Vegetable oil, usually a liquid, can be made into a semi-solid shortening by reacting with hydrogen.
Partial hydrogenation reduces the levels of polyunsaturated oils and also creates trans fats, which promote heart disease.
A committee of the U.S. Food and Drug Administration (FDA) concluded in 2004 that on a gram-for-gram basis, trans fat is even more harmful than saturated fat. Many food manufacturers have replaced hydrogenated shortening with less harmful ingredients. But there are still a lot of foods with trans fats.
The Institute of Medicine had advised consumers to consume as little trans fat as possible, ideally less than about 2 grams a day (that much might come from naturally occurring trans fat in beef and dairy products). Harvard School of Public Health researchers estimate that trans fat had been causing about 50,000 premature heart attack deaths annually, making partially hydrogenated oil one of the most harmful ingredients in the food supply.
Great news: Trans fats are deemed not safe in food
The Food and Drug Administration has finalized its determination that artificial trans fat is no longer generally recognized as safe for use in food. The long-expected move was praised by the Center for Science in the Public Interest (CSPI) as a public health victory which will result in a decreased incidence of heart disease.
About 85 percent of artificial trans fat has already been eliminated, thanks to a sustained public health campaign that has included disclosing trans fat on Nutrition Facts labels, litigation, and city, county, and state prohibitions on the use of partially hydrogenated oil in restaurants.
New York City was the leader on banning foods with trans fats
New York City’s move to phase foods with trans fats out of restaurant meals was a major milestone that demonstrated to the industry and federal regulators that it was relatively easy to replace partially hydrogenated oils for frying, baking, and for other applications, according to CSPI.
“Like most public health measures, at first the phasing out of artificial trans fats was controversial,” said Michael R. Bloomberg, Mayor of New York City from 2002 to 2013. “But as soon as New Yorkers understood that taking trans fats out of a dish didn’t impact the way their favorite foods tasted, and restaurant owners understood that the ban didn’t hurt business, the measure was widely accepted.”
In fact, the trans fat ban became a point of pride for many restaurants. “When the FDA finishes the work that we started in New York City, tens of thousands of lives will be saved each year by this sensible public health measure,” said Bloomberg.
Foods with trans fats won’t disappear right away
“The eventual elimination of artificial trans fat from the food supply will mean a healthier food supply, fewer heart attacks and heart disease deaths, and a major victory for public health,” says CSPI executive director Michael F. Jacobson. “The determination made by the Food and Drug Administration gives companies more than enough time to eliminate the last of the partially hydrogenated oil that is still used in foods like microwave popcorn, biscuits, baked goods, frostings, and margarines.”
Artificial trans fat promotes heart disease by raising LDL, or bad cholesterol, and lowering HDL, or good cholesterol, and perhaps in other ways, according to CSPI.
Fully hydrogenated oil is not the same as partially hydrogenated oil
By the way, fully hydrogenated vegetable oil does not have any trans fat, but it also does not have any polyunsaturated oils. It is sometimes mixed (physically or chemically) with polyunsaturated liquid soybean oil to create trans-free shortening. When it is chemically combined with liquid oil, the ingredient is called inter-esterified vegetable oil. Meanwhile, oil processors are trying to improve the hydrogenation process so that less trans fat forms.