Mercury in Fish? What you need to know

Should you worry about what’s in your fish? As both a health writer and eco-writer, I can tell you the decision you have to make about whether or not to eat certain kinds of fish is really a tough one. First, the information is not always readily available. Battles are always brewing between food companies and environmentalists over what to tell the public. Research on toxic chemicals in food can get quite a spin before it comes out to the public. So how are the rest of us to really know?

On the one hand, fish is one of the healthiest foods you can eat. It provides high quality protein and the essential fatty acids you and your baby need for growth and development. But industrial pollution in the oceans contaminates fish with mercury, which poses a major health threat, especially to a developing fetus.

Getting Beneath the Buzz

Unfortunately, new research indicates the problem is only going to get worse. We can expect a 50 percent spike in the Pacific Ocean’s mercury level by the year 2050, that is, if the world’s coal industry continues along its current path.

This dire prediction comes from a landmark study on Mercury in Aquatic Ecosystems, published by scientists from the U.S. Geological Survey.

Here’s a savvy tip for getting beneath the buzz: check the warnings for pregnant women, even if you’re not pregnant.

If there is any question about whether or not something is safe, the one thing corporate types and the safety conscious agree on is when pregnant women should stay away. Now, you may not need to be as cautious as expectant women, but this strategy will hep you stay informed, and it gives you a starting point.

Once you know what foods have issues, however controversial, you can decide for yourself how much of it to put on your plate.

What fish should pregnant women avoid?

The answer to that question depends on who you ask. Because fish contains both essential nutrition for health and toxic mercury that can harm fetal brain and nervous system development, The American Pregnancy Association recommends moderate intake of the types of fish deemed “safer” based on the the Natural Resources Defense Council (NRDC) list. (See the safer to least safe types of fish below.)

Although the FDA emphasizes the health properties of fish, the EPA urges much more caution. And here’s what the NRDC advises for pregnant women and young children:

Children under six, as well as women who are pregnant or planning to become pregnant, are the most vulnerable to mercury’s harmful effects. They should restrict or eliminate certain fish from their diet, including ahi or bigeye tuna, tilefish, swordfish, shark, king mackerel, marlin, orange roughy and fish caught in any waters that are subject to a mercury advisory.

Women with elevated mercury levels should ideally begin avoiding or restricting their consumption of mercury-laden fish as much as a year before they become pregnant.

Here’s the fish recommendations for pregnant women, from the NRDC. For personalized advice based on your weight, check out the NRDC’s mercury calculator. For those of you not pregnant, use this as a guideline for making conscious choices.

NRDC Fish safety list for pregnant women

LEAST MERCURY – Enjoy these fish:

• Anchovies, Butterfish, Catfish, Clam, Crab (Domestic), Crawfish/Crayfish, Croaker (Atlantic), Flounder, Haddock (Atlantic), Hake, Herring, Mackerel (N. Atlantic, Chub), Mullet, Oyster, Perch (Ocean), Plaice, Pollock, Salmon (Canned), Salmon (Fresh), Sardine, Scallop,Shad (American), Shrimp, Sole (Pacific), Squid (Calamari), Tilapia, Trout (Freshwater), Whitefish, Whiting

MODERATE MERCURY – Eat 6 servings or less per month:

• Bass (Striped, Black), Carp, Cod (Alaskan), Croaker (White Pacific), Halibut (Atlantic), Halibut (Pacific), Jacksmelt, (Silverside), Lobster, Mahi Mahi, Monkfish, Perch (Freshwater), Sablefish, Skate, Snapper, Tuna (Canned chunk light), Tuna (Skipjack), Weakfish (Sea Trout)

HIGH MERCURY – Eat 3 servings or less per month:

• Bluefish, Grouper, Mackerel (Spanish, Gulf), Sea Bass (Chilean), Tuna (Canned Albacore), Tuna (Yellowfin)

HIGHEST MERCURY – Avoid eating:

• Mackerel (King), Marlin, Orange Roughy, Shark, Swordfish, Tilefish, Tuna, (Bigeye, Ahi)