No link between prenatal mercury exposure and autism-like behaviors found

The potential impact of exposure to low levels of mercury on the developing brain — specifically by women consuming fish during pregnancy — has long been the source of concern and some have argued that the chemical may be responsible for behavioral disorders such as autism. However, a new study that draws upon more than 30 years of research in the Republic of Seychelles reports that there is no association between pre-natal mercury exposure and autism-like behaviors. (Credit: © Yoram Astrakhan / Fotolia)

“This study shows no evidence of a correlation between low level mercury exposure and autism spectrum-like behaviors among children whose mothers ate, on average, up to 12 meals of fish each week during pregnancy,” said Edwin van Wijngaarden, Ph.D., an associate professor in the University of Rochester Medical Center‘s (URMC) Department of Public Health Sciences and lead author of the study which appears online today in the journal Epidemiology. “These findings contribute to the growing body of literature that suggest that exposure to the chemical does not play an important role in the onset of these behaviors.”

The debate over fish consumption has long created a dilemma for expecting mothers and physicians. Fish are high in beneficial nutrients such as, selenium, vitamin E, lean protein, and omega-3 fatty acids; the latter are essential to brain development. At the same time, exposure to high levels of mercury has been shown to lead to developmental problems, leading to the claim that mothers are exposing their unborn children to serious neurological impairment by eating fish during pregnancy. Despite the fact that the developmental consequences of low level exposure remain unknown, some organizations, including the U.S. Food and Drug Administration, have recommended that pregnant women limit their consumption of fish.

“The Seychelles study was designed to follow a population over a very long period of time and focus on relevant mercury exposure,” said Philip Davidson, Ph.D., principal investigator of the Seychelles Child Development Study and professor emeritus in Pediatrics at URMC. “While the amount of fish consumed in the Seychelles is significantly higher than other countries in the industrialized world, it is still considered low level exposure.”

… lends further evidence to an emerging belief that the “good” may outweigh the possible “bad” when it comes to fish consumption during pregnancy. Specifically, if mercury does adversely influence child development at these levels of exposure then the benefits of the nutrients found in the fish may counteract or perhaps even supersede the potential negative effects of the mercury.

“This study shows no consistent association in children with mothers with mercury level that were six to ten times higher than those found in the U.S. and Europe,” said Davidson. “This is a sentinel population and if it does not exist here than it probably does not exist.”

Read entire article at ScienceDaily.