I can offer no objective evidence, but I can at least relply to those who say it is impossible.

When we eat bread or drink wine, some of the sub atomic particles in the bread and wine (protons, neurons electrons) will be digested and become part of the person who consumes them. These sub atomic particles will not have changed their appearance in scientific terms, but they will now belong to the person who consumed them. In the Catholic Mass, during consectration, the ownership of the bread and wine is transferred to the body and blood of Jesus. They will still have the appearance of bread and wine, but they are now the body and blood of Jesus.

I am aware that some sects of devil worshipers are willing to pay money for consecrated hosts in order to abuse them in their rituals, and they say they are able to discern if they have been consecrated.