Heavy metal exposure during pregnancy may contribute to autism, according to a study recently completed and published by the National Institute of Environmental Health Sciences (NIEHS).
NIEHS is a branch of the the National Institutes of Health (NIH) that focuses on finding the link between environmental factors and various health conditions.
The study, published on June 1, 2017 in Nature Communications, the NIEHS examined heavy metal levels in baby teeth. Baby teeth have growth rings that reflect different developmental periods as a child ages, to include pre-natal growth. They limited the study participants to twins only, to control for genetic influence.
Leading the study was Cindy Lawler, Ph.D., and head of the NIESH Genes, Environment, and Health Branch. While she notes that larger studies will be required to fully establish the link between maternal/prenatal heavy metal exposure and autism, this most recent study lays important groundwork.
“We think autism begins very early, most likely in the womb, and research suggests that our environment can increase a child’s risk. But by the time children are diagnosed at age 3 or 4, it’s hard to go back and know what the moms were exposed to. With baby teeth, we can actually do that”, said Lawler.
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The study suggests that the levels and type of heavy metal exposure, as well as how a young infant/child processes them may affect on the child’s risk of autism. In addition to noting the high levels of heavy metals like lead, autistic children had lower levels of essential nutrients like manganese and zinc. Higher levels of lead and lower levels of manganese and other nutrients may be harmful to brain development during early stages of life, according to previously established research.
Autism is a condition that is influenced by both environment and genetics. Studying environmental influences is difficult to do, but the method and approach of being able to examine children’s baby teeth is a “major advantage” according to Lawler.