system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why can we eat almost any part of most living things without incident, but eating some brains and cows with mad cow disease are dangerous to us?
gpt
This is because of prions, which are infectious misfolded proteins. They exist only in the brain and are transmitted when someone/thing eats infected brain matter. The prions cause the host's proteins to misfold, causing cell death. This creates the characteristic spongy brain associated with prion diseases like Kuru and Mad Cow. In short, don't eat brains.