A new clinical trial has revealed that eliminating plastic from food storage, preparation, and packaging can dramatically reduce levels of harmful chemicals in the human body in as little as seven days. Researchers from the University of Western Australia found that participants who switched to plastic-free alternatives experienced a 44 percent decrease in phthalates and a 50 percent decrease in bisphenols, chemicals known to interfere with hormones and linked to infertility and heart disease.

What Chemicals Are Hiding in Your Food Storage?

The PERTH Trial (Plastic Exposure Reduction Transforms Health) tracked plastic chemical exposure in 211 healthy adults across Perth, Western Australia, over three years. The findings, published in Nature Medicine, revealed a sobering reality: 100 percent of participants showed high levels of plastic chemicals in their bodies, with each person recording at least six different chemical types on any given day.

More than 16,000 chemicals are commonly used in the manufacture of plastic for food and beverage packaging, kitchen utensils, cling film, and plastic containers. The two most concerning are phthalates, used to soften plastics, and bisphenol A (BPA), used to make hard plastic. Both chemicals can interfere with the body's hormonal system and have been linked to reduced fertility, compromised immune function, and increased cancer risk.

"We investigated two major types of plastic chemicals, bisphenols and phthalates, both of which can interfere with endocrine or hormonal functions in our body and have been linked to infertility and cardiometabolic disease," explained Clinical Professor Michaela Lucas, principal investigator of the study.

Clinical Professor Michaela Lucas, Medical School, University of Western Australia

The research team identified that highly processed, packaged, and canned foods and beverages were significant contributors to plastic chemical exposure. Acidic foods like tomato sauce and fatty foods like lasagne are particularly prone to absorbing more chemicals from plastic containers than others, and the transfer increases dramatically when food is heated.

How to Reduce Plastic Chemical Exposure in Your Kitchen?

• Replace plastic food containers: Switch to glass or ceramic containers for storing all foods, especially hot foods and leftovers that will be reheated. Glass and ceramic do not leach chemicals into food and remain safe even after repeated use and washing.
• Use plastic-free kitchenware: Replace plastic utensils, cutting boards, and food preparation tools with stainless-steel pots, pans, kettles, and wooden chopping boards. The PERTH Trial participants used these alternatives and saw significant chemical reductions.
• Avoid heating food in plastic: Never microwave food in plastic containers, even if labeled microwave-safe. A microwave-safe label only means the container won't melt; it does not indicate that chemicals won't leach into your food when heated.
• Choose fresh, unpackaged foods: Purchase foods that have not been processed or packaged in plastic whenever possible. Work with local farmers and producers who use alternative packaging methods.
• Store cold foods only in plastic: If you must use plastic containers, limit them to storing cold foods and beverages only. The Academy of Nutrition and Dietetics advises against using plastic for hot or heated foods.

To test the effectiveness of these changes, researchers selected 60 individuals from the original study and divided them into five groups for a randomized controlled trial. Each group received low-plastic alternatives for food, beverages, kitchenware, and personal care products. The results were consistent across all groups: after just seven days, urinary plastic chemical levels decreased significantly compared to a control group that continued using plastic.

"By altering a participant's lifestyle to include the consumption of low plastic food, prepared with low plastic kitchenware and the use of low plastic personal care products, phthalates decreased by more than 44 percent and bisphenols such as BPA and BPS by more than 50 percent," noted Dr. Andrew Lucas, co-first author of the study.

Dr. Andrew Lucas, Co-first Author, PERTH Trial

The research team went to extraordinary lengths to ensure the intervention was comprehensive. Dietitians worked with over 100 farmers and food producers to educate and transform their food handling processes and packaging to reduce plastic exposure from farm to table. Participants had access to any type of food they would normally consume, including pasta, salads, meats, butter, chocolate, fruit, and snacks, ensuring that energy intake remained the same.

Why Should You Be Concerned About BPA Alternatives?

One particularly troubling finding from the PERTH Trial was the high prevalence of BPS (bisphenol S) in healthy participants. BPS is a chemical used as a replacement for BPA in many "BPA-free" plastic products. However, emerging evidence suggests that BPS may cause similar harms to human health as BPA itself. This raises serious questions about the effectiveness of simply switching to BPA-free products without addressing the broader issue of plastic chemical exposure.

"The high prevalence of BPS in healthy participants as an alternate chemical used to replace BPA should ring warning bells for food standards regulators as it is becoming clear these replacements are likely to cause similar harms," warned Clinical Professor Michaela Lucas.

Clinical Professor Michaela Lucas, Medical School, University of Western Australia

In response to mounting evidence about BPA's health risks, the European Commission introduced a ban on BPA in food contact materials in 2024, meaning it is being phased out in the manufacture of everyday products like water bottles and food containers. However, the widespread use of replacement chemicals like BPS suggests that regulatory action alone may not be sufficient to protect public health.

The PERTH Trial offers a message of hope: you don't need to wait for regulatory changes or perfect alternatives to reduce your exposure to plastic chemicals. By making deliberate choices about how you store, prepare, and consume food, you can significantly lower the levels of these harmful substances in your body in just one week. The next phase of the PERTH Trial will investigate the effects of plastic chemical exposure on fertility, potentially revealing even more compelling reasons to make the switch to plastic-free living.