Lifespan-extending treatments increase variation in age at time of death
Medical Xpress
February 25, 2026
AI-Generated Deep Dive Summary
A recent study by Dr. Tahlia Fulton and Associate Professor Alistair Senior from the University of Sydney explores how lifespan-extending treatments like dietary restriction, rapamycin, and metformin impact variation in age at death among vertebrates. While these interventions are known to extend life expectancy, the research reveals a surprising trade-off: they may also increase variability in the age at which individuals pass away. This finding challenges earlier assumptions that such treatments would uniformly reduce differences in lifespan across populations.
The study, conducted through a comprehensive meta-analysis, examined the effects of dietary restriction—a well-documented method to enhance longevity—and two drugs, rapamycin and metformin, on survival curves in various animal models. While these interventions successfully extended overall lifespan, they often resulted in a broader spread in the ages at which death occurred. For instance, some animals lived significantly longer while others died earlier than typical control groups.
This discovery has important implications for aging research. The original goal of extending life while reducing variation in age at death—known as "squaring the survival curve"—is more complex than previously thought. While these treatments offer hope for increased longevity, they also highlight the need to better understand and address the factors contributing to lifespan variability. This balance between extending life and ensuring
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Originally published on Medical Xpress on 2/25/2026