FDA and EPA to pregnant women and parents: More fish

Two federal agencies teamed up recently to update recommendations on fish consumption, and the new guidelines suggest that pregnant women and children eat more fish, mostly varieties low in mercury.

by John B. Tyburski, PhD, MPH, Advisory Board Member

Copyright © 2014 Youth Fitness Council, LLC. All rights reserved.

First published at Youth Fitness Council on September 22, 2014

Long-hailed have been the value and importance of fish oil consumption during pregnancy, and evidence exists for the benefits of diets emphasizing fish consumption, the so-called “Mediterranean diet” in particular. However, concerns over the potential exposure to mercury from eating fish and the toxicity of consumed mercury have traditionally formed the basis for a cautious regulatory approach to fish consumption guidelines. One June 10, 2014, two federal agencies involved in guiding domestic fish consumption, the U.S. Food and Drug Administration (FDA) and the U.S. Environmental Protection Agency (EPA), announced that they are seeking public comments on new fish consumption guidelines. The updated recommendation recognizes the potential health benefits for children by increasing the amounts of low-mercury fish recommended for consumption by pregnant women, women who may become pregnant, and children.

The draft updated recommendation is consistent with guidelines set forth in the 2010 Dietary Guidelines for Americans, published by the U.S. Department of Agriculture (USDA). The decision to align with USDA guidelines was informed by over ten years of research suggesting an increase in fish consumption will support prenatal and early childhood development, growth, and health through the nutrients acquired from eating fish. The essential change is to the recommendation for eight to 12 ounces of fish every week, and the fish should be selected from varieties that are known to be low in mercury. These include canned light tuna, catfish, cod, Pollock, salmon, tilapia, and shrimp.

The joint draft recommendation also provides a number of other guidelines. Women and children should eat two to three servings of fish per week. For young children, the serving sizes should be appropriate for their size and caloric need. Minimize mercury exposure by sticking with commonly consumed fish and avoiding shark, swordfish, king mackerel, and tilefish from the Gulf of Mexico. Limit white (albacore) tuna to six ounces per week. When choosing fish caught from local waterways, check with local authorities for fish advisories related to the waterways. If no information can be found for local waterways fish, limit consumption of these fish to one to three ounces per week. Finally, when increasing fish consumption, it is important to maintain caloric balance to avoid overfeeding. Details are available in the draft update recommendation.

Until this draft was released, concerns over potential mercury exposure prompted the FDA and EPA to approach fish consumption recommendations with caution. Mercury is a naturally occurring metal that can also be put into the environment through human activities. Mercury may collect in oceans, lakes, rivers, and streams as methylmercury, a soluble form of mercury. Methylmercury is what is found in fish. Predatory fish such as sharks and swordfish exhibit what is called “bioaccumulation” because as they eat smaller fish containing small amounts of methylmercury, they in turn absorb it and deposit it into their tissues. Absorbed methylmercury does not leave the predatory fish bodies. Therefore, the level in each predatory fish increases as it consumes more smaller fish containing even just trace amounts of methymercury.

Methylmercury is a neurotoxin that can cause damage to the brain and other parts of the nervous system at high enough levels. The toxicity of methylmercury is profound in prenatal, infant, and early childhood development. Exposure of these groups to critical levels may cause deficits in cognitive thought, memory, attention, language, and fine motor and visual spatial skills. More information on the health effects of mercury and methylmercury are available from the EPA.

The most commonly consumed fish do not contain but trace amounts of methylmercury and can be safely eaten at the levels suggested in the draft update. The draft update is currently in the public comment phase, and anyone may provide comment. To do so, visit regulations.gov and submit input on document FDA-2014-N-0595-0001 (link). When the comment phase ends, the draft update will be evaluated for ratification.

“Eating fish with lower levels of mercury provides numerous health and dietary benefits,” said Nancy Stoner, the EPA’s acting assistant administrator for the Office of Water, in the press release. “This updated advice will help pregnant women and mothers make informed decisions about the right amount and right kinds of fish to eat during important times in their lives and their children’s lives.”