Beef and dairy fats are mostly saturated fats. Liquid oils are usually unsaturated fats, including monounsaturated fats in olive and canola oils and polyunsaturated fats in safflower, corn, soybean and fish oils. Cut the saturated fat, and your blood-cholesterol levels and your risk for heart disease drop. Your risk for cancer also decreases. A diet with more polyunsaturated fats, rather than saturated fats, lowers total blood-cholesterol levels, but unfortunately also drops HDL levels, so you lose both good and bad cholesterol.
Olive oil is another story.
This oil lowers total-blood cholesterol and LDL cholesterol without causing HDL levels to drop. By using olive oil, you can decrease your total-cholesterol levels while maintaining your HDL levels, thus decreasing your risk for heart disease. Fish oil also lowers heart-disease risk. Consequently, olive and fish are the oils of choice. This process also rearranges the molecular shape of the remaining unsaturated fats.