Michael Greger M.D. FACLM August 21st, 2017 Volume 37
Studies of populations who eat a lot of coconuts are “frequently cited” by those who sell coconut oil “as evidence” that it does not have harmful effects. For example, there was an apparent absence of stroke and heart disease on the island of Kativa. What were they eating? Well, their diets centered around tubers, like sweet potatoes, with fruits, greens, nuts, corn, and beans. Yes, they ate fish a few times a week, but they were eating largely whole food plant-based diets. So, no wonder they may have had such low rates of artery disease, and one of those whole foods was coconut, not coconut oil.
Now, if you go to Pukapuka, they eat even more coconuts. And, there’s even an island where that’s most of what they eat—and they get high cholesterol. What’s a population eating 87% plant-based—red meat, chicken, and eggs only eaten seldomly, no dairy—doing with cholesterol levels over 200? Well, they’re eating all these coconuts every day. What are their disease rates like? We don’t know. There’s no clinical surveys, no epidemiological data, no autopsies. They did do some EKGs, which can sometimes pick up evidence of past heart attacks, and found few abnormalities, but the sample was too small to be a definitive study. And, even if they did have low disease rates, they weren’t eating coconut oil; they were eating coconuts. Coconut oil proponents pointing to these studies is like the high-fructose corn syrup lobby pointing to studies of healthy populations who eat corn on the cob.
Or, the sugar industry pointing to studies on fruit consumption, and saying see, eat all the refined sugar you want. But, fruit has fiber—and so do coconuts. Just like adding psyllium fiber—Metamucil—to coconut oil can help blunt the adverse effects on cholesterol, fiber derived from defatted coconut itself can reduce cholesterol levels as much as oat bran. And, the plant protein in coconut—also missing from the oil—may also help explain why whole coconut may not have the same effects on cholesterol.
Although coconut fat in the form of powdered coconut milk may not have the same effects on cholesterol as coconut oil, frequent consumption—defined as three or more times a week—has been associated with increased risk of vascular disease, stroke, and heart attack. And no wonder, as coconut milk may acutely impair artery function—as badly as a sausage-and-egg McMuffin. They tested three meals, three different meals: a Western high-fat meal, comprised of an egg McMuffin, a sausage McMuffin, and two hash browns, versus a local high-fat meal (this was done in Singapore; so, the more traditional high-fat meal was rice cooked with coconut milk, though there were also anchovies and an egg), vs. the same amount of calories in an unhealthy low-fat meal, comprised of Frosted Flakes, skim milk, and juice.
Here’s the artery function—the ability of the arteries to relax normally—before Mickey D’s, and after, significantly crippling down artery function within hours of consumption, and the same thing with the coconut milk. So, whether mostly meat-and-oil fat, or coconut milk fat, the arteries similarly clamped down, whereas that horrible sugary breakfast had no effect, no bad effect, on artery function, because, as terrible as it was, it had no saturated fat at all—though it also didn’t have any egg, which may have helped.
Coconut oil proponents also try to argue that coconut oil has MCTs—medium chain triglycerides—shorter-chain saturated fats that aren’t as bad as the longer-chain saturated fats in meat and dairy. But you can’t apply the MCT research to coconut oil. Why? MCT oil is composed of MCTs, the medium chain fats, caprylic and capric acid, about 50% of each, whereas those MCTs make up only like 10% of the coconut oil. Most of coconut oil is the cholesterol-raising longer-chain saturated fats, lauric and myristic. “It is therefore inaccurate to consider coconut oil to contain…predominantly [MCTs].” So, you can’t extrapolate from MCT studies to coconut oil.
That’s actually quite a common misconception, that the saturated fat in coconut oil is mainly MCTs. Actually, coconut oil is mainly lauric and myristic, which have potent LDL (bad cholesterol)-raising effects. “Coconut oil should therefore not be advised for people who should or want to reduce their risk of” the #1 killer of U.S. men and women—heart disease.
It’s like how the beef industry loves to argue that beef fat contains stearic acid, a type of saturated fat that doesn’t raise cholesterol. Yeah, but it also has palmitic and myristic that, like lauric, does raise cholesterol. If you compare the effects of different saturated fats, yes, stearic has a neutral effect on LDL, but palmitic, myristic, and lauric shoot it up. And, frankly, so may MCT oil itself, bumping up LDL like 15% compared to control. So, this “[p]opular belief,” spread by the coconut oil industry, that “coconut oil is healthy” is “not supported by [science].”
So, basically “coconut oil should be [treated no] differently than [animal] sources of dietary saturated fat.” The latest review, published in March 2017 in the Journal of the American College of Cardiology, put it even more simply in their recommendations for patients: “Avoid.”
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