Catechism of the Catholic Church §1416 — excerpt
Communion with the Body and Blood of Christ increases the communicant's union with the Lord, forgives his venial sins, and preserves him from grave sins.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.