Microwave Popcorn Flavoring Linked to Respiratory Problems: Study

The food additive meant to replace diacetyl during microwave popcorn production, which provides the butter flavoring, may be just as capable of causing severe lung problems, according to new research. 

In a study published this week in the American Journal of Pathology, scientists indicate that the food ingredient 2,3-pentanedione (PD) may be as likely to cause a lung condition known as bronchiolitis obliterans, even though it has largely been introduced in response to concerns about the chemical diacetyl causing the same rare respiratory problems.

The microwave popcorn industry phased out diacetyl after it was linked to an increased risk of bronchiolitis obliterans, which have become commonly known as “popcorn lung” due to the number of microwave popcorn factory workers affected by the ailment.

Researchers from the Health Effects Laboratory at the National Institute for Occupational Safety and Health and West Virginia University exposed rats to both PD and diacetyl for six hours. They found that the rats that inhaled PD suffered similar airway damage as those who were exposed to diacetyl.

The rats showed signs of respiratory epithelial injury in the upper nose, which is believed to be a cause of popcorn lung. The rats nasal tissues were found to be undergoing necrosis, or cell death and there were also signs of neurotoxicity.

The findings suggest that food industry workers who thought they were safe once diacetyl was removed from microwave popcorn manufacturing may be in just as much danger from PD.

Diacetyl was used for years to give microwave popcorn its buttery smell before it was linked to popcorn lung. The microwave popcorn industry turned away from the additive once its links to popcorn lung disease became widely recognized and have used a variety of substitutes to duplicate its effects. However, diacetyl is still used as a food additive in some other industries.

Popcorn lung causes 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.

More than 300 popcorn lung lawsuits have been filed nationwide, with most of those coming from employees of popcorn manufacturers. However, a number of popcorn consumers have also been diagnosed with the disease and have filed lawsuits against companies that manufactured or used the flavoring.