Wednesday, September 19, 2012

Striking a balance between health and sustainability: a study inspired by a love for sushi



Sushi for sale (Source)
by Jeanne Garbarino, DXS biology editor

A conservation scientist walks into a [sushi] bar…
You've probably heard that eating a diet including fish, especially fatty fish, is good for us. Fish can be a source of high quality, lean protein, and also provide heart-healthy omega-3 fatty acids. However, there are risks associated with eating some types of fish. For instance, fish that are at the top of the food chain or have a long lifespan (or both!) can accumulate high levels of mercury or chemicals called polychlorinated biphenyls (PCBs).  Exposure to high amounts of these compounds could be particularly harmful for pregnant/nursing women or young children.
On the other hand, there is the issue of sustainability. We are seeing a wide-scale collapse of many marine fish populations, which is primarily the result of overfishing.   While there are conservation efforts in place to help consumers make eco-friendly choices, it is not clear if raising consumer awareness is impacting fishing or marine farming practices. Furthermore, many consumers will choose fish based on their nutritional value and safety without really considering ecological consequences.
In an attempt to better educate consumers on both nutrition and sustainability with regard to making the best seafood choices, Leah Gerber, professor of Ecology, Evolution and Environmental Science at Arizona State University, has evaluated current fish “eco-ranking” schemes. In a study recently published (PDF) in Frontiers in Ecology and the Environment, Dr. Gerber provides a model that quantifies both the health benefits and sustainability level of individual fish species.
Interestingly, her group found that fish with the highest health benefits, determined by omega-3 fatty acid content, generally had low mercury levels. Similarly, fish that are unsustainable -- meaning that fishing threatens their existence -- tended to have higher levels of mercury, and lower omega-3 fatty acid amounts.  Basically, fish populations that are not threatened by overfishing are generally heart healthy and have low mercury. A win-win!
The novel thing about this study is that it is the first to consider multiple types of sustainability rankings as well as health impacts, and Dr. Gerber is taking her message to the streets. It is her hope that she and her colleagues will be able to develop tools so that consumers can easily make seafood choices that are both good for you and good for the environment.
But the coolest thing about this study is that Dr. Gerber is not a 'fisheries person', per se.  However, her passion for learning about human impact on the natural environment combined with her love of sushi prompted a closer look at the fishing industries and how to make good choices when it comes to seafood.
This is an excellent example of how a scientist is applying her knowledge to promote science in one of its most relatable forms –- eating!  I mean, we all have to eat, and it is particularly awesome when we can do so in the most educated way possible. Kudos to Dr. Gerber for taking this on since we all benefit from knowing.  

The opinions expressed in this article neither necessarily reflect nor conflict with those of the DXS editorial team.

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