Researchers developed ClinBAG, a biological aging clock using just 22 routine blood and anthropometric measurements from 14,328 individuals in the All of Us Research Program. The clock demonstrated cross-ancestry applicability and predicted neurological disease risk in 152,733 additional participants, showing 2% increased dementia risk and 1.4% increased Parkinson's disease risk per unit of accelerated biological aging. The study identified ancestry-specific genetic drivers, including HBB variants in African ancestry individuals and FADS1/FADS2 in Europeans, alongside common loci like NPRL3. Mechanistically, ClinBAG-associated genes were overexpressed in double-negative T cells in an age-dependent manner, suggesting neuroinflammation pathways. This represents a significant advance over existing biological clocks that often lack cross-population validity and require expensive specialized testing. The use of standard clinical measurements makes this approach immediately implementable in healthcare settings for personalized aging assessment. However, this preprint awaits peer review, and the observational design cannot establish causation. While the large diverse cohort strengthens generalizability, longer follow-up periods would better validate disease prediction accuracy across different populations and age groups.