A new study released by the University of Montana showed that symptoms of Alzheimer’s disease were present in those who had been exposed to air pollution from a young age—most disturbing was the finding that even babies showed signs of Alzheimer’s in the brain, suggesting that the disease begins much earlier than previously thought, and that environmental factors like air pollution could play a role.
The team looked at the autopsies of 203 Mexico City residents between the ages of 11 months and 40 years old. They measured the build-up of two proteins that accumulate in Alzheimer’s patients: tau and beta-amyloid. When they compared the levels of protein of the Mexico City residents to people not exposed to air pollution, they saw that the protein levels were above normal in 99.5 percent of participants.
With a population of 24 million, Mexico City has higher concentrations of fine particulate matter and ozone pollution above what the U.S. Environmental Protection Agency has deemed as standard. The kind of pollution caused by fine particulate matter, a particle 30 times smaller than the diameter of human hair, is a hazy, thick smog that can make it difficult to breathe.
Lead researcher Lillian Calderon-Garciduenes has been conducting research on the neurodegenerative effects of pollution for years. While this study doesn’t prove that pollution causes Alzheimer’s, it does show a correlation that Calderon-Garciduenes has found in other studies, including a similar study on dogs in Mexico City.
There was only one infant included in the study, so it’s hard to say when signs of Alzheimer’s might first show up in individuals living in polluted areas. But young adults in the study also showed higher levels of the proteins associated with Alzheimer’s.
Study authors said the way we diagnose Alzheimer’s should be defined differently based on how the brain changes before symptoms of Alzheimer’s begin, and recommendations for how to prevent Alzheimer’s should start much earlier.
“We recommend the concept of preclinical Alzheimer’s be revised and emphasize the need to define pediatric environmental, nutritional, metabolic and genetic risk factor interactions of paramount importance to prevent Alzheimer’s,” wrote the authors. “Alzheimer’s evolving from childhood is threatening the wellbeing of our children and future generations.”
This study was published in the journal Environmental Research.