In article ,
Sacha wrote:

I think I remember someone saying you
could eat it, when we had a similar discussion years ago but I may be wrong,
so don't try it!

Googled around and found no evidence. Maybe you should only eat it
in the severest of famines. There are lots of recipes out there
for using the stuff to make biodynamic teas which either
enhance fungal activity or act as a fungicide depending.
If you've got a heart condition, an ability to read russian
and $9.28, you might find this useful:-
http://www.russianfoods.com/showroom...C6/default.asp

Japanese knotweed is edible though
http://www.wildmanstevebrill.com/Pla.../Knotweed.html