I dont see a reason not to eat them as they dont suddeny turn poisonous (Let me know if im wrong!!!), but the floavour may be different.. but people i know tend not to compost leeks to avoid the risk of spreadng rust etc.

if they are poisonous' perhaps your next of kin will warn us, the leeks are ok cut out the flowering stem were it is exposed, check all of them and keep your eye on them , you may have over fed them, leeks are better on what you fed somthing else last year, I never put fertiliser under my leeks, I still get big leeks and they don't bolt, were can we send the flowers, lol

As Cliffo says just remove the woody centre from the leeks and they will be fine to eat.

I am still alive and i have eaten the flowers too. :o)