Toxic chemicals used in food preparation leach into human bodies, study finds

Wrapping foods in plastic wrap are just one of many ways that humans are exposed to food contact chemicals, experts say. (Moment RF/Getty Images via CNN Newsource)

More than 3,600 chemicals that leach into food during the manufacturing, processing, packaging and storage of the world’s food supply end up in the human body — and some are connected to serious health harms, a new study found.

“This is a staggering number and shows that food contact materials are a significant source of chemicals in humans,” said Martin Wagner, a professor of biology at the Norwegian University of Science and Technology in Trondheim, in an email.

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“The study is the first to systematically link the chemicals we use in materials to package and process foods to human exposure,” said Wagner, who was not involved in the research.

Seventy-nine of the food-processing chemicals found in the body are known to cause cancer, genetic mutations, endocrine and reproductive issues, and other health concerns, according to the study published Monday in the Journal of Exposure Science & Environmental Epidemiology.

Many more chemicals may be harmful in ways that science does not yet know, said senior study author Jane Muncke, managing director and chief scientific officer at the Food Packaging Forum, a non-profit foundation based in Zurich, Switzerland, that focuses on science communication and research.

“We’re measuring not only the chemicals that were known to be used in the food manufacturing process, but all the gunk as well — the byproducts and impurities that we call non-intentionally added substances,” Muncke said.

“Those substances are always present in plastic, in can and package coatings, in printing inks and so on. They may not have a technical function in the food processing, but they are there regardless and migrating into people, and we measure them.”

The American Chemistry Council, an industry association, told CNN that its members are dedicated to food safety.

“It is essential, however, when assessing potential risks to consider a broader context, including existing regulatory frameworks, scientific evidence, and the actual levels and degree of exposure that may exist, a council spokesperson said via email.

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“Any proposed actions lacking this context, particularly when causality has not been definitively established, is inconsistent with risk-based U.S. chemical regulation laws.”

However, while food contact materials may comply with current government regulations, the study highlights that these chemicals may not be fully safe, Muncke said.

“We don’t know exactly what the amount is that’s been used in food packaging or other food contact materials versus the amount that’s being used for cosmetics, personal care products, textiles and so on and so forth, right? I would like to have that information,” she said.

“I think it would be fantastic to make it a regulatory requirement for companies to declare how much and what type of chemicals they are putting into my food or plastic water bottle.”

Well-studied toxic chemicals found in food

One chemical the study detected in both food and the human body is bisphenol A, or BPA, that had been used to create baby bottles, sippy cups and infant formula containers until frightened parents boycotted those products more than a decade ago.

BPA is an endocrine disruptor that has been linked to fetal abnormalities, low birth weight, and brain and behavior disorders in infants and children. In adults, the chemical has been linked to the development of diabetes, heart disease, erectile dysfunction, cancer and a 49 per cent higher risk of early death within 10 years.

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Bisphenol A can leach into food from the linings of canned foods, polycarbonate tableware, food storage containers and water bottles, according to the National Institute of Environmental Health Sciences.

“The study also shows that food contact materials can contain mutagenic chemicals that harm our DNA, such as heavy metals,” Wagner said. “There is strong evidence that humans are exposed to PFAS, so-called forever chemicals, from food packaging that are very persistent, bioaccumulate and cause organ toxicity.”

Perfluoroalkyl and polyfluoroalkyl substances, or PFAS, are present in the blood of an estimated 98 per cent of Americans, according to the National Academies of Sciences, Engineering, and Medicine. The hormone-disrupting chemicals are so worrisome that in July 2022 the Academies set “nanogram” levels of concern and called for testing of high-risk individuals, including infants and older adults. (A nanogram is equivalent to 1 billionth of a gram.)

Another chemical group in food packaging that has migrated into people is phthalates, the research revealed. Found in shampoo, makeup, perfume and children’s toys as well as food containers, phthalates have been linked with genital malformations and undescended testes in baby boys and lower sperm counts and testosterone levels in adult males.

Previous studies have also linked phthalates to childhood obesity, asthma, cardiovascular issues, cancer and premature death in people ages 55 to 64.

Only a few food chemicals are tracked in humans

In the new study, researchers compared 14,000 chemicals known to come in contact with food during the packaging process with worldwide databases that monitor human exposure to potential chemical toxins. All the research data has been uploaded to an open database for scientific use.

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“We’ve got, say, 60 years of research into the migration of chemicals into food from food processing and packaging equipment. It’s been studied very extensively,” Muncke said.

“And at the same time, there’s increasingly good, powerful studies coming out on Bisphenol A, on phthalates, on PFAS, brominated flame retardants and so forth that are associated with diseases in people.”

What was lacking in the literature was a comparison between what was found in people and the chemicals known to migrate during food processing into food. To connect the dots, Muncke and her colleagues looked at national and regional biomonitoring databases that track chemicals in human blood, urine, breast milk, tissue samples and other biomarkers.

For the study, researchers used data from the U.S. National Health and Nutrition Examination Survey, or NHANES, which gathers yearly health and nutrition data on Americans. Other databases included the Canadian Health Measures Survey, Human Biomonitoring for Europe, the Korean National Environmental Health Survey and Biomonitoring California, a state database.

Of the 14,000 chemicals known to migrate into food during processing and packaging, only a few hundred are measured in people by these programs, according to the study. For example, only 172 chemicals detected in food contact materials are monitored in the United States by the National Health and Nutrition Examination Survey — 144 of these chemicals have been detected in some populations, Muncke said.

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“Given that there are (tens) of thousands of food contact chemicals, biomonitoring programs do not have the capacity to test for all chemicals we are potentially exposed to,” Wagner said. “This creates biases towards very well studied substances and leaves a big gap in our knowledge on all the other chemicals we potentially have in our bodies.”

Of course, having a chemical in the body does not necessarily mean the chemical is harmful, said Melanie Benesh, vice president of government affairs for the Environmental Working Group, or EWG, a consumer organization that monitors exposure to PFAS and other dangerous chemicals.

“Yet you’re not supposed to be born with any chemical inside of you,” Benesh said. “The bigger question is do we really need these chemicals to process our food? When there are chemicals in our bodies that we know have the potential to cause us harm, we should be eliminating every route of exposure that we can.”

'Generally recognized as safe'

Since 2000, nearly 99 per cent of any new food contact chemicals were greenlit for use by the food and chemical industry, not the U.S. Food and Drug Administration (FDA), according to a 2022 analysis by EWG.

In that 22-year period, food manufacturers asked the FDA’s permission to introduce a chemical 10 times, the analysis said. Instead, “companies have exploited a loophole for substances that are ‘generally recognized as safe,’ or GRAS. The loophole lets food manufacturers — not the FDA — decide a substance is safe,” the EWG report stated.

Created by an amendment in the 1950s to the 1938 Federal Food, Drug and Cosmetic Act, GRAS was intended to be applied narrowly to common ingredients such as sugar, vinegar and baking soda.

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The U.S. Government Accountability Office released a report in November 2022 highlighting FDA limitations in monitoring the nation’s food safety, including the agency’s lack of legal authority over food manufacturers.

“In addition, FDA does not track the date of the last pre- or postmarket review for all food contact substances in a way that allows FDA to readily identify substances that may warrant a postmarket review because new safety information may have emerged,” the GAO report stated.

FDA’s deputy commissioner for human foods, Jim Jones, told U.S. House Committee on Energy and Commerce’s subcommittee on health last week that the FDA has made food chemical safety a top priority.

“However, there are also important gaps that need to be addressed as we undertake the work to strengthen our food chemical safety activities,” he said. “Ready access to safety information and consumer exposure data on chemicals in need of review would help us conduct faster and more robust safety evaluations and reassessments. Access to this data would allow FDA to take any necessary regulatory actions in a timely manner to protect consumers and help ensure food safety.”

For the first time, the FDA will hold a public hearing, slated for Sept. 25, on enhancing its assessment of chemicals found in food, including food and color additives, food contact substances, potential contaminants and pesticides, and ingredients considered generally recognized as safe.

“This is unprecedented,” the EWG’s Benesh said. “This is the first time the FDA is talking about standing up a rigorous review program that puts human health first, that puts chemical safety first, and that restores some of the trust consumers have lost in the agency.”