Does Microwave Popcorn Cause Cancer?

Certain chemicals pose risks

Microwave popcorn bag

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According to many studies, flavoring additives like diacetyl and chemicals used in microwave popcorn bags were deemed unsafe because of irreversible lung damage and other potential health risks.

As a result, between 2002 and 2015, diacetyl and other substances were eventually phased out from microwave popcorn and its packaging. Still, consumers should be aware that some chemicals continue to be in use.

Is Popcorn a Healthy Snack?

Among the more popular snacks, popcorn is considered as one of the healthier choices. Three tablespoons of air-popped yellow popcorn is a little over a quart and has up to 120 calories. Nutrients include 4 grams of protein, 1 gram of total fat, 28 grams of carbohydrates, zero milligrams of cholesterol and sodium, and 5.02 grams of total fiber.

Popcorn is a high-fiber whole grain, and these are associated with reducing the risk of diseases linked to a poor diet and excessive weight, such as diabetes, heart disease, and cancer says the American Heart Association (AHA). However, the AHA warns that not all popcorn treats should be considered optimal snacking choices.

Movie popcorn served in a large tub can be a greasy, high-calorie snack, clocking in at 1,090 calories with a whopping 2,650 milligrams of sodium—two major contributors to high blood pressure that could lead to a stroke and/or heart disease.

Another unhealthy choice is caramel popcorn that has a high sugar and fat content. If you’re hankering for popcorn, the healthiest option is using an air popper followed with light seasoning, as recommended by the AHA.

Chemicals in Microwave Popcorn

If you’re avoiding unhealthy snacks by simply opting for low-fat and low sodium treats like microwave popcorn, you may want to take into consideration the chemicals used to coat its packaging. According to the Environmental Protection Agency (EPA), these chemicals might include perfluoroalkyl and polyfluoroalkyl substances (PFAS).

They may include a subset of PFAS like PFOA or C8, PFOS, GenX, and other chemicals found in common nonstick household products and in fast food packaging (pizza, burgers, fries, and microwave popcorn bags).

A 2020 report examined microwave popcorn packaging and 407 samples of paper, including paperboard food wrappers used by fast food chains coated with five common PFAS (PFOA, PFOS, perfluorononanoic acid, perfluorodecanoic acid, and perfluorohexanesulfonic acid).

They found the coated PFAS paper products affected the blood serum levels of people who habitually consumed microwave popcorn and restaurant fast food versus cooked meals prepared from grocery store products.

The data showed 90% of the food purchased from the grocery store was less likely to be tainted by PFAS from packaging in contrast to the wrapped or boxed fast food. This led to higher concentrations of PFAS in blood serums of fast food consumers and those who snacked on microwave popcorn, as compared with those who cooked their meals.

 A 2017 study identified 46 different PFASs found in microwave popcorn bags manufactured in 12 European (Spain, France, Austria, The Netherlands, Hungary, Germany, Italy, Ireland, Czech Republic, Sweden, United Kingdom, Portugal), three American (Mexico, Brazil, and the U.S.), and two Asian countries (China and India) from 2015 to 2016.

The EPA reports that several PFAS have been phased out and are no longer produced in the United States, however as noted above, they are still manufactured in other countries and continue to appear in a number of consumer products that are imported into the United States.

What's in the Packaging?

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemical compounds, that are found in a variety of food packaging. PFAS are currently used in a wide variety of common products from firefighting foams to paints as well as nonstick household products, but also in fast food packaging and microwave popcorn bags that are water and grease resistant.

Approximately 4,700 PFAS are available in the global market. Exposure to the chemicals can be through direct contact with the products, but also through diet, drinking water, air, and dust. PFAS are not susceptible to high temperatures and are not easily broken down in either the environment or the human body. They can accumulate over time.

What Is Popcorn Lung?

Bronchiolitis obliterans (popcorn lung) is a condition of scarred air sacs in the lungs that thicken and narrow the air passageways. It causes a number of symptoms (coughing, wheezing, and shortness of breath) that are similar to chronic obstructive pulmonary disease (COPD). Although a rare, chronic disease, popcorn lung becomes worse over time eventually leading to respiratory failure. 

Popcorn lung was brought to the public’s attention in 2000 when public health authorities learned of workers at a Missouri microwave popcorn facility had inhaled excessive and concentrated amounts of diacetyl—a butter flavoring—and were later diagnosed with irreversible lung disease.

A 2012 study provides three case studies of exposure to diacetyl through consuming several daily portions of microwave popcorn. Researchers from the National Institute for Occupational Safety (NIOSH) discovered that long-term exposure of diacetyl had a direct relationship with reduced lung capacity.

Diacetyl

Recognized for both its buttery aroma and flavoring, diacetyl is a natural compound that appears naturally in foods such as butter, yogurt, a variety of cheeses, sour cream, but is also added to numerous foods including microwave popcorn.

In a 2015 report, the U.S. Food and Drug Administration deemed diacetyl to be “generally recognized as safe (GRAS)” as shown by centuries of human exposure to its natural presence in foods without any dire health consequences. However, in animal toxicology studies, heated butter flavoring damaged cells that line the airways of mice.

In the case of workers at microwave popcorn facilities across the Midwest, NIOSH studies found that mixers who worked with diacetyl and heated soybean oil for more than a year were exposed to higher levels of diacetyl fumes and experienced more shortness of breath than workers employed for less than 12 months or who worked elsewhere in the plant.

Perfluorinated Compounds (PFCs)

Similar to PFAS, perfluorinated compounds such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA or C8) are used in several consumer products including water-proof textiles, nonstick cookware, lubricants, grease and water-proof coating for food packing, and microwave popcorn bags. And like PFAS, these chemicals exist in the environment and appear in blood samples in humans.

Research studies using PFOA on rats resulted in liver, testicular, and pancreatic cancers, but studies in humans have not been statistically significant. However, a link appeared with levels of PFOA in blood serum and kidney cancer and testicular cancer in chemical plant workers where PFOA was produced, and also in persons who lived near the facility.

In 2001, residents within living distance of the plant filed a class-action lawsuit, suing the company for groundwater contamination. The court appointed three epidemiologists to study whether PFOA had any role in contributing numerous health issues. They concluded that PFOA most likely had played a role in contributing to health problems.

From 2011-2012, four reports were presented to the court that PFOA had possibly been the cause of six cases of kidney cancer, testicular cancer, ulcerative colitis, thyroid disease, hypercholesterolemia, and pregnancy-induced hypertension.

By 2002, PFOS were phased out both in production and use. Manufacturers in the United States terminated PFOA emissions and content in products by the end of 2015. Despite the phasing out and cessation in the U.S. and Europe, it is unclear whether production has moved to Asia.

A 2019 study analyzed seven popcorn corn bags for PFOA and PFOS concentrations and compared to those between 2005 and 2018, researchers found two of the microwave popcorn bags were above the accepted limit while the remaining five were below the limit of detection.

A Word From Verywell

Although microwave popcorn no longer appears to be damaging to your health due to the removal of diacetyl and other chemicals, consumers should be aware that some substances are still used in the packaging.

In addition, many of the ingredients used (emulsifiers, trans fats, and artificial flavoring) are not optimal for nutrition or health. If popcorn is the snack of choice, follow the guidelines of the American Heart Association to make your own healthy version.

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