- As the prevalence of autism and ADHD continues to rise, researchers believe several factors may be driving that increase.
- One of the factors they are examining is environmental factors.
- Researchers recently found biochemical evidence of a link between BPA—a common plastic additive— and the development of autism or ADHD.
Although both of these neurological disorders are different, there are some similarities in symptoms. Previous research has found one in eight children diagnosed with ADHD simultaneously have autism.
As the prevalence of both autism and ADHD in children continues to increase every year, researchers have been searching for reasons behind this rise. Some of those potential reasons are environmental factors such as heavy metal residues in food and air pollution.
Now, researchers from the Rowan-Virtua School of Osteopathic Medicine have found evidence suggesting children with autism and/or ADHD have a reduced ability to clear out the common plastic additive bisphenol A (BPA) from their bodies, resulting in increased exposure to the chemical.
This, the researchers state, provides biochemical evidence of the link between BPA and the development of autism or ADHD.
This study was recently published in the journal PLOS ONE.
What is BPA and is it harmful?
BPA is a synthetic chemical that has been around since the 1950s and is used to make polycarbonate plastics.
These types of plastics can sometimes be found in:
- water bottles
- metal food cans
- water supply pipes
- eyeglass lenses
- food items packaged in plastic containers
- dental materials
- cash register receipts
Previous research has linked BPA to several health issues, including infertility, cardiovascular disease, type 2 diabetes, and cancer.
Prior studies have also found a correlation between BPA exposure and fetal brain development and behavioral issues in children, including anxiety, hyperactivity, inattention, and depression.
Other research has associated BPA in the body with neurological disorders, including Parkinson’s disease, multiple sclerosis, Alzheimer’s disease, and amyotrophic lateral sclerosis (ALS).
BPA can enter the body in a variety of ways, explained Rebecca Fuoco, director of science communications for the Green Science Policy Institute, who was not involved in this study.
“We are exposed because they leach from containers and other products into the food we eat, the water we drink, and the dust we inadvertently ingest or inhale. We are further exposed through skin absorption,” she detailed.
Once BPA is in the body, it needs to be removed.
“As part of [typical] living, the body encounters many toxic compounds either from the diet, from the environment, or (as) by-products of metabolism,” Dr. T. Peter Stein, professor of surgery at the Rowan-Virtua School of Osteopathic Medicine and lead author of this study told Medical News Today when explaining how BPA is normally removed from the body.
“Most of these are insoluble and so cannot be excreted directly into the urine. To make them water soluble so they can be transported in the bloodstream to the kidneys and then excreted, the liver adds a very water-soluble compound, glucose, to the toxin,” he explained.
“Doing so enables the formerly insoluble compound to be easily and rapidly excreted in the urine. The process of adding glucose to one of these other insoluble compounds is known as glucuronidation,” he noted.
According to the researchers, a person’s ability to detoxify BPA from the body varies genetically. Those who have a harder time eliminating BPA from their system find their organs and tissues exposed to the chemical at higher concentrations for longer periods.
Lowered BPA removal abilities
For this study, Dr. Stein and his colleagues recruited about 150 children from clinics at Rutgers-NJ Medical School.
They then measured how efficiently three different groups of young participants — those with autism, those with ADHD, and those without either condition used as a control group — were able to use glucuronidation to remove BPA from their bodies.
The study found the glucuronidation ability of children with autism was 10% less than that of the control group. And study participants with ADHD were 17% less efficient than children without either condition.
“With regard to autism, we felt the hypothesis was plausible and put a lot of work into evaluating it. We were pleased [t]hat the study confirmed the autism part of our hypothesis,” Dr. Stein said. However, he said they did not expect the same results with the ADHD group.
“We were surprised to find the same compromised glucuronidation with ADHD. We had hypothesized that the BPA effect was unique to autism, so ADHD served as a second control group,” he added.
Dr. Stein said the next steps planned for this research will be to complete a study examining whether or not compromised glucuronidation of BPA is inherited from the mothers to children with autism.
After reviewing this research, Fuoco commented that this study sheds new light on potential mechanisms behind previously established links between BPA and neurodevelopmental harms.
“However, BPA isn’t just a concern in obstetrics and pediatrics, as it is associated with obesity, type 2 diabetes, heart disease, decreased fertility, prostate cancer, and more. Doctors can and should share tips for reducing exposure,” Fuoco said.
“For example, it’s best to opt for glass, porcelain, or stainless steel containers and tableware, particularly for hot food or liquids. People should also avoid microwaving plastics and handling cash register receipts. Of course, to reduce exposure to not just BPA but many other chemicals of concern, it’s important to wash your hands before eating.”
— Rebecca Fuoco
Fuoco said while many products are now labeled “BPA-free,” the BPA is often replaced with bisphenol S (BPS) and bisphenol F (BPF), which are less studied but appear to have similar hormone-disrupting effects.
“There should be more research into similar potential neurodevelopmental harms from the other bisphenols used to replace BPA,” she added.