Many women avoid eating fish during pregnancy over fears of mercury contamination. Findings of a new study, however, show that eating fish may not be as dangerous as previously thought.
Findings of a new study published in the American Journal of Clinical Nutrition on Jan. 21 provided evidence that the benefits of eating fish on prenatal development outweighs the risks linked with exposure to mercury. It is believed that when large amounts of mercury accumulate in the body, this can cause reproductive problems and nervous system disorder.
The new study, however, suggests that the fatty acids that are found in fish may provide a form of protection from potential mercury damage. Thirty years of research in Seychelles provide evidence that high consumption of fish by pregnant women, equivalent to about 12 meals per week, do not cause developmental problems in their children.
Edwin van Wijngaarden, from the University of Rochester Department of Public Health Sciences, and colleagues followed over 1,500 mothers and their children, who underwent a series of tests 20 months after birth to assess their communication skills, motor skills and behavior. The researchers likewise analyzed the samples of the mothers' hair during pregnancy to measure their level of prenatal mercury exposure.
Wijngaarden and colleagues found that the mother's exposure to mercury during pregnancy did not correlate with lower test scores in their child and this collaborated with the study that followed children in the remote island nation of Seychelles into their 20's that showed no association between fish consumption in mothers and the subsequent neurological development of their child.
"They eat a lot of fish, historically about 12 fish meals a week, and their mercury exposure from fish is about 10 times higher than that of average Americans," Wijngaarden said. "We have not found any association between these exposures to mercury and developmental outcomes."
The researchers likewise measured the polyunsaturated fatty acids (PUFAs) that were present in the pregnant women and found that the children whose mothers have higher levels of fatty acids known as omega 3 (n3), the ones that can be found in fish, performed better on certain tests.
N3 are known to have anti-inflammatory properties. Interestingly, mercury causes damage through oxidation and inflammation leading the researchers to suggest that N3 does not just provide benefits for brain development. They can also counteract the unwanted effects of mercury.
"These findings indicate that there may be an optimal balance between the different inflammatory properties of fatty acids that promote fetal development and that these mechanisms warrant further study," said study researcher Philip Davidson, professor emeritus at the University of Rochester.