A blood test that can spot if a patient’s brain is ageing faster than the rest of their body could help predict dementia decades before it develops, research suggests.
It means conditions such as Alzheimer’s could be caught and treated in the vital early stages.
A US study found patients whose organs were ageing faster had a higher risk of developing diseases in that organ within 15 years.
Accelerated ageing of the brain and blood vessels was found to be a better predictor of Alzheimer’s progression than the best blood-based biomarker.
Researchers checked levels of almost 5,000 proteins in the blood of 1,398 healthy patients aged 20 to 90 at an Alzheimer’s research centre.
The Stanford University study focused on 11 key organs including the brain, heart, muscles and vascular system.
Researchers flagged all the proteins whose genes were four times more highly activated in one organ compared with others.
They found 858 organ-specific proteins and trained their algorithm to guess a person’s age based on them. The study – published in Nature – revealed almost 20% of patients showed “strongly accelerated age” in one organ, while 1.7% showed ageing in multiple organs.
Accelerated organ ageing is linked to 20-50% higher mortality risk, researchers said.
Study leader Professor Tony Wyss-Coray said: “We can estimate the biological age of an organ in an apparently healthy person.
“That predicts a person’s risk for disease related to that organ. If we can reproduce this finding in 50,000 or 100,000 individuals it will mean that by monitoring the health of individual organs…we might be able to treat people before they get sick.”
Dr Leah Mursaleen of Alzheimer’s Research UK said it could help in treating dementia.
She said: “The diseases that cause dementia can begin in the brain decades before symptoms appear. New treatments on the horizon have only been shown to work in the early stages of Alzheimer’s. The development of more accurate and less invasive methods to detect age-related disease, including the earliest signs of Alzheimer’s, will take us closer to curing them.”