Chemicals linked to breast cancer leach into our foods, study finds

Nearly 200 chemicals connected to breast cancer are used in the making of food packaging and plastic tableware, and dozens of those carcinogens can migrate into the human body, a new study found.

“There is strong evidence that 76 known or potential breast carcinogens from food contact materials recently purchased all over the world can be found in people,” said study coauthor Jane Muncke, managing director and chief scientific officer at the Food Packaging Forum, a nonprofit foundation based in Zurich, Switzerland, that focuses on science communication and research.

“Getting rid of these known or suspected carcinogens in our food supply is a huge opportunity for cancer prevention,” Muncke said.

Of the recently detected chemicals in food packaging, 40 are already classified as hazardous by regulatory agencies around the world, according to the study.

“So many of these chemicals have already been classified as human health hazards, yet they are still allowed to be used in food contact materials, thus allowing them to migrate into the food we eat,” said Jenny Kay, a research scientist at Silent Spring Institute, a scientific research organization focused on the link between chemicals, women’s health and breast cancer. She was not involved in the study.

Rates of early-onset breast cancer in women under 50 are increasing, and experts said the trend cannot be explained by genetics alone.

“Rates of colon cancer are also rising in younger people,” said Dr. Len Lichtenfeld, former deputy chief medical officer for the American Cancer Society who was not involved in the study.

“Is it obesity? Is it alcohol? Is it the lack of physical activity? Is it environmental? There are a lot of reasons,” Lichtenfeld said, “and it’s going to take a long time to sort which has the most impact, as some of these chemicals may be high risk, some low risk.”

“Packaging exists to protect and keep food safe for consumption,” said Sarah Gallo, the association’s senior vice president of product policy and federal affairs, in an email.

“The FDA reviews and approves food contact substances through their science and risk-based system before they go to market,” Gallo said. “The agency’s post market review also provides continuous safety analysis and regulation of the approved substances.”

The FDA has been under fire for its failure to act quickly on health concerns about some 14,000 chemicals known to be added to food. The agency will hold a public meeting Wednesday to present its ideas on how to improve its post-market food analyses.

Possible breast carcinogens

In 2007, Silent Spring published a list of 216 chemicals that can cause mammary tumors in rodents — a key method for determining toxicity, according to experts.

A January 2024 update to that list found 921 possibly carcinogenic chemicals, including 642 that may stimulate estrogen or progesterone production, another known risk factor for breast cancer.

“The fact that so many potential breast carcinogens are present in food packaging and can migrate into our food is just one example of how many chemicals we are unwittingly exposed to every day,” said Kay, who coauthored the 2024 study update published in Environmental Health Perspectives.

“Many of the mammary carcinogens are hormone disruptors, too, and many of the chemicals on our list can also damage DNA,” she said. “Consumers should not have to keep track of all of the scientific literature on what chemicals to avoid. It should be on regulators to recognize the danger and take action.”

Carcinogens in plastic, paper and cardboard

The new study, published Tuesday in the journal Frontiers in Toxicology, compared the Silent Springs database of known carcinogens for breast cancer with the Database on Food Contact Chemicals Monitored in Humans, or FCChumon.

FCChumon, created by the Food Packaging Forum, is a list of food contact chemicals that have been detected in human breast milk, blood, urine and tissues.

“The new study took our list of potential breast carcinogens and compared it to their list of chemicals that have been found in food contact materials to find out which of potential breast carcinogens could be getting into people’s diets,” Kay said. “That’s a great way to prioritize chemicals for regulatory action.”

The study found such chemicals as benzene, a known carcinogen connected to breast cancers in animals and people; 4,4’-Methylenebis-(2-Chloroaniline), a probable carcinogen linked to bladder cancer; 2,4-Toluenediamine, found to cause breast and other cancers in animals; and 3,3′-Dimethylbenzidine and o-Toluidine, which are dyes used to color plastic and paper.

“Dyes can be used in plastics, paper, cardboard and the like and can have some pretty toxic properties,” Kay said. “Plastics are not the only culprit.”

In fact, while the study found most of the exposure to carcinogens came from plastics used in food packaging, 89 suspected carcinogens were found in paper and cardboard containers.

“Paper has additives such as emulsifiers and adhesives, say if papers are glued together, or there’s a plastic layer glued to the paper,” Muncke said.

A number of the chemicals found in the study were bisphenols, phthalates or perfluoroalkyl and polyfluoroalkyl substances, known as PFAS — worrisome chemicals that have been linked to many health concerns.

Often called “forever chemicals” because they do not break down in the environment, PFAS are used in food packaging to prevent grease and water from soaking through food wrappers and beverage cups. PFAS can also be found in the ink used to print logos and instructions on food containers.

Chemicals in the PFAS family are linked to high cholesterol, cancer and various chronic diseases as well as a limited antibody response to vaccines in both adults and children, according to a report by the National Academies of Sciences, Engineering, and Medicine.

Phthalates have been linked to childhood obesity, asthma, cardiovascular issues, cancer and premature death in people ages 55 to 64.

Bisphenol A, or 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% higher risk of early death within 10 years.

Steps to take to reduce exposure

While it’s up to regulatory agencies to make sweeping changes to protect the food supply, there are steps consumers can take to reduce the risk of toxic chemicals and carcinogens, according to Silent Spring.

Avoid burning or charring food, as the muscle meat of beef, pork, fish or poultry produces DNA-damaging chemicals when grilled at high temperatures or over an open flame. Use a ventilation fan when you cook.

Pollutants such as polychlorinated biphenyls, or PCBs, accumulate in fat, so remove the fat and skin from meat and fish before cooking and drain off any that forms during meal preparation.

Choose smaller, younger seafood that will contain less mercury and other toxins than larger, older seafood, according to Silent Spring.

While many canned foods and lined cartons have moved away from BPA, some still do use the chemical in the lining. Replacements include acrylic and polyester resins as well as polyvinyl chloride resins, or PVC. Currently, scientists aren’t sure about safety profiles for these substitutes.

Choose organic produce, meat and dairy over conventional when you can — while heavy metals may still be present, organic food is exposed to fewer pesticides.

Toss plastic containers. Instead, store and microwave all foods in glass rather than plastic, don’t use nonstick pans for cooking and replace any plastic bottles and coffee makers with glass or stainless steel.