I read this in the book “The Apples of Appolo, Pagan and Christian Mysteries of the Eucharist”.
(Caveat: I have not read this book in its entirety) Based on the excerpts from the book on the following page
csp.org/chrestomathy/apples_apollo.html it seems that the thrust of this book is to show that everyone involved in religious ritual of any sort, including Christian ones, around the Mediterranean and elsewhere was eating fly agaric, a psychoactive mushroom, and that Jesus was basically presenting Himself as the ultimate 'shroom in the Eucharist. Not sure I buy that premise (note that I do not disagree with seeing Christianity as one of the mystery religions of the time, I just doubt the hallucenogenic drug focus that appears to be the main theme of the book). The book seems somewhat similar to a book from the 70s, “The Sacred Mushroom and the Cross: A Study of the Nature and Origins of Christianity within the Fertility Cults of the Ancient Near East,” by John Marcus Allegro that portrayed Jesus as the personification of this hallucenogenic mushroom.
amazon.com/exec/obidos/ASIN/0340128755/freecomputersoft/
The wikipedia entry for theophagy
en.wikipedia.org/wiki/Theophagy lists Frazer’s “Golden Bough” as a primary source for the widespread practice of this sort of ritual, but unless I am very mistaken, The Golden Bough and many other books contemporary to it have not stood up to further and more recent scholarship. I have read Walter Burkert’s “Greek Religion” and don’t recall any mention of human sacrifice in the Eleusian mysteries or of the Greeks believing they were practicing literal theophagy in the way that the Catholic Church teaches it. I suppose it’s possible, but the concept of literally sacrificing and consuming one’s God is not something that seems a common theme in what I have read.
In searching around a bit, it seems that other pages mentioning a pagan theophagy (literally, “god-eating”) are comparing it to the Tauroctony in Mithraism. Here’s a link to a page on Mithraism from someone whose scholarship I personally trust, who disagrees with that (and note that he is a Neopagan who is disagreeing that Christianity borrowed from Mithraism, and says, in fact, that any borrowing was likely the other way around):
ceisiwrserith.com/mith/whatmithisnt.htm
"Mithraism had a ritual meal. This is true. Mithraic temples were set up for this very purpose, and we are told by both Tertullian and Justin Martyr that Mithraists had ritual meals of bread and wine (or bread and water) (Clauss, pp. 108 - 109). As Clauss writes, however, “In the case of these analogies, there can be no question of imitation in either direction. The offering of bread and wine is known in virtually all ancient cultures, and the meal as a means of binding the faithful together and uniting them to the deity was a feature common to many religions” (p. 109).
In some lists, such as that given by Acharya S., this meal is referred to as a “Eucharist,” or “Lord’s Supper.” This choice of words is clearly meant to assert a connection with Christianity simply by applying similar words. Those words are, however, highly inappropriate, since they possess meanings that we don’t find in Mithraism. “Eucharist” comes from a Greek word meaning, “grateful, thankful.” There is no evidence of such an attitude in the Mithraic ritual meal. Its modern meaning implies some sort of presence of a deity in the food and drink consumed; again there is no evidence of this in Mithraism. In fact, since the meal of Mithras and Sol, which is surely the prototype of the Mithraic cult meal, has as its main element the meat of the bull, the cult meal could not have had the meaning of eating the god. “Lord’s Supper” is equally loaded, since it implies a similarity with the Last Supper of Christianity. But the first supper eaten after an ascension which did not involve death is a very different thing from a last supper eaten before death."
These may or may not be the only groups upon which the assertion about pagan theophagy is based.
