Vegetable shortening is a common ingredient used in cakes, pies, breads, doughnuts and other baked goods. It is also typically used in fast food restaurants to prepare fried foods such as onion rings, breaded fish and chicken, and breakfast sausage. Although vegetable shortening features prominently in the diets of many Americans, some types are loaded with unhealthy trans fats.
The production process determines whether vegetable shortening contains trans fats. Some types of vegetable shortening are partially hydrogenated, which means they are infused with hydrogen atoms to create an oil that is solid at room temperature but melts at cooking temperature. The chemical reaction turns the oil in the shortening into trans fats. Other types of shortening are fully hydrogenated -- they will not melt at cooking temperatures by themselves. Fully hydrogenated shortening must be infused with non-hydrogenated vegetable oil, which reduces the melting point to make it suitable for cooking. Fully hydrogenated shortening does not contain trans fats, although the hydrogenation process results in saturated fats, which can lead to heart disease.
The primary benefit of hydrogenation is increased shelf life -- shortening can be stored for long periods of time at room temperature without turning rancid. Shortening made with hydrogenated oil is cheaper to produce by volume than non-hydrogenated oil, which reduces costs for restaurants and consumers. Because shortening can be stored at room temperature, it also decreases the need for refrigerated space.
Trans fats found in partially hydrogenated vegetable shortening raise low-density lipoproteins in your bloodstream, according to the American Heart Association. Low-density lipoproteins can contribute to lipid blockages in your blood vessels, increasing your risk of heart attack, stroke and coronary artery disease. Trans fats also lower high-density lipoproteins, which are components of blood cholesterol that help clear lipid deposits from your circulatory system.
Unsaturated fats are healthier alternatives to the partially hydrogenated and fully hydrogenated fats found in vegetable shortening. Unlike shortening, unsaturated fats are free of saturated fats and trans fats. Pure vegetable oil and olive oil are unsaturated fats -- although they are more expensive and have a shorter shelf life than shortening, they do not raise low-density lipoproteins or deplete high-density lipoproteins. These oils pose less risk of blood vessel blockages. The monounsaturated fats in pure olive may lower your risk of heart disease, according to the American Heart Association.