I have heard and read from more than one source that when we consume pork it kills off some of our blood cells. I'm not exactly sure what happens and I can't find where I read it at the moment and my mom has the audio tape it's on. But basically it kills off blood cells which appear as "ghost" cells under the microscope. This is why we feel tired after eating pork because of the decrease in hemoglobin. Type "dangers of pork" in a search engine and lots of links come up. Pretty crazy stuff.