"My friend David Kritchevsky, who was probably the leading researcher in this area until his death, found40 that "protein of animal origin is more cholesterolemic [leading to higher cholesterol in the bloodstream] and atherogenic [contributing to heart disease] than protein of plant origin for rabbits," citing several studies41--a distinction between types of protein that was first noted in regard to atherosclerosis more than sixty years ago.42 He found the same to be true for humans, as well.43 We observed a similar distinction between soy and casein protein (the principle protein in milk) in my lab when they were compared in our studies on experimental cancer with rats."