The science of aging
Aging is biology. Biology can be changed.
Scientists no longer treat aging as simple wear and tear. It is a set of measurable processes inside our cells, and many of them respond to how we live and, increasingly, to medicine.
Two clocks
Lifespan vs. healthspan
Lifespan is how long you live. Healthspan is how long you live free of serious chronic disease and disability. Across 183 countries, people spend an average of about 9.6 years in poor health at the end of life, and in the United States the gap is 12.4 years, the largest measured.
The goal of longevity medicine is to close that gap: keep function high for as long as possible and compress decline into the shortest window at the end. That idea, called the compression of morbidity, was first proposed by James Fries in 1980.
The 12 hallmarks of aging
The cellular roots of getting older.
In 2023, the researchers who first defined the hallmarks of aging expanded the list to twelve processes. Each is measurable, each worsens with age, and slowing it in animals tends to extend healthy life.
How the hallmarks connect
Damage, response and consequence.
The hallmarks fall into three families that feed one another. That is why single-target fixes rarely work on their own.
Primary hallmarks
The sources of damage
Genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis and disabled macroautophagy steadily erode the cell’s information and machinery.
Antagonistic hallmarks
Responses that backfire
Deregulated nutrient sensing, mitochondrial dysfunction and cellular senescence start as protective responses but become harmful when they persist.
Integrative hallmarks
What you feel and see
Stem cell exhaustion, altered intercellular communication, chronic inflammation and dysbiosis show up as frailty, slower healing and disease.
Measuring what matters
Your birthday says one thing. Your cells may say another.
Biological age clocks use DNA methylation or blood proteins to estimate how fast someone is aging. In 44,498 UK Biobank participants, people with eight or more biologically “old” organs had about eight times the risk of death. Clocks are promising research tools and trial endpoints, but they are not yet validated replacements for clinical outcomes.
From cells to capacity
What we track for each pillar of youthful longevity.
These are common, well-studied measures. Which ones matter for you is a decision to make with your physician.
01
Performance
VO₂ max, resting heart rate, heart-rate variability
02
Cognition
Processing speed, memory testing, sleep quality
03
Muscle & bone
Grip strength, leg power, lean mass and bone density (DEXA)
04
Metabolic health
Glucose, HbA1c, insulin, lipids, body composition
05
Cellular vitality
Inflammatory markers and research-grade biological age clocks