Is Microwave Popcorn Bad For You? Cancer & Butter Flavor Risks

Don’t eat that, it causes cancer!

That’s a phrase we have all become numb to, at least to some extent. Everyday we are told something in our diet is unhealthy or dangerous and we need to stop eating it.

Eventually, it feels like there’s nothing left to eat!

Though in the case of popcorn, there are a lot of good reasons to heed the warnings.

Yes, there are exaggerated claims out there that popcorn can kill or cripple you. Setting the myths and unproven aside, the fact is that many microwave popcorn bags are lined with concerning chemicals. Even the “butter flavoring” you eat could be a chemical which has reportedly been linked to lung damage and other unhealthy side effects.

Why shouldn’t you eat it?

There’s no denying that fresh-popped tastes way better, however there are reasons to avoid many types which are made in the microwave.

You will want to avoid these 7 things which are bad for you or at the very least, give cause for concern.

1. Bags with PFOA

Short for perfluorooctanoic acid, this chemical is used in the manufacturing of some non-stick cookware brands.

Is Teflon safe? It’s not PFOA but rather PTFE (polytetrafluoroethylene) which makes the coating non-stick. It’s believed to normally be safe, until it begins breaking down at temperatures above 500 °F (260 °C).

Teflon coatings contain PTFE but when it comes to PFOA, DuPont stopped using it in their manufacturing process from 2013 onward. 3M phased it out even earlier.

Guess who continued using PFOA?

Microwave popcorn manufacturers.

Many of the brands used it to line the inside of their bags, to prevent the kernels and “butter flavor” from sticking. Right up until it was banned in 2016.

While you won’t find PFOA today, other dubious non-stick liners are being used which give cause for concern. If you want to make it in the microwave, your best bet is to get this brand on Amazon which uses no chemical or plastic coatings.

Will microwave popcorn give you cancer?

Exposure to PFOA has been linked to testicular, pancreatic, and liver cancers in animal research. It’s unknown as to how much of this chemical humans ingested during the decades it was used to line popcorn bags and what health effects may have resulted. No one has proof or evidence that this exposure caused cancer in humans.

The below chart is NOT related to popcorn.

It’s from statistics compiled by Cancer Research UK as to how many people in that country are diagnosed with cancer by age, irrelevant of the cause, for all types excluding melanoma. (1)

It’s a good visual to show you how this disease is slow progressing. A cell mutation you had as a teenager may not manifest itself as a detectable tumor until decades later. For example, brain tumors caused by radiation exposure can take 10 to 30 years to form. (2)

Being that tumors take years and sometimes even decades until they’re detected, it’s no surprise that finding the root cause for any given cancer case is often impossible.

Going back to the topic of PFOA exposure from bags of popcorn, no one can claim the historical exposure from was safe or unsafe. Nor can anyone claim PFOA is a definite cause of cancer in humans.

However looking elsewhere, there is plenty of evidence to suggest this chemical might be carcinogenic.

There was a study involving 32,254 people who lived near a chemical plant in Ohio that manufactured PFOA and the conclusion was (3):

“PFOA exposure was associated with kidney and testicular cancer in this population.”

The World Health Organization classifies PFOA under Group 2B carcinogens, which corresponds with “possibly carcinogenic to humans.” (4)

We are told by the industry that the amounts which ended up in the popped corn are safe and do not cause cancer. Perhaps that’s true but why would you want to intentionally eat this bad chemical, even if it’s in small and “safe” amounts? (5)

After the ban, is it possible you are still being exposed?

Even though food packaging and wrappers are supposed to no longer use PFOA, it seems reasonable to question what’s currently being used.

PFOA and other chemicals which are molecularly similar, yet strangely legal, typically come from China, who is the biggest manufacturer of them. (6)

Although a study hasn’t been done on today’s popcorn packaging, scientists from the EWG and various universities published a study in 2017 on fast food wrappers.

From McDonald’s and Burger King, to those perceived as having higher quality food, like Chipotle, Panera, and Starbucks, were included. In total, it was 327 wrappers from 27 different restaurant chains.

Reportedly, those specific places all tested positive for PFCs, which is the class of chemicals that includes PFOA and similar compounds. Overall, 40% of the fast food chains tested positive for fluorine, which is the marker for this class of chemicals.

Now that fluorine doesn’t automatically mean PFCs were in them but it’s a very good clue as to their likely presence.

Furthermore, some samples were positive for traces of PFOA when that was tested for specifically. If it wasn’t intentionally added, they speculated it might be coming from recycled papers that were used to make the wrappers and boxes.

For that reason you may want to avoid microwavable bags made from recycled paper. (7)

2. Bags with PFOS

Is PFOA-free popcorn healthier? Maybe not.

A similar compound is PFOS, which is short for perfluorooctane sulfonate. It too has been used for many years in wrappers, pizza box linings, and yes, those bags you microwave. Its main purpose is to keep the oils and liquids inside from passing through the paper. In other words, it’s a grease barrier.

It was initially dubbed as a “next generation” PFC (perfluorinated) compound to replace PFOA.

As is often the case with these things, sometimes the replacement is just as bad or perhaps even worse.

In 2016 the FDA also revoked the approval of PFOS for food wrappings and barriers. Just a bit late to the game, considering that the European Union banned PFOS in 2008. (8)

Today no one is supposed to be using PFOS or PFOA, though you should remain wary of old stocks for sale at discount stores, as well as bags made from recycled paper.

Today almost all brands advertise PFOA-free and PFOS-free, but that’s not the same as chemical free microwave popcorn. There are nearly 100 other PFC compounds which are not banned. The truth is that many popcorns use similar chemicals which are legal, yet they have limited human safety data on them.

3. The “butter flavor” diacetyl

What is butter flavoring?

Normally, butter flavoring is not the same as butter extract. It does not contain dairy since it’s not made from cow milk.

This ambiguous ingredient is seen on most brands of microwavable butter-flavored popcorn. Movie theaters also use it. This flavoring can be made out of diacetyl (butane-2,3-dione) which is a natural byproduct created during the fermentation of some bacteria. This compound, along with acetoin, give butter its taste. Gluten free and vegan, since it’s technically dairy free.

While it is naturally occurring in some foods, only small amounts are present. Since diacetyl is the main flavor compound in butter, snack manufacturers have been synthesizing it and using as a substitute for the real thing.

Why it’s toxic

Recent lab research has found that diacetyl may increase the formation of beta-amyloid plaques in the brain, which are a telltale sign of Alzheimer’s disease. However that risk remains unproven and is secondary to a more established risk this chemical carries. (9)

When heated and aerated, diacetyl can cause permanent damage to the lungs and airways. Nicknamed “popcorn lung” and officially named bronchiolitis obliterans, breathing in diacetyl vapors can obstruct the smallest airways of the lungs (bronchioles) by causing them to be inflamed.

Multimillion dollar lawsuits over microwave popcorn are not a myth.

Wayne Watson, a Colorado man who ate two bags daily as a snack for a number of years, was awarded a $7 million settlement for the “popcorn lung” he developed. 20% was paid by the grocery stores Kroger and Dillon Foods that sold it to him, while the other 80% was paid by Gilster-Mary Lee Corporation, which is a private-label manufacturer for microwave popcorn. (10)

While eating two bags daily may sound ridiculous, remember that it’s an otherwise relatively healthy snack, at least in terms of calories and fat. That’s why the lightly or non-buttered versions are popular for dieting. SkinnyPop even markets it as “guilt-free” snack.

Eric Peoples, an employee at a Missouri manufacturing plant, won $20 million for lung damage he endured while working there. A few years later in 2010 there was a similar verdict for a Chicago-area man of $30 million. (11)

ConAgra, who is the maker of Orville Redenbacher and Act II popcorn, was accused in another lawsuit of:

“…bronchiolitis obliterans, severe and progressive damage to the respiratory system, extreme shortness of breath and reduced life expectancy…”

But this case was a win for ConAgra because it ended up being dismissed. It was said the plaintiff’s “statements are not based on sufficient facts or data.” (12)

Given the history of litigation, it’s no surprise those brands began phasing it out over a decade ago. Even years before the biggest settlements, in 2007 it was announced that diacetyl would no longer be used.

Diacetyl-free popcorn brands now include Act II, Orville Redenbacher, Pop Secret, Jolly Time, and Pop Weaver, who also makes the Trail’s End brand that Boy Scouts sell.

However this compound has never been outlawed, nor has it officially been classified as being toxic when used in food.

Some companies still use diacetyl. Even for those who don’t, they still might contain small amounts.

Even your non-GMO corn made with real organic butter will contain a little diacetyl.

Per the FAQ section on Newman’s Own website (13):

“Diacetyl is not added to any of the Newman’s Own varieties of microwave popcorn. However, it is a naturally occurring substance found in butter in miniscule amounts.”

Granted, the tiny amounts naturally present pale in comparison. Still though, bombarding butter with microwaves is quite different than spreading it on a lukewarm slice of bread.

Setting aside the Alzheimer’s concern for a moment, the reason diacetyl is dangerous is because when it’s in the form of a gas, it enters your lungs.

Many speculate it might be similar to the mechanism of vitamin E acetate in some vaping products; the substance burns the lungs.

Unless you are eating or cooking with butter that is actively boiling or steaming, that shouldn’t be happening with other foods containing it, that are served at lower temperatures.

For today’s microwave bags made with real butter, the problem is that you open them and your face is engulfed in a cloud of steam. It continues steaming as it cools down. So your lungs can still be exposed to diacetyl, albeit in much lower amounts.

This is why it’s probably safer to drizzle melted butter or vegan margarine on after popping, rather than have pre-coated kernels with it that are heated to extreme temperatures and create steam in your kitchen. Those with asthma, COPD, and other lung diseases should be even more cognizant of this danger.

If diacetyl has been mostly phased out, what’s the new “butter flavor” made of and is it safe?

That brings us to the next concerning compound…

4. The “butter flavor” acetylpropionyl

You won’t even know whether popcorn is made with this. FDA labeling regulations don’t require specific flavors to be identified by name.

Since it’s possible to find acetylpropionyl and diacetyl in nature, manufacturers can list both of these chemicals as “natural butter flavor” or simply “natural flavoring.” They don’t even need to use the word artificial. Even USDA certified organic microwave popcorn can use them.

Many people don’t realize that the USDA’s National Organic Program (NOP) allows for flavors to be used that are non-organic.

Technically known as 2,3-pentanedione, acetylpropionyl is molecularly very similar to butane-2,3-dione (diacetyl).

Acetylpropionyl, which is sometimes written acetyl propionyl, can be found in minuscule amounts in peaches and yogurt, but that’s far different than the concentrated sources which are used to trick your tongue into thinking you’re tasting butter. As with its predecessor, it’s also vegan and gluten free. (14)

Toxicity reports on acetylpropionyl were not even published until 2010. The National Institute for Occupational Safety and Health (NIOSH) says in a peer-reviewed paper that:

“…acute inhalation exposures to 2,3-pentanedione cause airway epithelial damage that is similar to diacetyl in laboratory studies (Hubbs et al. 2012).”

More specifically, a National Institute of Environmental Health Sciences (NIEHS) rat study found that:

“2,3-pentanedione caused proliferation of fibrous connective tissue in the walls of airways and projections of fibrous connective tissue sometimes extended into the air passageways (Morgan et al. 2012a). Preliminary data suggest that repeated exposures to either 2,3-pentanedione or diacetyl can cause airway fibrosis in rats (Morgan et al. 2012b).”

Oh but wait, lung fibrosis might actually be the good news, relatively speaking. Because the next sounds even scarier:

“…changes in gene expression were noted in the brain (Hubbs et al. 2012).”

So that’s on research that was done for occupational exposure to this chemical. In terms of food safety and your exposure as a consumer eating it, there seems to be limited data out there. Remember the NIOSH said that toxicity reports weren’t even published until 2010 and that’s despite that it was already in widespread use as a diacetyl butter flavor replacement in popcorn. (15)

5. Unhealthy oils

This is last and actually least, because even the bad ones like palm oil and those which are partially hydrogenated (trans fat) might be less concerning than some of the other reasons listed.

Still, less bad doesn’t make it good for you.

Because of the intense heat of the microwave, you actually don’t want oils that would otherwise be healthy at room temperature, like flax, walnut, and unrefined oils. Those all have low smoke points so when they are heated, they oxidize and create dangerous compounds that actually harm you.

Refined versions of coconut, olive, and sunflower all have some of the highest smoke points, at 450°F and above. That benefit should trump others like omega 3 content, which will just get damaged during the microwaving.

6. Excessive sodium

Again, something much less concerning than the PFOA-lined bags and the diacetyl butter flavoring. But you still want to pay attention to how much salt they add.

With how much we have elsewhere in our Western diet, ideally you should go with salt-free popcorn. Though understandably, this may be weekend treat and if salted popcorn is your indulgence, it certainly isn’t the worst thing you could be eating.

The American Heart Association advises no more than 1,500 mg of sodium per day.

To give you an idea of how much sodium is in the most popular brands…

Ignoring the other potential drawbacks, the majority of these have a reasonable calorie count but an unreasonable amount of salt.

7. TBHQ “for freshness”

You may see that phrase listed on the ingredients label. TBHQ stands for tertiary butylhydroquinone. It’s a food preservative, mainly for oils and fats.

Despite what Food Babe may claim, it’s not “created from butane” (lighter fluid) though it does contain a butyl moiety, something else you probably don’t want to eat.

It’s not approved in Japan. In the United States, it’s allowed in concentrations of up to 0.02% of oils. (16) (17)

There is no reason to believe it causes cancer, though “vision disturbances” have been reported by people exposed to this chemical. In cultured human cells, single strand DNA breaks have been observed which would definitely not be good for you.

In animals, side effects seen have included enlarged livers, convulsions, and medullary paralysis, which is when your reathing and vital functions stop.

On the flip side, those are case reports and studies based on high amounts. There’s no evidence to suggest that the amount of TBHQ in popcorn is dangerous or even causes side effects. Though many people would prefer to simply avoid this unnecessarily added chemical “for freshness.” (18)

What is the healthiest microwave popcorn?

The best brands to buy will be those without “butter flavor” since they might contain the potentially dangerous diacetyl and/or acetylpropionyl. Avoid bags coated with PFOA, PFOS, or any perfluorinated compound (PFC). Basically, you want a paper bag filled with organic corn kernels and nothing else.

It’s healthier to add your own butter flavoring after popping. That way, you don’t have the vapors of diacetyl or acetylpropionyl. Remember that small amounts of diacetyl are in dairy products so if you’re using real butter, it’s best to melt separately at lower temperature, rather than zapping it for 2-3 minutes and turning it into a gaseous vapor.

What we recommend is flavoring with coconut oil. It gives you that buttery sensation with an ample of amount of medium chain triglycerides (MCT oil) that’s digested in a different manner than the long chain fatty acids you get with butter and olive oil.

Fat is technically tasteless, as it’s the texture of the triglycerides on your tongue that you enjoy so much. Yes, butter does have a flavor, but it’s not coming from the fat. It’s the flavor molecules which make up less than 1% of the volume.

You may not yet know it yet, but it’s less of the taste and more of the texture you crave. Coconut oil will give that to you.

Currently the only brand we are aware of that offers the perfect snack for movie night is Quinn. What they call Pure Pop bags are made of just plain paper without any chemical or plastic coatings.

On Amazon you can get the “Just Sea Salt” flavor and then jazz it up as you please, with whatever flavoring you fancy. It’s vegan.

If you insist on not hassling with DIY flavors, that’s completely understandable too.

They do have a version made with dried rBGH-free butter from real cows. It’s not that fake “butter flavoring.” Before eating though, make sure you allow for it to cool a couple minutes so you don’t breathe in the steaming butter. You can also buy Quinn butter and sea salt on Amazon.