On Thursday the FDA made the surprise announcement that it would move to ban artificial trans fats, which are found in foods containing partially hydrogenated vegetable oils. The ban would not apply to naturally occurring trans fats, such as those found in meat and dairy products. Adoption of the proposal, which is open to public comment until Jan. 7, 2014, would mean that food producers who want to use partially hydrogenated oils would first have to prove to the FDA the safety of the ingredient.
Considering that the FDA’s announcement this week declared preemptively “that there is no safe level of consumption of artificial trans fat,” the burden of proof for future trans fat use would appear to be quite high.
What does trans fat research say?
Studies on artificial trans fats have found generally that they raise the amount of bad cholesterol (LDL) and lower the amount of good cholesterol (HDL) in the blood. (More here on HDL and LDL generally.)
But a recent meta analysis, Effect of Animal and Industrial Trans Fatty Acids on HDL and LDL Cholesterol Levels in Humans—A Quantitative Review, published in the open-access, peer-reviewed journal PLOS ONE in 2010, concludes that those negative effects may also be shared by natural trans fats. The study looked at the results from twenty-nine human studies in which subjects were fed artificial trans fats and six studies in which subjects were fed natural trans fats derived from milk fat. It found the impact of artificial and natural trans fats on HDL and LDL levels to be roughly equivalent.
Like the 2010 PLOS ONE study, a 2005 book by the Institute of Medicine that appears to form much of the basis for the FDA’s action (the agency went so far as to link to it in yesterday’s FDA press release) appears to make no distinction between artificial and natural trans fats.
What’s more, the IOM appears torn over trans fats. On the one hand, it refers to them as “not essential” and says they “provide no known health benefit.” The FDA cites these points, of course. But the IOM also concludes in the same paragraph “trans fatty acids are unavoidable in ordinary, nonvegan diets.”
How much trans fats do we eat?
Thanks to the fact many food producers have responded to consumer demand and removed trans fats from their foods in recent years, the FDA’s press release noted that “trans fat intake among American consumers has declined from 4.6 grams per day in 2003 to about 1 gram per day in 2012.”
The American Heart Association, meanwhile, suggests Americans consume “less than 2 grams of trans fats a day.” So if the FDA and AHA are correct, then current consumption levels—prior to and without any ban—are well within safe levels. Still, that didn’t stop the AHA from endorsing the FDA’s suggested ban.
And what about natural trans fats? According to the USDA, a pound of ground beef contains more than 8g of trans fat.
What is the FDA doing?
Attorney Mark Itzkoff told Politico that the FDA’s move against trans fats was “virtually unprecedented.”