Coconut oil – the pros, the cons, and the 'as-yet unknowns'

 Vegan nutrition - there are some health benefits of coconut oil but also some health risks

Not many food products in history have boomed in popularity like coconut oil has in recent years, with a 500% increase in global demand for the product over the last decade.

But not many food products in history also come with such conflicting messages about their effects on health.

Even as a nutritionist, until I looked a little deeper into the research, I didn’t really know what to make of all the information out there.

What I did notice was that information touting the health benefits of coconut oil seem to mostly focus on the topical uses (such as applying to hair or skin) as well as the health benefits of medium-chain triglycerides (a type of saturated fat that makes up over half of the fats in the oil).

And while there are good quality studies behind some of the health benefits of coconut oil, other information comes from more questionable sources like celebrity endorsements, food producers / retailers with a financial interest, and low quality studies (e.g. done on mice).

Comparatively, the quality of the evidence warning us of the detrimental health effects seems to be much more robust (see my article on which types of evidence to believe here).

Here’s a breakdown of the most significant pros and cons of coconut oil, along with any issues with the credibility of the evidence:

Coconut oil: health benefits

Coconut oil is very high in saturated fat, and while most sources of saturated fat are made up of a high proportion of long-chain triglycerides, more than half of the saturated fats in coconut oil are medium chain triglycerides (MCTs). It's these MCT's that are behind most of the health claims behind coconut oil:

  • MCTs can be easily converted to ketones by the liver, providing an alternative energy source for the brain which can be beneficial in the treatment of Alzheimer’s disease (1). However, there is no evidence that coconut oil can prevent Alzheimer’s from developing in the first place.
  • MCTs do have some antibiotic properties – they can disrupt the cell membranes of bacteria and inhibit the growth of some pathogens (2). However, this has only ever been shown in vitro (i.e. in test tubes, petri dishes etc). There are no studies to show that eating coconut oil can prevent diseases in the human body.
  • Some studies suggest that MCTs can aid in weight loss (3,4) compared to other fats. However, the evidence is not the highest quality (most studies have been done on mice, or very low numbers of humans).
  • Coconut oil can be used topically to treat dermatitis (5) and there’s some anecdotal reports that it can prevent dandruff, possibly due to the lauric acid content, which has antimicrobial and antifungal properties.   

Coconut oil: the health risks

  • While coconut oil has been shown in some studies to aid in weight loss, these changes are very minor and the reports encourage many people to add too much of it to their diets. All fats contain 9 calories per gram, and coconut oil is no exception. Therefore, if you are adding extra coconut oil on top of what you’d normally eat, you’re likely to gain weight, not lose weight. There are many MUCH more effective, healthier, and cheaper ways to help with weight loss! 
  • A systematic review (one of the best forms of evidence) evaluated 21 human studies of coconut oil and concluded that it raised total cholesterol and LDL cholesterol (the bad type) more than unsaturated plant oils such as olive oil (6). They concluded that replacing coconut oil with unsaturated plant oils alters blood lipid profiles and reduces risk factors for cardiovascular disease.
  • The environment should be taken into consideration too - of course coconuts do not tend to grow in the West so transporting them from top producing countries like Indonesia and The Philippines requires burning through more fossil fuels than if we used home-grown oils like rapeseed. Coconuts also tend to be grown as a mono-crop, meaning large areas of land with low biodiversity which can effect the environment. Lastly, large proportions of small-scale coconut farmers live in poverty, averaging about $1 per day throughout the year. 

What should we make of all this?!

To summarise, there is some (slightly weaker) evidence behind the health benefits of coconut oil, and some (slightly stronger) evidence behind the negative effects. But there are still a lot of 'as-yet-unknowns' too. Any article you read that shows a very strong opinion either way is probably biased somehow, as none of the scientific evidence is overwhelmingly strong. 

While I'll enjoy watching out for any higher quality future studies, I for one plan to continue using coconut oil occasionally. It does help to enhance the flavours of certain dishes like curries, and also because it's solid at room temperature it can improve the consistency of homemade sweet treats like these vegan brownies. As I mentioned in a previous post about fats, we certainly shouldn't avoid fats altogether. But I will limit how much I use - as with any oil it contains about 120 calories per tablespoon, and the evidence behind the effects on LDL cholesterol is pretty strong. 

Regarding the sustainability of coconut oil, buying Fair Trade goes a long way, because as well as helping the environment by improving water conservation and proper waste disposal, it also helps to ensure safe working conditions and fairer pay for coconut farmers. 

So, if like me, you plan to continue using coconut oil but perhaps a little more sparsely, you can afford to go for a higher quality Fair Trade variety. 

References

1.       Newport, Vanitallie, Kashiwaya, King, & Veech. (2015). A new way to produce hyperketonemia: Use of ketone ester in a case of Alzheimer's disease. Alzheimer's & Dementia: The Journal of the Alzheimer's Association, 11(1), 99-103.
2.       Shilling, M., Matt, L., Rubin, E., Visitacion, M., Haller, N., Grey, S., & Woolverton, C. (2013). Antimicrobial effects of virgin coconut oil and its medium-chain fatty acids on Clostridium difficile. Journal of Medicinal Food, 16(12), 1079-85.
3.       Lei, T., Xie, W., Han, J., Corkey, B., Hamilton, J., & Guo, W. (2004). Medium-chain Fatty acids attenuate agonist-stimulated lipolysis, mimicking the effects of starvation. Obesity Research, 12(4), 599-611.
4.       Liau, K., Lee, Y., Chen, C., & Rasool, A. (2011). An Open-Label Pilot Study to Assess the Efficacy and Safety of Virgin Coconut Oil in Reducing Visceral Adiposity. ISRN Pharmacology, 2011, 7.
5.       Verallo-Rowell, V., Dillague, K., & Syah-Tjundawan, B. (2008). Novel antibacterial and emollient effects of coconut and virgin olive oils in adult atopic dermatitis. Dermatitis : Contact, Atopic, Occupational, Drug,19(6), 308-15.
6.       Eyres, Laurence, Eyres, Michael F., Chisholm, Alexandra, & Brown, Rachel C. (2016). Coconut oil consumption and cardiovascular risk factors in humans. Nutrition Reviews, 74(4), 267-280.