CONTROVERSIAL: Many disagree with the new idea and say the causes of autism are complex and still not completely understood. Picture: Pixabay
About one percent of the world’s population has autism spectrum disorder.

Over the years, the causes of this disorder, which impacts the nervous system, have left experts dumbfounded and confused. Now paediatrician Dr Harvey Karp – best known for The Happiest Baby series – has come come up with his own theory on what he thinks causes autism.

At a recent Healthy Child Healthy World and Environmental Working Group luncheon, Karp mentioned that there had been shift in diagnosis, saying: “We’re just calling things autism that we didn’t used to call autism.”

He also said there were cases that never existed before and that shouldn’t be happening.

Karp’s theory comes down to the chemical used in plasticised plastic called bisphenol A (BPA).

BPA is an endocrine disrupting chemical and was first created to be an oestrogen. This common chemical found in plastics made headlines in 2008 when it was found that it had effects on the human brain, behaviour and unborn children. It can be found in water bottles, the lining of canned foods and drink cans.

“They found they could put it into plastics. Every single one of you have BPA in your bodies from all the exposure you have,” said Karp.

He explained that all these chemicals have a hormonal effect and “the weird thing is that hormones are signallers – they tell cells ‘Do this, don’t do that’ – and what can happen is these hormonally active chemicals make it into the brains of young babies or even before birth and shift the brain’s development.”

Karp believes this could be related to autism because the disorder isn’t split evenly between the sexes. “Boys get four times more autism and are diagnosed nine times more with Asperger’s syndrome.”

But Sandy Usswald, the national director of Autism SA, rubbishes Karp’s theory, saying that unfortunately there was no definitive answer to what causes autism.

“There are varied opinions, and often scaremongers scare parents into believing they have done something wrong,” she says.

Usswald also suggested there were some holes in Karp’s hypothesis, saying the logic used that BPA causes autism and, therefore, more boys have autism doesn’t make sense at all.

“Baby girls also drink out of bottles and it doesn’t explain how babies that are breastfed also present with autism.”

She added there were no peer-reviewed studies that support his theory, and Autism SA was strongly aligned to evidence-based practice. “What we do know is that there is a genetic predisposition, and studies are now indicating that various genes are responsible for various manifestations of autism, but there is no causal link to anything just yet.”

However, Dr Das Pillay, a paediatrician at St Augustine’s Hospital in Durban, who has a special interest in autism and autistic spectrum disorders, does tend to agree with Karp to a certain degree.

“The theory of BPA sounds plausible, but needs to be proven in a double-blind randomised trial.

“Karp’s suggestions about BPA being in baby bottles and canned food is an interesting theory. We have also known for years that preservatives and additives have had an effect on the brain, its development, and the manner in which it functions.”

Pillay says to all his patients, “you are what you eat”, and that parents should give their children natural, wholesome foods, and stay away from additives, preservatives and carbonated drinks.

The jury is still out on the far-reaching effects of BPA, but most manufacturers now use only low levels of it.

Zero-waste warrior Colleen Black has strong concerns about BPA and tries to avoid it. “I generally store all my food in glass, even in the freezer, as much as possible.

“All these chemicals in our cleaning products and toiletries are detrimental to our health,” she said.

“They are laced with known hormone disruptors and many have been linked to cancer and fertility problems as well as other illnesses.”

Black advised that consumers should start reading product labels and be aware of what “we’re eating and put on our skin”.