Eating Fish During Pregnancy May Benefit Kids' Brain Health

Pregnant women have generally been advised to limited -- or even eliminate -- their consumption of fish, fearing high levels of mercury could harm their unborn child. While it's true that fish that contains the toxic chemical mercury, a new study has found that women who consume fish during pregnancy tend are more likely to give birth to smarter children.

Researchers in Spain closely monitored 2,000 women during their pregnancy and for several years afterward. Throughout the study, the women were asked questions about how much fish they consumed. Some participants consumed as much as five servings per week, while others consume little-to-no fish. The average amount of fish consumed by the study's participants was three servings per week.

After the women had given birth, researchers tested their children for cognitive function, using a scale that measures the symptoms of autistic spectrum disorder. Researchers found that women who ate the most servings of fish throughout their pregnancy were more likely to give birth to children who scored high on cognitive thinking tests and with fewer symptoms of autistic spectrum. More specifically, consuming 600 grams of fish per week, which is roughly the same amount as three-to-four servings, had a 2.8 increase in their children's IQ scores.

What's really interesting is that large fish, such as tuna, yielded the greatest benefits. Large fish have long been discouraged by health professionals because they contain higher concentrations of mercury. While it's true that all fish contain at least some trace levels of mercury, this toxic chemical is far more prevalent in larger varieties, such as tuna for instance. But this study suggests that consuming large fish could actually prove beneficial.

"I think that in general people should follow the current recommendations. Nevertheless this study pointed out that maybe some of them, particularly the American ones, should be less stringent," said the study's lead author.

It's unclear exactly how fish is able to provide these cognitive benefits to children during the mother's pregnancy. However, fish has long been viewed as a "brain food," as it contains omega 3 and 6 fats (the good kind), which have been shown to improve brain health. As with most things in life, though, it's best to consume fish in moderation, creating a balanced diet complete with fresh vegetables, fruit, whole grains, and other lean meats.

This study was published in the American Journal of Epidemiology