New research provides a way to balance the benefits of eating fish for a developing baby’s brain with the potential risk of mercury exposure. When expecting, it can be confusing to know whether or not to eat fish. On one hand, fish provide important nutrients like polyunsaturated fatty acids, selenium, iodine, and vitamin D that are crucial for brain development. On the other hand, they also contain methyl mercury, which can harm the brain. This has led the US Food and Drug Administration to advise pregnant women to limit their fish intake, causing many to avoid it altogether.The consumption of fish can lead to exposure to methyl mercury, but the health risks posed by mercury are difficult to understand because the nutritional benefits of fish may reduce its toxicity. A recent study published in the American Journal of Epidemiology, based on data from a group of residents in a coastal community in Massachusetts, aims to simplify these questions and provide clearer guidance on fish consumption for pregnant women. The study introduces a new framework that could help unravel the complexities of mercury exposure and its effects on health.Researchers, including Sally Thurston, PhD from the University of Rochester Medical Center, Susan Korrick, MD, MPH from Harvard T.H. Chan School of Public Health and Brigham and Women’s Hospital, and David Ruppert, PhD from Cornell University, aimed to improve evidence-based advice on the risks and benefits of fish consumption. The study sought to address the limitations of previous models. The team emphasized the need to separate mercury exposure into fish intake and the average mercury content of the consumed fish, especially in fish-eating populations. The new research is based on an analysis of data from the New Bedford Cohort.The study was designed to evaluate the health of kids whose mothers lived near the New Bedford Harbor Superfund site in Massachusetts. The study involved 361 children born between 1993 and 1998 who underwent neurodevelopment assessments at the age of eight, including tests for IQ, language, memory, and attention.
The researchers measured mercury exposure during the third trimester of pregnancy by collecting hair samples from the mothers after giving birth. While hair samples have been traditionally used to study maternal mercury exposure, this method alone cannot differentiate between mothers who frequentThe researchers found that mothers who ate low-mercury fish more often had better outcomes for their babies compared to those who ate high-mercury fish less often. To address the limitations of previous studies, the researchers developed a new model that took into account the amount of mercury exposure per serving of fish. This was made possible by collecting information from mothers in the study about their fish consumption during pregnancy. By estimating the average mercury levels in different types of fish and combining that with the mothers’ dietary information, the researchers were able to create a more accurate way to assess the impact of fish consumption on pregnancy outcomes.The study looked at the effects of eating fish during pregnancy on brain development. The researchers found that the impact of fish consumption on neurodevelopment depended on the levels of mercury in the fish. Eating fish with low levels of mercury was good for development, but eating fish with higher levels of mercury was not. The researchers suggest that future studies should consider both mercury levels and the nutritional content of fish to better understand the risks and benefits.The researchers stated that eating fish is an important part of a healthy diet. They are also planning to use this model in other studies on how fish consumption during pregnancy affects children’s development. One of these studies is the Seychelles Child Development Study, in which Thurston is involved. The study in the American Journal of Epidemiology was funded by the National Institute of Environmental Health Sciences.