[syhprum (OP)]

History or maybe myth records cases of aged Popes wishing to extend their lives or prisoners condemned to die of starvation being kept alive by their daughters.
It would not be difficult for political leaders in the old days with plenty of slaves and no ethics commutes to get adequate supplies but experiment might be difficult today, would there be digestive problems ?

[Hayseed]

There are communities that have a diet of milk and blood that are and have existed for hundreds of years.  And there has never been a time......of less ethics.  This is the age of delusion.

[Bored chemist]

"How well would an adult do on a diet of human milk ?"
Badly.