Harvard Health Blog
By Heidi Godman
I felt guilty. I looked like any other health-conscious customer in the grocery store, perusing Nutrition Facts labels. But I was really there to hunt down a dangerous ingredient on store shelves called artificial trans fat. It’s the worst type of fat in our food supply — so bad, in fact, that the FDA is essentially banning it in processed food starting in 2018.
But that’s a long way off. How much artificial trans fat is on store shelves today?
The fuss about the fat
Artificial trans fats come from partially hydrogenated oils, which are made by a process using hydrogen gas to turn liquid vegetable oils into solids. The fats extend a food’s shelf life and improve flavor and texture. That’s made them a mainstay for decades in processed foods like margarines, crackers, cookies, corn chips and pastries.
We didn’t know the fats were bad for us until the 1970s, when studies began linking them to heart disease. Today we know that trans fats increase “bad” LDL cholesterol, decrease “good” HDL cholesterol, raise the risk of blood clots, and boost inflammation — all of which increase the risk of heart disease, stroke and diabetes.
But it wasn’t until 2006 that the FDA required food makers to start listing trans fats on Nutrition Facts labels.
The hidden fat
Listing the amount of trans fats on a label doesn’t always make them visible, however. “The FDA doesn’t require trans fat to be listed until there’s a half gram or more per serving, so the label may show zero grams of trans fat, even if a serving contains almost half a gram,” says Kathy McManus, director of the Department of Nutrition at Harvard-affiliated Brigham and Women’s Hospital.
The trick to finding trans fats: read the ingredient lists on Nutrition Facts labels. If partially hydrogenated oil is among the ingredients, you’ll know the food contains trans fat, even if the label states that a serving has zero grams of trans fat.
In stealth mode, I picked up package after package. Sure enough, most nutrition labels listed zero grams of trans fat, even when partially hydrogenated oils were clearly listed in the ingredients. And I found many kinds partially hydrogenated oils — soybean, coconut, cottonseed, corn and canola.
There were the usual foods with trans fat: sugary breakfast cereals, refrigerated dough for biscuits and pastries, cake and brownie mixes, soft-baked chocolate cookies, ready-to-use frosting, granola bars, microwave popcorn, coffee creamer, vegetable shortening, cereals, soup, salad dressing, dips, sauce mixes, peanut butter, taco shells, cocoa mix and even low-fat ice cream.
But some trans-fatty foods surprised me: fancy frozen fish fillets (potato-crusted cod), coffee drink mixes (double mocha cappuccino) and seasoned Italian breadcrumbs (although I should have expected that, since it’s a bread product).
I was also surprised by what I didn’t find. There weren’t as many products with partially hydrogenated oils as I expected. In some cases, I had to look at dozens of types of products to find partially hydrogenated oils. In other cases, I couldn’t find any partially hydrogenated oils where I knew they once existed (in canned soup, for example).
That ousting of oils is the result of food makers addressing consumer demand to remove trans fats, or getting on board with the FDA program early, since the end for trans fats in processed foods is coming.
Avoiding trans fats
Partially hydrogenated oils won’t go away until the middle of 2018, so we still have to be vigilant about consuming them. They’re out there, although you’re more likely to spot them in ingredient lists rather than trans fat listings. And even if the product contains less than half a gram of trans fat, it’s still bad for you. “No amount of trans fat is acceptable, from a health standpoint,” says McManus. And it’s worse, she points out, if you have a little bit of trans fat in a lot of products; it adds up.
And life without trans fat is healthier. Based on FDA estimates, researchers at the CDC report it is possible that eliminating trans fats in the diet may prevent as many as 10,000 to 20,000 heart attacks and 3,000 to 7,000 deaths from heart disease each year.
So by all means, avoid foods with partially hydrogenated oils. Go on your own fact-finding mission in the grocery store, read those nutrition labels, and let us know what you find; no stealth mode required.
(Heidi Godman is the executive editor of the Harvard Health Letter.)