Blood Test May Predict Alzheimer's Risk in Healthy Adults

A blood test measuring the protein p-tau217 may predict the likelihood of symptom-free older adults developing Alzheimer's disease within five to 10 years, researchers reported Wednesday. This development could significantly accelerate drug development by enabling researchers to identify and enroll individuals at high risk into clinical trials for potential Alzheimer's treatments and preventive strategies. Large-scale clinical trials are already underway to test drugs that could prevent or delay the disease, making an accessible method for identifying suitable candidates crucial.

The study, published in JAMA and presented at the Alzheimer's Association International Conference in London, found that symptom-free older adults with very high levels of p-tau217 faced a 38% risk of cognitive impairment within five years, a figure that rose to 78% over 10 years. The p-tau217 test detects a form of tau protein that correlates with the buildup of amyloid plaques and the formation of tau tangles in the brain, key pathological markers of Alzheimer's disease.

Researchers from Mass General Brigham Neuroscience Institute analyzed data from 2,684 older adults who were cognitively healthy at the start of long-running Alzheimer's studies. These participants underwent the p-tau217 blood test at enrollment and received annual cognitive assessments. While the test shows promise for risk prediction, senior author Dr. Reisa Sperling emphasized that it is too early for healthy individuals to seek out the test. She advised that current recommendations for maintaining brain health—including a healthy diet, adequate sleep, regular exercise, and cognitive engagement—remain the primary course of action for the general population.