A common plastic additive found in everything from pacifiers to metal food cans to even paper receipts has been linked to an increased risk of autism in boys.
The new research, which tracked the development of over 600 infants, found that higher levels of chemical bisphenol A (BPA) in a pregnant mother’s urine more than tripled the chances that a young boy would develop autism symptoms by age two.
Worse, those same boys were six times more likely to be diagnosed with autism by age 11 — compared to those whose mothers had lower BPA levels during pregnancy.
BPA, a chemical intended to harden plastics and prevent metals from rusting, among other uses, has also been linked to higher risks of obesity, asthma, diabetes, and heart diseases across over two decades of increasing scrutiny on the compound.
New research out of Australia – which tracked the development of over 600 infants – found higher levels of chemical bisphenol A (BPA) in a pregnant mother’s urine more than tripled the likelihood that a young boy would develop autism symptoms by age two
In addition to surveying over 600 human children, tracked since 2010, the study also tested lab mice to track the effect BPA has on brain development and autism. Photomicrographs of cortical neurons in lab mice (above) show the damaging impact of BPA
It has also been has been dubbed a ‘gender-bending’ chemical due to its apparent role spurring hormonal and sexual disruptions in humans, fish and other species.
But the new study not only identified the apparent link, it also uncovered evidence toward unravelling the specific chemical reactions that contribute to autism cases.
‘Our work is important because it demonstrates one of the biological mechanisms potentially involved,’ epidemiologist and public health physician Dr Anne-Louise Ponsonby, said in a statement on her team’s study.
‘BPA can disrupt hormone-controlled, male fetal brain development in several ways,’ Dr Ponsonby explained, ‘including silencing a key enzyme, aromatase, that controls neurohormones and is especially important in fetal male brain development.’
Aromatase, the new study noted, helps to convert some male sex hormones in the brain, known as neural androgens, into neural estrogens.
These estrogens help all people, regardless of gender, to regulate inflammation in the brain, maintain the flexibility of the synapses that help neurons communication within the whole nervous system and also aid in managing of cholesterols.
The brain is the human body’s most cholesterol-rich organ — employing roughly 20 percent of the whole body’s stores of these fatty molecules to do its vital functions.
‘We found that BPA suppresses the aromatase enzyme and is associated with anatomical, neurological and behavioral changes,’ reported study coauthor and biochemist Dr Wah Chin Boon.
‘This appears to be part of the autism puzzle,’ Dr Ponsonby said.
The team’s research, published this Wednesday in the journal Nature Communications, took two separate research approaches to arrive at these findings.
‘BPA can disrupt hormone-controlled, male fetal brain development in several ways,’ public health physician Dr Anne-Louise Ponsonby explained, ‘silencing a key enzyme, aromatase, that controls neurohormones and is especially important in fetal male brain development’
The team experimented with the addition of a type of fatty acid called 10-hydroxy-2-decenoic (10HDA) which they found could help mitigate the negative impact that BPA plays on the developing brain’s aromatase system. Above 10HDA reducing BPA’s impact on mouse neurons
First, it drilled-down into data collected since 2010 by two Australian universities who have been tracking a battery of health metrics for over 1,000 participating children and their parents, known as the Barwon Infant Study (BIS) birth cohort.
Within the BIS data, 676 infants had sufficient testing on early age autism symptoms for the team to draw statistical conclusions.
These assessments, drawn from the Autism Spectrum Problems scale of the Child Behavior Checklist (CBCL ASP), were weighted to cancel out for any genetic predispositions or other variables to isolate the role that BPA plays during pregnancy.
The result of this weighted analysis was that young boys with ‘low aromatase activity’ were discovered to be 3.56 times more likely to show signs of autism by age two.
This continued as the boys aged, they noted: ‘CBCL ASP at age two years predicted diagnosed autism strongly at age for and moderately at age nine.’
The connection to an autism diagnosis was true for 92 percent of the four-year-olds and 70 percent of the nine-year-olds, their study found.
But the team also conducted tests on lab mice in an effort to understand how BPA undermines this critical aromatase activity and what treatments may help combat it.
During those tests, the team experimented with the addition of a type of fatty acid called 10-hydroxy-2-decenoic (10HDA) which they found could help mitigate the negative impact that BPA plays on the developing brain’s aromatase system.
‘When administered to animals that have been prenatally exposed to BPA,’ Dr Boon explained, ’10-hydroxy-2-decenoic acid shows early indications of potential in activating opposing biological pathways.’
10HDA, a major fatty lipid ingredient found naturally in the royal jelly of honeybees, competes inside the brain with BPA, preventing the disruptive compound from binding to estrogen receptors.
In their mouse studies, the addition of 10HDA to the BPA-exposed male mice improved their ability to socialize with other mice.
‘It warrants further studies to see whether this potential treatment could be realized in humans,’ Dr Boon said.
