# Blood test may identify high Alzheimer's risk in healthy adults Researchers can predict cognitive decline within 5-10 years using p-tau217 biomarker. - **Source:** [Fast Company](https://www.fastcompany.com) - **Published:** 2026-07-15 - **Original article:** - **On Brifing:** https://brifing.si/s/8d3439c3-3b6b-47b1-b34d-4d0965f7164d ## New hope for Alzheimer's blood test Scientists discovered that a p-tau217 blood test could predict Alzheimer's symptom development in seemingly healthy older adults within 5-10 years. This test may accelerate drug development by identifying high-risk candidates for clinical trials. However, experts warn it's too early for routine use, emphasizing current limitations in individual prognosis. ## Interpreting test results The study shows individuals with high p-tau217 levels face a 38% risk of cognitive impairment in 5 years, escalating to 78% by 10 years. The test measures a tau protein form correlated with amyloid plaques - Alzheimer's hallmark. Low-level participants demonstrated significantly reduced risk, offering potential reassurance. ## Clinical significance Mass General Brigham researchers analyzed data from 2,684 healthy elderly participants in longitudinal studies since 2004. Findings published in JAMA reveal strong links between blood test results and cognitive decline. The test provides novel insights into amyloid-tau dynamics, advancing understanding of Alzheimer's progression. ## Expert cautions Physicians stress the test isn't yet precise enough for individual predictions. With limited 10-year follow-up data, long-term estimates remain less reliable. Complicating factors like cardiovascular issues may influence dementia risk differently. Currently, the test should only be used in research contexts, not clinical practice. ## Premature patient demand Despite family history concerns, experts strongly discourage early testing. Banner Institute's Langbaum notes predictive value depends on future preventive drug development. Current trials focus on pre-symptomatic treatments, making premature testing clinically irrelevant until effective interventions exist. ## Breakthrough in Alzheimer's fight These findings represent a pivotal advancement in early detection and prevention. Blood biomarkers could revolutionize disease monitoring. However, researchers reiterate that lifestyle factors (nutrition, exercise, sleep) remain the most effective preventive measures against cognitive decline, regardless of test results. ## Sources covering this story - https://www.fastcompany.com/91574131/alzheimers-risk-healthy-people-may-identified-blood-test-study-shows — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._