Magnetic Particles may be the Invisible Cause of Alzheimer’s Disease

By Chris Melore

A silent killer may be floating through the air you’re breathing right now. It’s no secret that air pollution is bad for your health, but a new study is explaining how certain magnetic materials may play a key role in the development of Alzheimer’s disease. Researchers in Australia have found that magnetite, a common air pollutant, appears to be a potential trigger for the disease.

Alzheimer’s, a debilitating condition leading to memory loss, cognitive decline, and decreased quality of life, affects millions worldwide and is a major cause of death among the elderly. The research, spearheaded by Associate Professors Cindy Gunawan and Kristine McGrath from the University of Technology Sydney, notes that magnetite is a magnetic iron oxide compound.

Results discovered higher concentrations in the brains of those with Alzheimer’s, with the particles originating from sources such as vehicle exhaust, coal-fired power stations, and even the wear and tear of brake pads and engines. The study’s findings suggest that when inhaled, these fine particles can bypass the body’s defenses and directly disrupt the brain, potentially leading to Alzheimer’s.

“Fewer than 1% of Alzheimer’s cases are inherited, so it is likely that the environment and lifestyle play a key role in the development of the disease,” explains Associate Professor Gunawan, from the Australian Institute for Microbiology and Infection (AIMI), in a media release. “This is the first study to look at whether the presence of magnetite particles in the brain can indeed lead to signs of Alzheimer’s.”

In the Alzheimer’s affected brain, abnormal levels of the beta-amyloid protein clump together to form plaques (seen in brown). (Credit: National Institute on Aging, NIH. All Rights Reserved.)

The researchers conducted experiments on mice and human neuronal cells in the laboratory, exposing them to iron particles, magnetite, and diesel hydrocarbons over a four-month period. They observed that magnetite exposure led to significant Alzheimer’s disease pathologies, including the loss of neuronal cells in critical brain regions associated with memory and sensory processing, increased formation of amyloid plaques, and behavioral changes indicative of Alzheimer’s.

“Magnetite is a quite common air pollutant. It comes from high-temperature combustion processes like vehicle exhaust, wood fires and coal-fired power stations as well as from brake pad friction and engine wear,” says Associate Professor McGrath from the UTS School of Life Sciences.

“When we inhale air pollutant, these particles of magnetite can enter the brain via the lining of the nasal passage, and from the olfactory bulb, a small structure on the bottom of the brain responsible for processing smells, bypassing the blood-brain barrier.”

These alarming findings indicate that magnetite can induce an immune response, causing inflammation and oxidative stress, which damages cells and is a known contributor to dementia. Notably, the negative effects of magnetite were observed even in healthy mice, suggesting that exposure to this pollutant could be a risk factor for Alzheimer’s disease regardless of an individual’s genetic predisposition.

The study’s authors argue for the inclusion of magnetite particles in air quality safety thresholds and advocate for measures to reduce emissions from vehicles and coal-fired power stations.

The findings are published in the journal Environment International.

Top photo by Pétrin Express from Unsplash