Common food preservatives could impact human immune system

For many consumers, one of the defining characteristics of their staple pantry snacks is shelf life. Consumers generally appreciate that the chips, cereals, bars and snacks they purchase can be kept in their pantries, unrefrigerated, often for many months before the threat of spoilage. The shelf life of these products helps reduce not only wasteful spending, but the wasting of excess spoiled food as well.

However, a recent study conducted by the Environmental Working Group (EWG) indicated common preservatives in many popular snacks could have unintended negative consequences for the human immune system (Int. J. Environ. Res. Public Health. 2021;18[7]:3332).

The study authors sought to examine “the most common chemicals added to food as well as per- and polyfluoroalkyl substances (PFAS) shown to migrate to food from packaging materials or processing equipment,” to determine any unintended health consequences those chemicals may pose. In addition to PFAS, the antioxidant preservative tert-butylhydroquinone (TBHQ) was also analyzed. Using screening data from the U.S. Environmental Protection Agency (EPA) ToxCast program, the researchers determined TBHQ “showed activity both in ToxCast assays and in classical immunological assays, suggesting that it may affect the immune response in people.” The study concluded, in part, “Joint consideration of toxicological and high-throughput screening data suggests that chemicals directly or indirectly added to food for decades—such as PFAS and TBHQ—may show previously unanticipated effects on the immune system.”

The authors noted PFAS was discovered in the wrappers, bags and boxes used by many popular fast-food chains during a 2017 nationwide testing survey. A December 2020 study performed by researchers at Harvard’s T.H. Chan School of Public Health indicated “People who had elevated blood levels of a toxic chemical called perfluorobutanoic acid (PFBA) [a subclass of PFAS] had an increased risk of a more severe course of COVID-19 than those who did not have elevated levels” (PLoS One. 2020; 0244815).

Even without being aware of the specific risks associated with TBHQ and PFAS, cleaner preservatives and more sustainable packaging have been on consumer wish lists for quite some time. Ingredients like rosemary extract and other polyphenol-rich botanical antioxidants continue to grow in popularity as formulators work to preserve their products in more sustainable, safer, cleaner ways. In August 2020, FDA announced a voluntary phase-out of a certain type PFAS that contain 6:2 fluorotelomer alcohol (6:2 FTOH), which may be found in certain food contact substances used as grease-proofing agents on paper and paperboard food packaging. Informa Markets also unveiled its Sustainable Packaging Toolkit in June 2020 to assist brands looking to switch to cleaner packaging.

“The pandemic has focused public and scientific attention on environmental factors that can impact the immune system,” said Olga Naidenko, Ph.D., lead study author, in a release. “Before the pandemic, chemicals that may harm the immune system’s defense against infection … did not receive sufficient attention from public health agencies. To protect public health, this must change.”