Bronchiolitis Obliterans Lung Disease Linked to Diacetyl: Study

A group of North Carolina researchers believe they may have found a link between the food additive diacetyl and a rare respiratory condition known as bronchiolitis obliterans. 

The findings were published last month in the Journal of Agricultural and Food Chemistry, marking the first study to find a likely mechanism for why exposure to the buttery-smelling chemical can cause bronciolitis obliterans, which is commonly referred to as “popcorn lung disease” due to the number of people stricken with the ailment who worked at microwave popcorn factories, where the chemical is used to provide artificial butter flavoring.

Researchers from the National Institute of Environmental Health Sciences and RTI International, both in North Carolina, subjected the chemical diacetyl to a battery of tests, and found that it could alter certain proteins inside of human cells in certain conditions. The researchers said follow-up studies are already underway to see how the body’s immune system responds to the altered cells.

This latest discovery comes as California declared that it will be the first state to put in place regulations to protect food production workers from exposure to diacetyl. The state’s new safety rules will affect any facility that makes products using concentrations of diacetyl of 1% or higher. The flavoring is no longer in use in microwave popcorn, but is still used in other foods and occurs naturally in butter and some alcoholic beverages. 

Bronchiolitis obliterans is characterized by the scarring and inflammation of small airways, known as bronchioles, which leads 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 bronchiolitis obliterans lawsuits have been filed nationwide, with most of those coming from employees of popcorn manufacturers. However, some heavy consumers of popcorn have also been diagnosed with the lung disease and have filed lawsuits against companies that manufactured or used the flavoring.