Tradition, tradition!

For a lot of them, yes, there was a health reason.

Take Kashrut, mixing milk and meat. This had to do with the propensity of milk to curdle (no ice or refrigeration back then) and for meat to spoil.

Pork had to do with trichinosis and eating diseased pigs.

Shelled seafood (lobster, crab) had to do with the filthy stuff undersea getting in under the shell and not being able to decide what was “clean”.

For almost all of them, there are historical ancient antecedents to the religious rules of those days. Of course, that doesn’t mean much in 2019, where there are US FDA rules for food cleanliness.

I wonder why, instead of banning it, they did not just made the rule “cook it through”, or “only eat the fresh ones”.
And why did they not ban birds, as well? Salmonella is pretty bad, too.

@ragingloli I think it wasn’t as perfect as pork made some people sick and so it was banned. Maybe they didn’t figure out cooking it thoroughly will kill the bad organisms, or maybe it was like a game of telephone. Someone said pork was bad and then the gossip chain started about the pig being dirty and a garbage can. Shellfish also are seen as garbage cans of the sea. Eventually, it got written down as not being kosher probably for a combination of health and superstitious reasons.

Just like diets today often are an umbrella of belief the population holds about a food; enough people believe it and then it’s accepted as true. Sometimes there are some scientific reasons, sometimes not.

Meat and dairy are not a bad idea to eat in separate meals. Together it is a heavy load of fat and protein. I’ve read some kosher explanations that it was thought unfeeling to eat and animal in some form of its mother’s milk. I don’t really know if that was actually a thought or just a story I read.

A lot of the explanations for why kosher is good came after the rules were invented. Modern dietary explanations for why the rules wound up being a good thing.