It has been six years since the Food and Drug Administration (FDA) began requiring packaged foods to list trans fats on the label. Though animal foods like butter contain tiny amounts of natural trans fats, most trans fats in our food supply are synthetic, created when unsaturated vegetable oils are partially hydrogenated. This gives the oils a semisolid consistency that’s more suitable for many processed foods. Synthetic trans fats raise LDL (“bad”) cholesterol and have other adverse effects that increase the risk of heart attack and stroke.
In response to the labeling law, many manufacturers voluntarily reduced or eliminated partially hydrogenated oils—and thus trans fats—from their margarines, baked goods, snacks and other foods. Some fast food restaurants got rid of trans fats in French fries, while California and New York City banned artificial trans fats in restaurants altogether. Reassuringly, a 2010 study in the New England Journal of Medicine found that most reformulated foods do not contain higher levels of saturated fats, as feared. Instead, food makers and restaurants have largely replaced partially hydrogenated oils with healthy unsaturated oils.
These government and industry steps seem to be paying off now. According to a large study from the Centers for Disease Control and Prevention (CDC) published in the Journal of the American Medical Association , blood levels of trans fats decreased nearly 60 percent between 2000 and 2009, thanks to the removal of trans fats from processed foods. Such a dramatic drop in blood trans fats “should help lower the risk of cardiovascular disease,” says Hubert Vesper, Ph.D., the study’s lead author.
That’s good news, but don’t let down your guard. Some supermarket and restaurant foods still contain trans fats, sometimes at very high levels. Here are some examples, cited by the Center for Science in the Public Interest:
- Jolly Time Microwave Popcorn (some flavors), 4 grams of trans fat per serving
- Marie Callender’s Lattice Apple Pie, 5 grams
- Long John Silver’s Clam Strips, 7 grams
- White Castle donuts, as much as 9 grams
Other companies cited include Celeste Pizza, Jimmy Dean, Pepperidge Farm, Giant, DiGiorno, and Betty Crocker. The American Heart Association advises that trans fats provide no more than 1 percent of your total daily calories (that’s less than 2 grams a day for someone eating 2,000 calories a day).
Bottom line: Check nutrition labels for trans fats, but you have to read between the lines. Because of a labeling loophole, manufacturers can say their products have 0 grams of trans fat if they contain less than 0.5 grams per serving. That may not sound like a lot, but the numbers add up if you eat several servings. To avoid synthetic trans fats in packaged foods, make sure that partially hydrogenated oil is not in the ingredients list. If you use margarine, soft (tub) margarines are much less likely to contain trans fats, or at least much less of them, than hard margarines. Keep in mind that products that contain trans fats tend to be junk foods anyway, often high in calories, fat, and sodium.