Many studies have already explored how air pollution negatively affects consumers’ health, but a new study conducted by researchers from the University of California Los Angeles has revealed how exposure to emissions can affect brain function.
The study showed that regular exposure to diesel exhaust increases the levels of the protein alpha-synuclein in the brain, which is most commonly linked with Parkinson’s.
“It’s really important to be able to demonstrate whether air pollution is actually the thing that’s causing the effect or whether it’s something else in urban environments,” said researcher Dr. Jeff Bronstein.
The researchers conducted their study on zebrafish because their brains respond similarly to humans’ brains and the team could track their brain activity without harming them. They first examined the fishes’ brain activity to ensure that all functions were being carried out properly, and then they began exposing them to diesel exhaust.
The researchers learned that exposure to the chemicals found in diesel exhaust disrupted a key brain activity known as autophagy. This process is essentially a cleaning of the brain’s proteins that allows older proteins to be broken down while making room for newer, healthier proteins. However, one of the key signs of Parkinson’s is the inability for the brain to properly complete this process, creating a buildup of proteins.
Exposure to the diesel exhaust interfered with the fishes’ ability to go through autophagy and left many of them with an abundance of old or damaged alpha-synuclein proteins. As the older proteins cluster in the brain, it can begin to affect the neurons, which can then alter brain function.
Though they couldn’t carry out this exact experiment on humans, the researchers were able to test the effect of diesel exhaust on human cells, and they noted similar outcomes to the zebrafish. The exposure to chemicals in diesel exhaust made it difficult to regenerate new proteins.
“Overall, this report shows a plausible mechanism of why air pollution may increase the risk for Parkinson’s,” said Dr. Bronstein.