One of the processes that decline with age is our cellular housekeeping. “Junk” accumulates.
It turns out that we can activate this process at will!
Autophagy (or autophagocytosis) (from the Greek auto-, “self” and phagein, “to eat”), is the natural, destructive mechanism that disassembles, through a regulated process, unnecessary or dysfunctional cellular components.
We turn it on with fasting, or perhaps with “protein fasting” (avoiding protein for a period of time).
Fasting and Autophagy (very good article)
Death Will Eat Itself (The Enormous Benefits of Autophagy, or Why You Should Stop Eating Once in Awhile)