Scientists are beginning to understand one of life's enduring mysteries - Diacetyl (DA) is a chemical that imparts the buttery flavour in microwave popcorn. It has a disease named after it because many microwave popcorn factory workers exposed to it have developed a lung condition called diacetyl-induced bronchiolitis obliterans or "Popcorn worker's lung".
New evidence found that DA intensifies the damaging effects of an abnormal brain protein linked to Alzheimer's disease.
A new study raises concern about chronic exposure of workers in industry to the food flavoring ingredient used to produce the distinctive buttery flavor and aroma of microwave popcorn, margarines, snack foods, candy, baked goods, pet foods and other products. The study appears in ACS' journal Chemical Research in Toxicology
Robert Vince and colleagues Swati More and Ashish Vartak explain that DA has been the focus of much research recently because it is linked to respiratory and other problems in workers at microwave popcorn and food-flavoring factories. DA gives microwave popcorn its distinctive buttery taste and aroma.
DA also forms naturally in fermented beverages such as beer, and gives some chardonnay wines a buttery taste. Vince's team realized that DA has an architecture similar to a substance that makes beta-amyloid proteins clump together in the brain -- clumping being a hallmark of Alzheimer's disease. So they tested whether DA also could clump those proteins.
DA did increase the level of beta-amyloid clumping. At real-world occupational exposure levels, DA also enhanced beta-amyloid's toxic effects on nerve cells growing in the laboratory. Other lab experiments showed that DA easily penetrated the so-called "blood-brain barrier," which keeps many harmful substances from entering the brain.
DA also stopped a protective protein called glyoxalase I from safeguarding nerve cells. "In light of the chronic exposure of industry workers to DA, this study raises the troubling possibility of long-term neurological toxicity mediated by DA," say the researchers.
David Michaels, of the George Washington University School of Public Health, said the finding is another reason for federal regulators to crack down on diacetyl exposure by workers and consumers.
"This letter is a red flag, suggesting that exposure to food flavor chemicals is not just killing workers, but may also be causing disease in people exposed to food flavor chemicals in their kitchens," Michaels wrote on his public health policy blog.
April McCarthy is a community journalist playing an active role reporting and analyzing world events to advance our health and eco-friendly initiatives.