Keeping a lid on plastics

An internationally lauded clinical trial by researchers at The University of Western Australia has shown there are quick and effective ways in daily life to reduce the levels of harmful plastic-associated chemicals in our bodies. But some unexpected results of the study were not so positive.

An editorial in Nature Medicine earlier this year heralded the results of a Western Australian-run clinical trial that had been able to reduce the levels of two plastic-associated chemicals (PACs) in the bodies of study participants, by limiting plastics use in the food chain and in people’s diet and everyday life.

The randomised controlled trial, led by internally renowned UWA clinical immunologist Professor Michaela Lucas, had even managed to lower the percentage of phthalates and bisphenols, known endocrine disruptors, in just seven days; and in the best-case scenario the reduction was more than 50%.

PERTH Trial team: Dr Andrew Lucas, Prof Michaela Lucas and Dr Amelia Harray.

This was a good news story, but the authors of the Nature Medicine editorial also picked up on some results in the trial that were unexpected.

“Additionally, they found that levels of di(2-ethylhexyl) phthalate [DEHP] increased in all low-plastic diet interventions… This leads to the question of whether these chemicals are in the food at the time it is harvested,” they wrote.

It’s a question that’s clearly on the mind of Professor Lucas, an AMA (WA) member, because she makes a point of talking about the DEHP results and something else in the RCT paper, published in Nature Medicine, that she thinks have been overlooked in mainstream coverage.

“The big message is that if you do what we’re doing in the trial, you can reduce the plastic-associated chemicals in your body in a period of a week. They really flush out consistently,” she says.

“But the other thing we found is that we could only reduce bisphenols and low-molecular phthalates. There is, however, this very dangerous chemical called DEHP, which is a high-molecular phthalate, and we weren’t able to reduce it.”

There were three groups in the Plastic Exposure Reduction Transforms Health (PERTH) Trial cohort who had a mandated healthier diet, with less processed food and more fruit and vegetables, and yet their DEHP levels went up rather than down.

“It wasn’t super significant, but there was a trend,” Prof Lucas says. “This raises the problem that if your exposure to this chemical is not coming from the packaging of the food and the touch points of the plastic, and it doesn’t come from your personal care products, where is it coming from?  This raises, of course, the possibility, raised in the editorial and what’s emerging in the literature, that some of these chemicals are literally inside the food.”