Platelet Activity Blood Test in Middle Age Could Identify Early Alzheimer’s Risk

Early detection of Alzheimer’s disease remains one of the biggest unmet needs in neurology, particularly because the biological changes underlying the disorder begin decades before memory symptoms appear. Now, a new study suggests that a simple midlife blood test for platelet activity could help flag individuals at higher risk long before cognitive decline sets in. The work

The study, co-led by The Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases at UT Health San Antonio (San Antonio, TX, USA) and the New York University Grossman School of Medicine (New York, NY, USA), highlights platelet aggregation, a component of vascular dysfunction, as a possible early indicator of Alzheimer’s-related amyloid and tau buildup in the brain. In the study, researchers analyzed data from dementia-free, middle-aged adults participating in the Framingham Heart Study, one of the longest-running cardiovascular research cohorts.

Using PET and MRI imaging, they investigated how platelet aggregation measured in blood samples correlated with known Alzheimer’s biomarkers. The team used light transmission aggregometry to assess platelet clumping in 382 participants with an average age of 56. They then compared platelet activity with PET imaging of amyloid and tau, the hallmark proteins of Alzheimer’s pathology, as well as MRI findings.

A clear association emerged: individuals whose platelets clumped more strongly also showed higher amyloid and tau burden in specific parts of the brain. This relationship was most apparent among participants whose platelet activity fell at the lower end of the tested range, suggesting an early vulnerability pattern that may precede clinical symptoms by decades. These findings, published in Neurology, support earlier observations in the Framingham cohort, where platelet aggregation independently predicted long-term dementia risk.

By clarifying how platelet-related inflammation connects vascular dysfunction to Alzheimer’s pathology, the study offers a potential blood-based method to identify at-risk individuals years before cognitive changes occur. This approach could ultimately enable preventive therapies that target platelet-mediated inflammation during midlife, a crucial window in the progression of Alzheimer’s disease.

“Our study underscores the need to further clarify the role of platelet-mediated inflammation in brain aging disorders and Alzheimer’s disease and related dementias in particular,” said Jaime Ramos-Cejudo, PhD, assistant professor of psychiatry and neurology at NYU, and first author of the study. “This may open new opportunities for interventions many years before symptoms are evident. We believe platelets may represent a unique bridge between vascular dysfunction and brain inflammation.”

Related Links:
Glenn Biggs Institute
NYU Grossman School of Medicine