AND test recently it got here to light, which caused quite a lot of media attention on the role of plastics in the development of autism.
The study looked specifically at exposure to the hard plastic ingredient bisphenol A, or BPA, in the womb and the risk of boys developing this neurodevelopmental disorder.
Importantly, the study didn’t find that plastics containing BPA had an impact on autism.
However, it does suggest that BPA may affect estrogen levels in infant and school-age boys, which can impact their risk of being diagnosed with autism.
Let’s take a more in-depth have a look at the details.
Remind me what BPA is?
BPA is a component of hard plastics which have been used for several many years. Because BPA is present in plastics used to make food and a few beverage containers, many persons are exposed to low levels of BPA on daily basis.
But worries The impact of BPA on our health has been circulating for a while, as this substance can, to a small extent, mimic the motion of the hormone estrogen in our bodies.
Even though this effect is weak, there are health concerns because we’re exposed to low levels throughout our lives. Some countries have ban on the use of BPA in baby bottlesas a precaution; Australia is voluntary withdrawal in baby bottles.
What is autism and what causes it?
Autism is a neurodevelopmental disorder diagnosed on the basis of difficulties with social communication and repetitive and/or restrictive behaviours.
People with autism may experience other problems, comparable to seizures, changes in motor skills (for instance, difficulty coordinating high quality movements comparable to holding a pencil or turning a key to open a door), anxiety, sensory issues, sleep problems, and bowel upset.
The severity of those symptoms varies greatly, making individuals with autism perceive on a regular basis life in a very different way.
To date, most studies have described autistic people who find themselves capable of interact thoroughly in the community, and will in reality reveal outstanding skills in some areas. However, there may be a big gap in our knowledge about the large variety of individuals with profound autism who require 24-hour care.
There is a powerful influence genetics in autism with over 1,000 genes related to it. But we do not know what causes autism normally. There are several reasons for this.
It isn’t standard practice to perform detailed gene sequencing in children with autism. Although there are some clear individual genes Although certain genes are answerable for some forms of autism, more often autism may result from a fancy interaction of many genes that may be very difficult to detect, even in large-scale studies.
Environmental aspects can even contribute to the development of autism. For example, some anticonvulsant drugs These drugs aren’t any longer prescribed to pregnant women attributable to an increased risk of their children developing neurodevelopmental disorders comparable to autism.
The latest study looks at one other possible environmental factor: BPA exposure in the womb. The research consisted of several parts, including studies in humans and mice.
What did they discover in humans?
Scientists checked out a gaggle (or cohort) 1074 Australian children; about half were boys. They found that 43 children (29 boys and 14 girls) had been diagnosed with autism between the ages of seven and 11 (average age 9).
They collected urine from 847 moms near the end of pregnancy and measured the amount of BPA. They then focused their evaluation on the samples with the highest levels of BPA.
They also measured genetic changes by analyzing blood from the umbilical cord at birth. This was to ascertain for activity of the enzyme aromatase, which is linked to estrogen levels. Babies with genetic changes that might indicate lower estrogen levels were classified as having “low aromatase activity.”
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The research team found an association between high maternal BPA levels and a greater risk of autism in boys with low aromatase activity.
In the final evaluation, the researchers found that there have been too few girls with autism diagnoses and low aromatase levels to investigate. So their conclusions were limited to boys.
What did they discover in mice?
The team also studied the effects of exposing mice to BPA in the womb.
Mice exposed to BPA in this fashion showed increased grooming behavior (purportedly indicative of repetitive behavior) and decreased social behavior (purportedly indicative of decreased social interaction).
The team also noted changes in the amygdala region of the brain following BPA treatment. This region is essential for processing social interactions.
The researchers concluded that prime levels of BPA may impair the activity of the aromatase enzyme, which in turn affects estrogen production and modifies the way neurons grow in the brains of mice.
But we ought to be cautious about the results of mouse studies for several reasons:
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we cannot assume that mouse behavior directly translates into human behavior
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Not all mice got BPA by the same method – some were injected under the skin, others got BPA in a sweet jelly. This could affect the level of BPA the mice actually received or the way it was metabolized
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the every day dose administered (50 micrograms per kilogram) was above the levels people in Australia would have been exposed to concentrations much higher than those detected in the urine of the moms participating in the study.
What is the message?
Finding a link between two aspects – on this case, BPA exposure in the womb and autism – doesn’t mean that one causes the other.
But researchers are proposing a mechanism, based on a study in mice. They propose that prime levels of BPA may suppress the enzyme aromatase, altering estrogen production and modifying the way neurons grow in the brains of mice.
Have we discovered what causes autism? Based on this study alone, no. Not all the children of ladies with BPA of their urine had autism, so exposure to those plastics alone isn’t enough to cause autism. There are likely various aspects, including genetics, that contribute.
This study suggests, nonetheless, that there could also be a gene-environment interaction, and that children with certain genetic variants could also be more liable to the effects of BPA and have an increased risk of autism. But we’d like more research to make clear this.
It is essential to know that there are numerous other possible contributors to autism for which there is analogous evidence. Ultimately, we still have no idea needless to say what causes autism in most individuals.