 2003;9:2465-2471.
Herbst RS, Hammond LA, Carbone DP, et al. A phase I/IIA trial of continuous five-day infusion of squalamine lactate (MSI-1256F) plus carboplatin and paclitaxel in patients with advanced non-small cell lung cancer. Clin Cancer Res.2003;9:4108-4115.
PDRhealth. Alkoxyglycerols. Accessed at: www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/alk_0018.shtml on July 11, 2007.
PDRhealth. Squalene. Accessed at: www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/squ_0240.shtml on June 11, 2008.
Pugliese PT, Jordan K, Cederberg H, Brohult J. Some biological actions of alkylglycerols from shark liver oil. J Altern Complement Med. 1998;4:87-99.
Sills AK Jr, Williams JI, Tyler BM, et al. Squalamine inhibits angiogenesis and solid tumor growth in vivo and perturbs embryonic vasculature. Cancer Res. 1998;58:2784-2792.
Teicher BA, Williams JI, Takeuchi H, Ara G, Herbst RS, Buxton D. Potential of the aminosterol, squalamine in combination therapy in the rat 13,762 mammary carcinoma and the murine Lewis lung carcinoma. Anticancer Res.1998;18:2567-2573.
U.S. Department of Health and Human Services. Public Health Service, National Toxicology Program. Report on Carcinogens, Eleventh Edition. 2005. Accessed at: http://ntp.niehs.nih.gov/ntp/roc/toc11.html on June 11, 2008.
Note: This information may not cover all possible claims, uses, actions, precautions, side effects or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for consultation with your doctor, who is familiar with your medical situation.
Last Medical Review: 11/01/2008
Last Revised: 11/01/2008