0210 GMT July 22, 2019
The procedure can detect rogue proteins in the brain thought to cause the devastating condition, express.co.uk reported.
Scientists found that abnormal amounts of the tau molecule — proteins linked to the nervous system — might identify future dementia patients.
An early diagnostic test would mean drugs could be given to ward off the disease and patients could be told to modify their lifestyles.
Smoking, poor diet and a lack of exercise all increase the risk of developing Alzheimer’s.
This comes after news that British scientists believe a test to catch Alzheimer's early could be just a decade away.
The University of Chile study, published in the Journal of Alzheimer’s Disease, said the identification of tau markers in blood could lead to the diagnosis of dementia before symptoms are present and could play a role in developing therapies to help prevent the illness.
Dr. Ricardo Maccioni said: “The use of a tau biomarker could lead to the identification of Alzheimer’s disease pathology before the clinical symptoms are evident, and it could play an essential role in preventive therapies.”