Friday, December 17, 2010

Sharks: Why They're Not Health Products

Alternatives to Shark Oil

Shark liver oil has been used for centuries by fishermen as a general tonic and folk remedy. Shark oils do contain many of the beneficial compounds that are also found in cold water fish, such as omega-3 fatty acids, vitamins A and D, which are important for optimal immune function. However, I do not consider shark oils to be appropriate substances for use in a health context.  As a naturopathic doctor I have never, and never will, recommend the intake of shark products to any of my patients. The risks are simply too great.

Why take such a stand on the shark-as-medicine issue? The naturopathic doctor's oath includes to "First, do no harm" and to "preserve the health of our planet for ourselves and future generations".  This means that the medicines I prescribe must be ecologically friendly.  Many of the world's sharks have come under survival pressures due to human activities - from intense demand for their fins for shark fin soup, or their cartilage for the mythological anti-cancer effects, to tragic bycatch losses whereby sharks are unintentionally caught in nets set for other species like tuna (a whole other issue), to spills and disasters, shark populations are particularly vulnerable to human follies because their slow rates of growth and reproduction and predator status makes them fewer in numbers relative to the "prey" species. Sharks are needed as predators to keep prey species healthy. Incidentally, dozens of "prey" species are also eaten by humans, so in helping sharks we would be helping ourselves maintain access to sustainable, healthy fish stocks (J. Sabau, Wake Shark & Ocean Educator 2009). A World Fishing & Aquaculture article published today noted that one third of Europe's shark species are currently considered threatened and the European Parliament has called for stronger policies against shark fin-removal on board ships.

Medicinal Properties of Shark Products Available From Alternative, Less Toxic Sources

Shark oils are widely touted on the internet as remedies for coughs and colds, immune dysfunction, asthma, eczema, cognitive decline, etc. etc. Are these claims plausible? Yes. Are there literally dozens of non-shark, naturopathic ways to treat these conditions without increasing pressure on vulnerable animal species? Yes. What's more, as predators, sharks bioaccumulate toxins that their prey and their prey's prey and their prey's prey's prey (you get the picture) consumed. Concentrations of fat-soluble toxins like mercury and PCB's increase in animals as you work up the food chain. This toxicological principle takes sharks (and tuna) right off the radar for me in terms of potential medicinal use. A LOT of processing would have to be done to bring shark products into compliance with Natural Health Products Regulations for heavy metals and environmental contaminants.  Oh and did I mention that sharks DO get cancer? Wake ecologist Julie Sabau, MSc, confirms that cancerous tumours have been proven to occur in wild sharks.  How tragic that so little was known about these mysterious creatures at the time of publication of "Sharks Don't Get Cancer" that its unfortunately catchy title evaded scientific dispute and became an urban legend. Shark products continue to be marketed internet-wide as anti-cancer remedies and are found in conventional products such as Preparation H (Pfizer) and some flu vaccines.

I respect the healing power of nature in its many forms, and I prescribe non-shark.

For more information on shark ecology, visit Wake Shark & Ocean Education at They even offer a free module for teachers to implement in their classrooms!

-Dr. Liz

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