A new blood test may predict the risk of developing Alzheimer's disease up to ten years before any symptoms emerge. The research, presented at the Alzheimer's Association International Conference and published in JAMA, focuses on a blood biomarker called p-tau217.
In a large study tracking nearly 2,700 cognitively healthy adults with an average age of 70 for a decade, researchers found those with very high levels of p-tau217 had a 78% chance of cognitive impairment within ten years. Even moderately elevated levels showed a 45% risk over the same period. The p-tau217 protein is linked to the damaging tau tangles found in Alzheimer's brains.
Lead author Rachel Buckley of Harvard Medical School said the findings offer the clearest evidence yet that dementia risk can be detected years in advance. Experts note that such early detection could be crucial for recruiting patients for preventive clinical trials and, in the future, guiding early treatment.
Researchers caution that the p-tau217 test is not a standalone predictor. Factors like age, genetics, kidney function, and race also influence risk. They emphasized the need for further studies in more diverse populations.