Study links p-tau217 levels to long-term dementia risk in women

Researchers from the University of California San Diego have found that a novel blood-based biomarker can predict a woman's risk of developing dementia as many as 25 years before symptoms appear. The study, published on March 10, 2026 in JAMA Network Open, shows that higher levels of phosphorylated tau 217 (p-tau217) - a protein linked to the brain changes seen in Alzheimer's disease - were strongly associated with future mild cognitive impairment and dementia among older women who were cognitively healthy at baseline, meaning at the start of the study before any memory or thinking problems were detected.

Our study suggests we may be able to identify women at elevated risk for dementia decades before symptoms emerge. That kind of long lead time opens the door to earlier prevention strategies and more targeted monitoring, rather than waiting until memory problems are already affecting daily life."

Aladdin H. Shadyab, PhD, MPH, first author of the study and UC San Diego associate professor of public health and medicine at the Herbert Wertheim School of Public Health and Human Longevity Science and the School of Medicine

The findings are based on data from 2,766 participants in the Women's Health Initiative Memory Study, a large national study that enrolled women ages 65 to 79 in the late 1990s and followed them for up to 25 years. All women were cognitively unimpaired when they entered the study. Blood samples collected at baseline were analyzed years later to measure p-tau217, a form of tau protein that reflects early brain changes associated with Alzheimer's disease.