Researchers from the UK and Mexico have revealed the presence of strongly magnetic magnetite nanoparticles in the human brain, with some previous research linking these particles to neurodegenerative diseases like Alzheimer’s. The shape and features of the nanoparticles found in the brain suggested to the scientists that they may have been taken in through an external source, such as air pollution, rather than being formed naturally in the body. The findings are published on Monday 5 September 2016 in the journal Proceedings of the National Academy of Sciences.
Magnetite is an iron mineral with strong magnetic properties and has been shown to occur naturally in small amounts in human tissue, including the brain. Due to their favourable properties, nanoparticles of magnetite are being explored for their potential in biomedicine such as improved drug delivery and in medical imaging. Some questions remain about the potential safety of such nanoparticles in the body and several studies have reported higher levels of magnetite particles in the brains of people with Alzheimer’s.
To explore this further, researchers studied the brains of 29 people aged 3 to 85 years who lived in Mexico City, as well as eight people aged 62 to 92 years from the Brain Bank in Manchester. These brains were collected under the Brains for Dementia Research Scheme, funded by Alzheimer’s Research UK and Alzheimer’s Society and supported by the Medical Research Council.
The researchers used detailed microscopy to examine the mineral content of the brain and study the shape and make-up of magnetite nanoparticles. They found evidence of magnetite nanoparticles in the brain, and based on the properties of the particles they observed, the team concluded that they were more reflective of magnetite nanoparticles found from external sources, such as from air pollution.
Dr David Reynolds, Chief Scientific Officer at Alzheimer’s Research UK, said:
“Little is known about the role of magnetite nanoparticles in the brain and whether their magnetic properties influence brain function. It’s interesting to see further research investigating the presence of this mineral in the brain, but it’s too early to conclude that it may have a causal role in Alzheimer’s disease or any other brain disease.
“We know that air pollution can have a negative impact on certain aspects of human health, but we can’t conclude from this study that magnetite nanoparticles carried in air pollution are harmful to brain health. It’s important to continue to study the impact of lifestyle and environment on brain health, although age and genetic risk factors also play an important role in influencing a person’s risk of Alzheimer’s.”