" Food processing began as a way to extend the shelf life of food by protecting it from these competitors. This is often accomplished by making the food less appealing to them, by removing nutrients from it that attract competitors, or by removing other nutrients likely to turn rancid, like omega-3 fatty acids. The more processed a food is, the longer the shelf life, and the less nutritious it typically is. Real food is alive—and therefore it should eventually die. "

― Michael Pollan , Food Rules: An Eater's Manual