Autophagy is a collection of similar processes for cellular housekeeping: recycling broken components so that they can't cause harm. More autophagy means a better running biological machine, and that in turn brings enhanced longevity. Aging, after all, is really nothing more than the accumulation of unrepaired biological damage. Here is another example of this principle in action: "Evidence for a regulatory role of the miR-34 family in senescence is growing. However, the exact role of miR-34 in aging in vivo remains unclear. Here, we report that a mir-34 loss-of-function mutation in Caenorhabditis elegans markedly delays the age-related physiological decline, extends lifespan, and increases resistance to heat and oxidative stress. We also found that RNAi against [autophagy-related genes] significantly reversed the lifespan-extending effect of the mir-34 mutants. Furthermore, miR-34a inhibits [gene expression of an autophagy-related gene] at the post-transcriptional level in vitro ... Our results demonstrate that the C. elegans mir-34 [loss of function] mutation extends lifespan by enhancing autophagic flux in C. elegans, and that miR-34 represses autophagy by directly inhibiting the [expression of autophagy-related genes] in mammalian cells."