Blood Test Predicts Alzheimer’s 20 Years Before Symptoms Appear

A blood test measuring phosphorylated tau protein (p-tau217) can predict Alzheimer’s disease up to 20 years before symptoms appear with about 90-96% accuracy, matching the performance of more invasive tests like cerebrospinal fluid analysis and brain imaging. This advance offers a practical, less invasive tool for early detection, enabling individuals to take preventive measures and participate in clinical trials long before cognitive decline begins. Wider availability of such blood tests could transform Alzheimer’s risk assessment and monitoring in routine healthcare settings[1][2][4][5].