How often do you eat microwave popcorn?
Q: I've been hearing a lot about PFAS and how they have an adverse effect on our health. I read that some food wrappers, like bags for microwave popcorn, use PFAS to keep food from sticking. My kids eat microwaved popcorn almost every night. Should I be worried?
A: The term PFAS refers to a large group of man-made chemicals known as polyfluoroalkyl and perfluoroalkyls substances. Previously known as PFCs, or perfluorochemicals, they were developed in the 1950s.
This family of chemicals is resistant to oil, grease, heat and water, which has led to their use in an extensive array of commercial and consumer applications. PFAS can be found in cleaning products, nonstick cookware; stain-resistant coatings for carpets, upholstery, textiles, paints and varnishes; and also makeup and personal care products, to name just a few. They are also widely used in paper products meant to hold foods that are hot, gooey or greasy. That includes the wrappers that hold fast food and, as you noted in your letter, microwave popcorn bags.
PFAS have a carbon-fluorine bond, which is one of the strongest single bonds in nature. As a result, these types of chemicals break down very slowly. This has led to their being referred to as "the forever chemical." PFAS also dissolve in water, which allows them to accumulate and persist, both in the environment and in our tissues. All of these factors, along with their widespread use, means PFAS are present not only in the environment, but also in the blood and tissues of humans and animals throughout the world.
Studies have linked PFAS to adverse health effects, including high blood pressure, decreased fertility in women, liver damage, cancer, low birthweight and an increased risk of asthma and thyroid disease. The use of some of the more common PFAS was gradually phased out in the United States between 2000 and 2015. However, other variations of the chemicals have taken their place. The newer PFAS tend to have shorter chains of the carbon-fluorine bond, and are thus more rapidly eliminated from the body. But the FDA says they continue to present a concern for human health.
Research suggests people who regularly consume microwave popcorn have markedly higher levels of PFAS in their bodies. A study published in 2019 analyzed a decade of data about the eating habits of 10,000 people, which was collected by the Centers for Disease Control and Prevention between 2003 and 2014. Blood samples from the study participants were also collected. The researchers found people who ate microwave popcorn every day over the course of a year had levels of PFAS that were up to 63% higher than average.
Considering the questions that continue to surround the safety of consuming PFAS, we think it would be reasonable to curtail the daily use of microwave popcorn. Instead, you could save it for an occasional treat. If your kids are flexible, you might switch to a different type of evening snack. Or if it has to be popcorn, you could turn the process of making stovetop popcorn into a family project.
• Dr. Eve Glazier is an internist and associate professor of medicine at UCLA Health. Dr. Elizabeth Ko is an internist and assistant professor of medicine at UCLA Health. Send your questions to email@example.com.