Marion Nestle: Well the Food and Drug Administration says that adding bovine growth hormone to cows who are producing milk produces milk that’s identical to cows who haven’t been treated, and that’s why it’s not labeled. I think for a lot of people the idea that cows are being artificially treated in a way that will cause them to produce more milk is not particularly good for the cow. It’s not natural. It’s not what nature intended. They don’t like it. They’re worried about it. It’s very difficult to prove that a food, or a hormone, or an ingredient in a food is perfectly safe. That’s really difficult to prove. It’s also hard to prove that it’s harmful in any way that’s measurable. People eat very complicated diets. Milk is only one portion of the diet that people eat. But they would rather not have it. It’s hard to explain to a consumer why you need to have this hormone in the milk. It doesn’t seem necessary, and so why have it?