How Researchers Used Children's Baby Teeth to Uncover Autism Risk Factors

Do baby teeth hold the solution to the mystery of autism? American researchers from the Autism Treatment and Research Center at Mount Sinai Hospital believe they might. The researchers examined babies' teeth and found that higher absorption levels of toxic substances and metals in the teeth were associated with a higher risk of being on the autism spectrum.

In addition to identifying substances and environmental factors that can pose a risk, the study also pointed to developmental periods during which exposure to these substances indicated a higher risk for autism later in life.

"We found significant differences in metal absorption between children with autism and their healthy siblings, but only during certain developmental periods," says Dr. Manish Arora, one of the study's authors. "More specifically, children with autism had higher lead absorption and reduced absorption of essential elements like magnesium and zinc, both during late pregnancy and in the first months post-birth. We identified these periods through an analysis of their baby teeth. Additionally, metal levels in the body three months after birth were found to predict the severity of autism eight or ten years later."

How can one tell from baby teeth when toxic metal absorption was higher? It turns out that during fetal development and childhood, a new layer of the tooth forms each week, leaving a trace of the chemical environment of that time. Just as tree rings indicate its age, these tooth layers can be revealed with laser technology to uncover the toxic absorption during each period.

The researchers emphasize that further research is needed to determine whether the difference in absorption of certain metals and nutrients in children with autism is due to differences in exposure levels as a fetus or infant or due to a genetic difference in how the child processes these substances.