Concept
Allostatic Load
Last updated Sat May 30 2026 00:00:00 GMT+0000 (Coordinated Universal Time)
The concept
Bruce McEwen and Eliot Stellar (1993) coined allostatic load to describe the cumulative cost of physiological adaptation to chronic stressors. The body’s stress-response systems (HPA axis, sympathetic nervous system, immune, metabolic) are protective acutely but damaging when chronically activated.
Measurement
Originally measured as a 10-item composite of:
- Cortisol.
- DHEA-S.
- Catecholamines (epinephrine, norepinephrine).
- Cardiovascular: SBP, DBP.
- Metabolic: waist:hip ratio, HbA1c (or fasting glucose), HDL/total-cholesterol ratio.
- Inflammation: CRP, IL-6, fibrinogen.
Scores above the population median for ≥4 items = high allostatic load.
Predictive value
In MacArthur Successful Aging Studies and other cohorts, higher allostatic load predicts:
- All-cause mortality (hazard ratios ~1.3–2 in highest vs lowest groups).
- Cardiovascular events.
- Cognitive decline.
- Functional disability.
- Frailty incidence.
It captures more than any single biomarker because chronic stress manifests across systems.
What modifies it
Same levers as inflammaging:
- Exercise.
- Sleep adequacy.
- Stress management (CBT, meditation, social support).
- Mediterranean / DASH diet.
- Weight management.
- Treating underlying conditions (hypertension, diabetes, sleep apnea).
Related entries
Frailty index, Inflammaging, Cortisol, Cardiovascular disease.
References
- McEwen, B. S. Protective and damaging effects of stress mediators. N. Engl. J. Med. 338, 171–179 (1998).