The consequences of bovine milk consumption are diverse, some of which are potentially deleterious. Although certain cultures shun cow's milk or milk-based products, Western societies consume large quantities of cow's milk. Although there are stronger similarities between bovine whey proteins and human whey proteins, the quantity and nature of casein in cow's milk differ markedly from human milk. We propose that the consequences of diets based on bovine casein should be more closely evaluated and certainly expanded beyond the simplistic approach of growth. What is good for the goose may be good for the gander, but what is good for the cow could be harmful to the human.