For anyone who loves freshly caught salmon or a lobster roll on a summer day, the thought of giving up seafood for 9 months might be discouraging. While there is reason to steer clear of certain fish during pregnancy, most types of seafood are safe and pack a nutritional punch. Fish is a great source of lean protein, healthy fats and essential vitamins and minerals. It’s relatively low in total fat compared to other animal products, and contain healthy omega-3 polyunsaturated fatty acids that are especially important during pregnancy. Unfortunately, though, not all fish is created equal when it comes to nutrition. Some fish contain high levels of toxins that can accumulate in the body and harm a developing fetus.
Mercury is a naturally-occurring metal that is used frequently in industrial products and consumer products like ointments and skin creams. Methylmercury, the most dangerous type of mercury, is formed when mercury from industrial activity gets into water. Small bacteria convert it to methylmercury, which gets absorbed by fish living in contaminated waters. The highest levels of methylmercury are found in older, larger fish.
Polychlorinated biphenyls (PCB’s)
PCB’s are industrial chemicals that are no longer used in the US, but still make their way into lakes, streams, rivers and oceans. Fish are a main source of PCB contamination: small fish become contaminated with the chemicals, and are then eaten by larger predatory fish, which in turn may be consumed by humans. PCB’s are known to cause cancer in animals, and are associated with a number of abnormalities including low birth weight and behavioral problems in babies.
According to the Food and Drug Administration, pregnant and breastfeeding women should avoid the following four types of fish, due to their high mercury content:
4. King Mackerel
In spite of the warnings about mercury and other toxins, though, there’s no need to completely cut out fish consumption during pregnancy and lactation. In fact, it’s recommended that women eat up to 12 oz. per week (that’s about 3 servings) of fish that are lower in mercury. The following types are good choices:
1. Wild-caught salmon
4. Tuna (limit albacore, or white tuna, to 6 oz. per week)
Living in Minnesota, we have access to countless lakes and streams that are full of delicious varieties of fish. Are these local types safe to eat? According to the Minnesota Department of Health, pregnant women should avoid large fish like Northern pike and walleye greater than 20 inches in length. However, smaller fish like perch, sunfish and crappies are perfectly safe.
The nutrients that fish and seafood provide far outweigh the concerns about mercury and toxin content. While it’s important that pregnant and lactating women avoid the four types of fish with the highest mercury content (tilefish, swordfish, king mackerel and shark), most seafood is not only safe but provides important vitamins and minerals that support fetal development. To learn more, check out the following resources:
Centers for Disease Control and Prevention. http://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=140&tid=26
United States Food and Drug Administration http://www.fda.gov/Food/FoodborneIllnessContaminants/Metals/ucm393070.htm
Ward, Elizabeth MS, RD. Expect the Best.