The use of coconut oil to replace other fat and oils in the diet seems to have become very popular amongst the health conscious, due to claims such as it is fat burning and assists with weight loss, also raising the good HDL cholesterol in the body, and reducing cardiovascular risk.
A simple yardstick has always been that fat or oil that is solid at room temperature contains lots of saturated fat, which is not as healthy as most of the plant based oils that are in liquid form at room temperature. The reason is that saturated fats, solid at room temperature, make cell membranes in the body less fluid, while unsaturated fats, liquid at room temperature, make cell membranes more flexible. Coconut oil is plant based, but solid at room temperature, as it consists of 92% saturated fat.
But the coconut oil proponents say that coconut oil has a different molecular structure that results in a type of saturated fat that is more easily absorbed in the body.
Saturated fats can be divided in various types, depending on the number of carbon atoms in the molecule. In the case of coconut oil, its saturated fat is in the 12 carbon atom count region. The carbon atom count gives an indication of the type of fatty acid in the fat or oil. Fatty acids are carbon chains that are classified by how long they are and how many double bonds they have. The significance of this is that saturated fatty acids with a carbon atom count of between 4 and 12 – called medium-chain fatty acids – are more easily absorbed in the body (being more water soluble) than long-chain fatty acids, which can be saturated or unsaturated.
Once inside body cells, fatty acids must be activated, before they can be oxidized for energy. Fatty acids of medium chain length (4-12 carbons) cross the mitochondrial membrane with ease and are then activated inside the mitochondrial matrix, before being oxidized to provide the cell with energy.
The 12 carbon atom count of coconut oil however is borderline between medium- and long-chain fatty acids and is therefore quite controversial. Does it behave like a medium-chain or like a long-chain fatty acid in the body? And does it actually promote weight loss and reduce the risk of cardiovascular disease? How valid are the research findings that tries to substantiate these claims?
The coconut oil health debate has prompted a comprehensive study by the Oils & Fats Specialist Group at the New Zealand Institute of Chemistry. This study reviewed the findings from 21 studies on humans that they could find, most of which examined the effects of coconut oil on cholesterol levels.
In a nutshell they found that the research to substantiate these pro-coconut claims are not conclusive, with most of the human research done with “small sample sizes, biased samples, inadequate dietary assessment and a strong likelihood of confounding.”
To quote Harvard Medical School about the findings of the study: “You can find claims about a host of health benefits related to coconut oil. They are largely unsupported by scientific study.” And concluded “Clearly there has been an upsurge in its use recently. But we’ll need more and better research to understand whether its newly found popularity is well-deserved, or just the latest flavor of the day.”
When applied to skin, coconut oil has a moisturizing effect – thus it is frequently found in creams, soaps and body washes. The use of coconut oil is a popular choice for sweet and biscuit manufacturers, because it gives a pleasant sensation in the mouth – the way a biscuit melts in the mouth is very important! For the same reason, coconut oil is often one of the “hidden” fats in processed food. Coconut oil is very stable, and as a more saturated oil, there is no problem of oxidation by air and light, producing off-flavors.
Sources:
Coconut oil consumption and cardiovascular risk factors in humans. Study by Laurence Eyers et al. Oils and Fats Specialist Group, New Zealand Institute of Chemistry, Auckland, New Zealand. Published in Nutrition Review, April 2016. (Publication of the US National Library of Medicine, National Institute of Health.) (www.ncbi.nlm.nih.gov)
Cracking the coconut craze. Harvard Health Blog, 10 April 2017. Harvard Medical School.
Cholesterol and coconut oil: Myths and facts. Posted on 1 February 2015, BMJ Health. (www.bmj-health.com)
Top 10 evidence-based health benefits of coconut oil. Posted on 11 January 2018, Healthline Newsletter. (www.healthline.com)
Can coconut oil really help you lose weight? Published 5 February 2018, Woman’s Health magazine. (www.womanshealthsa.co.za)
Effects of coconut oil on human health. Published 29 July 2015, Open Journal of Endocrine and Metabolic Diseases, 2015, 5, 84-87, Scientific Research Publishing. (www.scirp.org/journal/ojemd)
Coconut oil: heart-healthy or just hype? Published November 2017, Harvard Medical School.
Coconut oil. What’s behind its “health halo” and does the latest research back it up? Published in the October 2016 issue of Today’s Dietitian.
Coconut oil not a cure-all despite hype. Published 16 October 2016, p.10, Sunday Argus.
HEALTH INSIGHT. FEBRUARY 2018
