# SystemsAge

SystemsAge is a methylation-based biological-age clock that looks at multiple body systems. Sehgal et al. introduced it (2025, Nature Aging, Levine lab). From a single blood test, it estimates ages across 11 physiological systems. A related but separate idea is the 'organ age' model by Tian and colleagues (2023, Nature Medicine). That one used UK Biobank data to derive an MRI-based brain age plus seven body organ systems (cardiovascular, lung, musculoskeletal, immune, kidney, liver, and metabolic). The two share conceptual ground, but Tian's was not called 'SystemsAge'. Instead of one combined score, SystemsAge gives you a profile of organ ages. That lets you spot mismatched aging across your systems. In the UK Biobank, organ age gaps predicted organ-specific disease and all-cause death. And people whose organ ages were younger than their calendar age had lower death risk.

## Sources

- Tian YE, Cropley V, Maier AB, Lautenschlager NT, Breakspear M, Zalesky A. (2023). Heterogeneous aging across multiple organ systems and prediction of chronic disease and mortality. Nature Medicine. https://doi.org/10.1038/s41591-023-02296-6

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_Canonical: https://longevity-switzerland.com/en/glossary/systemsage · Part of Longevity Cities · Updated 2026-06-22_