New research from King’s College London has resulted in a blood-based test that could be used to predict the risk of Alzheimer’s disease up to 3.5 years earlier than conventional clinical diagnosis.

The study, published in the journal Brain, supports the idea that components in the human blood can modulate the formation of new brain cells, a process termed neurogenesis.

Neurogenesis occurs in an important part of the brain called the hippocampus that is involved in learning and memory.

Blood samples collected over the years from research participants who subsequently deteriorated and developed Alzheimer’s disease indicated an increased conversion of immature brain cells to hippocampal neurons.

While the underlying reasons for this increased neurogenesis remain unclear, the researchers theorize that it may be an early compensating mechanism for the loss of brain cells experienced by those developing Alzheimer’s disease.

In this study, the researchers aimed to understand the process of neurogenesis and to use changes related to this process to predict Alzheimer’s disease.

As a result, they found the first evidence in humans that the body’s circulatory system can have an effect on the brain’s ability to form new cells.

When the researchers examined blood samples collected furthest away from when the participants were diagnosed with Alzheimer’s disease, they found that the changes in neurogenesis occurred 3.5 years prior to a clinical diagnosis.

This finding is extremely important, potentially allowing doctors to predict the onset of Alzheimer’s much earlier and using a non-invasive approach.

This could complement other blood-based biomarkers related to the classical signs of the disease, such as the accumulation of amyloid and tau.

It is now essential to validate these findings using a bigger and more diverse group of people.