Popcorn Lung Risks May Extend to Alternative Butter Flavorings: Study

Amid concerns about a deadly lung disease commonly known as “popcorn lung”, the food industry previously moved away from the use of the chemical diacetyl as a butter flavor additive for microwave popcorn. However, new research suggests that the replacement may have risks of its own.  

In a study published in the December 2013 issue of the medical journal Food and Chemical Toxicology, researchers warn that alternatives to diacetyle used to provide butter flavor may be just as dangerous.

Popcorn lung involves scarring and inflammation of small airways, known as bronchioles, leading to diminished lung capacity and breathing problems. The disease is irreversible and severe cases may require lung transplants and can lead to death.

Scientifically known as bronchiolitis obliterans, the severe respiratory condition became known as popcorn lung because of its prevalence among workers in the microwave popcorn and flavoring chemical industries.

Diacetyl was used for years to give microwave popcorn its buttery smell before it was linked to a risk of popcorn lung. Although it is still used as a food additive in some other industries, diacetyl has been replaced by popcorn manufacturers.

Now the same laboratory that first raised concerns that diacetyl may be dangerous for workers in factors where microwave popcorn or the flavor additive are manufactured, indicates that alternative butter flavorings may also cause popcorn lung.

Replacements Structurally Similar to Diacetyl

The study looks at the chemicals 2,3-pentanedione, 2,3-hexanedione, 3,4-hexanedione and 2,3-heptanedione, which have been put forward as alternatives for diacetyl. Researchers found that the chemicals are structurally similar to diacetyl, and that they appear to cause similar allergic skin reactions, which were the first sign for researchers that there was a problem with diacetyl back in 2002.

The concentrations of exposure that led to the hypersensitivity reactions were similar to the levels of diacetyl that led to the same reactions.

“These results demonstrate the potential for development of hypersensitivity responses to these proposed alternative butter flavorings and raise concern about the use of structurally similar replacement chemicals,” the researchers concluded. The study does not say how widely the food industry uses these chemicals.

The findings are similar to those of an August 2012 study published in the American Journal of Pathology, that warned that 2,3-pentanedione, also tested in this study, could be just as likely to cause popcorn lung as diacetyl.

More than 300 popcorn lung lawsuits have been filed nationwide, alleging that inadequate warnings were provided about the risk of lung problems from diacetyl exposure. While most of the complaints have been filed by employees of popcorn manufacturers or flavoring manufacturers, a number of popcorn consumers have also been diagnosed with the disease and have filed lawsuits against companies that manufactured or used the flavoring.