Women who eat seafood while pregnant may be boosting their children's IQ in the process, according to new research published Friday in The Lancet.
The study results were surprising, say the authors, and contradict American and British recommendations that pregnant women should limit their seafood and fish consumption to avoid potentially high levels of mercury.
Mercury is found in small concentrations in fish and seafood, but can accumulate in the body. High amounts of the metal can damage the human nervous system, particularly those in developing fetuses. On the other hand, seafood including fish is also a major source of omega-3 fatty acids, essential to brain development.
While experts believe further research is necessary to confirm these conclusions, the study's failure to find evidence of increased harm from eating fish is significant. Because seafood contain both nutrients and toxins, it remains a dilemma for regulatory authorities what kinds of recommendations should exist for pregnant women.
The study, led by Dr. Joseph Hibbeln of the United States' National Institutes of Health, tracked the eating habits of 11,875 pregnant women in Bristol, Britain.
At 32 weeks into their pregnancy, the women were asked to fill in a seafood consumption questionnaire. They were subsequently sent questionnaires four times during their pregnancy, and then up to eight years after the birth of their child. Researchers examined issues including the children's social and communication skills, their hand-eye coordination, and their IQ levels. As with any study based on such self-reporting methods, however, the results cannot be considered entirely definitive.
The study was primarily funded by Britain's Medical Research Council, the Wellcome Trust, the University of Bristol, and the British government.
Hibbeln and his colleagues concluded that women who ate more than 340 grams per week of fish or seafood the equivalent of two or three servings a week had smarter children with better developmental skills. Children whose mothers ate no seafood were 48 percent more likely to have a low verbal IQ score, compared to children whose mothers ate high amounts of seafood.
"These results highlight the importance of including fish in the maternal diet and lend support to the popular opinion that fish is brain food," wrote Dr. Gary Myers and Dr. Philip Davidson of the University of Rochester Medical Center, in an accompanying commentary. Myers and Davidson were not connected to the study, reports AP.
Eating even more than three portions of fish or seafood a week could be beneficial, Hibbeln suggests. "Advice that limits seafood consumption might reduce the intake of nutrients necessary for optimum neurological development," he and his colleagues wrote.