Finding a specific cause for autism is a difficult challenge to take. Many have tried to uncover the possible causes of autism, as well as the conditions that increase the risks and possible treatments for autism spectrum disorder (ASD).

Now, a new research that used the unconventional method of looking at the baby teeth of children with autism and those without to compare their pre- and post-natal metal exposure found a stark difference in their levels of essential and toxic metals.

Twins' Baby Teeth

In an innovative study, researchers used baby teeth from sets of twins to control genetic influences. The study included 32 twin pairs and 12 individuals whose twins did not donate a tooth. What researchers found is a significant discrepancy in the metal uptake between children with ASD and those without at both pre- and post-natal periods.

The teeth from children without ASD showed higher levels of essential metals manganese and zinc and lower levels of the toxic metal lead throughout development. On the other hand, they observed a lower uptake of manganese in children with ASD as well as higher levels of lead.

More specifically, the teeth showed that the manganese levels of children with ASD were significantly lower between 10 weeks prior to birth and postnatal weeks 5 to 20, when their manganese levels were 2.5 times lower than their co-twins. Further, ASD cases also showed evidence of zinc deficiency, which is most prominent at week 8 before birth, when their zinc levels are 28 percent lower than their co-twins.

The study was done by using lasers to map out the growth rings in children's teeth, which showed their growth in various stages of development.

The results of the current study were developed through funding from the National Institute of Environmental Health Sciences (NIEHS), a part of the National Institute of Health (NIH), and published June 1 in the journal Nature Communications.

Environmental Factors

Though the authors of the study believe that further research needs to be done to confirm the connection between autism and metal uptake, they also point out their study's relevance in the quest to understand the causes of autism, especially since prior studies have also shown that essential metal deficiency and exposure to toxic metals can have a detrimental effect on brain development.

What's more, the importance of being able to take a peek into fetal development before diagnosis is relevant, as most diagnoses of ASD are made at age 3 or 4, when it is already too late to find the specific causes that increased the child's risks.