Consumers today who are trying to eat a healthier diet are increasingly turning to seafood. Health reports tout fish as an important source of protein, vitamins, and minerals. Most importantly, they are known to be a good source of Omega 3 fatty acids. There are two Omega 3 fatty acids present in fish, EPA and DHA. These fatty acids may help prevent high blood pressure and blood clots and therefore, heart attacks and strokes. The results of research on the subject, although not consistent, are compelling enough that most North Americans are advised to eat fish and other seafood twice a week. Sounds simple, right?
Unfortunately, it is not that simple. Our oceans and waterways are becoming increasingly polluted, and those toxins and pollutants are being absorbed into the flesh of the seafood that live in those waters. One of the major pollutants that concern us is methylmercury, formed from the emissions from coal-burning power plants. Methylmercury is something we all would like to avoid, but it can be particularly toxic to children and pregnant women. It crosses the placenta and goes right to the brain and nervous system of the developing fetus, causing disastrous birth defects.
Early signs of methylmercury poisoning include numbness and tingling, muscle weakness, fatigue, headache and inability to concentrate. These symptoms can be caused by any number of other disorders, making it difficult to know when you’ve been affected. The fish with the highest amount of methylmercury in its flesh are the large predatory fish, including shark, swordfish and tuna. (Albacore tuna has more than the chunk light tuna eaten from cans.) In 2001, the FDA also added King Mackerel and Tilefish to this list. Pregnant women and small children should not eat these fish in any amounts.
Another issue we need to consider is the amount of PCB’s and other toxic chemicals like DDT and dioxins present in our fish. Farmed fish, especially those fed on fish oil and fish meal, have the highest amount of PCB’s. Fattier fish have more PCB’s than lean ones, and fish caught for sport may have levels so high that they are not safe to eat. It depends on the waters they are caught in, what species they are, what they ate, and how large they grow. They only way to know for sure is to but your fish from a trusted seller who tests for these chemicals.
Another issue that needs to be considered is the effect of fish farming on the environment, our natural fish stocks, and our health. Some sources estimate that up to 90% of the world’s large fish have disappeared due to overfishing, so fish farms are increasingly stepping in to fill the void. These farms may seem like an easy way to increase our intake of seafood, but they are controversial. Farmed salmon, for example, are raised much like cattle in a feedlot. They live in large, crowded pens, swimming in pools of antibiotics, chemicals, pesticides, and their own waste. Escaping fish spread sea lice to wild fish, and mate with wild fish as well, reducing biodiversity. Farmed fish have twice the saturated fats of wild fish, and depending on what they are fed, they actually may have very little of the Omega 3’s that consumers are eating them for. Salmon are often fed the equivalent of dog food, and this food often contains feather meal from chicken farms, meat and bone meal from rendering plants, and soy meal and oil. They are also fed dyes to make the flesh the same appetizing pink as wild salmon, because without it, the flesh would be grey.
In June 2005, the Vancouver Sun reported that farmed salmon from British Columbia contain six times the PCB’s, dioxins and other chemicals than wild Canadian salmon.
To further muddy the waters, fish and other seafood are a major source of food-borne illness. According to the Centers for Disease Control, there are about 11 million cases of illness caused by seafood in the USA each year. These illnesses are caused both by poor handling, but also by “red tide” organisms, Vibrio, Listeria, hepatitis, E.Coli and Salmonella.
So, as someone who wants to be able to enjoy the occasional seafood meal without fear, what are you to do? Well, several independent organizations Like Seafood Watch and Environmental Defense have stepped in to try and make the choices somewhat easier for you. They produce extensive lists as well as pocket-sized cards that lists the “Eco-Best” and “Eco Worst” seafood. They take into account several factors, such as the nutritional value of the fish, how it is farmed, how it is harvested, and the levels of contamination it is likely to have. The web addresses where you can download and print these cards is listed below. Select no more than two servings per week from the list of the best and most sustainable seafood, and enjoy with few worries. And if you are pregnant or may become pregnant, it would be best to eat seafood seldom if at all, and certainly do not dine from the “Eco-Worst” list.
Another option is to eat seafood seldom, if at all. Omega 3 fatty acids can also easily be obtained from flax and hemp seed. A tablespoon in your cereal or smoothie in the morning provides all that you need without the health risks and troubling concerns about environmental damage and overfishing.
(Source: “What to Eat” by Marion Nestle, 2006.)
Source for Seafood cards, (or “Fish Lists”)
Blue Ocean Institute:
Seafood Safe Program: