Trans fat: An unhealthy substance, also known as trans fatty acid, made through the chemical process of hydrogenation of oils. Hydrogenation solidifies liquid oils and increases the shelf life and the flavor stability of oils and foods that contain them. Trans fat is found in vegetable shortenings and in some margarines, crackers, cookies, snack foods and other foods.
Trans fats are also found in abundance in "french fries." To make vegetable oils suitable for deep frying, the oils are subjected to hydrogenation, which creates trans fats. Among the hazards of fast food, "fries" are prime in purveying trans fats.
Trans fats wreak havoc with the body's ability to regulate cholesterol. In the hierarchy of fats, the polyunsaturated fats which are found in vegetables are the good kind; they lower your cholesterol. Saturated fats have been condemned as the bad kind. But trans fats are far worse. They drive up the LDL ("bad") cholesterol. which markedly increases the risk of coronary artery heart disease and stroke. According to a recent study of some 80,000 women, for every 5% increase in the amount of saturated fat a woman consumes, her risk of heart disease increases by 17%. But only a 2% increase in trans fats will increase her risk of heart disease by 93%!
The US FDA in 1999 proposed that the Nutrition Facts labels on vegetable shortenings and some cookies, crackers, margarines, and other foods may soon carry information about trans fatty acids, or trans fats. Beyond requiring that some labels list the amount of trans fats in the food, the FDA rule would also define the term "trans fat free" and limits the use of certain nutrient or health claims related to fat content, such as "lean" and "low saturated fat."
In the realm of dietary dangers, trans fats rank very high. It has been estimated that trans fats are responsible for some 30,000 early deaths a year in the United States. Worldwide the toll of premature deaths is in the millions.