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It's MORNING EDITION from NPR News. I'm Steve Inskeep.
RENEE MONTAGNE, host:
And I'm Renee Montagne. In Your Health today, what not to do when you're mad as hell and not going to take it anymore. We'll give you a few minutes to calm down while we give you the skinny on something else: trans fats. Yes, the ones you thought had been banished. Some cities have banned trans fats in restaurants. And public pressure combined with labeling requirements have pushed them out of many processed foods. But as NPR's Allison Aubrey reports, trans fats aren't completely gone.
ALLISON AUBREY: I went to the grocery store this week to give shoppers a quiz.
Ms. JOANNA ROBINSON (Shopper): My name is Joanna.
Ms. ROBINSON: Robinson.
AUBREY: Got it. So my question is, if you're looking at this cookie label here and you see that there are zero grams of trans fat per serving, what's your guess about how much trans fat might be in here?
Ms. ROBINSON: I would say zero. Yes. I would trust the label.
AUBREY: But that's not what every shopper said. Guy Powell is more suspicious about how much trans fat might be in cookies.
Mr. GUY POWELL (Shopper): More than zero.
AUBREY: So you're not buying the zero?
Mr. POWELL: No, I'm not buying the zero.
AUBREY: And what makes you skeptical?
Mr. POWELL: There's a lot of fats in cookies.
AUBREY: And sometimes those are fats that have been made thicker by adding hydrogen molecules. They're listed on food labels as partially hydrogenated cotton seed oil or partially hydrogenated palm kernel oil. There are others too. So it turns out that Guy Powell is right. The zero trans fat world still has some trans fats. But how much?
Laurie Guzzinati is a spokesperson for Kraft Food, which owns the Oreo and Chips Ahoy brands. She says the simple answer is that the FDA allows foods that have up to a half gram of trans fat per serving to be listed as zero on the label.
Ms. LAURIE GUZZINATI (Kraft Food): Anything below .05 grams of trans is appropriately labeled as containing zero grams trans.
AUBREY: So why does this matter? It's because trans fats can have the triple whammy effect of increasing bad cholesterol, lowering good cholesterol and raising triglycerides, all of which contribute to the risk of heart disease.
Now, this isn't going to matter too much to shoppers like Joanna Robinson, because she's not eating too many processed or fried foods.
Ms. ROBINSON: So I prefer, like, fresh vegetables, unprocessed foods. So that's another reason I'm not generally concerned about this.
AUBREY: But for people who munch on a few snack foods a day, trans fats can add up incrementally. Lynn Browne is a professor of food science at Penn State University. She says researchers have tested just how little trans fat it takes as a percentage of your overall calorie intake to do damage.
Professor LYNN BROWNE (Penn State University): They found that 3.8 percent of the calorie intake was sufficient to raise LDL.
AUBREY: That's the bad cholesterol. So in a 2,000 calorie diet the 3.8 percent translates to about eight grams of fat. So what's the chance you'd actually eat that much in a day? Well, it would take a serious cookie binge - say, a teenager wolfing down a whole package of cookies, or an adult who has coffee cake in the morning, cookies with lunch and some fries at dinner.
The good news is that across the board — from fast food chains to processed snack foods - trans fats have been reduced in the American food supply by more than 50 percent in the last several years. But experts say people should keep reading labels with an eye towards limiting partially hydrogenated oils.
Allison Aubrey, NPR News.