system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are people consistently allergic to things like coconuts and peanuts but not things like bananas or onions?
gpt
We don't know for sure, but it's theorized that people are allergic due to peanuts and other tree nuts having many proteins not present in other foods like bananas or onions. The immune systems of many people tend to overreact and treat peanuts as a threat due to their unusual protein structures.