Two new studies on rapamycin shows how short-term treatment with rapamycin very early in life may provide lifespan and healthspan benefits, but it also seems there is a cost in terms of growth (so this dosing strategy seems unlikely to be something that humans will implement).
…we subjected genetically diverse UMHET3 mice to the mTOR inhibitor rapamycin for the first 45 days of life and followed them up until death.
Treated mice grew slower, with most of the deceleration occurring in the first week, and remained smaller for their entire lives. Their reproductive age was delayed but without affecting offspring numbers.
Rapamycin initially reduced DNA methylation age of livers, however, that effect was lost with aging.
Overall, the results demonstrate that short-term rapamycin treatment during early life is a novel longevity intervention that establishes causality between pace of development and longevity in evolutionary distant organisms.
Lifespan can be extended during a specific time window early in life
Here, we found that a short rapamycin treatment during early life can prolong lifespan in Mus musculus and Drosophila melanogaster. Notably, the same treatment at later time points has no evident effect on lifespan, suggesting that we found a crucial time-window involved in lifespan modulation