God made animals to clean the earth to keep from spreading diseases. Isaiah chapter 65:4+5. Which remain among the graves, and lodge in the monuments, which eat swine's flesh,and broth of abominable things is in their vessels. Verse 5 Which, say, Stand by yourself, come not near to me; for I am holier than thou. These are a smoke in my nose, fire that burneth all day. Pig's don't have sweat glands except in there nose. So whatever they eat that poison stayes inside of them.
Seventh-day Adventists do not take pork or any unclean meat as established in the book of Leviticus and several of them avoid all meat for health reasons. Generally, pigs are safe to eat it's only some religious people avoid taking pork due to religious matters.
I'm not sure what seven day Adventists are, but I know Jews and Muslims don't eat pork. Jews don't eat it because pork is not a kosher animal, and should therefore be avoided. Muslims don't eat it for roughly the same reasons.
One of Gods laws is not to eat anything that doesn't chew it's own cud, which pigs don't. God, the all knowing, knew just how bad pork is for us. Although we are under a new covenant, many religions keep that law.