Researchers at Johns Hopkins University have found that high levels of iron in certain areas of the brain indicate a risk of cognitive impairment, or dementia, years before the first symptoms appear. The respective study is published in the journal Radiology.

As part of the long-term BIOCARD project, researchers monitored the elderly who did not have signs of dementia at the beginning of their work. Using quantitative magnetic resonance imaging (MRI), they assessed iron levels in 10 key areas of the brain. The participants underwent regular cognitive tests for almost eight years.

At the end of the monitoring, 27 people had developed mild cognitive impairment, or dementia. The analysis showed that excess iron also predicts the development of cognitive problems at the beginning of the study. The risk was almost twice as high in people with high levels of iron in their brain. The effect was particularly pronounced in those who already had amyloid plaques, a hallmark of Alzheimer’s disease.

According to senior author Xu Li, an associate professor at Johns Hopkins University School of Medicine, iron may serve as an early biomarker for neurodegeneration. Excess iron promotes inflammation and cell damage, and enhances the effects of other pathological proteins.

The researchers say their study opens up the possibility of using brain iron measurements as an early marker of risk and a potential therapeutic target. In the future, the team plans to expand this work to include more diverse patient groups, and examine the interaction of iron with other pathological processes, including amyloid and tau protein accumulation.