Today's edition of The New York Times featured a lengthy expose of farm-raised tilapia.
Their report – titled “Another Side of Tilapia, the Perfect Factory Fish” – detailed the environmental and dietary drawbacks of farm-raising this cheap “aquatic chicken”.
Their nutritional critique echoed one expressed by Wake Forest University researchers in 2008. (See “Farmed Fish Possess Unhealthful Fat Profiles”.)
They found that while farmed tilapia and catfish contain few omega-3s, they pack more omega-6s than burgers or bacon.
This unbalanced “omega-ratio” is proven to promote chronic low-level inflammation and the diseases that flow from it. (See “Farmed Salmon's Diet Yields Unhealthful Cardiovascular Effects”)
Many people seeking omega-3s from seafood don't know about this nutritional distinction between wild and farmed fish, and fall victim to a nutritional bait-and-switch.
As the Wake Forest team wrote, “…marked changes in the fishing industry during the past decade have produced widely eaten fish that have fatty acid characteristics that are generally accepted to be inflammatory by the health care community.”
The Times highlighted this key but oft-overlooked problem with farmed tilapia and catfish:
“Compared with other fish, farmed tilapia contains relatively small amounts of beneficial omega-3 fatty acids, the fish oils that are the main reasons doctors recommend eating fish frequently; salmon has more than 10 times the amount of tilapia.” (Rosenthal E 2011)
As the article explained, the omega-imbalance in farmed tilapia and catfish is a function of their diet:
“… farmed tilapia contains a less healthful mix of fatty acids because the fish are fed [omega-6-rich] corn and soy instead of [omega-3-rich] lake plants and algae, the diet of wild tilapia.” (Rosenthal E 2011)
Foreign tilapia farms have shaky eco reputations
The Times also exposed the serious environmental damage caused by some non-U.S. tilapia farms, located mostly in Latin America.
Currently, the Monterey Bay Aquarium's Seafood Watch program ranks U.S. tilapia a “best choice” – thanks to tough eco-protection standards – but it rates tilapia from Latin America as a “good alternative” and says tilapia from China is “to be avoided.”
While there are new efforts to get tilapia farmers to sign on to standards of sustainability, the Times notes that “… even the new rules allow for some practices considered unacceptable in the United States.” (Rosenthal E 2011)
And the article quotes scientists who've seen dire damage done to critical native plants and fish … changes that can cripple or kill lakes' ecosystems and their capacity to provide local people with free, wild fish and clean water.
You will find figures for the low omega-3 and high omega-6 levels of four farmed fish (tilapia, catfish, salmon, trout) in our 2008 article, “Farmed Fish Possess Unhealthful Fat Profiles”.
All we can say is, fish-buyer beware!
Rosenthal E. Another Side of Tilapia, the Perfect Factory Fish. The New York Times. May 2, 2011. Accessed at http://www.nytimes.com/2011/05/02/science/earth/02tilapia.html
Weaver KL, Ivester P, Chilton JA, Wilson MD, Pandey P, Chilton FH. The content of favorable and unfavorable polyunsaturated fatty acids found in commonly eaten fish. J Am Diet Assoc. 2008 Jul;108(7):1178-85.