Dementia affects more than 57 million people around the world and is one of the biggest health challenges of an ageing population.
It causes a gradual decline in memory, thinking, reasoning, and the ability to carry out everyday activities.
Although treatments can help manage symptoms, there is still no cure, making early detection extremely important.
Scientists have been searching for reliable warning signs that appear years before dementia develops.
Finding these early biological markers could help doctors identify people at higher risk and begin lifestyle changes or future treatments before major brain damage occurs.
A research team from Shandong First Medical University and Shandong Academy of Medical Sciences has identified a promising new marker inside the brain. Their study suggests that changes in a structure called the choroid plexus may predict who is more likely to develop dementia later in life.
The choroid plexus is a network of specialised cells found inside the brain’s fluid-filled spaces. Its main job is to produce cerebrospinal fluid, which cushions the brain and spinal cord, delivers nutrients, removes waste products, and helps clear harmful proteins that build up with ageing.
Researchers have suspected that poor removal of proteins such as amyloid-beta plays an important role in Alzheimer’s disease. Because the choroid plexus helps produce the fluid responsible for this cleaning process, the scientists wondered whether changes in this structure might appear before dementia develops.
To investigate this question, the researchers analysed brain scans from more than 45,000 middle-aged and older adults in the UK Biobank. None of the participants had dementia when the study began. The team then followed them for several years to see who later developed cognitive decline or dementia.
They measured both the size of the choroid plexus and the strength of MRI signals that reflect tissue health. They also examined memory, reasoning ability, hospital records, and brain shrinkage, which is a common feature of Alzheimer’s disease.
The study found that people with a larger choroid plexus or lower MRI signal intensity had a much greater chance of developing dementia in the future. The association was especially strong for Alzheimer’s disease. These individuals also showed greater brain shrinkage and worsening thinking abilities over time.
The researchers strengthened their findings by using a genetic technique called Mendelian randomisation. This approach suggested that the relationship may not simply be a coincidence and that changes in the choroid plexus could play a direct role in the disease process.
If future studies confirm these results, doctors may one day use routine brain scans to identify people at high risk years before symptoms appear. Earlier identification could allow earlier monitoring, healthier lifestyle changes, participation in clinical trials, and future treatments aimed at slowing disease progression.
This study provides important evidence that the choroid plexus may become an important biomarker for dementia risk. Its strengths include the very large number of participants, long follow-up period, and advanced genetic analyses.
However, further studies in other populations are still needed before these findings can be used in everyday medical care. The research represents an encouraging step toward earlier diagnosis and a better understanding of how Alzheimer’s disease develops.
If you care about dementia, please read studies about Vitamin B9 deficiency linked to higher dementia risk, and flavonoid-rich foods could help prevent dementia.
For more health information, please see recent studies that cranberries could help boost memory, and how alcohol, coffee and tea intake influence cognitive decline.
