Longevity, vaccination, and the limits of human lifespan

Two distinct scientific traditions drive contemporary longevity research, and understanding their relationship matters for practicing physicians who counsel patients about healthy aging. The first tradition is disease prevention through established, evidence-based means: adequate nutrition, regular physical activity, smoking cessation, and avoidance of alcohol and recreational drugs. The second tradition is more speculative and mechanistic, seeking molecular and neurobiological interventions—senolytics, mTOR inhibitors such as rapamycin, epigenetic reprogramming, and other approaches intended to slow or reverse the biological aging process itself, potentially extending life indefinitely. The first approach has a robust track record. The second, despite genuine scientific interest, remains largely experimental. Epigenetic “aging clocks” have shown that interventions such as caloric restriction, a Mediterranean-style diet, exercise, and certain pharmacologic agents can measurably lower biological age relative to chronological age in small human trials.1 Metformin combined with growth hormone and dehydroepiandrosterone reduced epigenetic age by roughly 2 years in one pilot study, and...