3 Fish You Should Never Eat

With plenty of important nutrients like protein, vitamin D, and omega-3 fatty acids, fish is one of the healthiest natural foods on the planet. But at the same time, some fish are heavily contaminated with metal, toxic chemicals, and pesticides that can wreck havoc on your health. Also, greedy and destructive fishing practices have led to overfishing and exploitation of several fish populations to the point of altering the entire marine ecosystem.

Determining what seafood options are good for you and the environment can be confusing, which is why we put together this quick guide for you. Here are three fish that should never be part of a healthy diet.

1. Tilapia

If you are wondering why is tilapia bad for you despite being one of the most popular seafood species for consumption in the U.S., here are some quick facts about this mild-flavored freshwater fish.

Why is tilapia bad for you?

There are a number of reasons why you should never eat tilapia. With very little healthy omega-3 fatty acids but high levels of omega-6 fatty acids that can worsen inflammatory conditions when consumed in excess, tilapia can be an extremely unhealthy food choice for people suffering from heart disease, arthritis, asthma, and other autoimmune disorders. In fact, a 2008 study conducted by researchers at the Wake Forest University Baptist Medical Center says that an average serving of farmed tilapia has higher inflammatory potential than hamburger or pork bacon.
If you are looking for more reasons why tilapia is bad for you, farmed tilapia from certain regions have also been found to contain high levels of mercury, antibiotics, antimicrobials, and other chemicals, including a carcinogenic substance called dioxin. Dioxin can remain in your body for many years and increase your risk of developing cancer while mercury exposure is particularly dangerous for pregnant women, nursing mothers, and young children. Contaminated fish is one of the most significant sources of mercury exposure through ingestion in human beings.

Is tilapia a real fish?

Yes, tilapia is actually a term used to refer to several related freshwater fish species with origins in the Middle East and Africa. However, some fish producers have been known to breed genetically-modified varieties that are easier and cheaper to grow, more flavorful, and resistant to disease.

Where does tilapia come from?

While the majority of the tilapia in the U.S. market today comes from fish farms, the species is believed to have originated from tilapia in the wild.

What does tilapia eat?

While tilapia in the wild feed on nutrient-rich algae, farmed tilapia are mostly fed a corn and soy-based diet, which lowers the fish’s nutritional value.

2. Atlantic cod fish

The first Europeans to reach North America were fishers who followed the cod population across the North Atlantic. For a long time, the Atlantic cod fishery thrived and supported the coastal economy of North America. However, years of overfishing and incompetent practices took a heavy toll on the Atlantic cod fish population, which took a drastic dive in the 1990s. The Atlantic cod fishery collapse not only put thousands of people out of work but also brought this popular fish species to the brink of extinction and caused fundamental changes in the North Atlantic food webs.

Why you should not eat Atlantic cod fish

Despite a moratorium on Atlantic cod fishing, trawling for other fish species in the area continue to negatively affect cod population recovery efforts because of which the Atlantic cod is still very close to extinction. If you can’t live without your regular supply of fish and chips (they are almost always made with cod fish!), you should avoid the North Atlantic cod fish and instead choose other whitefish like the Pacific cod, which has a strong population in Alaska.

Pacific cod vs. Atlantic cod

When you compare Pacific cod vs. Atlantic cod, you’ll notice several differences though they are closely related. The North Pacific cod is smaller in size and darker in color than Atlantic cod. The Pacific cod fillet also has a milder, savory flavor profile with firm, chunky flakes while the Atlantic cod is sweeter and has bigger flakes. Pacific cod contains low levels of mercury while the Atlantic cod is moderate in mercury.

Atlantic cod nutrition

Nutrition-wise, both Atlantic cod and Pacific cod are very similar. Both fish species are a good source of vitamin B, niacin, phosphorous, and selenium,

Atlantic cod nutrition: One serving of cooked Atlantic cod (85 grams) contains 90 calories, 19 grams of protein, and one gram of fat
Pacific cod nutrition: One serving of cooked Pacific cod (85 grams) contains 85 calories, 20 grams of protein, and less than one gram of fat

More Atlantic cod facts:

• If you regularly consume cod liver oil for its nutritional benefits, find out if it is sourced from wild Atlantic cod or wild Pacific cod. Wild Pacific cod sourced from Alaska is one of the best and most sustainable sources for fish liver oil.
• The female of the Atlantic cod species releases hundreds of millions of eggs during its lifetime though only a few of these reach adulthood.

3. Flounder

The flounder fish is a flat fish with both eyes on one side of its head. Though it has a firm texture and a mild, sweet taste, eating it is not good for you or the environment.

Why you should not eat Atlantic flounder fish

The flounder fish finds its way into the list of fish you should never eat as a result of high levels of contamination and a drastic depletion in population brought about by hundreds of years of overfishing. This is especially true for flounder fishing off the Atlantic coast. In the 1980s, more than 75% of the winter flounder caught in Boston exhibited symptoms of cancerous tumors and liver disease. Years of remedial efforts have brought about a huge improvement in flounder fish health in recent times though we still have a long way to go.

The Atlantic flounder fish also takes a long time to grow and mature (around 50 years), which is another reason why its stocks are taking a long time to revive. Also, the older the fish, the more it may have absorbed mercury.

Halibut vs. flounder

If you like whitefish, avoid purchasing Atlantic flounder fillet and instead choose the Pacific halibut , which is doing comparatively well and is a more eco-friendly and sustainable option. People often get confused between a halibut and a flounder because they are different types of flatfish. But while the halibut can grow up to eight feet and weight as much as 500 pounds, the flounder fish is much smaller and has an average length of three feet at maturity.

Flounder nutrition

Nutrition-wise, flounder fish is 80% water, which lowers its nutritional value. While the flounder fish does contain other nutrients like amino acids, proteins, minerals, and sodium, it has very less calcium and iron. The flounder fish also has very low levels of fish oils when compared to other fish like salmon and mackerel, which is why you are unlikely to find flounder fish oils in the market.