The Slippery Science Behind Coconut Oil Health Claims

Gwyneth Paltrow swishes it around her mouth to kill bacteria. Kourtney Kardashian adds it to her recipes as a metabolism-booster and immune system aid. Olympic gold medalist Apolo Ohno drizzles it on dinner the night before a big speed skating race, to give himself an energy boost the next day. Health and wellness influencers, from Instagram to The Dr. Oz Show, are recommending coconut oil as a “miracle” cure-all for skin problems, heart disease, and weight loss. But are its myriad health benefits all they’re cracked up to be?

In the latest episode of Gastropod, co-hosts Cynthia Graber and Nicola Twilley explore the history behind coconut’s global domination, from its spread across the tropics to the Paleo-fueled coconut oil health fad.

Historically, medical advice has warned consumers away from coconut oil, because it’s mostly made up of saturated fatty acids: It’s 92 percent saturated fat compared to butter’s 63 percent. The science on how saturated fat consumption contributes to heart disease is complex and evolving — it’s one of several interrelated dietary risk factors, and its impact is hard to tease out from overall diet and lifestyle. That said, all the major medical institutions — the World Health Organization, the American Heart Association, and others — recommend consuming less of it.

Over the past few years, however, coconut oil stans have claimed that, coconut oil can actually prevent heart disease and help with weight loss. These claims are staked on the idea that coconut oil is rich with medium-chain triglycerides (MCTs). Fats and oils are built from fatty acids, which can be classified two ways. The first is by whether they’re saturated or not: For example, olive oil is unsaturated, butter is saturated, and so is coconut oil. But another way fats can be classified is by the number of carbon atoms linked together in their tails: short, medium, or long chain. Nearly two-thirds of the fatty acids in butter, for example, are made up of fatty acids with long tails.

The fatty acids in coconut oil, by contrast, are nearly 50 percent lauric acid, which has fewer carbon atoms, and labeled medium chain. (Lauric acid is, coincidentally, a major component of breast milk — a fact coconut oil aficionados also like to mention as a reason it must be good for you.)

The chain lengths of fatty acids affect the ways in which our bodies process them. When it comes to digestion, the differences are super technical, but, basically, shorter-chain fatty acids seem to be fast-tracked into the liver and metabolized much more quickly, whereas longer-chain fatty acids circulate in the bloodstream before being broken down. These differences can then affect whether they’re used immediately as energy or laid down as fat, as well as influence overall blood cholesterol levels.

Fans claim that, thanks to its MCT content, eating coconut oil helps you to feel fuller faster, that it’s converted into energy rather than being stored in fat, and that it can raise your levels of HDL, otherwise known as “good cholesterol,” thus lowering your risk of heart attack and stroke. The reality, however, is nearly the opposite.

One issue is that the science on the benefits of MCT oil in humans is still very limited and inconclusive, to say the least. A few small studies, one in humans and one in mice, show some small benefits: men feeling slightly more full, mice having slightly lower cholesterol. But papers that looked at the entirety of the science to date on the topic have concluded that, as far as weight loss goes, “further research is required,” and that “MCT oil does not affect total cholesterol, LDL cholesterol, or HDL cholesterol levels.”

But there’s an even bigger issue. The studies that do show positive benefits from MCTs are using synthesized MCT oil, not coconut oil — and they’re not the same thing. “When you talk about MCTs, you are talking about one structure; when you talk about coconut oil, you are talking about another,” Jane Mara Block, an expert in fats and oils from Brazil’s Federal University of Santa Catarina, explained to Gastropod.

MCT oil can be synthesized from coconut oil, sure, but the final structure is made up of fatty acids that are different — and shorter — than the ones that make up coconut oil. The fatty acids in coconut oil are not only longer, but the majority either are long-chain fatty acids or act like them. As it turns out, when digested, lauric acid actually behaves metabolically like a long-chain fatty acid.

Block told Gastropod that it’s really not possible to extrapolate whatever benefits MCTs might have (which are already on shaky ground) to coconut oil, because their structures are different and so our bodies process them differently. In fact, the research that does exist on consuming coconut oil, rather than MCTs, shows that it actually raises total cholesterol, including both HDL and “bad” LDL cholesterol.

Even some of the most minor coconut oil benefits are largely unsupported. Coconut oil is often purported to be antimicrobial — hence Paltrow’s use of it for “oil pulling,” a technique that promises to reduce oral bacteria. This claim rests on the presence of a chemical within coconut oil that some studies suggest can inhibit the growth of certain bacteria in humans when it’s used as, for example, a mouthwash. But these studies have looked at the synthesized chemical rather than coconut oil itself.

As you may have noticed, all of these claims share a common problem: the magical properties attributed to coconut oil come from benefits derived from its individual components, rather than coconut oil as a whole.

This lack of context also applies to entire food cultures. Coconut oil fans like to point out that people who eat lots of coconut, whether in Polynesia, India, or the Philippines, have lower levels of cholesterol and fewer cases of heart disease than people in Western countries. Yet the people in these places tend to eat the oil as part of the coconut flesh, which also contains lots of fiber and a variety of minerals, and they also often eat diets that contain altogether less sugar, less meat, and less processed food than the standard Western diet. With all these other factors in play, it’s simply impossible to attribute their health to coconut oil.

“The whole thing, if you start putting it in a context, it starts getting a little bit complicated,” Block says. “And people don’t want that. People want quick and fast. People want a miracle.” If coconut oil is any kind of miracle at all, Block told Gastropod, it’s mostly a marketing miracle.

If you think that its oil is the first time coconut has sparked controversy, buckle up for coconut water wars, a coconut cult, and even some good, old-fashioned Monty Python in the latest episode of Gastropod. Follow and subscribe to join us as we explore how and why we all went coco for coconuts.