Eating fish during pregnancy may benefit brains of offspring

The research also showed that consuming fish during pregnancy may help reduce offspring's risk of developing autism.

"Consumption of large fatty fish during pregnancy presents moderate child neuropsychological benefits, including improvements in cognitive functioning and some protection from autism-spectrum traits,” the study said.

What surprised the researchers was that certain fish, such as tuna or tilefish, which pregnant women have been discouraged from eating because of their higher levels of mercury were linked to some of the biggest developmental benefits.

The findings suggest that high levels of a compound called docosahexaenoic acid (DHA) may outweigh any negative effects of mercury, according to the researchers.

Fish such as tuna that may have mercury also hold higher levels of DHA, an omega-3 fatty acid that plays a critical role in brain growth and development, said lead author of the study Jordi Julvez from the Centre for Research in Environmental Epidemiology in Barcelona, Spain.

"Maybe this effect is masking the negative effects that come from mercury," Julvez was quoted as saying by Live Science. 

Or, "maybe this is more beneficial than the toxic effect of the mercury itself," Julvez noted.

For the study, the researchers followed about 2,000 mothers and their children, beginning in the mothers' first trimester of pregnancy, and continuing until the children turned five. 

The study was published online in The American Journal of Epidemiology.