If communion is meant to represent the body and blood of Christ. Then surely this means when you are taking communion that you are partaking in eating the flesh and drinking blood. By every definition that classifies as cannibalism. Unless, I am not understanding but it does say in Eucharist "May Thy Body, O Lord, which I have received, and Thy Blood which I have drunk cleave to my heart."
It is certainly similar to cannibalism. For the Catholick who believes that they are consuming the actual blood and body of Christ, it should be, by definition, cannibalism to them. On the other hand, it doesn't really have the same connotations as actually going out and killing and eating an actual human, and after all, communion is nonsense anyway.
By taking Communion or the sacrament, we don't (As Mormons) think of it as partaking of Christ's flesh and blood. Rather, we take it as a means of remembering what he did for us. The Water reminds us of what happened in Gethsemane whereas the bread reminds us of Golgotha.
When you receive the Body and Blood of Christ, you are cleansing your soul and opening your heart to God. You are, in fact, consuming Jesus, but you are bringing yourself closer to Heaven. As you receive the Eucharist, you are taking part of your religion and showing that you believe in God. The word "Amen" means "I believe". So when you take Communion, you are saying to God, "Yes, Lord, I believe."
No, taking Communion is not akin to cannabilism, because transubstantiation is not real. The bread and cup do not become actual body and blood. Rather, they are only symbolic of Christ's death on the cross for our sins. Jesus said in the Bible to "Do this in remembrance of me." He did not tell us we would be eating his flesh.