The U.S. National Academies of Sciences, Engineering, and Medicine (NASEM) has completed its study on “The Role of Seafood in Child Growth and Development,” fulfilling an October 2022 request from the U.S. Food and Drug Administration (FDA). The aim of the research was to better understand the nutritional benefits of seafood consumption weighed against the health risks posed by toxic heavy metals and other contaminants present in seafood, specifically concerning pregnant/nursing women and children and the developmental/lifelong effects of exposure.  

The NASEM Committee on the Role of Seafood in Child Growth and Development will provide an overview of its conclusions and recommendations outlined in its report in an upcoming public webinar, held Tuesday, March 26, 2024 from 2:00–3:00 P.M. ET. Registration is required.

According to NASEM , although seafood is an important source of key nutrients, it can also be a source of exposure to contaminants such as methylmercury; persistent pollutants like per- and polyfluoroalkyl substances (PFAS), dioxins, and polychlorinated biphenyls; and microbiological hazards that may be detrimental to the growth and development of children. Still, the Dietary Guidelines for Americans 2020–2025 (DGA) includes an overarching recommendation that all U.S. adults aim to consume at least 8 ounces (two servings) of seafood per week. Children are recommended to consume two servings per week proportional to the child’s total caloric intake, beginning at six months of age.

FDA’s Closer to Zero action plan was launched in April 2021 with the goal of reducing children’s exposure to four toxic heavy metals that can harm childhood development—arsenic, lead, cadmium, and mercury—and the action plan serves as the foundation for DGA seafood recommendations. The juxtaposition of nutritional benefits and toxicological risks associated with the consumption of seafood led FDA to convene a committee to review the role of seafood in the diets of pregnant and lactating women and children, including adolescents, considering both the potentially detrimental components of seafood as well as those that are beneficial, to evaluate their respective, interacting, and complex roles in child development and lifelong health.

For its report, NASEM conducted systematic literature reviews on seafood consumption during childhood and adolescence and neurocognitive development, and on seafood consumption during pregnancy and lactation and neurocognitive development in the child. Additionally, the committee commissioned a de novo systematic review on toxicants in seafood and neurocognitive development in children and adolescents. Also considered were cross-sectional data analyses on seafood consumption and factors that affect decision-making and dietary patterns.

Overall, NASEM found that most women of childbearing age, children, and adolescents do not consume the recommended amounts and types of seafood, and the report calls for strategies to support increasing consumption toward meeting recommendations. Although the committee found the existence of insufficient evidence suggesting a need to revise seafood consumption guidelines, the need to identify strategies to help individuals meet current guidelines is clear. The report provides two recommendations for U.S. federal agencies to increase seafood consumption in pregnant and lactating women, and children and adolescents:

• The U.S. Centers for Disease Control and Prevention (CDC) should identify strategies to address gaps in current National Health and Nutrition Examination Survey (NHANES) monitoring to better assess the sources, types, amounts, and preparation methods of seafood consumed by women of childbearing age, pregnant and lactating women, and children and adolescents up to 18 years of age
• The U.S. Department of Agriculture (USDA) should reevaluate its federal nutrition programs, especially school meals, to support greater inclusion of seafood in meal patterns.

The evidence showed that some gains in neurodevelopment may be achieved during childhood and are apparent in the children of women who consume greater quantities of seafood during pregnancy, in comparison to those who consume less or no seafood. The committee underlined the benefits of omega-3 long-chain fatty acids in seafood, some of which are important to brain development and may have a protective effect against adverse neurocognitive outcomes.

The available literature indicates that seafood is a rich source of multiple nutrients, including vitamin D, calcium, potassium, and iron. Additionally, seafood is an important source of n-3 LCPUFAs, which are key nutrients for the prenatal period, during lactation, and throughout childhood. Without seafood consumption, intakes of n-3 LCPUFA’s are likely to fall below recommended amounts. Choline, iodine, and magnesium are additional nutrients that are provided by seafood and have important functions throughout childhood and adolescence.

On the other hand, toxins, toxicants, and microbes—including persistent bioaccumulative chemicals, metals, and metalloids, infectious organisms, microplastics, and microorganisms—may be present in seafood at hazardous levels. The concentration of these various contaminants in seafood depends on many factors, including species, trophic position, size, age, geographic location, and origin (wild caught or farm raised). The committee found polychlorinated biphenyl (PCBs) and mercury to be the key drivers for fish consumption advisories, and PCBs are mostly relevant in the Great Lakes region of the U.S. Additionally, aside from mercury, concentrations of other metals and metalloids tend to be limited to certain species and geographic areas.

NASEM found insufficient evidence to assess most consumers’ exposures to emerging contaminants in seafood, including PFAS, microplastics, and domoic acids. The committee found that polybrominated diphenyl ether (PBDE) exposure is not due primarily to seafood consumption; however, as PBDEs migrate into aquatic environments, risk of increased exposure through seafood may emerge. Seafood consumption remains an important predictor of methylmercury, arsenic, and PCB exposure and, based on the limited available evidence, may be important for assessing PFAS exposure.

FDA requested specific information about exposure to mercury through seafood, and NASEM found that, with the exception of some types of tuna, the most commonly consumed seafood species in North America contain relatively low concentrations of the metal. Among adults and children, seafood consumption is associated with higher levels of mercury in blood/hair/nail samples, but average intake levels of methylmercury from seafood are below Closer to Zero recommended limits among women of childbearing age, infants, and children (except for those who frequently consume tuna).

The committee concluded that the evidence reviewed for the report on health outcomes associated with seafood consumption for women of childbearing age, children, and adolescents is not adequate to support an accurate assessment of the health benefits and risks associated with meeting the recommended intakes of seafood for this population group. However, the report provides several recommendations to FDA and EPA regarding risk-benefit analysis:

• FDA should consider conducting a risk-benefit analysis of maternal and child seafood intake and child growth and development, and, in doing so, routinely monitor data and scientific discoveries related to the underlying model and assumptions to ensure the assessment reflects the best available science
• In conducting a risk-benefit analysis, FDA and EPA should include reviews of current evidence scans, systematic and supplemental reviews, approaches and metrics, benefit-harm characterization, and quality and assurance in evaluating the confidence in a risk-benefit analysis for policy decision-making
• FDA and EPA should create an integrated database to support risk–benefit analyses for fish consumption, thoroughly considering implications of using a metric that reflects transparency and conflicts of interest for both risk and benefit
• To maximize the use of a formal risk-benefit analysis, FDA and EPA should present conclusions, including a risk estimate, in a readily understandable and useful form to risk managers and be made available to other risk assessors and interested parties.