Eating fish is supposed to be good for you, but between Fukushima, farmed fish fed GMOs, and water pollution, there aren't too many fish left that are not hazardous to your health. There are alarming and potential drawbacks of consuming certain species of fish and Tilapia is one of them.
Health experts typically recommend to consume fish with high levels of omega-3 fatty acids. These healthy fats are plentiful in wild Alaskan salmon, particularly sockeye salmon. Wild salmon from Alaska is also less likely to contain mercury and organic contaminants than other species. Less expensive choices are sardines and herring, all of which provide omega-3s and are less likely to be contaminated with PCBs than larger carnivorous fish such as tuna.
Most food manufacturers, grocery chains and big box stores are not required to properly label their fish as farmed or wild. That's likely because the public is largely unaware of the dangers associated with cheap, high profit farmed fish that is so abundant in the conventional food supply.
The most common farm-raised fish are: salmon, tilapia, sea bass, catfish, and cod.
A June 2013 report from the Earth Policy Institute noted that worldwide production of farmed fish now not only exceeds the production of beef, but that consumption of farmed fish is soon expected to exceed consumption of wild-caught fish. 2013 may well be the first year that people eat more fish raised on farms than caught in the wild reaching a record 66 million tons.
One of the reasons for the popularity of tilapia is that they are short-lived and primarily vegetarian and therefore do not accumulate substantial amounts of mercury by consuming other fish, as other common predatory food fish (such as tuna) do. This factor also means, as reported in a June 2013 National Geographic article, that tilapia are more efficient to farm because they eat lower on the food chain. This causes a world of problems to the detriment of human health.
One of the issues with tilapia farmed in China is that smaller, independent farmers face economic pressures to use animal manure rather than more expensive commercial feed for farmed fish, a practice which contaminates water and makes the fish more susceptible to spreading foodborne diseases.
A July 2009 report from the U.S. Food and Drug Administration (FDA) on the safety of food imports from China noted that in that country "Fish are often raised in ponds where they feed on waste from poultry and livestock" and cited an increased rate of FDA rejection of fish imports from China between 2000 and 2008.
Similarly, an October 2012 Bloomberg article observed that the FDA had rejected 820 Chinese seafood shipments since 2007, including 187 that contained tilapia, and furnished examples of the practice of using manure as feed for farmed fish in China.
U.S. tilapia consumption was expected to rise by over 3 million tons by 2013. A study from researchers at Wake Forest University School of Medicine found that farm-raised tilapia, a very popular fish, has very low levels of omega-3s and very high levels of omega-6 fatty acids. We get much more of these fats than we need -- they're found in most snack foods, cookies, crackers, and sweets. The body constructs hormones from omega-6s that tend to increase inflammation (an important component of the immune response), blood clotting, and cell proliferation. Omega-3 fatty acids are anti-inflammatory.
The Wake Forest researchers said that the combination of fatty acids in tilapia could pose a danger for some patients with heart disease, arthritis, asthma and other allergic and auto-immune diseases, all of which are linked to chronic inflammation. In fact, the investigators said that the fatty acid profile of tilapia is worse than that of 80-percent-lean hamburger, doughnuts and even bacon.
Farm-raised tilapia also has a lower protein content. Not only that, because farm-raised tilapia are kept in cages, they have the tendency to be fattier, and can have even higher concentration of omega-6 acids than their wild counterparts.
Dibutylin levels, a chemical used in PVC plastics is said to be 2 times higher in farm-raised tilapia compared to wild ones. Dibutylin is toxic and can impair immune system function while also contributing to inflammation. Dibutylin may be the reason as to why there is a rise in asthma, obesity, allergies and other metabolic disorders in recent years.
Dioxins are also typically higher in farmed tilapia. The problem with dioxins is that once it enters our system, it can take a very long time until it is removed from the body. The half life of dioxin is about 7 to 11 years.
So although tilapia has one of the lowest concentrations of mercury in fish, most people should avoid tilapia and stick to better choices with dense omega-3 content. Wild Alaskan salmon is much more expensive than many other types of fish but likely the best choice due to lower concentrations of contaminants. However, at the rate that Fukushima is radiating the ocean, there may be no clean sources of wild fish left in the next the decade.