(eating pork was probably a health hazard until the 20th century)Human flesh and pork are practically indistinguishable; I've come around to the view that is what led to the prohibition on eating pork among the Jews, and later among the Muzzies.
I think it relates to the fact that pigs and humans have to eat the same thing. Cows, horses and etc can digest cellouse and humans and pigs can't. During a famine people would be pretty upset if you were the owner of pigs...whether you were the king or not, hungry people will kill you because they know you're feeding the pig something you could be eating.
Religious leaders probably recognized the potential for conflict and worked this prohibition into the religious texts.
Also, cattle are 75% more efficent at digesting cellouse than horses and archaeologists use the ratio of horse/cow bones to detect drought/famine conditions, especially out on the steppes.