Chemical exposure from ultra-processed foods may contribute to health issues

Toxic synthetic chemicals that migrate into ultra-processed foods from packaging, processing equipment and other sources may explain why these foods are so bad for our health, according to a new review article.

In addition to the foods’ poor nutritional value, these chemicals represent an “underappreciated and understudied” explanation for the link between ultra-processed foods and health problems such as obesity and other chronic diseases, the authors conclude in the article, published Friday in the journal Nature Medicine.

“The more (ultra-)processed a foodstuff, the greater its burden of synthetic chemicals generally is,” the authors wrote.

Ultra-processed foods such as candies, hot dogs and packaged soups are industrially made and contain many added ingredients not found in home kitchens, such as stabilizers and added colors and flavors. 

Thousands of harmful substances including bisphenols (such as BPA), phthalates, microplastics (tiny plastic particles) and per- and polyfluoroalkyl substances (PFAS) can leach into industrially produced foods during production, as well as from containers in which the foods are stored and while heating them up before they are eaten, according to the article. Emerging research suggests that even the “normal and intended use” of plastic materials that come into contact with foods along their journey to our plates can contaminate these products, the authors wrote.

Research increasingly shows that some of the same synthetic chemicals found in ultra-processed foods, as well as drinking water and other sources, are prevalent in our bodies. About 98% of the US population has PFAS in their blood, while microplastics and even smaller plastic particles (nanoplastics) accumulate in “just about every portion of your body…no organ is spared, really,” Dr. Sanjay Rajagopalan, director of the Cardiovascular Research Institute at Case Western Reserve University, said during a May 15 webinar hosted by the group Beyond Plastics. Plastic particles have been found in everything from the placenta to the brain, lungs and heart, he said. 

In a 2024 study, Rajagopalan and colleagues found a link between microplastics in the arteries and risks for heart attacks and strokes.

“The particles looked quite nasty,” he said. “They were jagged particles with sharp edges, very similar to cholesterol.”

Studies estimate that the economic cost of disease attributed to exposure to plastic-related chemicals in the US was about $249 billion in 2018. The estimated health costs that year related just to perfluorooctanoic acid (PFOA), a type of PFAS classified as carcinogenic by an international cancer research group, was at least $5.5 billion.

“Shortcomings in chemical risk assessment, management and enforcement” are one reason for the prevalence of chronic diseases linked to exposure to synthetic chemicals, wrote the authors of the new review.

While there may be as many as 100,000 synthetic chemicals that can migrate into foods from packaging, storage containers and processing equipment, most of these substances remain unknown, according to the review.

Studies to assess the safety of the chemicals scientists do know about typically involve animal experiments that test exposure to high doses. However, exposure to even very low doses of some substances that contaminate foods, such as endocrine-disrupting chemicals including BPA and phthalates, can lead to obesity and diabetes. And while chemicals are usually studied individually to assess their safety, in the real world people are exposed to mixtures of chemicals, which may have different health effects.

“Current approaches to testing food contact materials are outdated and need to be urgently updated,” said Jane Muncke, the managing director and chief scientific officer of the Food Packaging Forum in Zurich, Switzerland, an author of the review article.

 “Reductions in the numbers and types of direct food additives are necessary, as well as the way that food contact chemicals and food contact materials are regulated,” she added. “A post-market review of food contact chemicals that focuses on removing the most hazardous substances known to damage human health… is a good first step.”

(Featured image by Peter Secan on Unsplash.)