Biomarker
A measurable biological characteristic that indicates the state of a biological process, disease condition, or response to an intervention. In longevity science, biomarkers are used to track aging and assess healthspan.
A biomarker (short for biological marker) is any objectively measurable characteristic of a biological system that can indicate normal or abnormal processes, disease conditions, or the effects of an intervention.
In the context of longevity science, biomarkers are used in several ways:
- As aging indicators: measurements that reflect the pace and state of biological aging (e.g., epigenetic age, telomere length, inflammatory markers) - As disease risk signals: measurements that predict future disease risk before symptoms appear (e.g., fasting glucose, LDL particle size, coronary calcium score) - As intervention response trackers: measurements used to determine whether a lifestyle or medical intervention is having the desired biological effect
Longevity-relevant biomarkers include VO2 max, grip strength, fasting insulin, C-reactive protein, HbA1c, biological age estimates, and measures of cognitive function.
When a person starts a regular exercise program, their doctor might track CRP (C-reactive protein) as a biomarker of inflammation. If CRP decreases over several months, it suggests the intervention is reducing systemic inflammation, which is associated with better longevity outcomes.