47 This is why the Fathers felt they had a solemn duty to warn the faithful that, in reflecting upon this most sacred Sacrament, they should not pay attention to the senses, which report only the properties of bread and wine, but rather to the words of Christ, which have power great enough to change, transform, "transelementize" the bread and wine into His body and blood. As a matter of fact, as the same Fathers point out on more than one occasion, the power that does this is the same power of Almighty God that created the whole universe out of nothing at the beginning of time.
Source: Mysterium Fidei (Vatican.va)