If it were your job to create the world's unhealthiest food product, you might do well to duplicate trans fat, otherwise known as trans fatty acids. Trans fat's qualifications include increasing LDL (bad) cholesterol levels, reducing HDL (good) cholesterol levels, increasing arterial plaque production and causing general digestive disorders. There are also suggestions that trans fat reduces the absorption rate of essential vitamins and minerals. From a health standpoint, trans fat is often described as a heart attack in a box.
Food-based fats generally fall along three lines: saturated, unsaturated and trans fat. Broadly speaking, saturated fats are found in meats and other animal-based foodstuffs. Saturated fats are not especially healthy, but the body can tolerate modest amounts. Unsaturated fats occur naturally in vegetable-based oils and some seafood. Most unsaturated fats are considered very healthy, because they do not collect in the bloodstream and help reduce levels of LDL (bad) cholesterol found in saturated fats. The final category, trans fat, has become very controversial in recent years.
Trans fat shares many of the same characteristics as saturated fat, including the negative effect on cholesterol levels and the tendency to clog arteries. However, the base of many trans fat products is vegetable oils, which ordinarily provide healthy unsaturated fat. Trans fat is the result of an artificial process converting vegetable oil into a more stable form of shortening. Instead of using a saturated fat product such as butter, food companies often use trans fat products like Crisco or margarine.
Trans fat is created through a process called hydrogenation. Ordinary vegetable oils are placed in tanks with a reactive metal such as cobalt. Hydrogen gas is bubbled through the oil until the entire contents partially solidify. The resulting product is called partially-hydrogenated vegetable oil, since the hydrogenating process is stopped before the oil becomes completely saturated with hydrogen. There are some commercial examples of fully-hydrogenated vegetable oils, such as a form of Crisco shortening intended to replace the less healthy partially-hydrogenated variety.
The process for creating trans fat was created around the turn of the 20th century and has been a source of controversy ever since. The introduction of such consumer-friendly products as margarine and shortening were embraced by the public at first, since they replaced fats which often became rancid and unusable. Warnings against the prolonged use of margarine and other trans fat products were largely ignored or downplayed by the food industry. From a business standpoint, trans fat shortenings allowed convenience foods to be produced inexpensively, and with an increased shelf life.
Recent studies on the long-term effects of trans fat have led medical groups to speak out against the continued use of partially or fully-hydrogenated oils and shortenings. Beginning in 2006, commercial food producers must provide trans fat information on their nutritional labels, along with saturated and unsaturated fat contents.