Featured Research

from universities, journals, and other organizations

Prenatal mercury exposure may be linked to risk of ADHD-related behaviors; Fish consumption may be linked to lower risk

Date:
October 8, 2012
Source:
JAMA and Archives Journals
Summary:
A study of children in the New Bedford, Mass., area suggests that low-level prenatal mercury exposure may be associated with a greater risk of attention-deficit/hyperactivity disorder (ADHD)-related behaviors and that fish consumption during pregnancy may be associated with a lower risk of these behaviors.

A study of children in the New Bedford, Mass., area suggests that low-level prenatal mercury exposure may be associated with a greater risk of attention-deficit/hyperactivity disorder (ADHD)-related behaviors and that fish consumption during pregnancy may be associated with a lower risk of these behaviors, according to a report published Online First by Archives of Pediatrics & Adolescent Medicine, a JAMA Network publication.

ADHD is one of the most common neurodevelopmental disorders of childhood and affects 8 percent to 12 percent of children worldwide, although its cause is not well understood. The developmental neurotoxicity of mercury is known, but the findings from epidemiological studies are inconsistent with some studies showing associations between mercury exposure and ADHD-related behaviors and others reporting null associations, according to the study background.

Nonoccupational methylmercury exposure comes primarily from eating fish, and the U.S. Environmental Protection Agency and the U.S. Food and Drug Administration have recommended pregnant women limit their total fish intake to no more than two, six-ounce servings per week. However, fish is also a source of nutrients, such as omega-3 fatty acids, which have been shown to benefit brain development, potentially confounding mercury-related risk estimates, the study background also indicates.

Sharon K. Sagiv, Ph.D., M.P.H., of the Boston University School of Public Health, and colleagues analyzed data from the New Bedford birth cohort, a group of infants born between 1993 and 1998, to investigate the association of peripartum maternal hair mercury levels (n=421) and prenatal fish intake (n=515) with ADHD-related behaviors at age 8 years.

"In this population-based prospective cohort study, hair mercury levels were consistently associated with ADHD-related behaviors, including inattention and hyperactivity/impulsivity. We also found that higher prenatal fish consumption was protective for these behaviors," the authors comment.

Statistical analysis indicates mercury exposure appeared to be associated with inattention and impulsivity/hyperactivity and some outcomes had an apparent threshold with associations at 1 μg/g (microgram/per gram) or greater of mercury. For example, at 1 μg/g or greater, the adjusted risk ratios for mild/markedly atypical inattentive and impulsive/hyperactive behaviors were 1.4 and 1.7 respectively, according to the study results.

There also appeared to be a "protective" (lower risk) association for fish consumption of greater than two servings per week with ADHD-related behaviors, particularly impulsive/hyperactive behaviors (relative risk = 0.4), the study results show.

"In summary, these results suggest that prenatal mercury exposure is associated with a higher risk of ADHD-related behaviors, and fish consumption during pregnancy is associated with a lower risk of these behaviors," the authors conclude. "Although a single estimate combining these beneficial vs. detrimental effects vis--vis fish intake is not possible with these data, these findings are consistent with a growing literature showing risk of mercury exposure and benefits of maternal consumption of fish on fetal brain development and are important for informing dietary recommendations for pregnant women."

Editorial: Attention-Deficit/Hyperactivity Disorder a Preventable Epidemic?

In an editorial, Bruce P. Lanphear, M.D., M.P.H., of Simon Fraser University, Vancouver, British Columbia, Canada, writes: "The study by Sagiv et al, which tested whether prenatal exposure to methyl mercury was associated with the development of ADHD-related behaviors, is an important and rigorously conducted prospective birth cohort study."

"What are the implications of the Sagiv et al study and other research on environmental contaminants and ADHD? First, we can take some comfort in recent legislation to reduce mercury contamination, at least from domestic sources. Second, these studies should spur our efforts to enhance the collection of data needed to calculate national estimates and trends in ADHD," Lanphear continues.

"Third, it is time to convene a national scientific advisory panel to evaluate environmental influences of ADHD and make recommendations about what can be done to prevent it. Fourth, this study and a flurry of new evidence linking environmental contaminants with ADHD reinforce the urgency of revising the regulatory framework for environmental contaminants and toxicants," Lanphear concludes.


Story Source:

The above story is based on materials provided by JAMA and Archives Journals. Note: Materials may be edited for content and length.


Journal References:

  1. Sagiv SK, Thurston SW, Bellinger DC, Amarasiriwardena C, Korrick SA. Prenatal Exposure to Mercury and Fish Consumption During Pregnancy and Attention-Deficit/Hyperactivity Disorder–Related Behavior in Children. Archives of Pediatrics & Adolescent Medicine, 2012; DOI: 10.1001/archpediatrics.2012.1286
  2. Lanphear BP. Attention-Deficit/Hyperactivity Disorder: A Preventable Epidemic? Archives of Pediatrics & Adolescent Medicine, 2012; DOI: 10.1001/archpediatrics.2012.1900

Cite This Page:

JAMA and Archives Journals. "Prenatal mercury exposure may be linked to risk of ADHD-related behaviors; Fish consumption may be linked to lower risk." ScienceDaily. ScienceDaily, 8 October 2012. <www.sciencedaily.com/releases/2012/10/121008161854.htm>.
JAMA and Archives Journals. (2012, October 8). Prenatal mercury exposure may be linked to risk of ADHD-related behaviors; Fish consumption may be linked to lower risk. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2012/10/121008161854.htm
JAMA and Archives Journals. "Prenatal mercury exposure may be linked to risk of ADHD-related behaviors; Fish consumption may be linked to lower risk." ScienceDaily. www.sciencedaily.com/releases/2012/10/121008161854.htm (accessed September 17, 2014).

Share This



More Health & Medicine News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

President To Send 3,000 Military Personnel To Fight Ebola

President To Send 3,000 Military Personnel To Fight Ebola

Newsy (Sep. 16, 2014) President Obama is expected to send 3,000 troops to West Africa as part of the effort to contain Ebola's spread. Video provided by Newsy
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

AFP (Sep. 16, 2014) Since the arrival of Ebola in Ivory Coast, Ivorians have been abandoning their pets, particularly monkeys, in the fear that they may transmit the virus. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Study Links Male-Pattern Baldness To Prostate Cancer

Study Links Male-Pattern Baldness To Prostate Cancer

Newsy (Sep. 16, 2014) New findings suggest men with a certain type of baldness at age 45 are 39 percent more likely to develop aggressive prostate cancer. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

More Coverage


Low-Level Mercury Exposure in Pregnant Women Connected to ADHD Risk in Children

Oct. 8, 2012 A new study links low-level prenatal mercury exposure with a greater risk of ADHD-related behaviors. The study also finds that maternal fish consumption during pregnancy can help reduce the risk of ... read more
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

      Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins