While science has yet to find a definitive cause of Autism Spectrum Disorder, recent studies suggest a connection between heavy metals like lead. Using baby teeth, researchers were recently able to assess metal concentrations in 32 pairs of twins, the results of which suggest exposure to heavy metals may be a directly associated with the development of ASD. Read on to learn more about how the researchers reached their conclusions.
Researchers used lazers to to assess metal exposure in autistic subjects, finding that factors such as lead could be a direct cause.
The latest data from the Centers for Disease Control and Prevention (CDC) estimates that as many as one in 68 children in the U.S. have some form of Autism Spectrum Disorder (ASD). As researchers explore environmental factors that could cause autism, a new study has been published that suggests exposure to heavy metals, including lead, may be a predetermining factor for the development of autism. Using lasers, researchers analyzed growth rings in naturally shed baby teeth to accurately extract specific layers of dentine.
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The numbers are high, but a definitive cause of autism has not been identified, and researchers believe the condition develops as a result of interactions between a person’s genetic makeup and the environment.
While there have been studies published previously that link heavy metal exposure to autism, the new study is unique in that researchers were able to assess metal concentrations in the teeth. The study involved the teeth of 32 pairs of twins, in addition to the teeth of 12 individuals from twin pairs. In pairs of twins in which one twin is diagnosed with autism, the teeth of the affected child showed large differences in metal uptake levels, including much higher levels of lead in the dentine. The researchers noted the period after the twins’ birth showed the greatest difference between lead levels in children with ASD compared to children without the condition.
The research team also examined levels of zinc and manganese. It was shown that zinc levels were lower in children with ASD during the prenatal period, but that these levels increased beyond those in children without ASD in the period after birth. Children with ASD were found to have less manganese compared to children without ASD both prenatally and postnatally.
“We think autism begins very early, most likely in the womb, and research suggests that our environment can increase a child’s risk," Cindy Lawler, Ph.D., says. "But by the time children are diagnosed at age three or four, it’s hard to go back and know what the moms were exposed to. With baby teeth, we can actually do that.”