Trans Fat

Trans fats are a type of unsaturated fat that can be produced commercially by the process of hydrogenation of plant oils and animal fats. Trans fats are also produced naturally in meat and dairy products, but most trans fatty acids in the typical American diet come from hydrogenated foods.

A hydrogenation reaction occurs when oxygen or other elements are withdrawn from, or hydrogen is added to, a molecule. The ultimate result is the addition of hydrogen and, therefore, conversion of a polyunsaturated fat (the fats present in vegetables that lower your cholesterol) to a saturated fat. Vegetable oils are hydrogenated in order to make them capable of deep frying foods such as french fries and onion rings.

Trans fats are typically in processed foods such as margarines, baked goods, cookies, chips, salad dressings, fried foods, as well as cereals. Although they were developed with the intent of replacing the known blood vessel-blocking saturated fats (animal fats found in butter, creams, and meats), it is now known that the trans fats are likely even more damaging to the blood vessels than saturated fats because they live longer in the body.

Scientists continue to debate the extent to which trans fats contribute to the amount of bad cholesterol (low-density lipoprotein [LDL]) in the bloodstream. The bad cholesterol can build up on the walls of blood vessels and cause blockage. The blockage could lead to vessel ischemia (decreased oxygen supply) or even infarction (death) of the tissue to which the blood vessel supplies. In 2006, the Food and Drug Administration (FDA) voted to incorporate the reporting of trans fats on nutrition labels present on the packaging of marketed food products. Consumers are now able to make more informed food choices based on the known content of saturated, trans, monounsaturated, and polyunsaturated fats. Trans fats are not an essential (meaning that they must be obtained from a source outside of the body) component of the diet.