A study published in the Archives of Pediatrics and Adolescent Medicine earlier this week found a link between the amount of mercury that a woman consumed while pregnant and the risk that her child would develop attention deficit hyperactivity disorder (ADHD). In general, the more mercury that a woman consumed while pregnant, the greater the risk that her child would go on to be diagnosed with ADHD.
In order to measure the women's mercury consumption, researchers took hair samples from them shortly after they had given birth. They also had them fill out a food diary to track how often they had consumed fish while still pregnant.
Here is some of the key information regarding the new study's findings on the correlation between mercury and ADHD.
* The researchers studied 788 children who were born between the years of 1993 and 1998 near New Bedford, Mass. According to Reuters, the scientists involved decided to study the correlation between mercury and ADHD because previous studies had reached conflicting conclusions, with some studies finding in favor of fish consumption while pregnant and others cautioning against it.
* This study found a correlation between women who consumed fish at least twice a week and a significantly lower risk of their having a child that was diagnosed with ADHD.
* This correlation was particularly strong among male children. Overall, women who consumed more fish appeared to reduce their risk of having a child who was diagnosed with ADHD by up to 60 percent, according to the study.
* The counterbalance to that correlation, according to a report on the study by The Telegraph, was that women who consumed higher levels of mercury, commonly found in fish, increased their risk of having a child who was diagnosed with ADHD by between 40 and 70 percent.
* Researchers believe that part of the key may be eating more fish, but making sure to eat the right kind of fish to help keep overall mercury levels lower.
* According to the Reuters report, salmon and haddock are among the fish with the lowest levels of mercury, while the so-called "big fishes" like tuna and swordfish are among those that pregnant women should probably avoid because of the their high levels of mercury.
* Currently, the U.S. government recommends that women limit their consumption of fish while they are pregnant, in order to avoid raising the level of mercury in their bodies. While the study's lead author, Sharon Sagiv, told Reuters that the new study "does call into question" those guidelines, she also reiterated that more research is needed.
Vanessa Evans is a musician and freelance writer based in Michigan, with a lifelong interest in health and nutrition issues.