WASHINGTON, Nov. 7 (UPI) -- The U.S. Food and Drug Administration said Thursday hydrogenated oils, the source of trans fats, are no longer "generally recognized as safe."

Under the FDA's proposal -- open for public comment for 60 days -- the agency would declare partially hydrogenated oils no longer "generally recognized as safe," the legal category that has permitted its use, and would require companies to prove scientifically trans fats are safe to eat, a high hurdle given scientific literature, The New York Times reported.


Dr. Margaret A. Hamburg, commissioner of the FDA, said the new rules could prevent 20,000 U.S. heart attacks and 7,000 deaths from heart disease each year.

Introduced about 30 years ago, artificial trans fats are created when liquid oil is treated with hydrogen gas and made into a solid. It's used for frying and baking, and in products such as margarine as a cheaper fat than butter.

However, since then, scientific evidence has shown trans fats are worse than other fats for health because they raise the levels of low-density lipoprotein, the "bad" cholesterol that collects in the walls of blood vessels, causing the blockages of atherosclerosis that increase heart attack risk from a sudden blood clot in a clogged artery.

Trans fats were also found to lower high-density lipoprotein, the "good" cholesterol that acts as a scavenger in the bloodstream, removing the harmful bad cholesterol and lowering the risk of heart attack.

In 2006, the FDA required artificial trans fats be listed on food labels, a move that resulted in many food producers eliminating them from their products. In 2005, New York City told restaurants to stop using artificial trans fats in cooking and many major chains did so, the Times said.

However, trans fats were not banned and remained in many processed foods such as microwave popcorn, some desserts, frozen pizzas, margarine and coffee creamers.

Dr. Thomas R. Frieden, director of the Centers for Disease Control and Prevention in Atlanta, said artificial trans fats are required to be on the label only if there is more than a half gram per serving, a trace amount that can add up. As little as 2 or 3 grams of trans fat a day can increase the health risk, Frieden said.