Stanford Researchers Develop Blood Test to Gauge Organ Age

Scientists led by Tony Wyss‑Coray at Stanford University have created a blood‑based indicator that estimates the biological age of individual organs. By analyzing roughly 3,000 plasma proteins, the team assigned an age to 11 organ systems—including brain, heart, liver, and immune system—in a study of about 45,000 UK Biobank participants aged 40‑70, followed for up to 17 years.

The indicator revealed that a brain that appears "extremely aged" (top 6‑7% of older biological signatures) triples the risk of Alzheimer’s disease and raises overall mortality by 182% over 15 years. Conversely, an "extremely youthful" brain (bottom 6‑7%) cuts Alzheimer’s risk to a quarter and reduces mortality risk by about 40%. Researchers highlighted brain age as the strongest single predictor of longevity, suggesting the test could help forecast disease risk a decade in advance.

Findings were published in Nature Medicine, demonstrating how plasma proteomics can capture organ‑specific aging patterns and potentially guide early interventions.