You Should Know

November 2015 Issue

The Catch on Mercury in Fish

Donít let fear of mercury keep you from eating fish. Just make wise choices.

Fish contain an abundance of nutrients and health benefits. This high-protein food choice is a major source of long-chain omega-3 fatty acids, along with vitamin D, selenium, and antioxidants. Research suggests that fish consumption is important in the growth and development of children, as well as reducing the risk of heart attack, stroke, prostate cancer, depression, and Alzheimer’s disease.

Unfortunately, only about one-third of Americans eat fish once a week and nearly half eat it occasionally, if at all. Some people simply don’t like the taste of fish, but many avoid it due to the fear of mercury, a potentially dangerous toxin in our food supply.

What’s the line on mercury? According to the U.S. Food and Drug Administration (FDA), pollution releases mercury into the air, and as it accumulates in the ocean, fish absorb it and mercury builds up in their flesh. The National Institutes of Health advises that eating large amounts of fish with higher levels of mercury—namely tilefish, king mackerel, swordfish, and shark—may cause problems with neurological development in fetuses and children. The FDA and the Environmental Protection Agency recommend that women who may become pregnant, are pregnant, or are nursing, as well as young children, consume up to 12 ounces a week of lower-mercury-containing fish in order to gain the benefits of fish without the risks of high mercury exposure.

Scaling the evidence. The benefits of moderate fish consumption may outweigh the possible risks of mercury. In a large 2011 study, researchers found no evidence that higher levels of mercury exposure were associated with higher risk of coronary heart disease, stroke, or total cardiovascular disease. A January 2015 study found that even eating up to 12 servings of fish per week during pregnancy did not lead to developmental problems in the children; instead researchers concluded that the fatty acids in fish may provide protection from potential mercury damage.

The final hook. Given its benefits, eliminating fish only to avoid mercury may not be the wisest choice. The USDA’s Dietary Guidelines for Americans recommend eating at least two servings of fish per week. Focus on our list of Low Mercury Fish Choices to limit mercury exposure.

—Kaley Todd, MS, RD