Ultimate Longevity Bible

Geroscience encyclopedia

Ultimate Longevity Bible

A research-grounded encyclopedia of longevity science. Plain-language summaries of the hallmarks of aging, interventions, biomarkers, and the researchers shaping the field.

The Twelve Hallmarks of Aging

Based on the López-Otín et al. 2023 framework.

  1. 01

    Altered Intercellular Communication

    Age-related changes in hormonal, neuronal, and immune signalling between cells and tissues.

  2. 02

    Cellular Senescence

    Stable cell-cycle arrest accompanied by a pro-inflammatory secretome (SASP) that propagates dysfunction to neighbouring tissue.

  3. 03

    Chronic Inflammation

    Persistent low-grade systemic inflammation ("inflammaging") that accelerates most major age-related diseases.

  4. 04

    Deregulated Nutrient-Sensing

    Loss of homeostasis in the insulin/IGF-1, mTOR, AMPK, and sirtuin pathways that translate nutrient state into growth and repair decisions.

  5. 05

    Disabled Macroautophagy

    Decline in the bulk recycling pathway that engulfs and degrades cellular components, especially damaged mitochondria and protein aggregates.

  6. 06

    Dysbiosis

    Age-related shift in gut microbial composition and function, with knock-on effects on metabolism, immunity, and the brain.

  7. 07

    Epigenetic Alterations

    Age-related changes in DNA methylation, histone modifications, and chromatin remodelling that drift cells away from youthful gene-expression patterns.

  8. 08

    Genomic Instability

    Accumulation of DNA damage over the lifespan, driven by both endogenous and environmental insults.

  9. 09

    Loss of Proteostasis

    Decline in the cell's ability to fold, refold, and degrade proteins, leading to accumulation of misfolded and aggregated species.

  10. 10

    Mitochondrial Dysfunction

    Age-related decline in mitochondrial bioenergetics, biogenesis, and quality control, with downstream effects on ROS, inflammation, and cell death.

  11. 11

    Stem Cell Exhaustion

    Decline in the number and regenerative capacity of tissue-specific stem cells, impairing replacement of dying or damaged cells.

  12. 12

    Telomere Attrition

    Progressive shortening of chromosomal end-caps with each cell division, triggering senescence or apoptosis.

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