yes, they can....
my parents both....
donate blood for many many years....
now they are old (father over 70)
i remember one time, i made a joke and go with
my girlfriend to her blooddonating.....
and there the stuff ask me if i will donate too....
i say cure, and then they test uss both for hb level....
after a moment they come to me and say that they couldnt take
my blood cause i have only 8 hb and if its everythink right...
hehehehe...
panos
hehehehehe