Scientists have shown that chemicals from materials that come into contact with food can migrate into the food under certain conditions [1, 2] and are a source of exposure for harmful chemicals. A recent study found that there are over 12,000 food contact chemicals in use worldwide and identified 608 potentially hazardous substances that urgently need to be further evaluated, whilst many others lack thorough toxicological evaluation .
In fact, the American Academy of Pediatricians (AAP) and the Endocrine Society have pointed to food contamination through processing, packaging, cooking, and storing as an important health issue. The AAP issued a policy statement saying that “scientific evidence suggests potential adverse effects on children’s health from synthetic chemicals used as food additives… (including) those used in materials that may contaminate food as part of packaging or manufacturing .” Moreover, the Endocrine Society specifically points to food contact materials as a source of endocrine disrupting chemicals (EDCs) like BPA, phthalates, and PFAS and reports that the “possibility that low level environmental exposure may still have significant and/or long-term biological impact.” 
If the object of healthy eating is long term wellness and prevention, then it is important to include the materials that come into contact with food. Here are 3 areas that should be incorporated into the definition of healthy eating.
1) Avoid processed foods because of contamination during processing and packaging
While healthy eating generally discourages processed foods because they lack nutrients, processed foods should also be avoided because of contamination with harmful chemicals from packaging and during processing. Several studies show that switching to a fresh food diet was associated with lower urinary concentrations of certain phthalate metabolites and BPA (6, 7, 8, 9). BPA is found in the lining of canned foods and in other hard, clear, polycarbonate plastics and has been shown to leach into food (10). BPA is one of the most studied and well-known endocrine disrupting chemicals. More than a hundred epidemiological studies and hundreds of animal studies have been published showing associations between BPA and health effects, including brain development, abnormal neurobehaviors, adverse reproductive health outcomes, and metabolic diseases, and disrupted immune responses (11, 12, 13).
Phthalates are another endocrine disrupting chemical that are commonly found in food packaging and in equipment used to process food. Phthalates have been shown to reduce both testosterone and estrogen levels, block thyroid hormones (5), and some studies have shown they are reproductive toxicants (14).
Recently, more attention has been turned to per- and polyfluoroalkyl substances (PFAS), a group of synthetic chemicals that includes PFOA, PFOS, GenX, and many other chemicals. Several studies have shown that PFAS chemicals are used in greaseproof applications, such as pizza boxes, microwave popcorn bags, and takeout containers and paper food wraps (15,16). PFAS chemicals are known to bioaccumulate and build up in the body, and have relatively long half-lives of 3-5 years, so there is much concern. Many PFAS chemicals are endocrine disrupting chemicals and studies have shown strong associations between certain types of PFAS chemicals and cancers (5).
Since processed foods are contaminated with BPA, phthalates, and PFAS through processing and packaging, clinicians should advise patients and clients to reduce consumption, even if the processed foods contain healthier ingredients.
2) Use stainless steel, cast iron, carbon steel, glass, and enamel cookware and bakeware.
Nonstick cookware and bakeware are ubiquitous in the home. While PFOA (a specific PFAS chemical) has been largely phased out, other similar PFAS chemicals, including Teflon (PTFE) are used in nonstick coatings on cookware and bakeware (17). Nonstick coatings like PTFE break down and release hazardous chemicals, when heated to high temperatures above 400 F, which are common during baking and high heat cooking (18, 19). There is also some concern that small particles can be ingested when nonstick coatings are scratched and flake off, contaminating food (20).
In recent years, silicone rubbers have also been used in items that come into direct contact with food, such as baking molds. Scientists have shown that different substances may migrate into food from silicone, but there are not comprehensive toxicological assessments (21).
In order to reduce food contamination from cookware and bakeware, stainless steel, cast iron, carbon steel, glass, and enameled cookware and bakeware should be used to cook food. Dieticians, nutritionists, and clinicians should embrace healthy cookware and bakeware as an essential component of healthy eating. Patients and clients may not need to purchase new cookware, especially where cost is a concern. Community thrift stores, freecycle/buy nothing networks and town swaps may all be used as resources for acquiring healthier cookware, in addition to big box stores and online retailers which stock many of these items at reasonable prices.
3) Use glass, stainless steel, and ceramic food and drink storage containers
Similar to the issues mentioned above, food storage containers can be a source of food contamination, especially with foods that are hot, fatty and acidic. BPA is commonly found in plastic food storage containers, and even plastic containers labeled as BPA-free are not necessarily safe. They may contain similar chemicals without clear safety data, a phenomenon known as regrettable substitution (22). Choosing glass, stainless steel, and ceramic food storage containers is a good way to ensure that healthy food is not contaminated during storage.
Water bottles can also be a source of exposure to chemicals like BPA. A study showed that regular consumption of cold beverages from reusable plastic water bottles substantially increases urinary BPA concentrations (23). Thus choosing a reusable stainless steel or glass water bottle should also be advised. For those who already own an array of plastic food containers and water bottles, clients/patients may ask how to dispose of these responsibly. They can be recycled where appropriate, repurposed for home organization, and/or donated to a community center or school for science or craft projects.
Our definition of healthy eating needs to go beyond just ingredients! Healthy eating should mean limiting food contamination through processed foods, cookware, and food storage. Any definition of healthy eating should incorporate limiting harmful chemicals like BPA, phthalates, and PFAS from contaminating food.
- Arvanitoyannis, Ioannis S., and Loulouda Bosnea. "Migration of substances from food packaging materials to foods." Critical reviews in food science and nutrition 44.2 (2004): 63-76.
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- Gore AC, Chappell VA, Fenton SE, Flaws JA, Nadal A, Prins GS, Toppari J, Zoeller RT. EDC-2: The Endocrine Society’s Second Scientific Statement on Endocrine-Disrupting Chemicals. Endocr Rev. 2015;36(6):E1-150.
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- Schlummer, Martin et al. “Emission of perfluoroalkyl carboxylic acids (PFCA) from heated surfaces made of polytetrafluoroethylene (PTFE) applied in food contact materials and consumer products.” Chemosphere vol. 129 (2015): 46-53.
- Sinclair, et al. “Quantitation of gas-phase perfluoroalkyl surfactants and fluorotelomer alcohols released from nonstick cookware and microwave popcorn bags.” Environ Sci Technol. 2007 Feb 15;41(4):1180-5.
- Lohmann, Rainer, et al. "Are fluoropolymers really of low concern for human and environmental health and separate from other PFAS?." Environmental Science & Technology54.20 (2020): 12820-12828.
- Trasande, Leonardo. "Exploring regrettable substitution: replacements for bisphenol A." The Lancet Planetary Health 1.3 (2017): e88-e89.
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