Scientific study has proven that these unclean animals are more dangerous and unhealthy for human consumption. Doctors will sometimes give people instructions to avoid eating some of these animals to improve their health. The unclean animals carry desease, parasites, and toxins in their bodies. Pork is a known spreader of the influenza virus, and shellfish has a bad reputation of having high toxin levels that are dangerous for humans.
Aside from the obvious health benefits of eating kosher, it is also good for us to consider the possible spiritual affects of eating certain things. Remember that Yeshua cast the legion of demons into the heard of pigs. Why would the Messiah allow pigs to become demon possessed? Notice that he cast "unclean spirits" into the unclean animals. He would not have allowed the evil spirits to enter a flock of sheep, but he had no problem sending them in to the swine. Could this mean that there are deeper spiritual reasons for why God does not want us to eat these animals? I believe it is something we should at least consider.
I hope you enjoy this short video.