A study published in July by researchers at Wake Forest University School of Medicine showed that tests on farm-raised tilapia showed "very low levels of beneficial omega-3 fatty acids and, perhaps worse, very high levels of omega-6 fatty acid." The article, published in the Journal of the American Dietetic Association, caught national attention due to the claim that "the inflammatory potential of hamburger and pork bacon is lower than the average serving of farmed tilapia."
Farm-raised tilapia are generally identified as ‘environmentally responsible’ because they are fed a "vegetarian diet" (i.e., not fed other fish which could result in more ocean resources used than produced). "Vegetarian-fed" typically means it was fed corn. In other words, the same diet as cattle and swine. No wonder the dietetic concern.
But according to Tim Fitzgerald, a scientist with Environmental Defense Fund who specializes in health aspects of seafood, "The omega-3 claim is nothing new – these fish have never been a good source. As for their relative nutritional content, the statement about hamburger and bacon was itself inflammatory." He added, "In my opinion, these fish are better than no fish at all. And if you want omega-3s, there are plenty of good seafood options out there."
So, why are tilapia fed corn? Certainly that’s not what they eat in their natural habitats. Fewer and fewer fish these days are grown in polyculture systems in which different species co-habitate as they would in a natural environment. Polyculture is considered an ‘inefficient’ production system. Plainly stated, "Big-Ag" has made it to water as well as to land: we have "mono-cropped" seafood as we do with many fruits and vegetables.
So tilapia may not be the most nutritionally robust food you can eat, but don’t strike it from your shopping list. Perhaps the larger question, however, is about how farmed seafood is raised and what ‘sustainable seafood’ means in particular. Should we limit our definition of ‘sustainable’ food production to assessing whether production systems don’t harm the natural environment or raise the bar and ask how much they mimic natural ecosystems? ‘Do no harm’ is a good start but perhaps we ought to ask more sophisticated questions of food producers and demand more.
What are your thoughts?
-Helene York, Director of the Bon Appetit Management Company Foundation