What About Coconuts, Coconut Milk, and Coconut Oil MCTs?

Do the medium-chain triglycerides in coconut oil and the fiber in flaked coconut counteract the negative effects on cholesterol and artery function?

Studies of populations who eat a lot of coconuts are “frequently cited” by those who sell coconut oil “as evidence that coconut oil does not have negative effects on cardiovascular health.” For example, there was an apparent absence of stroke and heart disease on the island of Kativa in Papua New Guinea. What were they eating? Their diets centered around tubers, like sweet potatoes, with fruits, greens, nuts, corn, and beans. Although they ate fish a few times a week, they were eating a largely whole food plant-based diet. It’s no wonder they may have had such low rates of artery disease. And, one of the whole foods they were eating was coconut, not coconut oil.

Now, if you go to Pukapuka, even more coconuts are eaten. In fact, as you can see at 0:51 in my video What About Coconuts, Coconut Milk, and Coconut Oil MCTs?, there’s even an island where coconuts make up most of what people eat—and they do get high cholesterol. How can a population eating 87 percent plant-based, with no dairy and only rare consumption of red meat, chicken, and eggs, have cholesterol levels over 200? Well, they’re eating all those coconuts every day. What are their disease rates like? We don’t know. There are no clinical surveys, no epidemiological death data, and no autopsies. Some EKGs were taken, which can sometimes pick up evidence of past heart attacks, but they found few abnormalities. The sample was too small to be a definitive study, though. And, even if they did have low disease rates, they weren’t eating coconut oil—they were eating coconut in its whole form.

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 you can eat all the refined sugar you want. But fruit has fiber and so do coconuts. Just as 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. What’s more, the plant protein in coconuts, which is also missing from the oil, may help explain why whole coconuts 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 disease. And, no wonder, as coconut milk may acutely impair artery function as badly as a sausage and egg McMuffin.

Researchers tested three different meals including a Western high-fat meal that “consisted of an Egg McMuffin®, Sausage McMuffin®, 2 hash brown patties and a non-caffeinated beverage (McDonald’s Corporation)” a local high-fat meal, and an “isocaloric low-fat meal.” The study was conducted in Singapore, so the more traditional local high-fat meal was rice cooked in coconut milk and served with anchovies and an egg. These two different high-fat meals were put up against the same amount of calories in an unhealthy low-fat meal of Frosted Flakes, skim milk, and juice. At 3:21 in my video, you can see the artery function—that is, its ability to relax normally—before and after eating each of the three meals. Researchers found that artery function is significantly crippled within hours of consuming the McMuffins and also the local high-fat meal with coconut milk. So, whether the fat is mostly from meat and oil or from coconut milk, the arteries clamped down similarly, whereas that horrible sugary breakfast had no bad effect on artery function. Why? Because as terrible as the Frosted Flakes meal was, it had no saturated fat at all. (It also didn’t have contain any eggs, so that might have helped, too.)

Coconut oil proponents also try to argue that coconut oil has MCTs, medium-chain triglycerides, which are shorter-chain saturated fats that aren’t as bad as the longer-chain saturated fats in meat and dairy. You can’t apply the MCT research to coconut oil, though. Why not? Well, MCT oil is composed of MCTs—about 50 percent of the medium-chain fat caprylic acid and the other 50 percent of the MCT capric acid—whereas those MCTs make up only about 10 percent of 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 either predominantly medium-chain fatty acids or predominantly medium-chain triglycerides. Thus, the evidence on medium-chain triglycerides cannot be extrapolated to coconut oil.”

It’s actually quite “a common misconception” that the saturated fat in coconut oil is comprised of mainly MCTs. Actually, as we discussed, coconut oil is mainly lauric and myristic, both of which have potent bad LDL cholesterol-raising effects. “Coconut oil should therefore not be advised for people who should or want to reduce their risk of CHD,” coronary heart disease, which is the number-one killer of U.S. men and women. The beef industry, for example, loves to argue that beef fat contains stearic acid, a type of saturated fat that doesn’t raise cholesterol. Yes, but it also has palmitic and myristic acids that, like lauric acid, do raise cholesterol, as you can see at 5:12 in my video.

If you compare the effects of different saturated fats, as you can see at 5:29 in my video, stearic acid does have a neutral effect on LDL, but palmitic, myristic, and lauric acids shoot it up—and, frankly, so may MCT oil itself, as it bumps up LDL 15 percent compared to control. Bottom line? “Popular belief”—spread by the coconut oil industry—“holds that coconut oil is healthy, a notion not supported by scientific data.” The science just doesn’t support it.

So, basically, “coconut oil should be viewed no differently” from animal sources of dietary saturated fat. A recent review published in the Journal of the American College of Cardiology put it even more simply in its recommendations for patients. When it comes to coconut oil, “avoid.”

Okay, but doesn’t saturated fat boost HDL, the so-called good cholesterol? Check out Coconut Oil and the Boost in HDL “Good” Cholesterol.


Isn’t coconut oil supposed to be good for Alzheimer’s, though? See my video Does Coconut Oil Cure Alzheimer’s?

If you want to learn more about the original McMuffin artery studies, see The Leaky Gut Theory of Why Animal Products Cause Inflammation.

You may also be interested in Flashback Friday: Coconut Oil and Abdominal Fat.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Cancer Risk from Arsenic in Rice and Seaweed

A daily half-cup of cooked rice may carry a hundred times the acceptable cancer risk of arsenic. What about seaweed from the coast of Maine?

“At one point during the reign of King Cotton, farmers in the south central United States controlled boll weevils with arsenic-based pesticides, and residual arsenic still contaminates the soil.” Different plants have different reactions to arsenic exposure. Tomatoes, for example, don’t seem to accumulate much arsenic, but rice plants are really good at sucking it out of the ground—so much so that rice can be used for “arsenic phytoremediation,” meaning you can plant rice on contaminated land as a way to clear arsenic from the soil. Of course, you’re then supposed to throw the rice—and the arsenic—away. But in the South, where 80 percent of U.S. rice is grown, we instead feed it to people.

As you can see at 0:52 in my video Cancer Risk from Arsenic in Rice and Seaweed, national surveys have shown that most arsenic exposure has been measured coming from the meat in our diet, rather than from grains, with most from fish and other seafood. Well, given that seafood is contributing 90 percent of our arsenic exposure from food, why are we even talking about the 4 percent from rice?

The arsenic compounds in seafood are mainly organic—used here as a chemistry term having nothing to do with pesticides. Because of the way our body can deal with organic arsenic compounds, “they have historically been viewed as harmless.” Recently, there have been some questions about that assumption, but there’s no question about the toxicity of inorganic arsenic, which you get more of from rice.

As you can see at 1:43 in my video, rice contains more of the toxic inorganic arsenic than does seafood, with one exception: Hijiki, an edible seaweed, is a hundred times more contaminated than rice, leading some researchers to refer to it as the “so-called edible hijiki seaweed.” Governments have started to agree. In 2001, the Canadian government advised the public not to eat hijiki, followed by the United Kingdom, the European Commission, Australia, and New Zealand. The Hong Kong Centre for Food Safety advised the public not to eat hijiki and banned imports and sales of it. Japan, where there is actually a hijiki industry, just advised moderation.

What about seaweed from the coast of Maine—domestic, commercially harvested seaweed from New England? Thankfully, only one type, a type of kelp, had significant levels of arsenic. But, it would take more than a teaspoon to exceed the provisional daily limit for arsenic, and, at that point, you’d be exceeding the upper daily limit for iodine by about 3,000 percent, which is ten times more than reported in a life-threatening case report attributed to a kelp supplement.

I recommend avoiding hijiki due to its excess arsenic content and avoiding kelp due to its excess iodine content, but all other seaweeds should be fine, as long as you don’t eat them with too much rice.

In the report mentioned earlier where we learned that rice has more of the toxic inorganic arsenic than fish, we can see that there are 88.7 micrograms of inorganic arsenic per kilogram of raw white rice. What does that mean? That’s only 88.7 parts per billion, which is like 88.7 drops of arsenic in an Olympic-size swimming pool of rice. How much cancer risk are we talking about? To put it into context, the “usual level of acceptable risk for carcinogens” is one extra cancer case per million. That’s how we typically regulate cancer-causing substances. If a chemical company wants to release a new chemical, we want them to show that it doesn’t cause more than one in a million excess cancer cases.

The problem with arsenic in rice is that the excess cancer risk associated with eating just about a half cup of cooked rice a day could be closer to one in ten thousand, not one in a million, as you can see at 4:07 in my video. That’s a hundred times the acceptable cancer risk. The FDA has calculated that one serving a day of the most common rice, long grain white, would cause not 1 in a million extra cancer cases, but 136 in a million.

And that’s just the cancer effects of arsenic. What about all the non-cancer effects? The FDA acknowledges that, in addition to cancer, the toxic arsenic found in rice “has been associated with many non-cancer effects, including ischemic heart disease, diabetes, skin lesions, renal [kidney] disease, hypertension, and stroke.” Why, then, did the FDA only calculate the cancer risks of arsenic? “Assessing all the risks associated with inorganic arsenic would take considerable time and resources and would delay taking any needed action to protect public health” from the risks of rice.

“Although physicians can help patients reduce their dietary arsenic exposure, regulatory agencies, food producers, and legislative bodies have the most important roles” in terms of public health-scale changes. “Arsenic content in U.S.-grown rice has been relatively constant throughout the last 30 years,” which is a bad thing.

“Where grain arsenic concentration is elevated due to ongoing contamination, the ideal scenario is to stop the contamination at the source.” Some toxic arsenic in foods is from natural contamination of the land, but soil contamination has also come from the dumping of arsenic-containing pesticides, as well as the use of arsenic-based drugs in poultry production and then the spreading of arsenic-laced chicken manure on the land. Regardless of why south central U.S. rice paddies are so contaminated, we shouldn’t be growing rice in arsenic-contaminated soil.

What does the rice industry have to say for itself? Well, it started a website called ArsenicFacts. Its main argument appears to be that arsenic is everywhere, we’re all exposed to it every day, and it’s in most foods. But shouldn’t we try to cut down on the most concentrated sources? Isn’t that like saying look, diesel exhaust is everywhere, so why not suck on a tailpipe? The industry website quotes a nutrition professor saying, “All foods contain arsenic. So, if you eliminate arsenic from your diet, you will decrease your risk…and you’ll die of starvation.” That’s like Philip Morris saying that the only way to completely avoid secondhand smoke is to never breathe—but then you’ll asphyxiate, so you might as well just start smoking yourself. If you can’t avoid it, you might as well consume the most toxic source you can find?!

That’s the same tack the poultry industry took. Arsenic and chicken? “No need to worry” because there’s a little arsenic everywhere. That’s why it’s okay the industry fed chickens arsenic-based drugs for 70 years. If you can’t beat ’em, join ’em.

How can the rice industry get away with selling a product containing a hundred times the acceptable cancer risk? I cover that and so much more in my other videos on arsenic and rice, which also include concrete recommendations on how to mediate your risk.


Check out:

Pesticides were not the only source of arsenic. Poultry poop, too, if you can believe it! I cover that story in Where Does the Arsenic in Chicken Come From? and Where Does the Arsenic in Rice, Mushrooms, and Wine Come From?.

Chronic low-dose arsenic exposure is associated with more than just cancer. See The Effects of Too Much Arsenic in the Diet.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Where Does the Arsenic in Rice, Mushrooms, and Wine Come From?

What happens when our crops are grown in soil contaminated with arsenic-based pesticides and arsenic drug-laced chicken manure?

When arsenic-containing drugs are fed to chickens, not only does the arsenic grow out into their feathers, which are then fed back to them as a slaughterhouse byproduct, but the arsenic can also get into their tissues and then into our tissues when we eat eggs or meat, a cycle depicted at the start of my video Where Does the Arsenic in Rice, Mushrooms, and Wine Come From?. This explains why national studies have found that those who eat more poultry have tended to have more arsenic flowing through their bodies. Why would the industry do that? In modern poultry farms, often called CAFOs for concentrated animal feeding operations, there can be 200,000 birds under one roof and the floors of these buildings become covered with feces. While this so-called factory farming decreases costs, it also increases the risk of disease. That’s where arsenic-containing drugs and other antibiotic feed additives can come in: to try to cut down the spread of disease in such an unnatural environment. If you’re feeling a little smug because you don’t eat chicken, what do you think happens to the poop?

As depicted at 1:17 in my video, from chicken manure, the arsenic from the drugs in the animal feed can get into our crops, into the air, and into the groundwater, and find its way into our bodies whether we eat meat or not. Yes, but how much arsenic are we really talking about? Well, we raise billions of chickens a year, and, if, historically, the vast majority were fed arsenic, then, if you do the math, we’re talking about dumping a half million pounds of arsenic into the environment every year—much of it onto our crops or shoveled directly into the mouths of other farm animals.

Most of the arsenic in chicken waste is water soluble, so, there are certainly concerns about it seeping into the groundwater. But, if it’s used as a fertilizer, what about our food? Studies on the levels of arsenic in the U.S. food supply dating back to the 1970s identified two foods, fish aside, with the highest levels—chicken and rice—both of which can accumulate arsenic in the same way. Deliver an arsenic-containing drug like roxarsone to chickens, and it ends up in their manure, which ends up in the soil, which ends up in our pilaf. “Rice is [now] the primary source of As [arsenic] exposure in a non seafood diet.”

I was surprised to learn that mushrooms are in the top-five food sources of arsenic, but then it made sense after I found out that poultry litter is commonly used as a starting material to grow mushrooms in the United States. As you can see at 2:58 in my video, over the years, the arsenic content in mushrooms has rivaled arsenic concentration in rice, though people tend to eat more rice than mushrooms on a daily basis. Arsenic levels in mushrooms seemed to be dipping starting about a decade ago, which was confirmed in a 2016 paper that looked at a dozen different types of mushrooms: plain white button mushrooms, cremini, portobello, shiitake, trumpet, oyster, nameko, maitake, alba clamshell, brown clamshell, and chanterelle. Now, mushrooms are only averaging about half the arsenic content as rice, as you can see at 3:37 in my video.

Just like some mushrooms have less arsenic than others, some rice has less. Rice grown in California has 40 percent less arsenic than rice grown in Arkansas, Louisiana, Mississippi, Missouri, and Texas. Why? Well, arsenic-based pesticides had been used for more than a century on millions of acres of cotton fields, a practice noted to be “dangerous” back in 1927. Arsenic pesticides are now effectively banned, so it’s not simply a matter of buying organic versus conventional rice because millions of pounds of arsenic had been laid down in the soil well before the rice was even planted.

The rice industry is well aware of this. There’s an arsenic-toxicity disorder in rice called “straighthead,” where rice planted in soil too heavily contaminated with arsenic doesn’t grow right. So, instead of choosing cleaner cropland, they just developed arsenic-resistant strains of rice. Now, lots of arsenic can build up in rice without the plant getting hurt. Can the same be said, however, for the rice consumer?

It’s the same story with wine. Arsenic pesticides were used, decade after decade, and even though they’ve since been banned, arsenic can still be sucked up from the soil, leading to “the pervasive presence of arsenic in [American] wine [that] can pose a potential health risk.” Curiously, the researchers sum up their article by saying that “chronic arsenic exposure is known to lower IQ in children,” but if kids are drinking that much wine, arsenic toxicity is probably the least of their worries.

Hold on. Chickens are being fed arsenic-based drugs? See Where Does the Arsenic in Chicken Come From? to find out more.


 I expect the arsenic-in-rice issue brought up a lot of questions, and giving you answers is exactly why I’m here! Check out:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations: