Why Eat Fish?

Individuals who are pregnant or nursing and eat fish high in omega-3 fatty acids will pass these essential nutrients, that support healthy brain and eye development, on to their babies.

Fish provides many nutrients that are important for good health. Nutrients include: protein, vitamins (A, D), minerals (iodine, calcium, iron, selenium), omega-3 fatty acids (docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)) and antioxidants (astaxanthin). Fish is generally lower in saturated fats than meats. During pregnancy and nursing, many of these nutrients that the mother consumes are directly shared through the placenta to the developing fetus or through the mother’s breast milk to the nursing infant. The omega-3 fatty acid, DHA, is important for healthy brain and eye development in babies.

How Much Fish to Eat?

The short answer is, health experts recommend that those who are pregnant or nursing, or are planning on becoming pregnant should eat 8-12 ounces per week and children (age 2-6) eat 2-4 ounces per week.

The 2020-2025 Dietary Guidelines for Americans recommends that adults eat 8-12 ounces (weight before cooking) of fish per week. The American Heart Association recommends 2 servings (3 ounces per serving) of fish per week. The National Academy of Sciences, Institute of Medicine recommends that those who are pregnant or nursing consume 130-140 mg of EPA plus DHA per day. The American Academy of Pediatrics recommends that those who are nursing should consume 200-300 mg of DHA a day. Consumption of 1 to 2 servings of fish high in omega-3 fatty acids per week or DHA supplements will meet this recommendation.¹

There is scientific evidence that indicates those who have low levels of DHA when they become pregnant may benefit from high dosage daily DHA supplements. Talk to your doctor about omega-3 fatty acid intake to see if you and your baby may benefit from high dosage DHA supplements.²

Best Choices

8 ounces per week

Lowest in Mercury & Highest in Healthy Fats

Eating as little as 8 ounces of these fish will meet the recommendation for nutrients and minimize your intake of pollutants. Occasionally, we are asked if fish oil supplements are as good for sensitive populations as eating fish. Be aware that there are many nutrients in fish in addition to the healthy fats. Many of these nutrients are not found in fish oil supplements. If you do not or cannot eat fish, you may wish to consult with your physician about the option of taking a fish oil supplement. The amount that you should take will be 1 capsule per day which is much lower than the amount generally recommended on the label. Additionally, there are omega-3 eggs which will provide some of the omega-3 fatty acid, DHA. During the early stages of pregnancy, these eggs may be more easily tolerated than stronger tasting fish.

Best Choice species are low in pollutants and high in healthy fats. These are the preferred species for those who are pregnant or nursing and for young children.

The National Academy of Sciences, Institute of Medicine recommends that those who are pregnant or nursing consume 130-140 mg of EPA plus DHA per day. Best Choice species provide the recommended amount of healthy fats if 6 ounces of the cooked product is consumed each week. The amount of EPA and DHA in these fish was determined by the USDA.

Lowest Mercury

12 ounces per week

The lowest mercury species can be consumed up to 12 ounces per week. Some of these species are low in omega-3 fatty acids while others are quite high in these healthy fats.

In the past decade or two there has been a controversy surrounding the safety of farmed salmon due to PCBs (polychlorinated biphenyls). A number of scientists have examined this issue and found that the levels of PCBs and other contaminants in farmed salmon are extremely low. This controversy is being driven by groups who feel that salmon farming is not environmentally friendly and by companies that have been economically impacted by the lower costing farmed salmon product. Also, subsequent scientific studies have reported that levels of PCBs in farmed salmon have declined due to changes in feed composition made by the salmon industry. Farmed and wild salmon are safe to eat- both an equally healthy choice for adults and children.

Moderate Mercury

4 ounces per week

Eat up to 4 ounces of Moderate Mercury species per week. If you eat 4 ounces from the moderate category, don’t eat any more fish from this category until the next week.

Shelf stable tuna is one of the most popular fish in the U.S. Shelf sable tuna is typically packaged in cans or pouches. It is popular due to its great taste, convenience and low cost. There are 2 main types of shelf stable tuna (Albacore/White and Light). Albacore/White tuna is moderately high in mercury while most of the tuna sold as light tuna is low in mercury. Media reports indicate that there is also a ‘Deluxe’ Light tuna product which is moderately high in mercury. This product contains Yellowfin tuna which is just as high in mercury as Albacore tuna. Some tuna manufacturers have started to including the species on packaging label. Most Light tuna is made using Skipjack tuna which is low in mercury. The omega-3 fatty acid content in Albacore/White tuna is moderately high but low in Light tuna. The FDA/EPA Fish Advisory for sensitive populations recommends that women limit their consumption of Albacore/White tuna to 6 ounces per week. The Advisory does not recommend limiting their intake of Light tuna. Here, we recommend that pregnant or nursing individuals limit their consumption of Albacore/White or Yellowfin tuna to 4 ounces per week. We recommend that those who are pregnant or nursing eat up to 12 ounces of canned Light tuna that contains Skipjack tuna. Due to its popularity, it has been estimated by the Environmental Protection Agency that canned tuna contributes ~34% of the mercury that enters our bodies.

Moderate Mercury fish, contain mercury residues as reported by the Food and Drug Administration. To determine which fish to list as Moderate Mercury species, we used the Environmental Protection Agency’s Reference Dose (0.1 µg mercury/kg body weight/day) and estimated a safe intake for a 60 kg (132 pound) woman.

High Mercury/PCB – Do Not Eat

0 ounces per week

High Mercury/PCB fish have been found to contain mercury or PCBs at levels that exceed safety standards for sensitive populations like pregnant or nursing women, women that will become pregnant, and young children. The mercury concentrations for most of these species were obtained from the Food and Drug Administration. The Environmental Protection Agency’s Reference Dose of 0.1 µg mercury/kg body weight per day was the safety limit that was used to establish our advice. This limit has been evaluated by the National Research Council and found to be protective of health for fetuses and nursing infants. Individuals should not eat fish listed in this category if they are pregnant or nursing or planning to become pregnant within 1 year. Mercury takes about 1 year to clear from the body. In addition, these fish should not be fed to children younger than 6 years of age.

The Food and Drug Administration and the Environmental Protection Agency have issued a joint Fish Consumption Advisory for sensitive populations which advises childbearing-aged women to completely avoid eating swordfish, shark, king mackerel and tilefish (Gulf of Mexico). Unfortunately, the maximum dosage or safety limit that was used to arrive at their advice was never reported. So, we have used the Environmental Protection Agency’s Reference Dose to determine which species should be added to this list. In this latest version of the wallet card, we have added two commercial species (striped bass and bluefish) which have higher concentrations of PCBs (polychlorinated biphenyls) and moved walleye to the Moderate Mercury category. PCBs are typically not a major concern in commercial fish but are a significant concern in recreationally-caught fish. Like mercury, PCBs are developmental toxicants that can harm the developing brain.

Recommended Reading

¹ Johnston M Landers S Noble L Szucs K and Viehmann L for the Section on Breastfeeding (2012). Breastfeeding and the use of human milk. Pediatrics 129:e827‐e841. [online] Available at: http://pediatrics.aappublications.org/content/129/3/e827.full.pdf+html [Accessed April 16, 2014]

² Susan E Carlson, Byron J Gajewski, Christina J Valentine, Elizabeth H Kerling, Carl P Weiner, Michael Cackovic, Catalin S Buhimschi, Lynette K Rogers, Scott A Sands, Alexandra R Brown, Dinesh Pal Mudaranthakam, Sarah A Crawford, Emily A DeFranco, Higher dose docosahexaenoic acid supplementation during pregnancy and early preterm birth: A randomised, double-blind, adaptive-design superiority trial, EClinicalMedicine, Volume 36, 2021, 100905, ISSN 2589-5370. Available at: https://doi.org/10.1016/j.eclinm.2021.100905.