I honestly can't see why they should have trouble with it at all. Well meaning followers of our Christ believe in earnest that He is the word incarnate - God the Son of the Trinity, yet on the other hand believe He's incapable of giving sacrificing His body and blood when we take communion.
They are as those who were present at the time when they said this just can't be. Their contention was yes we believe you as the Messiah to be capable healing the sick and raising the dead yet what is this talk of us eating your flesh?
Jesus was very adament about this, He verily repeated Himself many times, even on His last night upon this earth. He didn't fudge His words or speak in any kind of parable. The Eucharist with it's immense power then went on to change the face of the earth, and gave us all Christianity we see today.
It's very sad that we've gotten away from it, we're like those who abandoned Him that day.
If the Eucharist is actually His flesh, then do you not believe Jesus Christ is indeed resurrected in the body and now ascended in heaven? If so, what part of His body does He send down or reproduce? (I suspect the premise is false.)