The Environmental Health News of January 3, 2011 reports: "The beneficial effects of eating fish during pregnancy on a baby's brain development are relatively well accepted. However, some fish can contain high levels of mercury ... Government agency advisories suggest women of childbearing years eat fish with low mercury levels as well as limit consumption of fish that contain high levels." [environmentalhealthnews.org]
When a nutrient is shown to be beneficial, we are usually advised to obtain it from food rather than a supplement. Omega 3 looks like an important exception. While adequate Omega 3 is essential for pregnant women and young children, it is even more important to avoid mercury exposure.
Mercury is a well known neurotoxin which affects the development and functioning of the brain and nervous system, especially fetal and infant systems. Mercury is concentrated in fetal blood – the Centers for Disease Control and Prevention found umbilical cord blood levels to be 1.7 times that of the mother’s. Mercury pollution has spread across the oceans and freshwater bodies so finding uncontaminated fish is getting more difficult. The cleanest sources are fish from northern and Antarctic waters. Since mercury is concentrated going up the food chain, smaller fish such as sardines and anchovies are safer than large predator fish such as tuna.
Fish oil supplements made from small cold water fish species are mercury free. Krill, which is even lower on the food chain, is another safe source of Omega 3s. Reputable companies like Ascenta, Norwegian Gold, and others, test and certify every batch for mercury and other contaminants. With careful selection, and in moderation, fish can still be part of a healthy diet – just don’t depend on it for your essential fatty acids, especially during childbearing years.
This article is intended for educational purposes only; for medical advice consult your licensed health practitioner.