Coconut Oil Explained (In a Lot of Detail) – Is Eating it Good for Your Health?

When our neighbors moved from Atlanta to San Francisco sort of suddenly, they gave my roommate and me a bunch of food they weren’t allowed to pack on the moving truck. They shop at Cosco, so everything was bulk. This was about two years ago, and we are still eating our way through 5 pounds of Quaker old fashioned oats. Three pounds of butter have been used over 2 holiday baking seasons. We have basmati rice for centuries.

The one thing we haven’t really used, though, is the 54-ounce container of extra virgin, unrefined coconut oil they left us. I know, shocking.

Coconut oil is the best at everything right now. Your hair, your skin, your nails. Your heart, your brain, your waistline. Coconut oil probably has 80 million Twitter followers.

Maybe you’re on this tropical bandwagon. But maybe, just maybe, you’re like a lot of people out there wondering, is coconut oil really all it’s cracked up to be?

coconut oil

Coconut oil is made from coconut flesh (obvi) and comes in two versions: virgin and refined. The refined oil undergoes this whole sexy bleaching and deodorizing process. The virgin variety is made by gently pressing the oil from the coconut meat. The virgin oil actually tastes like coconut. The refined stuff is used in food processing because it’s odorless and flavorless.

Coconut oil is very, very high in saturated fat: it’s 92% saturated fat (compared to butter, which is 54% saturated). The reason people claim coconut oil has health benefits despite its high concentration of saturated fats is because coconut oil is high medium-chain triglycerides.

Let’s break for some chemistry fun!

Fatty acids are basically a bunch of carbon atoms held together by chemical bonds. They can be saturated (all the carbon atoms are saturated with hydrogen atoms) or unsaturated (there are some carbons on the chain with a free spot or two, creating a small “kink” in the fatty acid carbon chain and making a world of difference).

saturated-vs-unsaturated

Fatty acids come in all shapes and sizes. Short, medium, long, and very long. Short chain fatty acids (SCFA) contain up to 6 carbon atoms, medium chain fatty acids (MCFA) contain 8-12 carbons, and long chain and very long chain fatty acids (LCFA and VLCFA) contain greater than 12 carbons.

Fat exists in food as triglycerides – three fatty acids attached to a glycerol molecule. So, when three MCFA are attached to a glycerol “backbone”, the result is a medium-chain triglyceride (MCT).

Fatty acids and triglycerides have differing characteristics depending on their saturation and length. SCTs and MCTs are small, soluble in water, and are typically liquid at room temperature (even if they’re saturated!), whereas saturated LCTs are solid at room temperature and are not soluble in water. They behave differently inside your body when compared to LCTs. MCTs can float around in your blood without assistance from proteins, and they can be (and are) quickly oxidized in the liver and used for fuel because of this ready availability. LCTs, however, don’t like the watery environment of blood, so they get packaged up in these complex formations, and are forced to travel through your lymphatic system, making them less available for use as immediate fuel and more likely to get stored in your fat tissue. MCTs also put less stress on the pancreas (which secretes enzymes that break up dietary fat) because they’re smaller. *

I hope you’re still with me.

A couple paragraphs up, I said coconut oil is high in MCFAs, or MCTs, and this is technically true. Coconut oil contains three major MCTs: capric acid, caprylic acid, and lauric acid. Capric acid and caprylic acid together make up about 15% of coconut oil. An overwhelming 45-48% of coconut oil is made up by lauric acid.

While capric and caprylic acids have 10 and 8 carbons, respectively, lauric acid has 12 carbons. Although lauric acid is technically a MCFA in name, it turns out (due to its longer length) it shares more chemical properties with the LCFAs than its shorter counterparts. It’s not water soluble, it’s solid at room temperature. Further, lauric acid can act like a LCFA in biological systems (like your bod).

Since lauric acid makes up such a large portion of the fat in coconut oil, we would expect coconut oil to take on the properties of lauric acid. And if you’ve ever seen it (and maybe have a huge jar of it sitting on a shelf in your pantry, like I do) you know that it does – it’s solid at room temp and it’s not soluble in water.

OK, chemistry lesson over (sad).

The reason we advise people to limit dietary saturated fats is because of its unfavorable effect on blood cholesterol – it has been shown to increase total cholesterol and LDL cholesterol. High cholesterol and high LDL cholesterol are associated with increased risk for cardiovascular disease (CVD). Not all saturated fats are created equal, though. Some, like stearic acid (long-chain), have a neutral effect on cholesterol, while others, like myristic (long-chain), palmitic (long-chain), and lauric (remember, medium-chain), have been shown to increase total cholesterol and LDL cholesterol. These latter three fats make up greater than 70% of coconut oil.

Yet, coconut oil is sporting a bling health halo these days. Why?

The two main arguments are as follows:

  1. MCTs are heart healthy
  2. Indigenous peoples from tropical and subtropical countries eat lots of coconut and enjoy low levels of CVD

Shall we dig a little deeper?

The first claim is this: According to research, MCTs are heart healthy. Coconut oil is high in MCTs. Therefore coconut oil is heart healthy. The problem, though, is that research done with MCTs uses mostly refined MCT oil preparations from capric and caprylic acids. The MCT in coconut oil is predominantly lauric acid. We can’t extrapolate data from studies using refined MCT oil preparations to coconut oil. So there goes that argument.

Some studies1-4 we CAN use (because they tested coconut oil’s effect on cholesterol using actual coconut oil) show that coconut oil does in fact cause an increase in total, LDL, and HDL cholesterol.**

The second claim is based on observational studies5-7 that show that tropical and subtropical countries (Sri Lanka, Philippines, India, Melanesia, and Polynesia), whose populations eat lots of also tend to have low incidences of CVD and favorable cholesterol profiles. Of course, we know that observational studies do not show cause and effect, because of the potential confounding factors present. In this case, these people are eating coconut flesh and milk, not just extracted oil. They are also eating a native diet high in fish, fruit, vegetables, and fiber, and low in processed, refined carbohydrates, and they are very physically active. So we can’t say that it is coconut in particular that benefits heart health. In fact when we look at Pacific islanders whose diets have been heavily influenced by Western culture (because of incoming Westerners or because of a move to a Westernized country), this protection drops off8,9.

When it’s all said and done, my take on coconut oil is not going to be ground-breaking, people. I would say it could be a good substitute for butter, but that using an unsaturated vegetable oil like canola or safflower would be your best choice. And of course, use any fat in moderation, especially if you’re weight-minded, because fat is very calorically dense.

If you are going to choose coconut oil, choose the virgin kind. It retains some of the polyphenols (antioxidants) in the coconut flesh which could be beneficial to heart health (based on rat studies, so don’t go crazy here)10-11. And use it as part of healthy diet rich in fruits, veggies, whole grains, and lean proteins like fish and chicken, and low in highly processed, refined carbohydrates. A double-chocolate cheesecake brownie recipe that calls for coconut oil instead of butter is NOT a healthy brownie recipe.

Now, what should I do with this coconut oil? These roasted veggies look pretty delish … http://www.averiecooks.com/2013/01/lemon-rosemary-coconut-oil-roasted-vegetables.html

~ Courtney

*MCT oil preparations are used in clinical settings as medical nutrition therapy for people that can’t process long-chain fats (due to pancreatitis, liver disease, or metabolic disorders), or in people with digestive system dysfunction.

**Of note, lauric acid and coconut oil in general has been shown to increase HDL cholesterol as well. HDL is known as the “good” cholesterol, so coconut oil enthusiasts use this fact to support the claim that coconut oil is heart healthy. But a rise in HDL is not inherently a beneficial thing. In actuality, when it comes to HDL, it’s quality over quantity. The activity of the HDL is more important than the amount present – and we don’t know yet whether coconut oil enhances HDL activity.

References:

  1. http://www.jlr.org/content/36/8/1787.long
  2. http://www.ncbi.nlm.nih.gov/pubmed/9756121
  3. http://ajcn.nutrition.org/content/42/2/190.long
  4. http://www.ncbi.nlm.nih.gov/pubmed/2383532
  5. http://www.ncbi.nlm.nih.gov/pubmed/15563444
  6. http://www.ncbi.nlm.nih.gov/pubmed/8450295
  7. http://ajcn.nutrition.org/content/22/5/594.long
  8. http://www.ncbi.nlm.nih.gov/pubmed/6937778
  9. http://www.ncbi.nlm.nih.gov/pubmed/19710163
  10. http://www.ncbi.nlm.nih.gov/pubmed/15329324
  11. http://www.ncbi.nlm.nih.gov/pubmed/24513138

Other articles used as references for this post:

http://www.heartfoundation.org.nz/uploads/Evidence_paper_coconut_August_2014.pdf

http://www.todaysdietitian.com/newarchives/111114p32.shtml

http://ajcn.nutrition.org/content/36/5/950.full.pdf+html

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1 Comment

Filed under cardiovascular disease, Saturated fat

One response to “Coconut Oil Explained (In a Lot of Detail) – Is Eating it Good for Your Health?

  1. From one RD to another, THANKS for sharing this!

    Like

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