09/17/2026
CAN A BLOOD TEST HELP PREDICT FUTURE ALZHEIMER'S DISEASE?
A large study of **2,684 cognitively healthy older adults** examined whether blood levels of **plasma phosphorylated tau 217 (p-tau217)** could predict future cognitive decline.
Research showed that higher p-tau217 levels were consistently associated with:
-Greater risk of developing cognitive impairment**
-Faster rates of cognitive decline**
-Increased risk that remained significant even after accounting for amyloid PET measurements
What was the 5-year risk....
Compared with people who had lower p-tau217 levels:
-People with high p-tau217 had 24% risk of progressing to cognitive impairment within 5 years
-People with very high p-tau217 had 38%** risk within 5 years. The very-high p-tau217 group also experienced a substantially faster rate of cognitive decline.
Why does this matter?
-p-tau217 is emerging as one of the most promising **blood-based biomarkers of Alzheimer’s disease pathology. It may eventually help clinicians identify individuals who are at higher risk **before noticeable cognitive symptoms develop**.
IMPORTANT: A high p-tau217 level does NOT mean that someone will definitely develop Alzheimer’s disease. These results came from selected research cohorts, and the authors emphasize that further validation in broader, real-world populations is needed before using p-tau217 to determine an individual's prognosis.
BOTTOM LINE: p-tau217 may provide valuable information about Alzheimer’s-related pathology and future cognitive risk—potentially years before symptoms become apparent.
**THIS TEST IS AVAILABLE AT VALLEY INTEGRATIVE HEALTH AND IS AFFORDABLE WITHOUT HEALTH INSURANCE COVERAGE**
Source: Longitudinal pooled analysis of 2,684 cognitively unimpaired older adults across 6 cohorts; follow-up through 2025.*