A couple of week back I saw a socialite come pseudo-nutritionist post a picture of her 'healthy' breakfast. It was bacon. Cooked in coconut oil.
Coconut oil in smoothies. Coconut oil in porridge. Coconut oil in your damn coffee. It's everywhere; it must be healthy, right? (I'm not even going to touch the bacon thing rn).
Whole Foods (who exclusively sell healthy things), reported they sold 6 tonnes of coconut oil in February 2015 alone. Coconut oil evangelists rave that it 'boosts metabolism', makes your skin 'glow', (presumably in the dark?), is heart healthy, prevents dementia, reduces cholesterol, helps you lose weight, boosts the immune system, cures diabetes, Crohn's disease and IBS.
Not to be a total downer, but it's all BS.
This is another example of marketing getting one over on science, and then laughing in its face. Recently, the British Nutrition Foundation published a review of the available evidence around coconut oil, and basically, they're pissed.
Coconut oil is 99.9% fatty acids. Of those, 92% are saturated fats. Just to put that into perspective - butter is about 60% saturated fat (not that you should be going HAM on butter either). Just in case you forgot, saturated fats are the things that raise your LDL-cholesterol (bad) and raise your risk of heart disease (very bad). Heart disease is the number one killer of human people in the US and number two in the UK. Not cool, you guys.
UK dietary guidelines say you need to keep saturated fats to less than 11% of calories, about 20g for women, and about 30g for men. And just to be clear, that's the upper limit. And if you still don't think that dietary saturated fats are linked to heart disease, well then you can get in the bin.
So, where do the health claims of coconut oil come from? Well, as the BNF point out, a lot of times they're based on studies done on animals and ones done in test tubes (in-vitro). Sometimes they do them in human people - but using extracts of coconut oil - not the oil itself. And the rest of the time, we get very mixed results. Some studies show that there is no association between coconut oil and LDL cholesterol - others show that the more coconut oil in the diet - the higher the LDL cholesterol. The problem is that all of these studies have pretty major flaws in their design - like not taking into account other dietary or lifestyle variables that can influence the results. By and large these studies are observational, meaning we're just looking to see what happens - you can't prove cause and effect from this type of study.
But what about when scientists get in there and feed coconut oil to people? Their cholesterol goes up (even the good kind, but scientist don't think that's important anymore) and when you stop feeding them coconut oil, it goes down again. One study showed that coconut oil (and palm) oil can raise markers of inflammation, as compared to olive oil, and although this is just one study, there are loads of studies that show the proinflammatory effects of saturated fats.
Saturated fats are not essential in the diet - we can synthesise our own cholesterol in the liver (and in fact, most cells). According to a recent Cochrane review (they're kind of a big deal) cutting down saturated fat can lead to a 17% reduction in cardiovascular disease risk.
Most oils are made up of long chain triglycerides - ones with 12 or more carbons in them. Coconut oil is around 60% medium chain triglycerides - oils with 6-12 carbons. Coconut oil advocates like to point out that these MCTs have a relatively simple digestion and absorption process than the longer chain ones. These pass straight through the small intestine, and go directly to the liver to be burned off, leaving less fat to circulate through the body and be dumped in fat tissue.
Some small studies have reported that coconut oil leads to weight loss, and the effect is attributed to MCTs.
But just hold the phone a sec; one of these such studies instructed the participants to replace their usual cooking oil with either soya bean oil, or coconut oil for 12 weeks. Both groups lost weight. Then again, both groups had cut their calorie intake by about 10%, had been instructed to walk for 50 minutes per day, and changed their overall dietary pattern towards a healthier one. So, they lost weight.
The study only had 20 people in each group, and they were obese to begin with. And there was no control group. Now that's just bad science.
Most of the studies looking at the influence of MCT oils are flawed; small sample sizes, no control groups, questionable methodology, and very short term follow-ups. And remember that coconut oils is only 60% MCTs, so studies from MCTs cannot be extrapolated onto coconut oil; it's not the same thing. In their review, the British Nutrition Foundation (loving your work, you guys) concluded that "there is insufficient, good quality evidence at present to conclude that the consumption of coconut oil leads to a reduction in adiposity (fat)".
Lastly, there are no studies showing any 'immune-boosting' or 'brain-boosting' effects of coconut oil. Sorry guys.
So, if it's your thing, use coconut oil to take off your makeup but leave it the f*ck out of your smoothies. Have you heard that coconut oil has a higher smoke point than other oils and therefore generates less free radicals when heated up? Yeah, that's BS too. If you must use it in cooking, use the least amount possible. Capisce?