One of the great perks of being around during this phase of human history is that we seem to have a relatively good understanding of food. Which doesn't mean that we are necessarily heading in a great direction (junk food and its ilk seem rather self-destructive to the species), but through trial and error, we have a lot of wisdom behind us. We know that steaming the bud of an otherwise intimidating thistle flower yields a delicious cooked artichoke and that beyond the menacing claw of a lobster awaits yet another delicacy.
We can also thank our foodie forefathers for discovering the things that can kill us. To those who discovered that belladonna and hemlock should not be eaten: we salute you. But we're a funny bunch. Although our most basic instinct is for survival, we continue to eat poisonous things, or parts of them at least. If you doubt it, consider the following foods.
Also see: 8 alarmingly unhealthy snacks