It would seem that pigs have been barred from Jewish diets for thousands of years. A defining moment is seen in the capture of Jerusalem by King Antiochus IV Epiphanes. The king sacrificed a pig in the temple to celebrate his victory, thus defiling the space. When the Jews recaptured the city the began the festival of Hanukkah, Festival of Light, which bears many resemblances to Christmas, candles, presents, feasting. Of interest naturally is once again the links between conflicting associations. A website offering further information is available here.
Related to the History of Pork is the development of a vegetarian diet. The following quote is new to me:
Albert Einstein, physicist, Nobel Prize 1921