Harmful Impact: Moderate Coffee Roasting Compound and Mild Flu Potentially Harm Lung Health

A recent study conducted by researchers at the University of Rochester Medical Center has raised concerns about the safety of diacetyl, a flavoring chemical found in many foods and beverages, for coffee roasters. The study, published in the American Journal of Physiology - Lung Cellular and Molecular Physiology, suggests that short-term exposures to diacetyl can cause significant lung damage when paired with a second insult, such as the flu.

The research, led by Michael A. O'Reilly, Ph.D., professor of Pediatrics, and So-Young Kim, M.S., a technician in the McGraw lab, found that mice exposed to diacetyl for one hour a day over five consecutive days, similar to what coffee roasters encounter at work, followed by exposure to influenza A, showed significant impairment of lung function and airway repair compared to controls. Regardless of the order of exposure, the lungs of the mice were unable to fully heal, indicating that exposure to both chemical and virus leads to abnormal airway repair.

The study's findings could have implications for people who are occupationally exposed to diacetyl, such as coffee roasters. The team plans to collaborate with local coffee roasters to spread awareness of the risks of diacetyl exposure, assess existing exposure mitigation procedures, and survey workers for lung disease symptoms.

The study was supported by a pilot grant from the University of Rochester Medical Center Environmental Health Science Center and a Career Development Award from the UR Clinical and Translational Science Institute. It was also supported by the University of Rochester CTSA award number KL2 TR001999 from the National Center for Advancing Translational Sciences, and the National Institute of Environmental Health Sciences under grant number P30 ES001247.

This project is not the first to link diacetyl to lung disease. In the early 2000s, diacetyl was first linked to a lung disease among former microwave-popcorn factory workers. Similar lung disease has been seen among coffee roasters who inhale large concentrations of diacetyl.

McGraw's team is currently conducting a study in mice to determine how long after a flu infection it is safe to be exposed to diacetyl, which could help inform safe return-to-work practices for coffee roasters. B. Paige Lawrence, Ph.D., chair and professor of Environmental Medicine, and Andrew M. Dylag, M.D., associate professor of Pediatrics, are also authors of the study. Min Yee, a technical associate in the O'Reilly lab, is another author of the study.

The study conducted by McGraw's team shows that common environmental exposures, including seemingly harmless ones, can have serious impacts on lung function and long-term respiratory health when combined. The team hopes that their findings will lead to increased awareness and safer working conditions for those occupationally exposed to diacetyl.

Harmful Impact: Moderate Coffee Roasting Compound and Mild Flu Potentially Harm Lung Health