The belief that natural foods are safe stems from supermarket living, not reality.

Evidence

Note, if you are educated and Western, you might be thinking that my numerous examples of toxic plants and animals are merely special cases, because you might be under the impression that few plants need detoxification and that nature’s bounty is pure and safe. For many Westerners, “it’s natural” seems to mean “it’s good.” This view is wrong and comes from shopping in supermarkets and living in landscaped environments. Plants evolved toxins to deter animals, fungi, and bacteria from eating them. — Joseph Henrich, The Secret of Our Success, 342