9. Longevity Interventions Likely Matter Most Before Dominant Failures Are Established

If aging begins after embryonic ground zero, deleteriome accumulation starts early, and the earlier one begins to minimize its accumulation the better. However, the sooner the better strategy does not mean all interventions must start early. The optimal start depends on which trajectories are most modifiable at which ages, whether the intervention has cumulative or instantaneous effects, long-term trade-offs (e.g., growth and reproduction), and safety. Many interventions may be beneficial when they prevent or delay a deficiency from crossing a functional threshold. This argues for early measurement and risk stratification, with staged interventions that intensify as measurable trajectories diverge.