Remember the battle over trans fats? Yeah, the fats that did our hearts no favors.
As we've reported, the push to get these cholesterol-raising fats out of the food supply has been pretty successful. And now most packaged snacks are labeled as having zero grams of trans fat.
So what are food manufacturers using instead? One alternative is palm oil. But it's not an ideal replacement.
There are environmental concerns about how palm oil is produced. And what's more, from a health perspective, palm oil is high in saturated fat.
In one study, people who were put on a diet rich in palm oil for about five weeks saw their LDL cholesterol (that's considered the bad cholesterol) rise. This is very similar to what happens on a diet high in partially hydrogenated oils, which contain trans fats.
So what's the better alternative?
"Optimally, the substitution [for partially hydrogenated oils] wouldn't be palm oil. "It would be a vegetable oil" such as canola or soybean oil, says Alice Lichtenstein, professor of nutrition at Tufts University. These oils contain more unsaturated fat.
So how much palm oil is in our food supply? According to USDA data, U.S. imports of palm oil more than doubled between 2005 and 2012. Last year we imported about 2.7 billion pounds.
As my colleague Richard Harris estimates, this is about 380 million gallons, which is is enough to fill more than 500 Olympic swimming pools and, he points out, is more oil than BP spilled in the Gulf during the Deepwater Horizon disaster.
Much of the palm oil ends up in snack foods such as cookies, crackers and microwave popcorn. And a number of manufacturers are using a mix of oils in many of their products. For instance, it's typical now for crackers to contain a little palm oil as well as soybean, canola or cottonseed oil.
It's impossible to know exactly how much palm oil is in a food just by reading the label. But here's one rule of thumb: The more palm oil a packaged food contains, the higher the saturated fat content. So if you see palm oil listed as an ingredient but the saturated fat is low, you can assume that it has been mixed with other, unsaturated fat oils.
It's important to note that palm oil shouldn't be vilified. It contains about as much saturated fat as butter.
And both of these fats, let's face it, are found in calorie-dense foods that we're told to eat sparingly.
ROBERT SIEGEL, HOST:
From NPR News, this is ALL THINGS CONSIDERED. I'm Robert Siegel. Remember the fight against trans fat? About 10 years ago, there was a national campaign to get those fats out of fried foods and processed snacks. That's because trans fats were linked to an increased risk of heart disease. Well, it's been a success. These days, it's tough to find a food label that doesn't boast trans fat free.
So we were curious what food processors have been using instead and we found out that one replacement is palm oil, which raises concerns of its own. NPR's food correspondent, Allison Aubrey, joins me now to talk about it. Hi, Allison.
ALLISON AUBREY, BYLINE: Hi there, Robert.
SIEGEL: And give us the skinny on palm oil. It seems it's increasingly turning up in the food supply. Is it a good alternative to the oils that included lots of trans fat?
AUBREY: Well, I think there's unanimous consensus that getting rid of the trans fat has been a really good thing, but there's also agreement that palm oil is really not an ideal replacement. There are environmental concerns about the way palm oil is produced but more than that, from a health perspective, palm oil contains a lot of saturated fat and that's the kind of fat that's linked to heart disease.
So there was a study where researchers put people on a diet rich in palm oil for about five weeks, saw their levels of LDL cholesterol, that's the bad kind, go up. And this is actually very similar to what happens to people on a diet rich in partially hydrogenated oils, which contain trans fats.
SIEGEL: And how much palm oil is actually in our food supply?
AUBREY: Well, quite a bit more than I realized. It's produced in massive quantities in tropical countries, such as Malaysia and throughout Indonesia. And I actually looked up the palm oil import figures this morning and it turns out that imports to the U.S. have more than doubled since 2005. There's about 2.7 billion pounds of the stuff being imported.
SIEGEL: Now, I see you came to the studio just in case this went on for very long, with some snacks. You brought along some popcorn and some crackers and some cookies.
AUBREY: That's right. This is a show and tell here. And this is really interesting. If you look at these cookies here, on the front of the package you see all kinds of things. You see it says no high fructose corn syrup, no hydrogenated oil, zero grams of trans fat. But if you turn the package over, you'll see that this actually contains palm oil, as well as a mix of other oils.
And one of the reasons palm oil is used a lot is that it's fairly inexpensive and it's got the properties that work well for commercial bakers.
SIEGEL: So what should we be looking for on labels?
AUBREY: Well, I think the simplest advice is to check the saturated fat content. That's really what you're trying to limit and if you're going to buy these packaged snacky foods like I have here, ideally you really want to look for products that contain a mix of vegetable oils. They may have a bit of palm oil in them. Products like these crackers here are a good example. They also have a blend of soybean oil and canola oil.
These are higher in unsaturated fats and that's really what you're looking for.
SIEGEL: You're saying that's good.
AUBREY: That's right.
SIEGEL: Well, how does palm oil stack up against some of the very familiar fats - butter, olive oil?
AUBREY: Well, actually, palm oil contains about the same amount of saturated fat as butter. Actually, it contains a little less. So, you know, it shouldn't be vilified here. And like butter, a small amount is probably okay. But since both butter and palm oil are typically found in calorie dense, shall we say, treats like these cookies and crackers, the idea here is to eat sparingly.
And you asked about olive oil. I think that what's important to note is that olive oil has very little saturated fat and is much, much higher in something called monounsaturated fat, plus it's got other beneficial compounds. That's why you hear a lot about the benefits of the Mediterranean diet. So I think the bottom line here is read the label of food packages and know what fats you're looking for.
SIEGEL: Okay. Allison Aubrey, NPR's food correspondent. Thank you, Allison.
AUBREY: Thank you so much. Would you like some of these crackers here, Robert?
SIEGEL: I'll pass.
AUBREY: Okay. Transcript provided by NPR, Copyright NPR.