A new study found that bone fractures in older mice healed more quickly when they received blood from young mice.
And here we though Dracula was just a perv. What with his always putting the bite on young, nubile females, I mean. Turns out he had a perfectly practical, non-sexualized reason for it. Modern Science is discovering what the vampire has known all along: to wit, that blood from the young is more potent than blood from the aged. Thus it stands to reason that, by drinking from a younger victim, Dracula and his kith and kin are able to absorb a larger amount of those necessary reanimating energies that keep them eternally young and spry. Young blood hasn’t gone flat, in other words.
It works with mice, at least. Blood taken from a younger mouse promotes faster healing in older mice. (How long do mice live, anyway? Isn’t their average lifespan, like, a year? So how old would a “young” mouse be? Six months? No, that’d be middle-aged. Three months?) Thus we infer that young blood is better for the overall health of the Undead. Of course the blood of young MALES should in theory be just as nutritious as that taken from a bodacious babe, so maybe there’s a little bit of sexual undertone to Drac’s predations after all, ya think?