What is Longevity? Fundamentals and the Hallmarks of Aging
An introduction to the longevity field, the twelve hallmarks of aging, and what we know today about healthy aging.
What does "longevity" actually mean?
Longevity describes the science and practice of extending healthspan — the years lived in good health. It differs from raw lifespan extension: the goal is to compress morbidity, not just push the endpoint.
The twelve hallmarks of aging
López-Otín and colleagues expanded the original 2013 model in 2023. Today, twelve cellular and systemic mechanisms are considered core drivers of aging:
- Genomic instability
- Telomere attrition
- Epigenetic alterations
- Loss of proteostasis
- Deregulated nutrient sensing (mTOR, AMPK, sirtuins, insulin/IGF-1)
- Mitochondrial dysfunction
- Cellular senescence
- Stem cell exhaustion
- Altered intercellular communication
- Chronic inflammation (inflammaging)
- Dysbiosis
- Disabled macroautophagy
What does this mean in practice?
Several of these mechanisms are modifiable. Exercise, sleep, nutrition, targeted fasting, and select supplements demonstrably act on multiple of them simultaneously.
Common questions
Is aging a disease? Scientifically contested. The WHO briefly included it in ICD-11 in 2018 before retracting under criticism. Practically, aging is the largest risk factor for most chronic diseases.
Can I measure my biological age? Yes — via epigenetic clocks (GrimAge, PhenoAge, DunedinPACE). Tests are commercially available; clinical utility is still under study.
Where to start? The basics: sleep, resistance training, zone-2 cardio, adequate protein, social connection. Supplements come after.