New Research Recommends Changing Guidance Around Eating Fish While Pregnant—Here's Why

It's never a surprise to see seafood, and especially heart-healthy options like salmon and tuna, listed among the best protein sources you can keep in your kitchen. But for those trying to follow all the dietary rules and recommendations for a healthy pregnancy, choosing the right kind of seafood can be a little tricky.

Pictured Recipe: Swordfish with Olives, Capers & Tomatoes over Polenta

The Food and Drug Administration recommends that pregnant folks eat two or three servings each week of seafood in its "best choices" category, which includes sources with very little mercury, like some tuna, cod, salmon and scallops, or one serving each week from the "good choices" category, which contain slightly more mercury. Some seafood, like king mackerel, swordfish and big-eye tuna, the FDA suggests to avoid eating entirely during pregnancy, as their mercury levels are among the highest.

While those are still the best guidelines we have, a new study from the University of Bristol suggests that recommendations be broadened to encourage eating all kinds of seafood, regardless of mercury level. Published in NeuroToxicology, the study analyzed more than 4,000 mothers and their children from the United Kingdom and the Seychelles. Generally, researchers found that the density of nutrients in fish outweighed the risk of consuming too much mercury, and it was possible that those nutrients were protective against the effects of mercury.

As the FDA advice indicates, eating fish with a low mercury content can provide key nutrients to developing babies during pregnancy and breastfeeding. Fish are rich with omega-3 fats, iron, iodine and choline, all of which are among the nutrients that support development of the brain, spinal cord and immune system. Those benefits are backed up with years of research, but there's always a chance that pregnant folks will avoid fish entirely just to be on the safe side—that concern is part of what spurred this study out of Bristol.

"We found that the mother's mercury level during pregnancy is likely to have no adverse effect on the development of the child provided that the mother eats fish," study co-author Caroline Taylor, Ph.D., said in a media release. "If she did not eat fish, then there was some evidence that her mercury level could have a harmful effect on the child. This could be because of the benefits from the mix of essential nutrients that fish provides, including long-chain fatty acids, iodine, vitamin D and selenium."

To encourage more seafood consumption among those who are pregnant, study co-author Jean Golding, Ph.D., suggests that the recommendations around not eating certain fish high in mercury should be omitted, and guidance should suggest eating "at least two portions of fish a week, one of which should be oily," according to the same release.

More research should be done to confirm the limited effect of mercury on pregnant people who eat fish and their children, but those who are pregnant can safely eat two or three servings of low-mercury fish to scoop up those healthy benefits. Common grocery store and restaurant options like anchovy, sea bass, flounder, salmon, trout and canned light tuna all fall into the safest category, making them a great option for leveling up your fish consumption.

The Bottom Line

New research in NeuroToxicology suggests that pregnant folks don't have to base their seafood consumption on mercury levels—instead they should eat at least two servings of fish each week regardless of mercury content. Follow-up research will be required to confirm that fish has protective benefits that counteract the risk of higher mercury levels, but the study adds onto the pile of evidence that eating fish during pregnancy can be quite beneficial.

Fish like salmon, cod and catfish are all low in mercury and packed with critical nutrients. Recipes like our Garlic-Butter Salmon Bites, Cilantro-Lime Shrimp Bowl and Teriyaki-Glazed Cod with Cauliflower Rice are healthy pregnancy options that can help you meet nutrition suggestions and add more fish to your routine.