In the past few years, coconut oil has been called a superfood that can help you blast belly fat and raise your good cholesterol. The sweet and nutty trendsetter has been featured in many cookbooks as a substitute for olive or canola oil — and it can cost a bundle at the store.
A recent survey found that 72 percent of Americans say coconut oil is a "healthy food," but many nutrition experts aren't convinced.
The problem is that coconut oil contains a lot of saturated fat — the kind that is a big risk factor for heart disease, which kills more than 17 million people a year worldwide.
First, let's talk about fat. "In terms of calories, all fats are the same: butter, coconut oil, olive oil. They all have the same number of calories, but they are different in terms of your health," says Mary Donkersloot, a Beverly Hills nutritionist and host of a weekly Web video series called The Smart Eating Show.
Fat is not the enemy of our diets, despite what we were led to believe in the 1990s, when low-fat cookies and ice cream started popping up on the market. (Remember the SnackWell's craze?) Fat helps us feel full longer and stay satisfied. Eating some fat can actually help us snack less and potentially lose weight. But what kind of fat we eat matters — and how much.
In fact, one tablespoon of coconut oil has 12 grams of saturated fat — a big chunk of what is recommended for the whole day, says Donkersloot.
The U.S. government recommends keeping saturated fat below 10 percent of your total daily calories. For some people, that can be as low as 22 grams a day, although the American Heart Association recommends going even lower — more like 13 grams. So just one tablespoon of coconut oil gets you much of the way there. Forget dessert!
The concern about too much saturated fat in our diets is upheld by 50 years of research showing that a diet high in saturated fat is associated with an increased risk of heart attack and stroke, says Alice Lichtenstein, a professor of nutrition science and policy at the Friedman School at Tufts University who also runs the university's Cardiovascular Nutrition Laboratory.
Lichtenstein and her colleagues looked at several studies examining what happens when people replaced saturated fats found in foods like tropical oils and meat with unsaturated fats like those in olive oil, canola oil and flaxseed oil. As they reported in a recent American Heart Association advisory, those studies showed that making the swap was linked with a 30 percent reduction in the risk of cardiovascular disease. That's similar to what people can expect when they take statins, she says. The advisory was published in the journal Circulation.
So why does the idea that coconut oil is somehow good for us persist? No one is really sure.
"Why things like coconut oil somehow slipped under the radar is a little bit unclear, but it's not consistent with any of the recommendations that have occurred over the past 30, 40, 50 years," says Lichtenstein.
While some research has linked the main type of saturated fatty acid in coconut oil — lauric acid — to increased levels of HDL, or "good" cholesterol, it still raises LDL cholesterol, or "bad" cholesterol, she notes in the advisory, citing multiple studies.
And while enthusiasts point out that coconut oil is rich in antioxidants, there is little evidence that once the oil is refined, which is how most of us buy it in the store, those properties are retained.
Some research suggesting that saturated fat might be more neutral than previously thought has caused a few to question the American Heart Association and the government's recommendations on saturated fat.
But Lichtenstein and many others are not convinced. She says those studies did not take into account the kinds of foods replacing saturated fats in the diet, and that the saturated fat factor trumps the potential benefits of coconut oil.
So, if you like to cook with coconut oil, that's fine — "once in a while. If you're making Thai, go for it," says Donkersloot.
But don't think of coconut oil as a health elixir. And remember that when it comes to good nutrition, including fats, it's all about balance, Lichtenstein says. And there's more solid evidence behind the healthfulness of other plant-based oils such as extra virgin olive oil.
With the rise in popularity of low-carb diets embracing more fat in recent years, it's no wonder consumers are confused about which fats are best. And most oils contain more than one variety of fat. Iowa State University has a handy chart to help you compare the percentages of fats found in common oils.
STEVE INSKEEP, HOST:
Is coconut oil a healthy food? - certainly is promoted as one. Survey a broad group of Americans and 72 percent say, yes, coconut oil is healthy. Talk with some nutritionists, and they say, no, it's not. NPR's April Fulton reports.
APRIL FULTON, BYLINE: Let's get one thing out of the way. Fat is not the enemy. Fat helps us feel fuller longer and stay satisfied. Eating some fat can actually help us snack less and potentially lose weight. But there's something pretty important about fat to consider - what kind of fat we're eating and how much.
(SOUNDBITE OF FOOD SIZZLING)
MARY DONKERSLOOT: I'm going to saute my onions in extra virgin olive oil here.
FULTON: I'm in the kitchen with Mary Donkersloot.
DONKERSLOOT: It's my favorite oil for sauteeing.
FULTON: Donkersloot is a nutritionist in Beverly Hills. She's using olive oil because it's high in monounsaturated fat.
DONKERSLOOT: In terms of calories, all fats are the same. Butter, coconut oil, olive oil, they all have the same number of calories. But they're different when it comes to your health.
FULTON: And when it comes to health, Donkersloot is no fan of coconut oil because it has lots of saturated fat, which is associated with an increase in the risk of heart attack and stroke.
DONKERSLOOT: You know, a tablespoon of coconut oil has about 12 grams of saturated fat, whereas olive oil has two. Butter comes in the middle there around 7.
FULTON: So just one tablespoon of coconut oil contains most of the saturated fat many Americans are supposed to have in one day. That's not leaving any room for yogurt or meat. And forget dessert. Still, a lot of people think coconut oil is different.
DONKERSLOOT: Adding fat to your diet in this idea that it's going to bust your belly fat - no, not going to happen.
FULTON: Studies just haven't borne it out. While some preliminary research shows that coconut oil raises the levels of good cholesterol, it also raises the levels of bad cholesterol. Dankersloot says there are many options.
All right. Let's go check out the oils at the store.
FULTON: We drive to Jayde's, a local gourmet market near her house. Here the oil aisle looks a lot like the cereal aisle with tons of choices.
DONKERSLOOT: Wow. This is quite a beautiful array of oils. Here's grapeseed, walnut, almond oil.
FULTON: And bottles and bottles of olive oil.
DONKERSLOOT: How about this pumpkin seed oil? Never heard of it.
FULTON: So how do you choose? First, look for the oils with the lowest amount of saturated fat. Alice Lichtenstein directs the cardiovascular nutrition lab at Tufts University. She basically looks at how our diets affect our hearts. Since the 1960s, Lichtenstein says, well-controlled clinical trials have shown that too much saturated fat can be a problem.
ALICE LICHTENSTEIN: So that would be things like coconut oil, palm oil or palm kernel oil and then animal fat. So that would either be meat fat or dairy fat.
FULTON: Those studies also show that if we replace those types of fat with unsaturated fats like corn oil, sunflower oil or olive oil, we'll reduce our risk of cardiovascular disease and be healthier. Lichtenstein has seen a lot of fad diets come and go.
LICHTENSTEIN: Why things like coconut oil somehow slipped under the radar is a little bit unclear. But it's not consistent with any of the recommendations that have occurred over the past 30, 40, 50 years.
FULTON: So it's OK to use coconut oil, just don't use it all the time. What you want to do is shift the ratio more towards unsaturated fat and away from saturated fat. And that means more olive, flax and canola oil and less coconut oil and bacon. When it comes to your diet, it's all about the balance. April Fulton, NPR News, Los Angeles. Transcript provided by NPR, Copyright NPR.