Although it's been more than five years since coconut oil began its meteoric rise in the US marketplace, the confusion about it has not waned a bit. "Should I switch to coconut oil?" is consistently one of the most common questions that come across my desktop - not surprising given that you could throw a dart at the internet and hit a claim about the oil's amazing healing power. Mostly, there has been a paucity of good science on it, but a meta-analysis (a systematic review of the existing research) published this year in Nutrition Reviews has shed some light on the topic. I spoke with the lead researcher, Laurence Eyres, chairman of the Oils & Fats Specialist Group at the New Zealand Institute of Chemistry, for further insight.
The study found that coconut oil, which is 92 per cent saturated fat, raises LDL (bad) cholesterol less than butter does, but significantly more than unsaturated plant oils do. So when it comes to heart health, Eyres puts it plainly: "It would be dangerous, and rather silly, to replace your extra-virgin olive oil with coconut oil." There - that question is answered. But there are plenty of details and nuances where that came from, so read on.
Coconut oil has a lot going for it from a culinary perspective. It has a lovely, distinctive flavour that gives dishes a sumptuous tropical taste. It is solid at room temperature, a quality central to many recipes. But unlike most other solid fats, it is vegan, so it appeals to the ever-growing legion of plant-based eaters. Also, like other saturated fats, it is very stable in heat, so it is good for stir-frying and sauteing. (Contrary to a common myth, monounsaturated fat such as olive oil is also quite stable in heat, and good-quality olive oil is excellent for high-heat sauteing. Polyunsaturated oils such as corn oil are less stable in heat, and nut oils should not be heated much at all.)
But one of the biggest things coconut oil has behind it right now, unfortunately for the consumer, is a lot of marketing hype that makes it out to be a miracle food. "There is nothing wrong with coconut oil in moderation, but it is not a cure for everything or a wonder fat," Eyres says.
Many of the purported benefits of coconut oil point to it as a source of medium-chain fatty acids (MCTs), a type of fat that is processed differently by the body so it is absorbed and metabolised more efficiently than other fats. But the research on MCTs cannot be extrapolated to coconut oil. At issue is that lauric acid, a predominant fatty acid in coconut oil, is often cited as a medium-chain fatty acid, but, Eyres says, while "chemically it could be defined as either medium- or long-chain, [lauric acid] behaves like a normal long-chain fatty acid in the body." He says that "coconut oil has less than 3 per cent MCT. MCTs are as different to coconut oil as chalk is to cheese."
When it comes to coconut oil's impact on cholesterol, you often hear the argument that even though coconut oil raises LDL, it also raises HDL (good) cholesterol, resulting in a neutral - even beneficial - overall effect. But Eyres says butter raises HDL, too, and with coconut oil, "it's particularly the rise in small LDL particles that are worrisome because they are really atherogenic," meaning they promote the formation of plaque in arteries.
Touching on a broader issue facing the nutrition community, there is considerable discussion as to whether saturated fat, even with its cholesterol-raising effect, is truly problematic and how much it actually contributes to heart disease. It's a debate you can't miss, considering all of the "butter is back" cover stories in recent years. But when you read past the headlines, there is wide agreement that even if saturated fat turns out to be neutral when it comes to heart disease, unsaturated fats, especially antioxidant-rich oils such as olive oil, are actually protective, so there is good reason to make them your go-to fats.
Eyres adds: "The cholesterol picture is very simplistic. There are many factors to consider with regard to heart disease." Case in point is the discussion in his study of coconut products in the traditional diets of Pacific Island populations. The people there have historically consumed a lot of saturated fat from coconut products (although notably not as coconut oil per se, but as grated coconut flesh, coconut cream and coconut flour, all of which are rich in fibre), but they have low incidences of cardiovascular disease. Importantly, these traditional diets have also contained plenty of fish, fruit and vegetables, and little to no refined sugar, processed foods and soft drinks. Eyres points out in his study that in the context of this traditional eating pattern, consuming coconut products that contain fibre (not necessarily coconut oil, which has none) does not pose a risk for heart disease. But the use of coconut oil as a major player in a typical Western diet does.
So, go ahead and use some coconut oil in a vegetable saute or add shredded coconut to a smoothie - if you do that instead of grabbing takeout for dinner or snacking on chips, you'll be ahead of the game. Just don't buy into the coconut as cure-all hype, and do stick to unsaturated oil for everyday cooking.
The Washington Post
Krieger is a registered dietitian, nutritionist and author. She blogs and offers a biweekly newsletter at elliekrieger.com. She also writes weekly Nourish recipes in The Washington Post's Food section.
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