Grace & Peace!
Why do neither the Apostles’ nor the Nicene Creeds refer to the Eucharist?
I’m tempted to say that it shouldn’t be too surprising–neither Creed directly references the Sacraments. The Creeds aren’t meant to be catechetical in nature, but confessional–that is, they are symbols and expressions of the faith which finds its greatest liturgical expression in the Sacraments.
Perhaps also we could say that the Creed is a statement we make (by Grace) to God, and the Sacraments are statements (of Grace) that God makes to us. Grace moves us to speak the Creed, to return the symbol (to use very old parlance)–this gives us access to the gateway to all the Sacraments, Baptism, which allows us to participate fully in the Grace we confessed. The Eucharist then continues (and in a sense, completes) the work begun in us by Baptism by uniting us with Our Lord when we receive him in the Mystery. It is as if the Creed is a key (fashioned by Grace and composed of Grace), to the Household of Grace: the totality of the Seven Sacraments.
On another level, Eucharistic devotion (the way we know it) was not a part of the early church’s devotional repertoire.
On another level, the Fathers who wrote the Creeds were concerned with getting clear a right understanding of the faith. The efficacy of the Sacraments does not hinge on a right understanding (as they operate ex opere operato)–though through Christian initiation, it is to be hoped that a right understanding of the Sacraments would be received.
I’m sure someone else has a more scholarly answer, and can clarify things I have muddied or mis-spoken.
Under the Mercy,
Mark
Deo Gratias!