In a new study with mice, researchers found exposure to traffic-related air pollution led to memory loss and cognitive decline and triggered neurological pathways associated with the onset of Alzheimer’s disease.
“The link between air pollution and Alzheimer’s disease is concerning, as the prevalence of toxicants in ambient air is not just on the rise globally, but also hitting close to home here in Irvine,” says corresponding and senior author Masashi Kitazawa, associate professor of environmental and occupational health in the program in public health at the University of California, Irvine. “Our findings are just one example of what particulate matter can do to brain function.”
Alzheimer’s disease is the most common cause of dementia among the elderly and is a growing public health crisis in the US as well as several other countries. Despite extensive research on all aspects of Alzheimer’s disease, its exact origins remain elusive. Although genetic predispositions are known to play a prominent role in disease progression, growing bodies of evidence suggest that environmental toxicants, specifically air pollution, may cause the onset of Alzheimer’s disease.
Kitazawa and his team compared mouse models at two ages. Researchers exposed a group of 3- and 9-month-old mouse models to ultrafine particulate matter for 12 weeks via ambient air collected in Irvine. A second group was exposed to purified air. The differing ages were used to determine the potential impact of particulate matter exposure during highly vulnerable life stages: developing youth and the elderly.
The researchers conducted testing related to memory tasks and cognitive function and found that exposure to particulate matter impaired both benchmarks. Notably, they also discovered that their older models (12 months at the time of analysis) showed brain plaque build-up and glial cell activation, which are both known to increase inflammation associated with the onset of Alzheimer’s disease.
“Air pollution is one of the very few prominent, modifiable environmental risk factors in Alzheimer’s disease,” says coauthor Michael Kleinman, adjunct professor of environmental and occupational health in the program in public health. “Public and environmental regulatory agencies need to accelerate efforts to reduce particulate matter levels in order to reduce the risk of Alzheimer’s disease and other serious health conditions.”
“This evidence is alarming, and it’s imperative that we take action to adopt effective and evidence-based regulations, spread awareness on lifestyle changes, and work together to improve our air quality,” Kitazawa adds.
The study appears in the journal Toxicological Sciences. Additional authors are from Nagoya City University; the RIKEN Center for Brain Science in Wako, Japan; and UC Irvine.
The National Institutes of Health and UC Irvine’s MIND’s Women’s Alzheimer’s Movement Women’s Initiative grant funded the work.
Source: UC Irvine