Health benefits of coconut oil: Myths and realities2 February 2018
Coconut oil is hugely popular, with many believing it to be the answer to many health concerns, though recent studies have suggested it is no better for you than any other saturated fat. Abi Millar talks to the BDA’s Kiri Elliott and nutrition scientist Dr Stacey Lockyer to separate the facts from the hype.
Over the past few years, coconut oil has seen a reversal in its fortunes. Long a staple of Indian and Thai cuisine, it was never historically popular outside Asia. For many Westerners, coconuts meant pina coladas or Bounty bars.
Since 2012, however, virgin coconut oil has seen a huge increase in sales throughout Europe and North America, with an explosion of new start-ups and product launches.
According to market research firm Mintel, the European market for the ingredient doubled each year between 2012 and 2015. Although growth now appears to be stabilising, supply is struggling to keep up with demand. The Philippines, one of the world’s main coconut producers, increased its exports of coconut oil by 61% in 2015 alone.
The reason for this growth is clear – coconut oil has begun to market itself as a health food. Despite its high saturated fat content, it has received an enviable dose of good PR in the form of wellness bloggers and celebrity endorsements.
It has also benefitted from a climate in which fat is no longer quite so demonised, today’s chief nutritional bogeyman being sugar.
“Following from the rise in coconut water’s popularity, the oil became popular as part of the clean eating craze,” recalls Kiri Elliott, dietitian and spokesperson for the British Dietetic Association. “Although it’s a processed oil, it is often associated with words such as ‘raw’ and ‘natural’, which fitted well with the clean eating movement. It is also plant-based, so chimes with the values of the growing number of vegetarians and vegans.”
If you go by some of the claims found online, its benefits are considerable. Holland & Barrett’s website, for instance, states, “The superfood has been found to help slim belly fat, fight osteoporosis, boost endurance during exercise, ease arthritis, prevent gum disease, raise levels of ‘good’ cholesterol, and soothe dry skin.”
Well-being website Dr Axe lists 20 ‘proven’ benefits, ranging from cancer prevention to dandruff reduction, while Gwyneth Paltrow advocates swishing oil around in your mouth for teeth whitening.
This hype has translated directly into sales. As Elliott explains, “Some celebrities or bloggers have millions of followers and have a huge influence on what groceries their followers go on to buy. Seeing a rise in demand and therefore an opportunity for sales, food industry players were then quick to act.”
Not everybody is convinced coconut oil is such a nutritional wonder. Last year, the British Nutritional Foundation (BNF) published a paper in its Nutrition Bulletin, ‘Coconut oil – A nutty idea?’ which cast doubt on many of the claims.
“News stories were claiming that eating coconut oil had multiple health benefits, therefore BNF thought it was important to look into the effects of this food on human health,” says Dr Stacey Lockyer, a nutrition scientist and co-author of the paper. “Its saturated fat content is almost 90%, which is much higher than other fats including palm oil, butter and lard. Current UK dietary guidelines recommend that saturated fat is reduced in the diet and replaced with small amounts of unsaturated fats.”
Lockyer’s paper concludes that there is no good evidence that coconut oil has any health benefits. In fact, she points out, the reverse might be true – coconut oil may raise the risk of heart disease. This view is shared by Elliott and many other experts. So if coconut oil is truly not all that healthy, how did its ‘superfood’ status come about?
The answer, on one level, would seem to be bad reporting on bad science. As both Lockyer and Elliott reinforce, the health claims are often based solely on animal studies, which don’t tell us anything useful about the effects in humans. Of the human studies that have been published, many ohave methodological flaws, or focus on only one isolated component of coconut oil.
“When it comes to coconut oil, results of studies are usually extrapolated in a way that a sensational headline shines through, but it has been taken out of context and is therefore misleading,” says Elliott. “On the whole, health claims about coconut oil tend to be testimonials, rather than robust clinical evidence.”
Take the claim that the oil can ‘slim belly fat’. While there have been several papers published that suggest a relationship, these studies have been small and, according to Elliott, “not worthy of any hype”.
“The studies have been over a short period, such as four weeks, with no longterm follow-up. Also, there are limitations in study designs, such as participants not being randomised, no placebo and even no control of other factors that could affect results, such as participants’ other dietary intake and exercise,” she says.
Then there are the claims that coconut oil can improve cognitive function, particularly in patients with Alzheimer’s disease.
“Support for the use of coconut oil in Alzheimer’s disease is based on animal studies and anecdotal evidence... and there is typically a large placebo effect,” says Lockyer.
The question is why so many sources have latched onto such flimsy evidence, bearing in mind the oil’s nutritional profile. After all, just two tablespoons of coconut oil contains more than 20g of saturated fat, which is the maximum daily allowance of the average woman.
Fat lot of good
One answer, according to coconut oil aficionados, is that not all saturated fats are made alike. “The majority of the fat [in coconut oil] is made up of medium-chain triglycerides (MCTs) that your body breaks down for energy, rather than storing as fat,” says the Holland & Barrett website.
Unfortunately, recent studies have picked holes in this reasoning. In 2014, researchers in New Zealand concluded that coconut oil did not behave in the same way as MCTs, and that it was “totally erroneous and scientifically wrong” to describe it as one.
What’s more, while coconut oil is indeed high in lauric acid – a type of fat found in human breast milk – there is some debate about whether lauric acid can truly be considered an MCT.
“Coconut oil cannot be considered an MCT oil and needs to be studied in its own right,” says Elliott.
There is one further health claim that bears unpicking – namely that coconut oil might raise levels of ‘good’ (HDL) cholesterol. Observational studies have suggested this might be true, and a 2003 meta-analysis found that lauric acid did indeed have this benefit.
However, coconut oil also appears to raise levels of ‘bad’ (LDL) cholesterol, negating any possible benefits to heart health. In this regard, it behaves much like any other saturated fat.
“Looking at controlled trials in which individuals have consumed coconut oil regularly, using it in place of unsaturated fats or on top of their normal diet, blood cholesterol is found to increase,” says Lockyer. “Having raised blood cholesterol is known to increase the risk of developing heart disease.”
So, with coconut oil looking less like a superfood, do Elliott and Lockyer believe the craze is likely to fade away any time soon? And what do they recommend in the meantime?
“I hope that the fad does die down, as there just isn’t the evidence to support the health claims that have been made so far,” says Elliott. “It feels that the choice to use coconut oil is not an informed decision based on facts and unbiased scientific literature, but is more based on unfounded hearsay from celebrities. That said, there is more to learn about the role in the body of fats and coconut products in general, so there may be benefits we haven’t discovered yet.”
For Lockyer, the high cost of coconut oil is a real point of concern. “Consumers are being led to believe that coconut oil is worth spending considerable sums of money on because they will gain health benefits, when in fact it is more likely that consuming coconut oil regularly would be detrimental to health,” she says.
“Standard vegetable oil, which is normally rapeseed oil, is a cheaper and much healthier option for everyday use. If you like the taste of coconut oil, it can be included in the diet, but in small amounts and not very often.”
“For people consuming a typical Western diet, coconut oil used occasionally as culinary oil is not harmful in small quantities," adds Elliott. "However, those using a lot due to the current fad should consider limiting its use, perhaps in favour of cold-pressed mono-unsaturated oils such as olive or avocado.”