Coconut Oil is boasted to help in weight loss and cure a number of illnesses. But with a higher saturated fat percentage than butter, is it all it’s cracked up to be?
Despite a whopping 86.5 per cent saturated fat content, coconut oil has seen a huge surge in popularity recently, filling the shelves of health food shops and supermarkets nationwide.
The coconut oil of today is a long way from the most unhealthy trans fat-containing hydrogenated oil used in junk food in the ‘80s – but its saturated fat content is still a concern.
Most vegetable oils (soya, olive, sunflower and rapeseed) contain less than 20 per cent saturated fat. Butter contains over 50 per cent – far less than coconut oil.
So just why is it so popular?
Coconut: The stats
Like all plant foods, coconut is cholesterol-free. Although it is a fruit, coconut flesh has a very different nutritional content to other fruits.
A third of the flesh is composed of fat and nearly 90 per cent of that is saturated – the worst type as it increases cholesterol, which increases the risk of heart disease. Desiccated coconut (coconut flesh that has been flaked and dried) contains around two-thirds fat.
A similar amount is found in hazelnuts, almonds and Brazil nuts but most of that is polyunsaturated fat that can lower the risk of heart disease if taken in moderation.
The fibre content in desiccated coconut is two to three times higher than in nuts. Some studies suggest that coconut flakes lower LDL ‘bad’ cholesterol because they are a good source of fibre which has cholesterol-lowering properties. Processing coconut to produce oil strips away this protective fibre.
However, fibre is easily obtained from other fruit, vegetables, wholegrain foods and pulses that don’t contain so much fat. The recommended intake for fibre is 18g per day (this may soon rise to 30g). To increase your intake, choose high-fibre breakfast cereals (oats or muesli with no added sugar), switch from white bread, pasta and rice to wholegrain bread, pasta and brown rice and ensure you have at least five portions of fruit and vegetables a day.
A 1980’s study used to promote coconut oil described how Pacific islanders, who used coconut in every meal and so had a high intake of saturated fat, had lower than expected cholesterol and heart disease was rare.
However, they had low intakes of salt, sugar and cholesterol and consumed a healthy amount of fibre, plant sterols and omega-3 fats. They also had an active lifestyle and used little tobacco.
When the islanders moved to New Zealand and reduced their saturated fat intake, their intake of cholesterol, junk food, and sugar increased – and so did their risk of heart disease, proving that whole diet and lifestyle can have a profound effect on health.
But what’s so bad about saturated fat?
All major health organisations agree that saturated fat is a risk factor for heart disease. Most saturated fat in the average UK diet comes from: fatty meat, poultry skin, sausages and pies, whole milk and full fat dairy products, lard, coconut oil, palm oil, pastry, cakes, biscuits, sweets and chocolate.
Saturated fat drives up cholesterol levels and too much cholesterol can lead to fatty deposits that clog the arteries and slow blood flow and can break apart to cause a heart attack or stroke.
A study in 2012 found reducing saturated (animal) fat, but not total fat, cut the risk of heart attack and stroke by 14 per cent.
Are all saturated fats equal?
The saturated fats, lauric, myristic and palmitic acid are found in meat, dairy products, eggs, palm and coconut oil. They all raise cholesterol levels but not to the same extent:
- Myristic acid: found in palm kernel oil (not to be confused with palm oil), coconut oil, butter and other animal fats, is the most potent ‘bad’ cholesterol-raising.
- Palmitic acid: found in palm kernel oil, butter, cheese, milk and meat and raises cholesterol less than myristic acid.
- Lauric acid: comprises about half the fat in coconut oil. Found in smaller amounts in human breast milk, cow’s milk and goat’s milk. Has around one-third less cholesterol-raising power than palmitic acid
A quick lesson in cholesterol
- LDL ‘bad’ cholesterol can build up on the walls of the arteries and increase the risk of heart disease.
- HDL ‘good’ cholesterol protects against heart disease by taking the ‘bad’ cholesterol out of the blood and preventing it from building up in the arteries.
- Total cholesterol is a measure of LDL cholesterol, HDL cholesterol and other lipid (fat) components.
Medium and long-chain fats
One of the claims made for lauric acid from coconut oil is that is it metabolised (broken down and used) by the body differently to other saturated fats because it is made of medium-chain as opposed to long-chain fats.
Most fats in animal products are long-chain saturated fats which are made into cholesterol or stored as body fat. Medium-chain fats are transported directly to the liver from where they supply energy directly to the heart, brain and muscles – well that’s the theory anyway.
Studies on coconut oil and cholesterol have produced conflicting results. Some show medium-chain fats increase HDL ‘good’ cholesterol but others show they also increase LDL ‘bad’ and total cholesterol to the same extent as palm oil.
Yet other studies found no effect on HDL, LDL or total cholesterol. Medium-chain fats have also been found to increase plasma triglycerides (fats in the blood) in the same way long-chain fats do.
One possible explanation is that when the diet contains mostly medium-chain fats (when coconut oil is used in preference to unsaturated vegetable oils), some medium-chain fat may be diverted into the long-chain route leading to the production of cholesterol and fat deposits. This provides a compelling argument for not limiting your fat intake to just coconut oil.
Furthermore, medium-chain fats make up less than half of coconut fat, nearly a third is made up of the long-chain saturated myristic and palmitic acids (the major fats in red meat) which raise ‘bad’ cholesterol levels. The rest consists of small amounts of monounsaturated and polyunsaturated fats.
What’s the smoke point?
Another selling point for coconut oil is the reputed high smoke point (that’s when the fats in the oil break down or oxidise, creating harmful free radicals). However, many other oils have a higher smoke point. In fact, coconut oil has a relatively low smoke point compared to other commonly used cooking fats.
Sunflower Oil: 277°C
Soya Oil: 238°C
Rapeseed Oil: 204°c
Olive Oil: 193°C
Coconut Oil: 177°C
Flaxseed (linseed) Oil: 107°C
Criticism of coconut studies
Many of the health claims made for coconut oil are a mixture of anecdotal evidence, pseudoscience and poor reporting of a limited number of flawed studies (conducted over short periods of time with small numbers of participants).
The results are not yet significant enough to prove long-term benefit. Enthusiasts appear to have exaggerated the potential benefits beyond anything the science can confirm – whereas the research supporting the benefits of polyunsaturated plant oils are well-established.
So what about the claim that coconut oil may help treat or slow the progression of Alzheimer’s disease?
This have yet to be confirmed – according to a recent review in the British Journal of Nutrition: “It must be emphasised that the use of coconut oil to treat or prevent AD [Alzheimer’s disease] is not supported by any peer-reviewed large cohort clinical data; any positive findings are based on small clinical trials and on anecdotal evidence; however, coconut remains a compound of interest requiring further investigation.”
Like most ‘magic bullet’ food and health stories, there may be some truth in the claims made for coconut oil – it’s certainly healthier than butter and lard for example, but it’s unlikely including additional coconut oil in your diet would be beneficial.
While medium-chain fats in coconut oil may raise HDL ‘good’ cholesterol, they can also raise LDL ‘bad’ and total cholesterol. But replacing saturated fats with unsaturated fats (found in vegetable, olive, flaxseed and rapeseed oils, nuts and seeds), has been shown to increase HDL, lower LDL and improve overall cholesterol levels all at the same time.
According Walter Willett MD, chair of the Department of Nutrition at the Harvard School for Public Health: “We don’t really know how coconut oil affects heart disease, and I don’t think coconut oil is as healthful as vegetable oils like olive oil and soybean oil, which are mainly unsaturated fat and therefore both lower LDL and increase HDL.”
As always it’s the combination of a healthy diet and lifestyle that’s most important in disease prevention. It is better to eat a diet with a variety than to concentrate on individual foods as the key to good health. Coconut oil’s HDL-boosting effect may make it ‘less bad’ than its high-saturated fat cousins (butter and lard), but it is not the best choice of oils to reduce the risk of heart disease.
You are better off replacing saturated fats with healthier unsaturated vegetable oils such as olive oil and rapeseed oil for cooking and flaxseed oil for sauces and dressings.
Dr Justine Butler is a senior researcher and writer at Viva! She holds a PhD in molecular biology, BSc in biochemistry and diploma in nutrition. She has published an extensive list of reports, guides and fact sheets for Viva! Health and written many health articles for health journals, regional and national press.