Farmed fish: the pros and cons for your health

1. Do you ever look at the back of the packaging of the fish you buy in the supermarket? If you look a little further you can quickly see if this is freshly caught fish that has grown naturally or maybe farmed fish.

1. What is farmed fish? What is the difference with fish that are simply caught in nature and what do you need to know for optimal health?

A little more information about farmed fish

1. More and more people are eating fish. As a result, it is not always possible to keep emptying the oceans to meet the growing need. The fishing industry has tried to control some of the fish catching variables by breeding the most popular types of fish, such as salmon, trout and catfish.

1. During aquaculture, fish grow faster than the fish that normally grow up in nature. Often these fish are also softer (softer meat) and have a richer taste. When these fish are 'harvested' they often go without the stress and damage of a hook or net.

1. Currently, aquaculture accounts for about one third of all fish used for food worldwide (this includes crustaceans). This figure will only increase in the future as there is an increasing global demand for fish that we cannot meet by catching wild fish.

1. While some popular farmed fish - such as trout, tuna and salmon - can also be caught in the wild, others, such as tilapia and catfish, are almost just the farmed varieties.

1. Fish farming can be done responsibly, but not all fish farms are the same. For example, salmon and tuna are grown in sections in the ocean, but the nearby water is often contaminated with waste, food and antibiotics.

1. There have been cases of genetically modified aquaculture fish that have escaped into the immediate area where they compete with the surrounding wild population, and there are studies showing that fishmeal, the main component of fish feed for carnivore fish species (such as salmon and tuna) contains a higher amount of toxic substances. With toxic substances we often talk about dioxins, such as PCBs (polychlorinated biphenyls), which accumulate in the meat of these farmed fish.

1. Omnivorous fish, such as tilapia and catfish, are fed via vegetarian pellets and therefore do not have these dioxin problems.

1. Growing fish in inland ponds, lakes and basins is ultimately less invasive than raising fish in the ocean (although there is some concern about raw wastewater being discharged from farms and thus pollute groundwater), making the least harmful aquaculture products than normal freshwater fish with a few saltwater varieties farmed on land (sturgeon and turbot).

The pros and cons of naturally caught fish

1. The main disadvantage of wild caught fish is the risk of overfishing and the degradation of wild populations. Due to increasingly powerful technology and the highly destructive fishing methods commonly used today, the term 'naturally caught' can mean anything. This can mean that large nets are used, but also that fishing is done with dynamite, for example. Drift nets are also a big problem.

1. According to the Monterey Bay Aquarium, for every pound of shrimp that is caught, about 2 to 10 pounds of other marine life is caught bycatch, usually discarded overboard.

1. Overfishing

1. Overfishing is a serious threat to many species of favorite fish, such as bluefin tuna, Atlantic salmon, Mediterranean sea bass and North Atlantic cod. The resulting scarcity of these popular fish opened the door for companies to make these fish more widely available (and thus cheaper for consumers).

1. However, the term “wild caught” can also include more desirable trapping methods. For example when divers are looking for fish or when they are caught with underwater traps. When fish are caught in this way, it means that the waters where the fish are caught are not controlled and are only for fishing.

1. There are also wild fisheries, especially in the oceans, especially around the coast. But these fisheries can also occur in lakes and rivers. When fish are caught in the wild, these fish often contain more omega-3 essential fatty acids (the good kind of fat).

1. In addition, wild caught fish contain about 20% more protein, while the calorie content is 20% less than farmed fish.

The pros and cons of farmed fish

1. Unlike wild-caught fish, farmed fish and shellfish are often grown commercially on land. Often in baths or tanks, or offshore fish farm areas, these are parts of the ocean that are kept separate by a net to prevent the stock of fish from escaping. At fish farms, operators monitor the production of the fish and what these fish eat.

1. Thousands of fish are often crammed into a confined space, often leading to an increase in diseases and parasites requiring antibiotics and pesticides.

1. Certain diseases and parasites, which would normally exist in a relatively small amount of fish scattered across the oceans, can often spread quickly in densely packed oceanic breeding grounds. In order to survive, farmed fish are often vaccinated when they are small. Later, these fish are given antibiotics or pesticides to ward off infections.

1. PCBs (polychlorinated biphenyls), are man-made chlorinated industrial chemicals that are highly toxic. PCBs accumulate in the sediment at the bottom of streams, rivers, lakes and coastal areas. These chemicals can build up in the fatty tissues of fish and other animals.

1. When these PCBs occur in high concentrations, they pose serious health risks to people who regularly eat contaminated fish. Based on the available data on PCB concentrations in fish, several organizations recommend that we have a limited intake of certain types of farmed fish.

1. According to the EPA (Environmental Protection Agency - the federal agency of the United States charged with protecting the environment and protecting public health), contaminated fish is a persistent source of PCBs in our diet. PCBs are not extremely toxic with a single dose (such as eating a single meal), but long-term exposure (eg, eating contaminated fish for extended periods of time) can certainly be harmful.

1. The EPA therefore estimates PCBs as “Likely carcinogenic to humans” because they cause cancer in laboratory animals. Other tests on laboratory animals show damage from PCBs. The damage in these lab animals was often to their circulatory system, nervous system, immune system, endocrine system and digestive system.

1. In nature, fish trap carotenoids, especially astaxanthin (a class of predominantly yellow, orange, or red fat-soluble pigments, including carotene that provides the color of certain plants). In fish in nature, these carotenoids come from their natural environment, insects, crustaceans, and plants that serve as food. In aquaculture, fish cannot synthesize astaxanthin. Because of this, these carotenoid pigments must be artificially added to their aquaculture diet.

1. In other words, that rich color of some of these farmed fish comes from the use of synthetic pigments.

1. Industrial salmon farms add artificial color to their farmed fish. Most salmon normally have greyish-white flesh - but the addition of these dyes makes the flesh a "tastier salmon pink".

1. And it is now under discussion whether cantaxanthin, both as a fish feed and a food additive, could potentially pose a risk to public health.

1. In 2003 the European Commission already decided that salmon growers had to drastically reduce the amount of cantaxanthin. In America, fish with cantaxanthin can only be sold if it is clearly indicated on the packaging.

How do you reduce the PCB risk with farmed fish?

1. PCBs build up in fish and animal fats. As a result, proper cooking methods can actually help reduce our exposure to these potentially harmful substances: