Coconuts have been a valued food in tropical areas for thousands of years, traditionally enjoyed as coconut water from the centre of the coconut, coconut flesh, or coconut “milk” (made by steeping the flesh in hot water).
Solid white coconut oil (I’ll use this popular term, although technically it’s a fat not an oil) is now the darling of celebrities and bloggers, paleo enthusiasts and sellers of so-called superfoods. Claims for its supposed medical value reverberate around the internet, but how well do they stand up to scientific scrutiny?
1. It helps you lose weight
No study has found coconut oil helps weight loss. The claim made on hundreds of internet sites that it has some special ability to get rid of body fat is based on the erroneous idea that coconut oil is synonymous with a semi-synthetic laboratory product known as MCT oil.
Unlike regular edible oils, MCT oil is soluble in water and was originally designed for use in tube feeding or for people who were malnourished because they lacked normal enzymes that split fat. Unlike most fats that are absorbed into the bloodstream, MCT oil is absorbed directly into the liver. This means it can be used more rapidly for fuel than other fats.
There is some evidence MCT oil may help with weight loss, although the dose required and its side effects – at least initially – can include nausea, stomach cramps and diarrhoea. Even so, internet sites that assume the effects of MCT oil also apply to coconut oil are wrong. The two products are not equivalent and you can’t switch the findings of one to the other.
MCT is made up of two fatty acids – caprylic and capric acids. Coconut oil has small amounts of these acids, but its dominant fatty acid is lauric acid. Lauric acid is not digested in the liver but is digested and metabolised in the body like the fatty acids in other edible oils.
If munching on a piece of coconut flesh (which is a reasonable source of dietary fibre) helps you eat less overall, that could be useful. However, a study of different fats, including coconut oil, found no beneficial effect on hunger, fullness, satisfaction or current thoughts of food.