Answer
It is not only Islam that prohibits eating pork. As the Evangel and the Torah indicate, eating pork was prohibited in the dietary laws of previous religions as well. The reason commonly expressed for this prohibition is that pork is harmful for one’s physical and spiritual health, for it feeds on canonically unclean materials.
The Reason why Consumption of Alcoholic Beverages is Prohibited by Islam
By: Allamah Sayyid Muhammad Husayn at-Tabataba’i