By Linia Patel
Coconut oil.
People are using it in everything from stir-fries to smoothies. Considered a staple ingredient of the popular clean eating and Paleo diet trends, and hailed as the latest superfood that aids fat loss, boosts heart health, cures Alzheimer's and dementia – coconut oil has ignited a controversial debate. Are the touted promises true? Should you be signing up for an oil change? Let’s investigate.
What is coconut oil?
Coconut oil is made by pressing the fat from the white flesh inside the giant nut. The extracted oil is pure fat. Despite its name, coconut oil is a fat that is solid at room temperature. This is due to the fact that it contains 92% saturated fat – a higher percentage than found in butter. Historically, the belief has been that all saturated fats are bad fats – however, it’s not quite as simple as that. I'll save you the complicated biochemistry, but it is important to know that there are different types of saturated fats that seem to make a difference in terms of their health properties.
Coconut chemistry
On a basic level, fats are made of fatty acids. Fatty acids are strings of carbon atoms with a certain number of hydrogen atoms attached with or without double bonds. Saturated fats have no double bonds, which is what allows them to fit together compactly, making a solid fat. Fatty acids come in many lengths, from 4-carbon chains all the way up to 22 carbon chains. Most oils consist entirely of long-chain triglycerides (LCTs) which are more than 12 carbons long. Medium chain triglycerides (MCTs) are 6 – 12 carbons long. The difference in carbon atoms matters because our bodies metabolize MCTs differently to LCTs.
Coconut oil and cholesterol
Current guidelines indicate that consuming too much saturated fat (no more than 10% of food energy) is unhealthy because it raises "bad" low density lipoprotein (LDL) cholesterol levels, which increases the risk of heart disease. So it would seem that coconut oil would be bad news for your heart. However, one of the main arguments put forward by those who support coconut oil is that the saturated fat in coconut oil behaves differently to typical saturated fats, preventing any negative effects on heart health.
Coconut oil contains mostly (44%) lauric acid and (16%) myristic acid. Studies have shown that both lauric acid (C12:0), myristic acid (C14:0) increase “bad” cholesterol (LDL cholesterol) whilst also boosting “good“ cholesterol (HDL cholestrol). Coconut oil's special HDL-boosting effect may make it "less bad" than the high saturated fat content would indicate, but it’s no healthy heart magic bullet. Vegetable oils like olive oil lower LDL (bad cholesterol) and increase HDL (good cholesterol).
The good thing about coconut oil, however, is that it has a higher smoking point than olive oil, so you are able to cook at higher temperatures without making your own trans-fats so it does have a place within healthy eating guidelines.
Overall, whilst more research needs to be done, the general recommendations still stand true - keep saturated fat to under 10% of your overall fat calories (this equates to about 20g for women and 30g for men). But then within that recommendation, focus on the saturated fats that aren't processed, which is exactly where unprocessed, extra virgin coconut oil falls into play. Two tablespoons of coconut oil provided about 24g of saturated fat.
The fat burning fat
Coconut oil is also unusual as it contains a high percentage of medium-chain triglycerides (MCTs). MCTs are used by the body as an immediate source of energy and as such the body is not able to deposit them in fat tissues. This is where the bold claims about “coconut oil melting away pounds of fat” comes from. What does the scientific evidence say?
Well, the evidence behind weight loss claims is thin. One of the longest and largest studies was done at Columbia University. The study looked at 31 overweight/obese men and women who were given 1500 to 1800 calorie a day diet that got 1 % of their calories either from MCTs (1 – 2 tablespoons) or from olive oil. Over the four months of the study, the people getting MCT oil lost about four or more pounds than those getting olive oil. There’s no way of telling if the MCT users would have continued to lose weight beyond four months though. Since coconut oil contains only about half as much MCT oil, would coconut oil have just half of the modest impact on weight? There needs to be more studies done.
The fact remains if you are trying to lose weight it’s important to remember that with 121 calories per tablespoon, coconut oil should be used in moderation. Consuming too much will give you extra calories — and that can signal to your body that it's time to store more fat, even if the stored fat doesn't come directly from the coconut oil.
Maintaining brain health
There have been some claims that coconut oil could be used to prevent or even a cure Alzheimer's disease. These claims are based on the theory that early on in diseases like Alzheimer's and Parkinson's, the brain starts to lose its ability to use glucose, which leads to a kind of starvation of the brain. But the brain can still use other forms of energy such as ketones. When the body metabolizes the medium chain triglycerides (MCTs) in coconut oil it is able to produce ketones which may provide an alternative fuel source to keep the brain nourished. The reality, however, is that there is not enough scientific evidence to back up this hypothesis. More research is needed so that we can fully understand the effect of coconut oil on diseases like Alzheimer’s.
Other coconut oil advocates claim that it is rich in antioxidants, compounds that may help brain health, but you get a bigger antioxidant bang for your buck from vegetables, fruits, and whole grains.
Take home message
I like coconut oil - but with a caveat. It’s a healthier saturated fat: yes. But it is not the be-and-end all as some suggest. It does have a wonderful flavour and there's no problem using coconut oil occasionally. If you choose to use it, stick to unprocessed, extra virgin coconut oil.
The key thing to remember is that overall dietary habits rather than individual nutrients hold the key to optimal health. Want better health? Eat a diet that is rich in vegetables and fruit, pulses, whole grains, nuts and seeds, and have modest intakes of lean meat, poultry, white and oily fish. Depending on your goals use vegetable oils like olive or rapeseed oil and if you want to use butter or coconut oil use in sparingly. Sadly there is no magic formula, pixie dust or excessive dollops of coconut oil involved.
Linia Patel is a leading dietitian and sports nutritionist. She's passionate about empowering people to better manage their health and optimise their performance through learning the essence of healthy eating. Outside of work, Linia is a wannabe triathlete. Visit her website: www.liniapatel.com.
References
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Fnzifst LE. Coconut oil and the Heart, Evidence Paper (2014) New Zealand Heart Foundation.
DiNicolantonio JJ. The cardiometabolic consequences of replacing saturated fats with carbohydrates or omega-6 polyunsaturated fats: Do the dietary guidelines have it wrong? Open Heart. 2014;1. doi:10.1136/openhrt-2013-000032.
Ravnskov U, DiNicolantonio JJ, Harcombe Z, Kummerow FA, Okuyama H, Worm N. The questionable benefits of exchanging saturated fat with polyunsaturated fat. Mayo Clin Proc. 2014;89(4):451-453
Assunção ML1, Ferreira HS, dos Santos AF, Cabral CR Jr, Florêncio TM. Effects of dietary coconut oil on the biochemical and anthropometric profiles of women presenting abdominal obesity (2009). Lipids 44(7):593-601.
Fernando W, Marting I, Goozee K, Brennan C, Jaysena V. The role of dietary coconut for the prevention and treatment of Alzheimers’s disease; potential mechanisms of action. Br J Nutr. 2015. July 14:114 (1):1- 14
