New federal nutrition guidelines say that pregnant and breastfeeding women should eat 2 to 3 servings of fish every week. However, there are certain fish that should be eaten only once per week and other fish that should be avoided entirely by pregnant and nursing women.
One reason for the differentiation between certain types of fish is its likelihood of containing either very low or high levels of mercury.
Nearly all fish and shellfish contain traces of mercury. But some contain high levels. A type of mercury called methylmercury is most easily accumulated in the body and is particularly dangerous.
Eating large amounts of these fish and shellfish can result in high levels of mercury in the human body. In a fetus or young child, this can damage the brain and nervous system.
The highest mercury concentration belongs to fish that typically live a long time. Pregnant and breastfeeding women should avoid King mackerel, Marlin, Orange roughy, Shark, Swordfish, Tilefish from the Gulf of Mexico and Bigeye Tuna. These are fish that usually contain high levels of mercury.
The new guidelines come with a handy chart that gives you the best choices of fish, good choices and fish to avoid.
Naturally, many pregnant women are concerned about eating fish after hearing about the possibility of consuming any mercury whatsoever. It’s important to remember that most of the fish consumed by Americans falls into the safe category.
Studies show that fish provide an array of nutrients that are important for your baby's early development. Most experts agree that the key nutrients are two omega-3 fatty acids – DHA and EPA – that are difficult to find in other foods. Fish is also low in saturated fat and high in protein, vitamin D, and other nutrients that are crucial for a developing baby and a healthy pregnancy.
How do fish end up consuming mercury? Some of the sources (such as volcanoes and forest fires) are natural. It's also released into the air by power plants, cement plants, and certain chemical and industrial manufacturers, landfills and farming runoff.
When mercury settles into water, bacteria convert it into a form called methylmercury. Fish absorb methylmercury from the water they swim in and the organisms they eat. Methylmercury binds tightly to the proteins in fish muscle and remains there even after the fish is cooked. Fish that live a long time consume more mercury.
There are many benefits to eating fish; you just need to be aware of the kinds of fish you eat. To help you make the best choices, the new chart released by the FDA and EPA is shown below.
Story sources: Megan Thielking, https://www.statnews.com/2017/01/19/fda-guidelines-fish/