Tilapia: A Misunderstood, Sustainable Fish

Fresh produce and sustainable tilapia being grown in an aquaponics system at Disney Epcot’s “Living with the Land”

Tilapia is an increasingly popular food fish being grown and consumed around the world. This is because it’s primarily an herbivore (plant eating animal) that is easy to grow in a variety of conditions. It grows to market size relatively quickly and with less input compared to other cultured species. Because it’s a freshwater fish that’s generally easier to cultivate, tilapia is commonly used in increasingly popular aquaponic polyculture, the practice of growing fish and recycling the water and nutrient rich wastes to grow plants. When you find it on a restaurant menu or in a supermarket freezer, it is usually cheaper than most other fish options as well. Tilapia is among the most sustainable and affordable fish being produced for human consumption today. Tilapia farmed in the US, Canada, and Ecuador also have a “Best Choice” rating from Monterrey Bay Aquarium’s Seafood Watch, the leading organization for seafood sustainability, so why are some people so against it?

If you would like to skip the play-by-play, scroll down to see The Piscivore’s Recommendations. If you’d like to continue down the rabbit hole, keep reading.

The answer, more often than not, has less to do with the fish itself and more to do with where and how it was produced. For example, my father’s friend posted this article on Facebook about tilapia recently. After reading the article, I decided to address misinformation/provide context for information associated with tilapia and its production shared through this article and others in the media. It begins by trying to assert feeding “GMO” corn and soy to fish is a bad thing. If they had an accurate understanding of what a “GMO” actually is, they’d know most of the food we consume has to some extent been genetically modified, primarily through artificial selection. Also these “GMO” plants are broken down into more basic nutrient components (proteins, carbohydrates, etc), the same components that make up all organisms, when they are processed into pellets for feed. Their diets are formulated to consist of more than just corn and soy, as you can’t have a balanced diet off just corn and soy. Alternative protein sources, like soy, limit the inclusion of fishmeal into the feeds of fish produced by aquaculture. The use of fishmeal in agriculture and aquaculture is a controversial issue that deserves another post of its own, so I won’t go into it here more than to say limiting its use is a good thing. Since tilapia are primarily herbivores, they require little to no fishmeal to begin with, which makes their selection for sustainable aquaculture ideal.

“Fatten up the fish” Tilapia are grown, not fattened up, and are an excellent source of low fat protein. That is the main reason why they are a healthy diet choice. The next statement asserts tilapia is not healthy because it doesn’t contain as much fish oil, particularly omega-3 fatty acids, as other species of fish. While there are other fish, like salmon, that provide higher levels of omega-3s, there are certainly worse forms of food we consume than tilapia. Which is a better source of protein: a low fat filet of tilapia or a Big Mac? It’s not just the oils in fish that make them healthy diet option. In the majority of cases, protein derived from fish is healthier than proteins from terrestrial based agriculture and tilapia is no exception.

“Almost all tilapia sold in the US is hormone tested.” Wrong. Less than 2% of the seafood we import is tested for banned chemicals, antibiotics, hormones, etc. This is a problem that also deserves its own post. For now though, you should realize that concerns about contaminants often have more to do with where and how its produced, not the fish. That being said, tilapia have very few drug/contaminant violations from what testing is done. Another claim this section makes is that testosterone is used to create all male populations because males grow faster. This may very well be true in countries other than the US; however, the testosterone would be given early in life. Since it takes between several months to close to a year to reach market size, it is safe to say you probably shouldn’t be worried as that testosterone is long gone by then. Why is this a concern? It’s not, but without context a reader wouldn’t know any better.

I’ll address the second paragraph of this article regarding the nutritional components of tilapia later when I assess the arguments made by similar articles.

The entire last paragraph make claims about PCBs and other toxins in tilapia; however, the Washington Post article that’s used as the “study” source only discusses salmon and even goes so far as to say that the benefits of farmed salmon outweigh the consumption of trace amounts of PCBs. The actual study the WP article discusses also only refers to salmon. Since this is about tilapia though, this paragraph is largely fabricated in an effort to scare and mislead the reader, but contaminants in our food should always be a concern, regardless of species. It is a concern for tilapia, but not for the reasons mentioned in the living traditionally  article. As was mentioned before, tilapia are primarily herbivores and their diet contains little to no fishmeal, the major source of contaminants purposed in the salmon article. Not only is this WP article, and the actual study it reports about, more than 10 years old at this point and research on diets in salmonid aquaculture progressed considerably since then, the WP article fails to mention the source of the fish, mentioning only where it was sold, not where it was produced, as it compared to contamination. This is key to understanding the importance and impact of where and how tilapia, and other farmed fish, are produced.

There are plenty of other articles as well that try to dissuade their readers from consuming tilapia. Most amusing is it seems some of these articles, like the one discussed previously, use other articles as references, going so far as to copy and paste straight from the reference. This article takes issues from other species that have nothing to do with tilapia, fails to provide enough references to back up their claims even for those species, and uses them to mislead their readers. Another article, while singing the same tune, has a picture from the sustainable tilapia aquaculture demonstration at Disney Epcot’s “Living with the Land,” which produces the tilapia they use in Epcot’s restaurants. Farming in closed, recirculating systems prevents them from being introduced to wild environments, not to mention how its shows tilapia, a freshwater fish being grown in a recirculating system, some how impacts “native marine life.” I’d be willing to bet Disney doesn’t feed poor quality diets to their fish either. Reminds me of this example of repurposing images out of context to advance your cause. Let’s set the question of legitimacy aside and take a look at the arguments these articles and blog posts make against tilapia.

  1. Farm-raised tilapia may cause more inflammation, leading to diseases like atherosclerosis and congestive heart failure
  2. Farm raised fish (not just tilapia) have fewer healthy nutrients
  3. Dioxin levels are higher in farmed-fish compared to wild
  4. Farm raised fish (not just tilapia) contain high concentrations of antibiotic and pesticides
  5. Farm raised fish (not just tilapia) contain cancer causing organic pollutants
  6. Tilapia is an invasive species and is detrimental to native fish species
Sustainable tilapia being raised in recirculating systems at Disney Epcot’s “Living with the Land,” which qualifies as a “Best Choice” rating from Seafood Watch. This image was found without a caption or context in a blog post against tilapia.

While I’ve received coursework and training in nutrition as a veterinary student, I certainly wouldn’t consider myself an expert compared to someone specialized in nutrition, especially, human nutrition. I do feel confident in assessing scientific literature though, and I set out to evaluate claims 1 & 2 made above. Articles mention “recent studies” suggesting tilapia contain higher levels of n-6 fatty acids (aka omega 6 fatty acids), which may (or may not) contribute to certain human disease conditions. The “recent studies” also suggest tilapia contain less of beneficial n-3 fatty acids (aka omega-3 fatty acids). These “recent studies” are actually only a single study published in the Journal of the American Dietetic Association by researchers from Wake Forest University. This study attempted to evaluate the fatty acid profile of 30 different fish species. There were several flaws I found with this study, namely a small sample size where often only a single fish was used to represent a species and small pooled samples (in the case of tilapia, catfish, and others) regardless of country of origin. Because of these pooled samples, there are wide variations in their results, which they attributed to difference in where the fish is produced. This is acknowledged only briefly and the authors fail to discuss its importance.

Despite these issues and additional issues posed by more credentialed reviewers, let’s assume for sake of argument that the findings of this paper are sound. Our understanding of the role of dietary n-6 fatty acids and their impacts on the human body are controversial, as evidenced by the research editorial in response to the study, the study author’s response to the editorial, and the editorial author’s final comments. Indeed, in the study article, the authors acknowledge the role/impact of increased n-6 fatty acid intake is likely dependent on multiple factors. If dietary intake of arachidonic acid (a derivative of n-6 fatty acids) effects levels of it in the body (this is controversial in the literature), it would likely only contribute to disease in those vulnerable, particularly those lacking a gene to metabolize it, a very small portion of the population, that’s assuming it even does contribute to disease or inflammation (this is also controversial in the literature). Contrary to many web articles that cite this study, this study found that farm raised salmon and trout had favorable fatty acid profiles and higher omega-3 content compared to wild salmon species, in opposition to claim #2. While tilapia may not be as high in omega-3s as other fish species, this does not make the fish unhealthy, as multiple sources (referenced previously and below) also note.

Claims 3, 4, and 5 will be assessed together as “farmed fish contain more contamination from various undesired chemicals than wild fish.” This is actually a valid concern and has much to do with where and how the fish was produced (are you starting to see a pattern?). The United States has some of the strictest regulations regarding the production of seafood and only a limited number of approved drugs including only 3 antibiotics which are legal to treat specific conditions in specific species of fish (not to aid in fish growth), one anesthetic, one injectable hormone for inducing spawning (not to make fish grow or determine sex), and a few other medications for different external parasites all of which have established mandatory withdrawal periods to ensure no drug residue is present in the fish by the time its harvested. This is not the case in other countries, especially in places like China where there is little to no regulation. Obviously this has less to do with the fish itself than where and how it’s produced. Tilapia makes up a very small percentage of the number of drug/contaminant violations reported in imported seafood, thus, these arguments likely don’t apply, especially in the case of US produced tilapia, as was discussed previously with the Washington Post article.

Tilapia is an ideal aquaculture species, but this does not mean its been farmed responsibly in all the countries its grown. Recirculating systems and man-made pond culture are the usual and preferred methods of production that limit tilapia’s impact on native species significantly. In countries with less regulation, tilapia is sometimes grown in net pens in lakes where there is a risk they can escape and become established. That all being said, this has more to do with humans introducing fish to non-native regions through globalization and poor regulation than the fish themselves. Again, it’s where tilapia is produced and how it’s produced that matters and your power as a consumer makes the difference.

Finally, the New York Times published one of the more widely read articles on tilapia back in 2011. It is far from perfect, for many of the reasons addressed above. Because of this, it came under fire from multiple sources soon after it was published. I like the later article, “In Defense of Tilapia,” from Bon Appetit writer Helen York in response to the New York Times article, which takes the perspective of trying to work with producers to improve their methods and hold them to a higher standard to produce a fish that even non-fish eaters can enjoy.

In conclusion, tilapia is the ideal sustainable food fish for aquaculture. When farmed responsibly, it has minimal impact on the environment and provides an affordable source of low fat protein for piscivores and non-piscivores alike. There are concerns about how it’s produced in certain areas of the world, but as a consumer, you have the power to hold your fish markets/supermarkets to a higher standard of fish, who will then hold the producers to those standards. Ask for the source of the fish in the restaurants you visit. It can be daunting sometimes for the consumer to source their seafood but isn’t impossible and those that do will contribute toward the future of savory and sustainable seafood.

The arguments put forward by those against tilapia are intentionally misleading by failing to provide context, based on poor science, and often flat out fabricated by those with little understanding of the fish itself and the way its produced beyond what they probably read on the internet. Misinformation is shared, intentionally or not, by those who lack a complete understanding of the subject they are communicating to people like my father’s friend.

The Piscivore’s Recommendation:

Tilapia is here to stay and may very well become the fish that feeds the world. It’s sustainable, healthy, cheap, and appealing to non-piscivore palates. Its drawbacks come from where and how it’s produced more than the fish itself. For those who can afford to pay a little extra and search for it, tilapia farmed in the United States is the best way to consume it. Seafood Watch also gives fish from Ecuador (South America) a “Best Choice” rating and Asia a “Good Alternative” rating; however, the Piscivore recommends a “Good Alternative” and an “Avoid” rating, respectively. While there may be some producers in Asia voluntarily improving their standards and methods of culture, certainly not all are doing that and with little regulation for their industry, the Piscivore recommends you avoid tilapia farmed in Asia.

Enjoy your tilapia my fellow piscivores!

References are hyperlinked throughout the post. Questions regarding this post may be sent to thepiscivore@gmail.com.

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