Since 1970, scientists have made some fascinating discoveries from rigorous lab tests of various Eucharistic miracles both old and new. Among other things, the findings reveal both an identical Blood type common to each miracle (and to the Shroud of Turin), and that the Heart tissue — which is what the solid species was in all cases — was in a state of extreme stress and suffering.

Based upon this discovery of the suffering indicated in the tissue studied, one of our Sisters asked me two excellent questions that took me by surprise:

How does this square with theology’s assertion that, when we receive Holy Communion, we are receiving the resurrected, glorified Flesh of Our Lord? Why does the evidence point to His anguished, suffering, state and not to His glorified state?

For those who would like to know more of the facts behind Sister’s question, here is a helpful twelve-minute video that summarizes these fascinating and very moving discoveries in some impressive detail:

So that you can read the rest of this piece without having to take a break to watch that video, here is an executive summary of the principal scientific claims from the expert studies of five Eucharistic miracles (Lanciano, Italy; Buenos Aires, Argentina; Tixtla, Mexico; Legnica, Poland; and Sokółka, Poland):

• Every Eucharistic miracle studied contained AB positive blood, the identical type discovered in a 2024 study of blood stains on the Shroud of Turin.
• All five independent studies concluded that the flesh was myocardial (heart) tissue.
• Three of the studies concluded that the tissue came precisely from the left ventricle, the “largest and strongest chamber” of the heart, the one that “pumps the oxygenated blood [from the lungs] to all the other organs in the body” (source).
• Three of the studies concluded that the tissue was taken from a person experiencing extreme suffering, stress, or agony.
• Two of the studies attempted to sequence the DNA that was successfully extracted from the respective samples, but sequencing was impossible — even though there was more than sufficient material to do so — thus making it impossible to extract a genetic profile from the samples. (I will not comment on this data point below, but the gentleman in the video draws a fascinating conclusion from it. Hint: if you had only one human parent, your DNA probably wouldn’t be able to be sequenced, either!)

Watching the video is recommended.
Granted that my answers can only be speculative, the mere exploration of the question provides a wonderful opportunity to consider and meditate upon the great Mystery of the Holy Eucharist, moving from what we know from doctrine and theology to speculative conclusions about what we don’t know for sure. Here, then, is my attempt at answers to those questions.

The Significance of Jesus’ Blood Type

A couple of preludes are necessary. First, what is Our Lord’s blood type, and why is it significant? As the video above says, based on all five examined Eucharistic miracles and the Shroud of Turin, Our Lord was AB+, the only type called the “universal recipient” for red blood cell (RBC) transfusions because AB+ people can usually receive RBCs from any ABO type (O, A, B, AB). There is a rich theological significance to this: At first blush, one might superficially think that Jesus would be the universal donor because He gives His Body and Blood as food and drink. But, on the other hand, there is the doctrine of Saint Augustine which has it that while, in ordinary gastronomic interactions, the eater is greater than the food and assimilates it into himself; in the Eucharist, the Food is greater than the eater, and there is a reverse assimilation resulting in our divinization in Holy Communion. In The Bread of Life, Father Feeney makes this doctrine his own in the chapter entitled, “The Eucharist in Four Simple Mysteries.” Brother Francis, in introducing that chapter, summarized this doctrine:

The Eucharist, in Communion, comes to us under the aspect of food. Now, ordinary food is assimilated by the eater; but in Holy Communion the Food assimilates the eater! We, the Church, by Holy Communion, become an extension of His Reality! Listen to Father Feeney affirm this great fact: “In Holy Communion Jesus takes in me.” Again, “so much is this so, that Saint Paul was inspired to call us Catholics, ‘the fullness of Christ.’ We are the Mystical Body of Christ. ‘Mystical’ means the same Christ in endurance, even when He has gone away. He is the Vine, and we are the branches. He is the Head, and we are the members. We become in echo almost as divine as He was in utterance.” By this mystical but real unity with His Person, He makes us become sons of His eternal Father and true children of His Immaculate Mother. Holy Communion is the fulfillment of what is inchoatively contained in the Sacrament of Baptism.

I think Father Feeney would have been gratified to learn that the Precious Blood of Jesus bears the type of “universal recipient.” If this does not constitute empirical proof of his theology on the matter, it at least lends a kind of supporting evidence that argues for its cogency and fitness.

His Whole, Glorified Body Comes Down on Our Altars

The second prelude to answering the questions is to affirm that what the good Sister presupposes is quite true: “when we receive Holy Communion, we are receiving the resurrected, glorified Flesh of Our Lord.” It is the “whole Christ” that is received in the Blessed Eucharist, not a part of Christ, but His entire substance — albeit under the sacramental species — that is under the appearance of bread and wine. This is actually dogma that must be believed. Further, what is made present in transubstantiation is the substance of Our Lord Jesus Christ’s Body and Blood as they are now, that is, in their glorified state. This is a theological conclusion of, among others, Saint Thomas; for, as Saint Paul assures us, “Christ rising again from the dead, dieth now no more, death shall no more have dominion over him. For in that he died to sin, he died once; but in that he liveth, he liveth unto God” (Rom. 6:9-10).

An Image of the Holy Sacrifice

Now to answer the questions as well as I can (subject to correction from higher authorities!): “How does this square with theology’s assertion that, when we receive Holy Communion, we are receiving the resurrected, glorified Flesh of Our Lord? Why does the evidence point to His anguished, suffering, state and not to his glorified state?” I answer that the accidental appearance of the substance of our Lord’s Body as suffering does not contradict the truth that what is truly present is the glorified Christ because, first and foremost, what is being revealed to us in these Eucharist miracles is what is made present in the Holy Sacrifice of the Mass, namely, the selfsame Sacrifice of Jesus on the Cross on Good Friday.
Miracles have a purpose. They are to teach us something about God and His mysteries — not to reveal to us some new article of Faith (there is no such thing). In the case of Eucharistic miracles, what is being shown to us is some truth that we already must believe by faith. Speaking of Eucharistic miracles wherein a “part” of Christ’s Body, or His Blood, or Himself in the guise of a child appears, Saint Thomas says, “this is not deception, because it is done ‘to represent the truth,’ namely, to show by this miraculous apparition that Christ’s body and blood are truly in this sacrament.” (While he does not address the question we are taking up, the Angelic Doctor speaks matter-of-factly in that same question of the Summa of Christ’s presence in the Eucharist being that of His glorified Body.) Applying his logic to our question, we must say that the appearance in these miracles of distressed, suffering cardiac tissue from the left ventricle (a “part” of His Body) is “to represent the truth” — in this instance, the truth that the Mass itself is a sacrifice — the re-presentation of the bloody, violent Sacrifice on Calvary. In these miracles, we are being allowed to “see” the Sacrifice. Emphasizing the sacrificial character of the Divine Liturgy, St. Gregory Nanzianzen beautifully called the words of Consecration the “mystical sword” by which the Victim is slain. In these miracles, God miraculously shows us the “slaying.”

Moreover, depicting the accidents of the anguished, suffering Sacred Heart in these Eucharistic miracles emphasizes the enduring merit and the infinite value of that Sacrifice made once on the Cross, but mystically re-presented in every Holy Sacrifice of the Mass so that those merits might be applied to us in time. In light of this, it is “to represent the truth” of the Catholic doctrine of the Mass that God gives us these miracles in which scientists can catch a glimpse of the Passion.

In the five miracles discussed in that video, the accidents (appearances, species) of bread and wine are replaced, not by the total reality of what is present (the whole, glorified Christ), but by the accidents of one part of Christ’s Body — and that, in only one state, the living state just before the Sacrifice is consummated in Jesus’ death on the Cross. But, we should not get the idea that what is truly present under the sacramental veils is only cardiac tissue (and that, exclusively from the left ventricle), because such a conclusion would actually contradict the doctrine of the Council of Trent on Christ’s total presence in the Eucharist.

Again, we must emphasize that the Blessed Eucharist is the “whole Christ”; there is not one part of Him “left out.” Because of that, if the sacramental veils were lifted entirely and the sublime Reality that they conceal is depicted “in His proper species” (as Saint Thomas Aquinas would say), we would be seeing the glorified Jesus in majesty: not any part or parts of Him, but all of His beautiful Self at once! But He is only in His proper species in Heaven — where He is seated at the right hand of the Father.

Why Heart Tissue?

So far, we have answered why it is that we are given to see Christ in His suffering state in these miracles, but one aspect of the question still needs to be addressed: Why are we seeing exclusively heart tissue in these miracles, and that only from one specific part of the Sacred Heart? I argue that, in choosing to depict this, as the video suggests, God is teaching us a profound truth about the mystery of the Mystical Body of Christ — a fundamentally Eucharistic reality! — to whose members the left ventricle of the Sacred Heart circulates divine life while, at the same time, His AB positive Precious Blood assimilates us all into Himself. It is to represent this truth of our deifying Eucharistic union with Him in the Church that Jesus shows us the “largest and strongest chamber” of His Sacred Heart, the one that pumps the grace-infused Precious Blood from His inner sanctum to all the members of His Mystical Body.

For as often as you shall eat this bread, and drink the chalice, you shall shew the death of the Lord, until he come. Therefore whosoever shall eat this bread, or drink the chalice of the Lord unworthily, shall be guilty of the body and of the blood of the Lord. But let a man prove himself: and so let him eat of that bread, and drink of the chalice. For he that eateth and drinketh unworthily, eateth and drinketh judgment to himself, not discerning the body of the Lord. Therefore are there many infirm and weak among you, and many sleep. —1 Cor. 11:26-30

Pray God that we will not be among the unholy sleepers that Saint Paul mentions, but that we will be healthy, strong, and awake by lovingly and reverently discerning the Body and Blood of Our Lord Jesus Christ under the sacramental veils — partaking of them with a pure conscience. May the testimony of these astonishing Eucharistic miracles, supported even by secular science, arouse us and those we love out of a sickly spiritual somnolence, and may the grace of the Holy Ghost bring us into the radiant consciousness of a Faith perfected by the gift of Understanding.