Health & Family

Q&A: What are trans fats and why are they unhealthy?

Doughnuts. The Obama administration is cracking down on artificial trans fats, calling them a threat to public health.
Doughnuts. The Obama administration is cracking down on artificial trans fats, calling them a threat to public health. AP

You may not even know you are eating them, but trans fats will soon be mostly gone from your food. The Food and Drug Administration said this month it will require food companies to phase them out over the next three years because the agency says they are a threat to public health.

Among the foods that commonly contain trans fats: frostings, pie crusts, biscuits, microwave popcorn, coffee creamers, frozen pizza, refrigerated dough, vegetable shortenings and stick margarines. The fats help give a more solid texture and richness to certain foods, like baked goods and ready-to-eat frostings.

Questions and answers about the dangerous fats:

Q. What are trans fats?

A. Trans fats are created when hydrogen is added to vegetable oil to make it more solid, which is why they are also called partially hydrogenated oils. Trans fats can raise “bad” cholesterol and lower “good” cholesterol. That can contribute to heart disease – the leading cause of death in the United States.

Q. How will trans fats be phased out?

A. The FDA has determined that trans fats no longer fall in the agency’s “generally recognized as safe” category, which is reserved for thousands of additives that manufacturers can add to foods without FDA review. Once trans fats are off the list, anyone who wants to use them would have to petition the agency for a regulation allowing it, and the agency isn’t likely to approve many uses.

Q. Haven't they already been largely phased out?

A. Yes. The FDA says that between 2003 and 2012, people ate about 78 percent less trans fat as food companies began using other kinds of oils to replace them. But the FDA is aiming to get rid of those trans fats that are left in the marketplace, saying they are still a public health concern.

The FDA has required the amount of trans fats in foods to be listed on the backs of food packages since 2006, but that doesn’t always tell the whole story – companies are allowed to round less than half of a gram of trans fat to zero on the package label. Susan Mayne, director of the FDA’s Center for Food Safety and Applied Nutrition, says those hidden amounts can still “add up to a considerable intake of trans fats if you look at the overall diet.”

Q. Will I notice the change?

A. Probably not. Trans fats don’t have any particular taste, and in most cases other fats will simply be substituted. Bottom line: The Obama administration says the move will reduce coronary heart disease and prevent thousands of fatal heart attacks every year.