For years, women have been told to avoid eating ocean fish during pregnancy over fears of mercury contamination. However, a new study published in the American Journal of Clinical Nutrition (AJCN) on Jan. 21 has provided evidence that the benefits of consuming fish far outweigh the risks associated with exposure to mercury.
Originally, researchers believed that the consumption of fish during pregnancy would lead to the accumulation of mercury in the body, which would threaten fetal and child development. The new study conducted by a team of scientists from the University of Rochester Department of Public Health Sciences, followed over 1,500 mothers and their children in Seychelles in an attempt to address this concern.
Importantly, these women consume significant amounts of fish (about 12 meals per week) and their children underwent a series of tests 20 months after birth to determine their various behavioral, motor and communication-based skills. Contrary to what has been popularly reported, the mother’s exposure to mercury did not correlate with lower test scores. This finding supports another study also conducted in Seychelles that followed children into their 20’s and showed no association between fish consumption and the child’s eventual neurological development. In fact, the fatty acids derived from fish may shield the fetal brain from mercury damage.
As lead author Edwin van Wijngaarden said in a statement about the research, “…their mercury exposure from fish is about 10 times higher than that of average Americans. [Yet] we have not found any association between these exposures to mercury and developmental outcomes.”
In fact, the American Pregnancy Association (APA) has warned pregnant mothers that fish contain vital nutrients such as omega-3s, protein, vitamins and minerals such as iron that are essential for pregnant mothers and their developing fetuses. Yet the organization warns that there are four types of fish that women should avoid while pregnant or breastfeeding. These include tilefish from the Gulf of Mexico, king mackerel, swordfish and shark. The page, however, was last updated in Dec. 2014 and may not reflect the findings from this most recent paper.
Still, one of the authors from the 2015 AJCN study, Gary Myers, warns that there are differences between the Seychelles women and those in America. “They don’t really eat sushi…They ate quite a wide mixture of fish — much wider than what we have in the states, actually.” Thus, if there are certain fish to stay away from as described by the APA, women in Seychelles are less likely to consume significant amounts of the more toxic fish because of the variety of their diets.
As well, there are other reasons besides mercury that might inspire pregnant women to decrease the amount of fish they consume. Robert Felix, a teratologist, told ABC News that raw or undercooked fish could have high levels of parasites as well as bacteria or other substances that might affect the health of pregnant mothers and their children. The U.S. Centers of Disease Control and Prevention thus recommends that pregnant women eat fish cooked to at least 145 degrees Fahrenheit.
Ultimately, though the FDA is likely to change its guidelines concerning how much fish a pregnant woman can safely consume, it’s still best to stay away from raw sushi.
(Photo courtesy of Prayitno)