How Can Bread and Wine Change Into Flesh and Blood?

Ariel Dempsey
Thursday 7 July 2022
  1. Introduction and Hypothesis
  2. Fields of Study
  3. Discussion
  4. Conclusion

‘Take and eat.’ That is my people, make my body, which you now are…

~Candidus, early ninth century monk

1. Introduction and Hypothesis

Now as they were eating, Jesus took bread, and after blessing it broke it and gave it to the disciples, and said, ‘Take, eat; this is my body.’ (Matthew 26:26 ESV)

This is my body.” These mysterious words puzzled Jesus’ disciples at the Last Supper and have continued to puzzle theologians for the last two millennia. How can bread and wine become the flesh and blood of Christ?

How bread and wine can change into flesh and blood is a question explored in the field of theology and in the field of biochemistry. Could there be a connection between these two fields? In this article I explore an interesting connection arising from Candidus, an obscure monk from the Middle Ages with a unique perspective on the Eucharist.[1] Though Candidus wrote his theology in the early ninth century, his reflections on the Eucharist share striking similarities with modern biochemistry. In this theological puzzle I look at Candidus’ reflections on the Eucharistic and see how they open up a metaphor between theological and biochemical mechanisms. My hypothesis is that bringing together Candidus’ unique theology with the biochemistry of digestion can offer a new metaphor for modern Christians to imagine the Eucharist and experience its active relevance for Christian life.

Our scientific descriptions of the world rely on the tools of metaphor (Kuhn 1993; Soskice 1995). For example, the notion of a “biochemical mechanism” explains empirical chemical observations through a metaphor of mechanisms and machines. Metaphors are also an important tool in the field of Science and Religion—drawing upon physical realities to illuminate spiritual ones. A classic example is William Paley’s metaphor which likens an engineer’s design of a watch to God’s design of the universe (Paley et al. 1836). In the history of Eucharistic thought there is a long tradition of drawing metaphors between physical and spiritual feeding. Augustine, for example, draws parallels between physical and spiritual feeding on Christ, being connected to body of Christ and growing spiritually through doing so (Augustine and Hammond 2016, Book VII Ch X; Lienhard 2013). In Metaphorical Theology, feminist theologian Sallie McFague argues that metaphors preserve a sense of mystery because metaphors are and are not like the spiritual realities towards which they point (McFague 1983, 2-4). She proposes that “the metaphor sees in a glass darkly what we do not see and cannot know (McFague 1974, 645)”; and that the good metaphors are helpful for inspiring action and opening new ways of being in the world (McFague 1983, 17).

As McFague points out, metaphors can be taken with varying degrees of likeness and unlikeness. I leave it open for the reader to decide how literally to take the metaphor between biochemistry and the Eucharist. For one person, this metaphor may enrich the memorialist symbolism of the Eucharist. For another it might (like the metaphors of scientific theories) offer a biocausal account of the ways in which the bread and wine literally becomes flesh and blood. The way in which Christ’s body is present in the Eucharist has been a divisive debate throughout Christian history. I explore the relations between the Eucharist and biochemistry in metaphor because it gives the reader an active role and is broad enough to encompass a diversity of perspectives. Despite all the disagreements regarding the nature of the transformation of bread and wine in Eucharist, it is agreed upon that Christ’s presence in the Eucharist (be it physical or spiritual) is a mystery. My hope is that this metaphor between biochemistry and Candidus’ theology might honor the mystery of the Eucharist while also inspiring action, and opening ways of being in the world.

We will now begin to explore this metaphor. Section 2 breaks down Candidus Eucharistic thought and mechanisms of biochemistry, Section 3 joins the two together and Section 4 concludes with what this metaphor might offer for Christian life.

2. Fields of Study

2.1 Sacramental Theology

A sacrament is a Christian rite instituted by the Church. The field of sacramental theology includes reflection on Eucharist, baptism, confirmation, reconciliation, anointing of the sick, matrimony, and holy orders and ranges from patristics to contemporary theology.[2] According to tradition, a sacrament is both a visible sign of an invisible spirituality reality and a means of imparting the divine grace (Lombard 1971, Book III, Dist. 1, Chap. 4, No. 2, 2:233). The sacramental theology of the Eucharist is the focus of this puzzle, particularly, the Eucharistic theology of a little-known early ninth century monk named Candidus.

In the ninth century, the Carolingian monastery of Corbie was divided by Eucharistic controversy (Vaillancourt 2015). Some theologians, such as Paschasius Radbertus, argued that by the Holy Spirit, the bread and wine literally changed in substance to the flesh and blood of Christ. Other theologians, such as Ratramnus of Corbie argued that though Christ is spiritually present in the elements, the bread and wine still remain bread and wine. Though Paschasius and Ratramnus seem to offer opposing views, what strikes me is that both agree in speaking of the change that happens to the bread and wine as something that happens “out there.”[3] The bread and wine are objects observed and the believer is spectator to the change. Candidus offers a vision of the Eucharist that is radically different. In Opusculum de Passione Domini (On the Passion of the Lord), he writes, “‘Take and eat.’ That is, my people, make my body, which you now are…”(Patrologia Latina (PL)106.68D). For Candidus the bread and wine become flesh and blood of Christ in a significant sense. The bread and wine become flesh and blood in the body of the Church. 

Candidus stands as an outlier in his time. But he opens up an important line of thought we can develop as we explore the metaphor of eating and its relevance for individuals and communities. We now turn now to Candidus’ text Opusculum de Passione Domini (OPD).

Opusculum de Passione Domini

OPD is an early ninth century homily addressed to a community of monastic brothers (Jones 2018, 10). It is a work of exegesis on the passion narratives recorded in the gospels. Four of the five known manuscripts of OPD attribute the text to ‘Candidus’ but the identity of Candidus’ remains unknown (Jones 2019, 548:n12). Some scholars claim that the author of OPD is Candidus Brun of Fulda, a Benedictine monk and hagiographer from the Carolingian Monastery of Fulda (e.g. PL106.57B-.58C).[4] Other scholars argue that the author is Candidus Wizo/Witto/Watzo, an Anglo-Saxon priest who studied under Alcuin of York and Hygbald of Lindisfarne (e.g. Jones 2018, 7-8). Very little is known about either Candidus and thus the identity of the author is difficult to determine (Jones 2018, 1). Like the manuscripts, I refer to the author of OPD as “Candidus” and leave the question of true authorship for scholars of early medieval history.[5] For our purposes, it is not the text’s history that interests us, but it’s ideas and relevance for Christian life.

Though OPD is a beautiful text, it is scarcely known today. This article is one of only a few written on OPD. Furthermore, due to the obscurity of OPD, it was difficult to find a translation of the text from Latin. For this theological puzzle I am using the OPD text in the Patrologia Latina database (PL106.57D-.104A).

The OPD follows the events of Christ’s passion and harmonizes the gospel records. The Introduction begins by proclaiming that God sent “His Only-Begotten Son into the world for the salvation of the human race” (PL160.57D). Candidus invites his brethren to listen to story of the passion in order that they may be “filled with good works” and prepared to partake the fellowship of Christ’s life, suffering, death and resurrection. The passion story opens with the Passover and Judas’ betrayal, moves through the anointing of Christ by Mary Magdalene, washing of feet, last supper, garden of gethsemane, trials before Herod and Pilate, crucifixion of Christ and ends with Christ’s burial in the tomb. Chapter five, the chapter on the sacrament of the bread and wine, is that chapter which we will discuss.

OPD Chapter V (PL106.68B-.70D)

[Col.0068B] …And while they were eating, Jesus took bread and the rest. These are, brothers, the sacraments of our salvation; [Col.0068C] this is our spiritual sustenance; this is the salvation of our souls: we perform this sacrament daily on the holy altar; In this way, as you have heard from the Lord, after the old Passover was finished, he began. He then received the bread; therefore, he wished that this sacrament should be performed in bread, because the bread fitly fits the likeness of his Church; For bread from many grains that are broken and joined together passes through the fire, and becomes fit whence man’s life is sustained; and the Church, joined together from many saints and many tribulations within and without, as though crushed passes to heavenly life. The Lord took this bread, when he had assumed the human body, and blessed it by receiving it; for it was said after the transgression of our first parent Adam, ‘Cursed is the earth in your work.’ [Col.0068D] When, therefore, Christ had assumed a body from this earth, of which Adam was also made, he blessed that earth by his assumption, absolving it from being cursed, and broke it, when he had allowed the earth of which his body was formed to die on the cross, and gave it to his disciples, giving them the ministry of preaching among the Gentiles, saying: ‘Go, teach all nations.’ For this is what He says here: ‘Take and eat.’ That is, my people, make my body, which you now are, that is the body which is given for us. For what he had taken from that mass of the human race he broke by his passion and when it was broken raised it to life; for it is necessary for the bread to pass through the fire. What he began from us, then, he delivered for us. And you shall eat, that is, finish that body of the Church [Col.0069A] that the whole perfect one becomes one bread, as if one body, whose head is Christ. And if hitherto you are eating the bread of sorrow, yet when God gives his beloved sleep after toil (Psalm 127.2), then comes the inheritance of God in which [the saint] will abide for eternity.[6]

This is a highly complex passage. Two points emerging from this text will be our focus. The first is the recurrent theme of breaking and bonding in both physical sign and spiritual realities of the sacrament. The second is Candidus’ emphasis on the active role of believers in “making” Christ’s body.

First, breaking and bonding. Candidus begins with physical breaking of bread in the last supper, in the sacramental ritual of the Eucharist and in the processes used to make bread. He then draws a connection between the physical breaking of bread and the breaking of Christ’s physical body. The Earth is broken by Adam’s curse and the Earth of which Christ’s body is made is broken in Christ’s passion. Christ’s incarnation is framed as a breaking of Christ’s body by assumption of Adam’s curse. Christ’s passion (as recorded in the gospel accounts) is the continuation of breaking Christ’s body in the suffering of the betrayal, the beatings, the crucifixion and burial in a tomb. Finally, Candidus connects the breaking of the bread and breaking of the physical body of Christ with the body of Christ in the Church which is broken across nations and made of individual believers broken in suffering and death. The passion itself is breaking of Adam’s curse through the breaking of Christ’s body.

There is breaking and there is also bonding. In the Last Supper and the sacramental ritual of the Eucharist, breaking bread bonds believers together in fellowship with one another and Christ. Candidus points out that in the formation of bread the grains of bread are broken and pass through fire in order that they might be joined together to make the body of the bread. Something similar is true of Christ’s body which is broken in his passion and brought together again in the body of the Church. The Church is made of many believers and many nations, unified in their unity with Christ and bonded together by tribulations. Believers are broken as they partake in the fellowship of Christ’s passion, but by joining with Christ in his suffering death, they are united with Christ in his life. Christ breaks Adams curse because the passion which breaks his body also creates his body, uniting humanity with him.

Candidus predates the thirteenth century scholastic division of sacrament into sacramentum tantum (sign only) which is the bread, res tantum (reality only) which is the physical body of Christ, res et sacramentum (sign and reality) which is the body of Christ in the Church (King 1967). Yet, all three elements are present in his thought. At each level of the sacrament there is a motion of breaking and bonding.

Second, Candidus places emphasis on the active role of believers in “making” Christ’s body. For Candidus Christ’s passion is more than the historical record in the gospel accounts. Christ’s passion continues as it is assumed by individual believers who make his body, the Church. In taking the bread we become an essential part of the passion.

Candidus begins each section of OPD by breaking down quotation of scripture with exegesis and then joining it to a greater spiritual meaning. His exegesis of passages follows a rhythm that moves from the literal to allegorical to practical. Following Candidus’ style, I will now do the same as I move through a small section of his extraordinary text. The quotation below highlights our active role in continuing Christ’s passion:

Take and eat.’ That is, my people, make my body, which you now are, that is the body which is given for us (PL106.68D).[7]

‘Accipite et comedite.’ Id est, gentes, facite meum corpus, quod vos jam estis, istud est corpus quod pro nobis datur (PL106.68D).[8]

Take and eat

In Latin the word for “take”, is accipere. In the preceding lines (PL106.69A; PL106.68C), and other passages of OPD, Candidus uses accipere to refer to the way Christ “takes” on humanity in the assumption. Fascinatingly, accipere is used only in reference to Christ “taking” the assumption of humanity and “taking” the sacraments of bread and wine. This observation suggests that assumption is central to Candidus’ understanding of the sacrament. For Candidus, the Eucharist is understood through the assumption and the assumption through the Eucharist.[9]

In the sacrament of bread and wine, the bread has a special significance for Candidus. He relates the bread to Christ’s body in multiple senses. As he comments on the Eucharist in Ch V he writes, “The Lord took this bread, when He assumed the human body, and blessed it by receiving it” (PL106.68C). And later in Ch V, “The bread, therefore, is the body of Christ, which His Church assumed from the body” (PL106.69B). The bread is the body of Christ, his incarnation, his passion, and his Church.

But Christ is not the only one who “takes” the bread in the Eucharist. As believers “take the bread” they assume his passion as they consume his body. And this brings us to the next word in the sentence, which is “eat.”

The Latin word translated as “eat”, is comedite. In Chapter 16 of OPD, Candidus reflects on this rich and theologically laden word. He explains that eating the fruit hanging from the tree of knowledge of good and evil brought death to humanity. Inverting this powerful symbol, Candidus relates the body of Christ on the cross to a body of fruit hanging on a tree. Adam and Eve ate the fruit from the tree in the garden of Eden and brought death. Christ is the fruit hanging on the tree, which by eating (in the Eucharist) we have life. He who eats my flesh has eternal life (PL106.92A).

Like Adam and Eve in the Garden, Christ “takes and eats.” Christ “takes” the bread, takes incarnation of the body, takes assumption of humanity. Christ “eats” the fruit of the bread, eats the fruit of the curse and takes the curse of Adam upon himself.

In the Eucharist, we too are commanded to “take and eat.” We take the bread and eat Christ, the fruit which undoes the curse. We “take and eat” not as Adam but as Christ. By taking and eating the bread, Christ becomes a human body and assumes our death. By taking and eating the bread, we assume Christ’s death. And in assuming his death we become his body and assume his life. Our partaking in the Eucharist is partaking in his passion.

That is, my people, make my body, which you now are, that is the body which is given for us.

If the Eucharist means assumption of Christ’s passion the natural question follows, what is Christ’s passion? And now one begins to wonder if Candidus wrote On the Passion of Our Lord as an answer to that question. When seen in this light, the text becomes not just the story of the account of Christ’s passion but the story of our passion too.

Right at the moment Candidus’ readers would expect the words “this is my body Candidus writes the surprising words, “make my body.” The word “make”, in Latin facite, also means “do.” Christ’s taking of bread is taking a mission of salvation and redemption. Candidus links our taking of bread with the taking of a mission too. Facite is a second person plural imperative. It is a command to make Christ’s body, the Church, and to be Christ’s body here on Earth. Candidus writes, “and you shall eat, that is, finish that body of the Church(PL106.68D). There is work of the passion to be finished and it is work we are invited to do.

Throughout OPD Candidus draws spiritual allegories from bodily functions, (eating, sleeping, sweating, bleeding, etc.) Candidus takes ordinary acts from the physical processes in the passion narrative and imbues them with spiritual meaning. For example, in Ch V, he finds theological significance in the mechanisms of baking bread—reflecting upon on how the grains are broken apart and put through fire to join the separated grains together (PL106.68C). Candidus did not know biochemistry, but I imagine that if he did, he may have extended his biological-theological analysis to a molecular level—reflecting upon mechanisms by which the body breaks molecules of bread apart and puts it through a metabolic fire to join the separated molecules together.

Having looked at Candidus’ theology we now begin to ask how this might help us make some connections with biochemistry. Following Candidus’ creativity, I draw a spiritual metaphor from the biochemical mechanisms of bread metabolism. In Christian tradition there is a notion that God is revealed in the “book of scripture” and in the “book of nature” (Harrison 2006). Candidus read the books of the gospels. We now turn to book of biochemistry and consider a biochemical perspective on the clause, “make my body.”

2.2 Biochemistry

Biochemistry is the study of the chemical mechanisms of living organisms. At the molecular level, biochemistry analyzes processes such as protein synthesis, cell membrane transport, signal transduction, genetic modification, endocrine feedback loops, neural signaling, metabolism and much more. The chemical physiology of human digestion and metabolism is our area of interest (for an introduction to the material below see Da Poian and Castanho 2015).

Metabolism is the process by which nutrients are converted into energy and incorporated into the body. Metabolic reactions are broadly categorized into two types, catabolic and anabolic. Catabolic reactions (destructive metabolism), break down molecules to release energy in the form of adenosine triphosphate (ATP). Anabolic processes (constructive metabolism) synthesize molecules to be incorporated into the body for growth, repair and storage.[10]

Taking the bread of the Eucharist begins with catabolic processes that break the bread. The bread is broken down mechanically by mastication, (chewing), and chemically by enzymes in the saliva released by salivary glands. The enzyme, salivary amylase (α-amylase) breaks the polysaccharides of bread carbohydrates (starch, glycogen) into smaller units of oligosaccharides and disaccharides, (dextrin, maltose) by hydrolyzing α-linked glycosidic bonds (Joubert et al. 2017).

Figure 1 (Gopinath et al. 2017, 3)

As the bread bolus moves to the stomach, the α-amylase is deactivated by the stomach acidity and mechanical, peristaltic contractions continue to break down the bolus into a mixture called chyme. As chyme moves to the small intestine, the pancreas releases pancreatic amylase which (like α-amylase) breaks polysaccharides of bread carbohydrates into oligosaccharides and disaccharides. Small intestine brush border enzymes, maltase, sucrase, and lactase breaks oligosaccharides and disaccharides into monosaccharides small enough for absorption through the intestine wall. Maltase breaks maltose into two glucose molecules and breaks bonds between glucose and galactose. Maltose is a primary disaccharide found in bread. Sucrase breaks sucrose (also found in bread) into glucose and fructose. For more on the mechanics of bread digestion see (Bergeim 1926; Birkhed and Fuchs 1975; Bornhorst and Singh 2013; Joubert et al. 2017; Freitas and Le Feunteun 2019; Gao et al 2021).

Figure 2 (Rye et al. 2021)

These monosaccharides are transported into enterocytes (intestinal wall cells) via facilitated diffusion and active transport, absorbed into the blood and transported to the liver. In the liver, galactose is converted to glucose, fructose is broken to smaller carbon-containing molecules and glucose is either stored as glycogen through glycogen synthesis or transported back into the blood. Insulin, secreted by the pancreatic beta cells, signals cells to uptake the glucose to be used for energy or building macromolecules. In a biochemical pathway called glycolysis, the cells break down glucose in the cytoplasm into energy of ATP and into building blocks for organic macromolecules. Glycolysis of a single glucose molecule generates two molecules of ATP and pyruvate. Pyruvate can be broken down further in the cytoplasm through the anaerobic metabolic pathway of alcohol and lactic acid fermentation. Pyruvate can also be converted to acetyl Co-A and transported into the mitochondria to be broken down in aerobic metabolic pathway of the citric acid cycle (TCA). Through two cycles of the TCA, the metabolic products of one glucose molecule generate two GTP, six NADH and two FADH2. These molecules undergo oxidative phosphorylation on the mitochondrial membrane and generate a theoretical net production of thirty-two ATP (Chaudhry and Varacallo 2022).

Figure 3 (Alam et al. 2016, 3)

In short, catabolism of bread produces energy and materials used in anabolic processes that build up the body. Anabolic processes incorporate the molecules of bread into our bodies via a number of metabolic pathways. Below, I list a few:

  • Fatty Acids Synthesis in the liver and adipose cells uses Acetyl-CoA from glucose metabolism to generate fatty acids necessary for building cell membranes, intracellular signaling pathways, transcription factors determining gene expression and other important functions (Calder 2015).
  • The Pentose-Phosphate Pathway synthesizes ribose 5-P, the sugar backbone of DNA (deoxyribonucleic acids) and RNA (ribonucleic acids) from the glucose-6 phosphate product of glycolysis. This pathway not only plays an important role in genetics but also in cholesterol and fatty acid production necessary for endocrine hormones that regulate homeostasis.
  • Amino Acid synthesis uses 3-phosphoglycerate, phosphoenolpyruvate and pyruvate from glycolysis as well as oxaloacetate and α-ketoglutarate to create twenty types of amino acids necessary for protein synthesis. These proteins are used to build a repair tissue. They form muscles, cell structures, enzymes, hormones such as insulin, glucagon, hGH (human growth hormone), ADH (antidiuretic hormone), ACTH (adrenocorticotropic hormone), connective tissue such as keratin, collagen and elastin, ferritin to store iron, antibodies for immunity, carrier molecules for essential vitamins and minerals, hemoglobin for oxygen transport and much more.
  • Glycogen synthesis turns glucose into glycogen which can be stored and broken down for future use.
  • Ketogenesis transforms Acetyl-CoA into ketone bodies (acetoacetate and b-hydroxybutyrate) that the heart, skeletal muscles and brain can use for energy.

The above is a glimpse into the biochemistry of carbohydrate metabolism. Bread also contains proteins and other nutrients that are digested and absorbed through other enzyme catalyzed reactions but tracing the biochemical carbohydrate pathway is sufficient for our purposes (for more on mechanisms described above see Wilkins et al. 2021; Bonora et al. 2012).

“You are what you eat”, was the popularized slogan of the 1930’s American nutritionist Victor Lindlahr (Shapin 2014, 1-2). Candidus of Fulda couldn’t have agreed more. Biochemically, the molecules of the Eucharist bread are catabolically broken and anabolically incorporated into flesh and blood to build the body and generate energy for action of life.

3. Discussion

Having discussed Candidus’ theology and mechanisms of biochemistry we can now begin to explore some connections. Biochemically we have a breaking down and building up. We can discern a similar movement in Candidus’ Eucharistic theology. Christ’s body is catabolically broken in his passion to be anabolically bonded together in the Church. Furthermore, the mechanisms by which biochemistry and Candidus explain the change of bread into a body share remarkable parallels. Both involve breaking and bonding to make a body and release energy for action (3.1). In both we play an essential part in the transformation (3.2).

3.1 Breaking and Bonding

In biochemistry, the term “fractionate” means to separate or break. It is derived from the Latin word fractus, which is a word Candidus chooses to describe the breaking of bread and breaking of Christ’s body (PL106.68D). With regard to breaking and bonding, the Eucharist can be a visible symbol of both the biological and spiritual reality. In the liturgical act of the Eucharist, the bread is broken by the priest and the congregation of believers are joined together in the fellowship of taking the bread. Candidus says the bread fitly fits the likeness of the Christ’s Church and the reason he gives is that the bread is made of many grains that are broken, pass through fire and joined together to sustain life. On this criterion, the biochemical digestion of bread fits the likeness of Christ’s Church just as well. In the process of digestion elaborated above the molecules of bread, pass through metabolic fire to be joined together and sustain life.

Furthermore, this biochemical reality fitly fits the likeness of Christ’s passion, just as well as it fits the likeness of the Christ’s Church. Christ’s passion begins with his incarnation, the assumption of humanity, the “taking of bread.” His passion is the breaking of the bread, the breaking of his body as he passes through the fire of suffering on the cross that saves humanity and joins together his body, the Church. The Church is a continuation of that incarnation. The “taking of bread” is the assumption of Christ’s passion, passing through the fire of suffering, joining in his death so that we might be joined with him in life, and joining with each other to be the flesh and blood of Christ here on Earth.

Candidus’ Eucharist theology is as complex as a biochemical pathway. I can imagine using the tool of a biochemical diagram to illustrate ways in which elements of Candidus’ Eucharistic theology interweave and interact like dynamic metabolites. Perhaps levels of the Eucharist, sacramentum tantum, res tantum, res et sacramentum, could be metabolic pathways like glycolysis, TCA, Oxidative phosphorylation which take the same element, such as bread, and transform it into new products and byproducts that are incorporated in other reactions. Moments like incarnation and crucifixion could be like enzymes catalyzing reactions. Below I sketch an imaginative picture. This diagram shows catabolic and anabolic processes breaking and building the body of Christ in multiple pathways and in layers upon layers of reactions. The products (and by-products) of the pathways are transformed as they are drawn into processes that bond individual believers with one another, and with Christ to make Christ’s body.

Figure 4[11]

In summary, the passion incorporates catabolic processes of breaking to anabolically bond what was broken into one body. As in biochemistry, the bread is broken in order that the body might be made. These processes create energy to do Christ’s work and this brings us to the second point.

3.2 We Play an Essential Part in the Transformation

Candidus writes, “Take and eat.That is, my people, make my body, which you now are…” For Candidus the bread and wine do become flesh and blood of Christ in a significant sense. The bread and wine become flesh and blood of Christ in the body of the Church. Candidus reads this from the books of scripture; I read this from the book of biochemistry. As believers eat the bread and drink the wine of the Eucharist, biochemically, these elements are broken down by their digestive system and literally changed into the flesh and blood of their bodies. Similarly, in the Eucharist, the bread and wine also become flesh and blood in us. As Candidus is read in light of modern biochemistry, what emerges is a fresh vision of the Eucharist. Believers aren’t spectators, looking at the bread and wine and pondering its nature. Believers are just as much a part of the Eucharist as the bread and wine because it is in them that there is a change of substance as Christ’s body is made incarnate on Earth in the body His Church.  

A key implication of this theological-biochemical synthesis is that we are active agents in the Eucharist. We are as essential of an element of the sacrament as the bread. Taking the sacrament of bread and wine isn’t just a little ritual to be contained in Church walls on a Sunday morning. What if the Eucharist is the whole incarnational vision of Christian life and Church? What if to take the Eucharist is to assume in our bodies and our lives the passion of Christ? Perhaps the change that Christ makes in us, and that we are called to make in the world, is as radical as transubstantiation from dead bread to living flesh. Perhaps our agency and cooperation are as necessary for the Eucharist as for continuing the incarnation of Christ’s passion for salvation and redemption of the world.[12]

I can testify that this vision of the Eucharist I found in Candidus has changed my experience of the sacrament. I am lost in wonder and mystery and as I watch the congregation move towards the altar. I whisper to myself, “My God, it’s really happening. The bread and wine are becoming flesh and blood.” As I stand among the congregation I think, “That ordinary looking man to my left is Christ’s body. That old woman in front of me is Christ body. This little boy is Christ’s body.” I look at my hands and feet and think, “I am Christ’s body.” And this inspires a Eucharistic vision of my life extending beyond the walls of the Church and fills me with energy and desire to do good works of love.[13]

4. Conclusion

How can bread and wine change into flesh and blood? Biochemically and theologically the answer is this: bread and wine are changed into flesh and blood in us.

The sacrament of the Eucharist is a mystery. However, the physical science of biochemistry provides a new metaphor for engaging with this mystery. Candidus states that his purpose in writing OPD is that his brethren may be “filled with good works” and prepared to partake the fellowship of Christ’s life, suffering, death and resurrection. My aim is similar.

Drawing on a metaphorical synthesis of biochemistry and theology, I present a vision of Eucharist that offers a way for modern Christians to imagine consumption of the Eucharist as assumption of Christ’s passion. His passion our passion, his death our death, his life our life, his body our bodies. We are Christ, in flesh and blood, here on Earth.


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[1] See footnote 4-5 for Candidus’ background.

[2] For introduction to sacramental theology see The Oxford Handbook of Sacramental Theology (Boersma and Levering 2015a).

[3] Paschasius and Ratramnus wrote the first Latin theological treatises on the Eucharist. Both treatises were entitled De Corpore et Sanguine Domini (On the Body and Blood of Our Lord) but they came to very different conclusions regarding the nature of the bread and wine (Phelan 2010, 271). Paschasius’ and Ratramnus’ Eucharistic theology is complex and their differences are especially amplified as a result of later Reformation debates (Otten 2000). When focusing on conflicting aspects of Paschasius’ and Ratramnus’ thought, discussions tend to concentrate on the change in bread and wine as something that happens “out there.” Candidus provides a helpful corrective to this tendency.

[4] Patrologia Latina (PL106.57B-.58C) attributes the text to Candidus Fuldensis Monachus (Candidus Monk of Fulda) and dates the text Anno Domini DCCCXL (840 AD)

[5] For further sources on authorship see (Jones 2018, 10:n8-10; Jones 2019, 548:n10)

[6] My translation, emphasis original. I am grateful to Oxford University Professor of Early Christian Studies, Dr Mark Edwards, for assistance in translation. I’ve drawn on his translation with permission.

[7] This quotation appears to be an amalgamation of Matthew 26:26, Mark 14:22, Luke 22:19.

[8] Gentes could also be translated as “peoples”, “nations”, or “gentiles.” Jam could also be translated as “already.”

[9] Candidus does not use the word “Eucharist” (eucharistia) but instead opts for “sacrament” (sacramentum), “sacrament of Christ” (sacramenta Christi), “sacrament of Christ and the Church” (sacramenta Christi et Ecclesiae), “sacrament of God” (sacramentum dei). For ease of discussion, I call this sacrament the Eucharist.

[10] Anabolic processes can also release ATP.

[11] My drawing. Graphically illustrated with the assistance of artist, Janeil Foy. This diagram is a creative exercise, using symbolic tools of biochemistry to illustrate Candidus’ theological ideas. This diagram could be drawn many other ways; this is one example.

[12] “Active agents” can be contrasted with spectator. “Active” can also be contrasted with passive. The Latin word which Candidus chooses for “take,” accipere, enfolds the active notion of taking but also the passive notion of receiving. We “take” the bread of the Eucharist and also “receive” it. Our taking of the Eucharist is, like digestion, an active passivity.  

[13] For a Eucharistic vision of Christian life and church in modern theology and see for example, Vatican II Lumen Gentium (LG 1964, 1); Edward Schillebeeckx’s Christ: The Sacrament of the Encounter with God (Schillebeeckx 2014); Alexander Schmemann The Eucharist: Sacrament of the Kingdom (Schmemann 1988). For locating the real presence of Christ in the Eucharist in the encounter between the sacrament and the believer see Anglican Receptionism (Martin 1857).

Cite this article

Dempsey, Ariel. 2022. How Can Bread and Wine Change Into Flesh and Blood?Theological Puzzles (Issue 11).

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Ariel Dempsey
Email: [email protected]

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