You, metmom and others may find the following useful:
http://www.catholic.com/thisrock/quickquestions/keyword/Jehovahs%20Witness
Note the quick question that states, “Q:“
Jehovah’s Witnesses told me that Jesus’ commands to eat his flesh and drink his blood in John 6 could not be literal because Jesus would be advocating something against God’s law by commanding us to eat blood (cf. Gen. 9:4, Acts 15:28-29). What can I say to this?
””
Was eating/drinking blood forbidden by the Law and were the disciples under the Law?
Does saying that the wine is (estin in Greek) mean the wine was or became blood at some point? Or can estin mean the wine was a symbol of or represented his blood?
That would be a fair start.