Any normal person, Jewish or not, would be against eating human flesh and drinking human blood. The reason why those disciples abandoned Jesus is that they failed to understand that Jesus was using figurative speech to talk about spiritual concepts. Jesus let them go because he needed to die for our sins and that was only going to happen if Israel rejected him. That is why Jesus said: “...The knowledge of the mysteries of the kingdom of God has been given to you (i.e., to the apostles), but to others I speak in parables, so that, ‘Though seeing, they may not see; though hearing, they may not understand” (Luke 8:10). That also explains why he did not allow demons to reveal that he was the Son of God: “Demons also came out of many people, shouting, “You are the Son of God.” But He rebuked the demons and would not allow them to speak, because they knew He was the Christ.” (Luke 4:41). Yet, Jesus spoke clearly to his apostles, to whom he said: “The Spirit gives life; the flesh profits nothing. The words I have spoken to you are spirit and they are life. “(John 6:63). He told them this when they asked him what did he meant when he said that people needed to eat his body and drink his blood. Hence, it is evident that the wafer is NOT the literal body of Christ. Anyway, why is this topic so important to you? Do you believe that salvation comes from eating a consecrated wafer? For instance, would an unbeliever be saved if he stole consecrated wafers and ate them?