Evidence check: Cortisol in the context of Langlebigkeit

Cortisol is a key stress hormone regulated by the HPA axis. Chronically elevated cortisol is linked to hypertension, insulin resistance, immune suppression, and cognitive decline – all factors that can shorten healthspan and lifespan. However, direct evidence for a causal role in longevity is limited to observational and mechanistic studies; no robust RCTs exist. Consumer tests (saliva, hair) can indicate chronic stress patterns but are not diagnostic for longevity risk. Single measurements are unreliable due to high variability. Evidence level: human-moderate (observational) to mechanistic. Lifestyle interventions (sleep, exercise, stress reduction) have a much stronger impact than any single genetic variant in cortisol-related genes (e.g., NR3C1, FKBP5). Caveat: Do not use consumer cortisol tests to self-diagnose adrenal disorders; clinical evaluation is needed for suspected pathology.