Regarding grey hair...my boyfriend, who is in his early 20s, has a little grey hair, which seems "inherited" from his mother because she also greyed when she was young. My boyfriend's four older siblings (two males, two females) do not seem to have this problem. Since they all grew up in the same house eating the same things, I don't know why my boyfriend would have this issue but not his siblings...
What do you think would be the best herbs to stop the greying (I am also interested for my mother, though of course this is a purely esthetic reason, the greater benefit will be better overall health): the longevity spices, the iodine/potassium, both/anything else?