I just unwrapped a twice-baked chocolate croissant, and a silverfish fled from the wrapping. I destroyed the insect, then considered throwing the pastry, which I'd been anticipating for two days, away, for fear the bug had contaminated it somehow. I'm no expert in silverfish; all I know is that they must be destroyed on sight.
I ate the pastry. I figure if you're willing to put a twice-baked chocolate croissant in your mouth, you're long past the point of worrying about the negative health effects of what you eat.