Australian researchers find potential link between plastic additive and symptoms of autism and ADHD

Australian researchers have uncovered a potential link between the prevalence of a common additive to plastic and children being born with autism or symptoms of attention deficit hyperactivity disorder (ADHD).

The additive, Di-2-Ethylhexyl phthalate (DEHP), is used to make plastic more flexible and can be found in a number of household items such as rain-proof clothes, garden hoses, or shower curtains.

While children’s toys with more than 1 per cent DEHP are banned across Australia, a team from the Melbourne-based Florey Brain Research Centre suggests it may have an effect much earlier than first believed.

Past research had showed a correlation between high DEHP levels, autism and ADHD, while the Florey research shows a potential biological reason for it, Florey professor and head neuroepidemiologist Anne-Louise Ponsonby told 7NEWS.com.au.

Ponsonby said they were lucky to have a number of families who signed up to be tested for concentrations of phthalates in pregnant mothers’ umbilical cords during pregnancy.

Once the children were born, the researchers used AI to examine the children’s DNA and see if the chemical had caused specific genes linked to autism and ADHD to be “switched” before birth.

“At the gene-switching level, that pattern was associated with a higher risk of later autism and attention deficit hyperactivity symptoms at ages 2 and 4,” Ponsonby said.

“We call that an epigenetic signature because it seems to be an alteration associated with that high chemical at the gene-switching level.

“So there was a direct relationship between the people with no symptoms who had lower DEHP levels than the people who had more severe symptoms.”

She admitted the children are currently “far too young” to make concrete findings regarding DEHP and there’s a wide array of potential causes for either condition.

“We also like picking up early life symptoms at (ages) 2 or 4 because that’s closer to pregnancy,” she said.

“Obviously, if you get diagnosed with one of these conditions at age 30, you probably had a different type of causes.”

While the children are still young, Ponsonby said the research will continue as they age to see just how much of an effect the chemical has on them throughout their lives.

The team also found the genes that were switched by DEHP were also more likely to stay in place if the child had a high nutrition diet while in the womb.