John 6 "51 I am the living bread that came down from heaven. Whoever eats this bread will live forever. This bread is my flesh, which I will give for the life of the world.” 52 Then the Jews began to argue sharply among themselves, “How can this man give us his flesh to eat?” 53 Jesus said to them, “Very truly I tell you, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you. 54 Whoever eats my flesh and drinks my blood has eternal life, and I will raise them up at the last day. 55 For my flesh is real food and my blood is real drink. 56 Whoever eats my flesh and drinks my blood remains in me, and I in them. 57 Just as the living Father sent me and I live because of the Father, so the one who feeds on me will live because of me. 58 This is the bread that came down from heaven. Your ancestors ate manna and died, but whoever feeds on this bread will live forever.” 59 He said this while teaching in the synagogue in Capernaum."
It cannot get any clearer than this. The Holy Eucharist is indeed Jesus's actual flesh. Nothing symbolic. And it doesn't bestow "extra grace," but rather it bestows life itself.
Except 4 verses later in 63 Jesus says he was speaking spiritually.
I’m not sure why you are claiming? Are you, or the Catholic Church, saying the wine is actual blood with erythrocytes and lymphocytes and cytokines etc...?