Jehovah told the Israelites not to eat pork and other foods. The Israelites didn't know why they couldn't eat them, but those who obeyed were protected and blessed. I don't know why the legal department doesn't want us to do this copying and pasting and formatting for the benefit of others. At the same time I hope that by obeying, we'll be protected from something that I know nothing about.
Actually,
the Isrealites certainly would have known that as nomadic peoples pigs were not going to do well travelling. At best the pigs would get sick, and if you eat a sick pig you are likely to get sick too. As for shell fish... heck they knew nothing about shellfish and could easily pick up some red tide mussles and die eating them. So I'd say that modern readers of the mosaic laws
"didn't know why they couldn't eat them," but those ancient nomads certainly did know.