Many historians have recorded the accusations that the pagan Romans made against the Church. The Early Church was accused of cannabalism, most reputable historians, catholic or non-catholic have written about this.

Msgr. Philip Hughes three volume History of the Church is a good resource, it was also condensed into a one volume paperback A Popular History of the Catholic Church .

One of the reasons I like to use Msgr. Hughes, and Msgr. Ronald Knox when I discuss the Catholic Faith with Protestants is they were both very anti-Catholic Protestant ministers before they converted to the Faith. By reading the history of the early Church they were convinced that the same doctrines that the Apostles and the Bible teach are what the Catholic Church still teaches today. Most of their books have been reprinted, and older used copies are usually found in thrift shops, and used book stores, as well as online for reasonable prices.

Here is a link to the three volume History by Msgr. Hughes online.
http://www.franciscan-sfo.org/ap/hu/0-ha.htm