Blood test may predict Alzheimer's risk years before symptoms, study finds

Researchers reported a blood test can predict whether healthy older adults will develop cognitive decline within five to ten years.

• Older adults with elevated p-tau217 protein levels had a 38 percent risk of developing cognitive impairment within 5 years, rising to 78 percent within 10 years, the study found.
• Researcher Reisa Sperling advised healthy people not to seek the p-tau217 blood test now, saying they should "wait until it becomes possible to take action based on its results."
• The findings were published in the medical journal GAMA and presented at the Alzheimer's Association International Conference in London.
• Sperling said the test measures a form of tau protein linked to amyloid plaque buildup in the brain, currently used to diagnose Alzheimer's in people with cognitive problems.