The U.S. Food and Drug Administration (FDA) announced its next step in reducing the trans fat content in processed foods.  Specifically, the FDA issued a preliminary determination that partially hydrogenated oils (PHOs), the primary dietary source of artificial trans fat in processed foods, are not “generally recognized as safe” for use in food. The FDA’s preliminary determination is based on available scientific evidence and the findings of expert scientific panels.

One driving scientific resource was a report published by the National Academies Press from the Panel on Macronutrients, Subcommittees on Upper Reference Levels of Nutrients and Interpretation and Uses of Dietary Reference Intakes, and the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes.  The report noted that trans fats are not essential to the body and provide no known benefit to human health.  Also, trans fats are correlated with higher levels of bad cholesterol and higher risks of coronary heart disease.  Unfortunately, a normal nonvegan diet means that trans fats are generally included to some degree.  Major prepared foods, dairy products, and meats would have to be eliminated from the diet to completely remove trans fats, which may lead to an inadvertent decrease in necessary nutrients like protein.

According to the Mayo Clinic, trans fat is made by adding hydrogen to vegetable oil through a process called hydrogenation, which makes the oil less likely to spoil. Using trans fats in the manufacturing of foods helps foods stay fresh longer, have a longer shelf life and have a less greasy feel.  Commercial baked goods and many fried foods, such as doughnuts and french fries, may contain trans fats. Shortenings and some margarines can be high in trans fat.  Trans fat used to be more common, but in recent years food manufacturers have used it less because of concerns over the health effects of trans fat. Food manufacturers in the U.S. and many other countries list the trans fat content on nutrition labels.

Scientists are not entirely certain of the reason why, but the addition of hydrogen to oil increases cholesterol more than other types of fats. The thought is that adding hydrogen to oil makes the oil more difficult to digest, and the body recognizes trans fats as saturated fats.  In order to identify foods that contain trans fats, look at the nutrition label where it includes trans fats outright.  Also, the words “partially hydrogenated” with an oil indicate a source of trans fat.