Originally published in our Winter 2013 newsletter
We know that eating fish provides us with omega 3 essential fatty acids, a nutrient that is important for the health of our cardiovascular system and the development of the brain and nervous system in the fetus and infant. In fact, these essential fatty acids are a component of the cell membrane of every tissue in the body and are necessary for their proper functioning, so we must ensure we have an adequate supply.
However, we need to be very careful about our source of this nutrient. Industrial pollution has contaminated our planet and made its way into the oceans. These toxic chemicals, including heavy metals such as mercury, have shown up in fish, with the highest levels found in the fish at the top of the food chain, such as tuna, swordfish and mackerel.
Salmon has been considered an excellent source of omega 3 fatty acids. Wild salmon has lower levels of mercury and other toxins than most fish, but most of the salmon now sold is farmed. A study of farmed salmon from around the globe has shown that levels of pollutants such as PCBs and dioxins are significantly higher in the farmed fish. The source of these elevated chemicals has been traced to the fish pellets used as feed, which are made from smaller fish that have been contaminated with these pollutants. PCBs are toxic industrial chemicals that have been banned in North America for decades, but persist in the environment.
When women consume foods that contain high levels of PCBs and later have children, neurological deficits may appear in their offspring, affecting their IQ, short and long-term memory, and behaviour. For this reason, it is very important for women planning to have children to completely avoid eating farmed fish.
PCBs are also associated with higher incidence of cancer and disruption of the immune, reproductive, endocrine and nervous systems, and so it makes good sense that farmed fish be avoided by everyone.
Purified fish oil supplements from trusted manufacturers, prescribed by your health care practitioner, are a safer source of essential fatty acids. If you are concerned about possible exposure, talk to your Naturopathic Doctor about a detox protocol to remove these toxins.