1501 W. Beauregard
San Angelo, Texas 76901
Phone: (325) 658-7750
Fax: (325) 658-8381
Crisis: (800) 375-8965
or (325) 653-5933

Basic Information
Local ContentWhat is Autism?Historical & Contemporary Understandings of AutismSymptoms of Autism & Related DisordersDiagnosis of AutismAutism Interventions & Supportive ServicesAutism ResourcesMore InformationLatest News
Prenatal Vitamins Tied to Lower Autism Risk in Kids, Study FindsPrevalence of Autism Seems to Be Stabilizing in U.S. Children, TeensU.S. Autism Rates May Be StabilizingNeuroanatomic Abnormalities ID'd in Those at Risk for AutismMaternal Multivitamin Use Tied to Lower Risk of Child ASDResearchers Learn More About Gender's Role in Autism RiskGenetics a Cause of Autism in Most Cases: StudyCould Folic Acid Fight a Cause of Autism?Does Autism Risk Reside in Cells' Energy Engines?Therapy for Kids With Autism Pays Off for Moms, DadsCan Scans Predict Some Autism Cases?Guidelines Developed for Art Therapy for Children With ASDAntidepressants in Pregnancy Tied to Slight Increase in AutismCan a Spritz of 'Love Hormone' Help Kids With Autism?Why People With Autism Avoid Eye ContactWhen is Tourette Syndrome Actually Autism?Study Cites Top Reasons Young Autism Patients Are HospitalizedFever During Pregnancy Tied to Autism in StudySpecial Brain Scans May Predict Autism in High-Risk BabiesBaby Teeth Study Points to Links Between Autism, Lead LevelsCommunication Problems Not at Root of Tantrums in Kids With AutismNo Proof Special Diets, Supplements Work for AutismCould a Century-Old Drug Help Ease Autism Symptoms?Autism's 'Worryingly' High Suicide Rates Spur ConferenceSpecial Diets, Supplements for Autism Still a Question MarkProdromal Intervention Effective for Infants at Risk of AutismProgram Helps Young Adults With Autism Find JobsTreat Autism Even Before Symptoms Show?Tracking Devices May Ease Minds of Parents of Kids With AutismYoung Adults With Autism Need Help Managing Money: StudyFDA Warns Against Bogus Autism 'Cures'1 in 3 Teens With Autism Licensed to Drive, Study Finds'Video Feedback' Program Might Help Treat Autism in BabiesMuppet With Autism Makes Her 'Sesame Street' DebutParents of Kids With Autism May Sacrifice 'Couples Time'Teens With Autism More Likely to Land in ER, Study FindsHigher Risk of Death From Injury Among Individuals With AutismAutism Greatly Boosts Kids' Injury Risk, Especially for DrowningCould a Blood Test Spot Autism in Childhood?MRI Can Identify Early Signs of ASD in High-Risk InfantsExperimental Test Can Spot Autism in InfancyBrain Differences Hint at Why Autism Is More Common in MalesU.S. Legislation Boosted Access to Autism Services, With No Added Cost to FamiliesObstetric Complications Tied to Slightly Upped Risk for AutismMicrobiota Transfer Therapy Could Help Children With AutismFecal Transplant Shows Early Promise Against AutismGuideline Changes Have Asperger's Community on Edge
Questions and AnswersLinksBook Reviews
Related Topics

Childhood Mental Disorders and Illnesses

Baby Teeth Study Points to Links Between Autism, Lead Levels

HealthDay News
by By Alan Mozes
HealthDay Reporter
Updated: Jun 2nd 2017

new article illustration

FRIDAY, June 2, 2017 (HealthDay News) -- An analysis of chemicals in baby teeth suggests that exposure to lead in pregnancy or shortly after birth might make infants more vulnerable to developing autism.

At the same time, the investigators found that babies who don't get enough zinc and manganese during the same time frame may also face an increased risk for the developmental disorder.

Zinc and manganese are typically found in certain foods.

The teeth used in the study came from a pool of twins who were studied at various points in their development. The scientists determined lead, zinc and manganese levels by using lasers to map the growth rings in baby teeth.

Environmental exposures can change constantly, explained study author Dr. Manish Arora, vice chairman and division chief of environmental health at the Icahn School of Medicine at Mount Sinai in New York City.

That means that "we need to consider not only how much of a chemical someone is exposed to, but also when that exposure happens," he noted.

"We found that the environmental neuro-toxicant lead was higher in autistic children than their unaffected twin siblings, and this higher exposure started before birth. We also found that the essential elements zinc and manganese were lower in children affected by autism spectrum disorder," Arora said.

Teeth are considered a reliable "record of environmental exposure," given that they continuously develop throughout pregnancy and after birth. Tooth layers, therefore, serve as time-stamped "imprints" of chemical exposure, much like tree rings indicate growth patterns, the researchers said.

For the study, tooth analyses were conducted among 32 Swedish twin pairs, born in 1992 or later. Of these, 17 were identical twins and 15 were fraternal twins. Pairs variously included two autistic siblings, one sibling with autism, or two healthy siblings. Tooth samples were also taken from 12 children whose twin siblings did not participate.

Beyond finding a link between autism risk and varying exposure to lead and/or zinc and manganese, the team also found evidence that metal exposure in early infancy might affect autism severity when it develops.

For example, higher lead exposure when an infant reached the 3-month mark was linked to a higher risk for greater autism severity. Lower manganese at the same point was also linked to worse autism severity. No such link was observed with respect to zinc exposure, however.

That said, Arora cautioned that the exact mechanism by which metal exposure affects autism risk and severity remains unclear. And the study did not prove that metal exposure causes autism risk to rise or fall.

For example, Arora noted that lower exposure to zinc and manganese may not actually "cause" autism risk to go up. Rather, it could be "that autistic children are unable to process some of these essential nutrients" to which they are, in fact, adequately exposed.

In that scenario, the proactive taking of supplements to minimize risk "would not be very useful," he said.

Harvard research scientist Andrea Roberts agreed, and added caveats of her own.

"Although the study is interesting, it is very small [with] only 19 persons with autism," she noted.

And because "the mother's diet intake of zinc and manganese would have been the same for both children with and without autism, it is the differences in how the children metabolized the metals, rather than differences in the mother's behavior, that distinguished kids with and without autism," Roberts said.

But Thomas Frazier, chief science officer for Autism Speaks, characterized the findings as "very important."

"The major implications I see are that this may suggest either a direct effect of lead or lack of minerals like zinc/manganese on early life brain development," he said, "increasing risk for autism or a gene-environment interaction.

"This," Frazier said, "may mean that supplementation is a useful approach, such as appropriate prenatal vitamins."

At the same time, he agreed with Arora and Roberts "that the low levels may reflect issues with regulating and processing elements rather than just a simple issue of low levels that need to be remediated."

Arora agreed, saying, "It is too early to make any such [supplementation] recommendation. Additional work is needed, and we have now expanded this study to other countries to dig deeper into the mechanisms underlying our finding."

The findings were published June 1 in the journal Nature Communications.

More information

There's more on autism risk and toxin exposure at Autism Speaks.