How can both sides of this argument be so far apart? The pro-coconut-oil group says it's a miracle health food... but the anti-coconut-oil camp says it'll kill you. Welp, someone's wrong. Let's get to the bottom of it...
The Saturated Fat Thing
As mentioned above, coconut oil is high in lauric acid and myristic acid, which are considered to be two of the most heart-stopping fatty acids in existence. This evidence is largely based on short term studies using isolated fatty acids, showing that their consumption increases cholesterol levels (1, 2). As I explained in my last post on nutritionism, this is interesting and good to know, but it doesn't necessarily mean eating foods high in these fats, like coconut oil, will have the same effect. Food is more complex than we know. This is a piece to the puzzle, but not the only piece to the puzzle. What about studies involving real coconut oil?
Virgin Coconut Oil vs. Refined Coconut Oil
Most of the research on coconut oil is done using the refined variety. To my knowledge there are only two studies out there involving unrefined virgin coconut oil, and they're essentially the same study. And they weren't even human studies; they were done with rats. On the good side though, they were well controlled, and they tested virgin coconut oil against its refined counterpart!
For all intents and purposes, the design of both studies was the same, and they were done by the same researchers (3, 4). They split the rats up into three different groups: virgin coconut oil, copra oil (refined coconut oil), and sunflower oil. All three groups ate the same diet, other than the source of fat. The results?? The virgin coconut oil group lowered their total cholesterol, LDL, and triglyceride levels, while increasing HDL cholesterol levels. In addition, the polyphenols present in virgin coconut oil were found to prevent LDL oxidation, which is a major contributor to heart disease. Thumbs up! The refined coconut and sunflower oil groups? Well they didn't see these benefits. Overall, this study doesn't prove anything in humans. What it does show, though, is that there is a significant difference between virgin coconut oil and refined coconut oil... the former being the better choice. Yet they have the same fatty acid breakdown... like I said, food is more complex than we know.
Coconut Oil and Abdominal Obesity
On to real humans now. This one was a controlled trial involving women with large tummies. All subjects were instructed to follow a low-calorie diet... half of them supplemented with 30 ml of coconut oil (I assume it was refined since the researchers didn't specify), and half of them supplemented with 30 ml of soybean oil (5). The results were pretty amazing in my opinion. Both groups lost the same amount of weight, but the coconut oil group lost significantly more fat from the abdomen. This is important, because abdominal obesity in particular is highly correlated with chronic disease... you don't want fat in your belly. In terms of blood lipids, the coconut oil group ended up with higher HDL levels and a better LDL:HDL ratio. The soybean oil group, on the other hand, presented an increase in total cholesterol, LDL, and LDL:HDL ratio, while HDL diminished. Winner: coconut oil.
The Rest of It...
Overall, the rest of the human data on coconut oil are sort of neutral; there's some good stuff, some bad stuff, and a lot that falls somewhere in between. This study shows no difference in blood lipids in coconut oil vs. sunflower oil (6), this one shows no connection between coconut/coconut oil consumption and heart disease in India (7), here's an observational study showing an increase in heart disease upon replacing coconut oil with vegetable oils in India (8), and here we have one showing an increase in LDL, triglycerides, etc. with coconut oil vs. beef fat and safflower oil (9). It's really all over the place, maybe slightly more positive than negative, but overall it's inconsistent and doesn't tell us much of anything. Don't forget, too, that this is refined coconut oil we're talking about here, not the unrefined virgin variety. Only the rats were lucky enough to get the good stuff.
Let's step off of coconut oil for a moment, and focus on the whole coconut. It's slightly different, yes, but still relevant; coconut is mostly fat anyway. We've got a few sets of people out in the Eastern Pacific island area who eat a lot of coconut... unrefined coconut of course... and there's a lot we can learn from them. If the medical establishment is right, that the fats in coconut clog our arteries and kill us, then these people should be in serious trouble.
Tokelau - The first example is the island of Tokelau, which was the subject of a major epidemiological study from 1968-1982 (10, 11). The Tokelauan diet is based on coconut and fish; over half their calories come from coconut, hence 40-50% of their total calories are from saturated fat. This is absurdly high. For reference, the Dietary Guidelines recommend that number be less than 10%... because any more than that increases your risk for cardiovascular disease. So are these Tokelau coconut eaters dying left and right? No. According to the study, they have low rates of diabetes, healthy blood pressures, good cholesterol levels, and no trace of any recent heart attacks. No trace! Coconut for the win.
Kitava - The diet on the island of Kitava has been studied extensively as well (12). While the available foods are similar to those on Tokelau, the Kitavans eat them in very different proportions. The Kitavans get about 21% of their calories from fat, 17% of which is from saturated fat. Just about all of this is from coconut, and although less than on Tokelau, it's still far more saturated fat than we are recommended to eat. Overall, their diet is very high in carbohydrates, about 69%, and most of that comes from starchy tubers like sweet potatoes and taro. But are they healthy? Heart disease or stroke? No trace. Obesity? Nope. Diabetes? No sir. Senile dementia?? Not even a little. What about longevity? There were reports of one man reaching over 100 years of age. And if you didn't die in infancy or of infectious disease, it was expected that you would live well into your 70s. Quite impressive if I do say so myself. No killer coconut here.
Neither of these societies are plagued with the chronic diseases we see every day, and they eat more coconut fat than maybe anyone else in the world. Take it for what it's worth, it's just an observation... but if coconut fat were really that bad, these people would have died off long ago.
The Verdict on Coconut Oil
Here are the basic facts we can come up with based on all of this information...
- Virgin coconut oil improves blood lipid numbers vs. refined coconut oil in rats
- Polyphenols in virgin coconut oil (not present in refined oil) prevent LDL oxidation
- Coconut oil targets fat loss in the abdomen and improves HDL levels in overweight women
- There's no association between coconut oil consumption and heart disease in India
- Tokelauans get 40-50% of their calories from coconut fat, and they're in great health
- Kitavans get about 20% of their calories from coconut fat, and they're in even better health.
Let's connect the dots, shall we? Is coconut oil a miracle food? No, I don't think so. Is it deadly? No, definitely not. As is usually the case, the truth lies somewhere in the middle. Coconut oil is, at the very least, not unhealthy. If you take the research on refined coconut oil alone, it comes out looking pretty neutral... it's not the villain it's made out to be. Virgin coconut oil, however, is clearly superior. Natural coconut fat has sustained entire civilizations for generations; to me that's a good indicator that these fats can support health. The fats in coconut may be dangerous when isolated in a lab, but eating them in an unrefined product like virgin coconut oil or in the coconut itself? Different story entirely. It's healthy, not harmful.
So for one final last final conclusion, here is your coconut oil hierarchy... isolated lauric acid < refined coconut oil < virgin coconut oil. Get out there and do your best, eat virgin coconut oil, cook with it, bake with it, and stay away from beakers of lauric acid.