Lichtenstein is a member of the American Heart Association's Nutrition Committee. According to the University of Florida, the difference between saturated and unsaturated fat is hydrogen. All fats contain carbon, hydrogen and a little oxygen to form fatty acids. Fats not completely full of hydrogen are termed unsaturated. Animal fat tends to be highly saturated with hydrogen, while most vegetable fats are unsaturated to varying degrees.
Cholesterol is important in producing vitamin D, essential to the metabolism and cell formation.
Hu says that one way to help prevent heart disease is to replace saturated fats with liquid vegetable oils. Lichtenstein says that the nurses with better diets also lived healthier, and that also cut their risk for heart disease. They exercised more, and they tended to smoke less. So, just as you can't separate out one particular form of saturated fat as a villain, it is also hard to see individual behaviors as influencing risk. Connors agrees with Hu that calling stearic acid a safe form of saturated fat is just not worthwhile.