28. What are longevity intervention types?

A practical way to organize longevity interventions is to separate three intervention types, which differ in what they can plausibly change and in their evidentiary status. (i) Remodeling interventions. State-shifting interventions move organisms between quasi-stable physiological setpoints through systemic remodeling (e.g., metabolic/endocrine remodeling under caloric restriction-like regimes, rapamycin-like nutrient-sensing shifts). These interventions can meaningfully extend healthspan and increase mean lifespan, largely by changing the rate and coupling of deleteriome production to function, but they are unlikely by themselves to break species-level maximal lifespan. (ii) Personalized interventions. Heterogeneity-targeting interventions act on the fact that aging is not perfectly synchronized: organs, tissues, cell types, and structures diverge, creating locally accelerated trajectories that become the dominant failure points. Interventions that diagnose and selectively slow, repair, replace, or reset these accelerated components can square the survival curve, improving healthspan and mean lifespan, without necessarily changing the species ceiling. (iii) Limit-breaking interventions. These interventions aim to increase maximal lifespan by overcoming species-level constraints through more radical approaches that reduce the residual deleteriome burden and/or repeatedly reset or replace limiting components (e.g., deep age-reset strategies, comprehensive replacement/regeneration, hybrid bioengineering). In practice, combinations across types may be required, but the distinction clarifies what each approach can and cannot plausibly achieve.