Study shows a blood test can help identify healthy people at high risk for Alzheimer’s disease

July 15, 2026 - 17:03

A new study suggests a simple blood test might do more than just help diagnose Alzheimer's disease. Researchers have found that the same test could also identify healthy older adults who are at high risk of developing the condition in the future.

The study focused on measuring levels of a specific protein called p-tau217, which is known to build up in the brain during the early stages of Alzheimer's. Scientists analyzed blood samples from a large group of cognitively normal participants and then tracked their health over several years. The results showed that those with elevated p-tau217 levels were significantly more likely to develop memory problems and other symptoms of Alzheimer's later on.

This finding is important because it moves beyond diagnosing the disease after symptoms appear. Currently, doctors often rely on expensive brain scans or invasive spinal taps to detect early signs. A blood test would be cheaper, faster, and easier to administer during a routine checkup. It could allow doctors to flag high-risk individuals years before noticeable decline begins.

Experts caution that the test is not yet ready for widespread use. More research is needed to confirm the findings in diverse populations and to set clear cutoff points for risk. However, the study opens the door to earlier intervention. If a person knows they are at high risk, they might adopt lifestyle changes or join clinical trials for new treatments before significant brain damage occurs.

The study was published in a leading medical journal and adds to a growing body of evidence that blood biomarkers can play a key role in the fight against Alzheimer's disease. While no cure exists yet, early identification remains one of the best tools researchers have.