Blood biomarker could forecast dementia risk decades ahead in older women.

A UC San Diego-led study of 2,766 women aged 65–79 from the Women’s Health Initiative Memory Study found that higher blood levels of the biomarker p-tau217 are strongly linked to future dementia and mild cognitive impairment, suggesting a simple blood test could identify those at greatest risk up to 25 years before symptoms. While promising for early prevention and monitoring, blood-based testing for Alzheimer's is not yet recommended for routine screening, and results may not apply to men or younger populations.