A new study revealed tiny magnetite particles caused by air pollution have found a way into human brain tissue — and may even be linked to Alzheimer’s disease.
The study from Lancaster University looked at brain samples from 37 people who lived in either Mexico City where there are high levels of air pollution, or Manchester, England.
It found that many of the samples with high traces of magnetite, the mineral form of iron, were found in two groups: people from Mexico’s capital under 40 years of age and had been exposed to high amounts of air pollution and people from the northern English city who are over 65 years of age with moderate or severe Alzheimer’s at the time of their death.
While magnetite is known to form naturally in the brain, the particles are crystal-shaped, while the magnetite found in the study samples were large, spherical and linked to pollution.
In fact, the ratio of particles linked to pollution to those naturally occurring found in the samples was 100 to one.
Magnetite is believed to be toxic because of its ability to react and release free radicals that damage and kill brain cells.
Dr. Rhonna Shatz, director of UC Health’s memory disorders clinic, has spent 25 years researching Alzheimer’s.
Currently, she is focusing on the inflammations caused by the environment and to see whether those inflammations could lead to diseases like Alzheimer’s.
Her study is showing iron-containing nanoparticles passing into the brain externally.
“External means that we already know there’s iron produced in the body and it forms sub particles that were found in the brain. This one links it to external forces in the environment,” Shatz said.
The link between pollution and Alzheimer’s has not been fully investigated, and further steps must be taken to strengthen it, according to Shatz.
Though, she said research surrounding the possible link is intriguing.
“There have been several researchers who identified that people who live in areas with concentrations of a lot of air pollution have the inflammatory genetic markers at a higher rate in their brain than people who don’t live in these areas,” said Shatz.
Through autopsy studies, researchers found a relationship between high concentrations of air pollution and the presence of magnetic particles, such as magnetite, according to Shatz.
At the time these studies were done, just a couple years back, they hadn’t directly looked at external sources, but they saw a possible link, according to Shatz.
“Now this [new study] kind of provides the evidence that environmental sources of these iron particles can insight inflammatory markers in the brain and lead to the early changes that can ultimately lead to Alzheimer’s,” said Shatz.
Ultimately, the cause of Alzheimer’s cannot be directly attributed to any one factor, according to Shatz.
“I think in general there’s a feeling that Alzheimer’s is really many different things—that its underpinnings are related to anything that could cause inflammation,” said Shatz.
These could include high body weight, chronic inflammatory illnesses or exposure to air pollution particles such as magnetite.
Though the brain can compensate for inflammatory changes for long periods of time, eventually a process will be set in motion that leads to progressive illnesses, according to Shatz.