A study published in June 2017 found that baby teeth taken from children with autism contain more toxic lead and less of the essential nutrients zinc and manganese compared to teeth from children without autism. Scientists studied twins to control genetic influences and focus on possible environmental contributors to the disease.
The findings suggest that differences in early-life exposure to metals, or more importantly how a child’s body processes them, may affect the risk of autism. These differences were most evident during the months just before and after birth.
This timeline was determined by using lasers to map the layers or growth rings in baby teeth generated during different developmental periods. Teeth begin forming prenatally and add a new layer daily. Each new layer holds many of the chemicals circulating in the body at that time. By studying these layers, the researchers were able to build a timeline of metal exposure during the prenatal and early childhood period.
The findings build on previous research suggesting that exposure to toxic metals, such as lead, and deficiencies of essential nutrients, like manganese, may harm brain development while in utero or during early childhood. Although manganese is an essential nutrient, it can also be toxic at high doses. Exposure to both lead and high levels of manganese has been associated with autism traits and severity.
The study was led by Manish Arora, Ph.D., an environmental scientist and dentist at the Icahn School of Medicine at Mount Sinai in New York. According to Dr. Arora, autism is a condition where both genes and environment play a role but figuring out which environmental exposures might increase risk has been difficult.
“What is needed is a window into our fetal life,” Dr. Arora says. “Unlike genes, our environment is constantly changing, and our body’s response to environmental stressors not only depends on just how much we were exposed to, but at what age we experienced that exposure.”
Continuing his research, Dr. Arora and other scientists published another research article in May 2018 that once again involved measuring metals in the layers of baby teeth. They found that the cycles of copper and zinc metabolism were disrupted in children with autism spectrum disorder (ASD) and they were then able to develop a method to predict the emergence of autism spectrum disorder with 90% accuracy.
Christine Austin, Phd, one of the researchers, says:
Baby teeth, which we used in this study, are shed after clinical symptoms of ASD are evident. Our future research will look at measuring copper and zinc cycles in other biological samples that are available at birth which could lead to a diagnostic test that can be applied in early life. Detection of ASD at an early age could improve outcomes by enabling early introduction of therapies.
I find it heartening that there are so many dedicated scientists delving into the mysteries of autism. These studies involving baby teeth, in particular, are encouraging as they might very well lead to early detection as Dr. Austin suggests. And who knows, maybe with continued research, one day these teeth might lead to a cure for this puzzling illness.