Here's an interesting thought I had at lunch the other day.
Most people don't eat certain things because it's bad for your health. The Wikipedia article for Judaism states,
Major prohibitions exist on eating pork, which is considered an unclean animal...
which conforms to our expectations.
However, there's also the case of Hinduism, for which Wikipedia has,
Observant Hindus who do eat meat almost always abstain from beef. The largely pastoral Vedic people and subsequent generations relied heavily on the cow for protein-rich milk and dairy products, tilling of fields and as a provider of fuel and fertilizer. Thus, it was identified as a caretaker and a maternal figure. Hindu society honors the cow as a symbol of unselfish giving. Cow-slaughter is legally banned in almost all states of India.
Interesting how the final result (of abstaining from a food) is the same, but the rationale is the complete opposite.
(For those wondering, I knew about the eating habits before. I just find quoting Wikipedia so much easier than trying to explain it myself.)