Trans Fats: The Science and the Risks (cont.)

The FDA, while requiring manufacturers to put the amount of trans fats on nutrition labels, will not require a percent daily value (DV) for trans fat because there is not enough information at this time to establish a such a value, she says. Food labels do offer such information about saturated fats.

How Do Trans Fats Compare to Saturated Fats?

"Trans fats raise (bad) LDL cholesterol levels slightly less than do saturated fats," says Lichtenstein. "But saturated fats also raise levels of high density lipoprotein (HDL) or "good" cholesterol, and trans fatty acids don't." Trans fats may actually lower HDL. Thus, some researchers say trans fats are worse. Lichtenstein, however, figures the two fats probably cause equal harm in our diets because we eat far more saturated fat than trans fats.

The FDA estimates that Americans adults eat 5.8 grams of trans fats per day -- that's about 2.6% of our daily calories. By comparison, we eat four to five times more saturated fat per day. About 40% of our trans fat intake comes from cakes, cookies, crackers, pies, and bread, while 17% comes from margarine.

Who Should Be Concerned About Trans Fats?

Of course, everyone should try to limit their consumption of trans fats and saturated fats. However, "individuals who are told by their physicians that they have elevated LDL cholesterol should be most concerned," Lichtenstein says. "They should minimize their intake of both trans fats and saturated fats."

Kava adds: "The most important thing is looking at the number of calories and then serving size. Then check out saturated fat and trans fat on the label. It might help some people make smarter decisions."

Are All Fats Bad?

Not at all. Polyunsaturated and monounsaturated fats -- found mainly in canola, olive, and peanut oils -- can result in less LDL and more HDL production in the body, says Boston-based community nutritionist Dana Greene, MS.

"That's a good thing," Greene says. But we should still limit our daily fat intake to 30% or less of our daily calories, she stresses. Her advice? "Choose heart-healthy fats including nuts, avocado, peanut butter, and trans-fat-free margarines such as Promise and Smart Beat."

Originally published July 17, 2003.
Medically updated July 6, 2006.

SOURCES: Ruth Kava, PhD, RD, director of nutrition, American Council on Science and Health, New York. Alice H. Lichtenstein, Dsc, professor of nutrition, Friedman School of Nutrition Science and Policy, Tufts University, Boston. Dana Greene, MS, nutritionist, Boston.

©2006 WebMD Inc. All rights reserved.

Last Editorial Review: 7/21/2006