Blood test may flag Alzheimer's risk years before symptoms appear

A large international study led by Mass General Brigham found that older adults with very high blood levels of the biomarker p-tau217 had a 38% chance of cognitive impairment within five years, rising to an estimated 78% over ten years. The research pooled data on 2,684 cognitively healthy people from North America, Japan and Australia and was published in JAMA.