While I have heard the poisonous warnings, all I can tell you is that it was a treat for us all through my childhood. Worst thing that happened to me was the 5,000 mosquito bites I got picking the stuff.
Now, if Poke stalks make one a cranky old lady....that I'd buy.
There's a plethora of information for and against.
I think if one were to make it a major part of one's diet, eat the older parts or heaven forbid the berries, one would be in trouble.
However, moderation in everything, including moderation, are words to live by.