I also don’t recommend any other oils, for that matter, as I advocate for whole food plant-based diets.
Oil is a highly-processed product which is extracted from fruits, nuts and seeds, and I recommend that people eat the fruit/nut/seed whole (or ground, as per tahini or peanut butter), and get the benefits of the fibre and phytochemicals, which are compounds found in plants which have well-studied health benefits.
The delicate oils in fat-rich foods are also highly unstable, hence why nature keeps them protected from light and heat (and oxidation) by wrapping a nifty little coating or shell around the nut, seed or fruit. Great work, nature! But what do humans do? We extract the oil from these wonderful whole plant foods and then package it in clear plastic or glass bottles where sunlight and heat can slowly destroy it. Nature 1; Humans 0.
Pure oil is also the most concentrated source of energy (calories or kilojoules) you can consume of any food on the planet, at 612kJ/146 calories per tablespoon, being 100% fat. Furthermore, a whopping 92% of the fat in coconut oil is saturated fat, which is higher than butter (54g saturated fat per 100g).
'But it’s a different type of saturated fat that is metabolised differently!' I hear you say. The ‘different type’ refers to the lauric acid, which only makes up between 45 and 48% of the fatty acids (fats) in coconut oil. Lauric acid is known to favourably affect blood cholesterol levels, by increasing the HDL (good) cholesterol.
'Metabolised differently' refers to the fact that as medium-chain fatty acids are quite small, they are soluble in water, compared to long-chain fatty acids. As they are water soluble, they are absorbed directly into the hepatic portal circulation and proceed directly to the liver to be metabolised, compared to long-chain fatty acids, which after incorporation into micelles are absorbed into the lymphatic system.
The thing is, there is a marked decrease in solubility of fatty acids as they get longer than only 10 carbon atoms, and lauric acid contains 12 carbon atoms, hence, lauric acid actually act more like a long-chain fatty acid in our gastrointestinal tract (1).
But if lauric acid only makes up 45-48% of the fatty acids in coconut oil, what are the other 52-55%? Myristic acid (14-18%), palmitic acid (7.5-9.5%), oleic acid (6-8.2%), caprylic acid (7.8%), capric acid (7.6%), stearic acid (5%) and linoleic acid (aka omega-6) (1-2%). Interestingly, the second and third most abundant fatty acids in coconut oil (myristic and palmitic acid) are the ‘chief saturated fatty acids implicated in cholesterol elevation', according to a FAO report (2010)(2).
Ok, so what effect does whole coconut oil have on cholesterol levels? Coconut oil raises total cholesterol levels, and although a large part of this comes down to the fact that is tends to raise the 'good' (HDL) cholesterol, it does also elevate the 'bad' (LDL) cholesterol (3)(4)(5). To summarise, coconut oil is not as bad as butter (which raises LDL cholesterol), or trans fats (which raise LDL cholesterol AND lower HDL cholesterol (double whammy bad), but it’s also not as good as polyunsaturated fats, which can both raise HDL cholesterol and reduce LDL cholesterol.
And how do I feel about coconut milk? Good, as it’s a whole food product, but in moderation, as it’s still a high-fat food (with around 20g fat per ½ cup). I occasionally use coconut milk in curries, but I’m certainly not doing so to reap any perceived benefits of the saturated fat.
Coconut milk and cream are staples in numerous tropical countries such as India, Sri Lanka, the Philippines and Papua New Guinea and have been for centuries. Coconut oil has not. The diet and lifestyle habits of one such population - the people of Kitava island of Papua New Guinea – was extensively studied in the 1990s by a group of Swedish researchers as they were consuming a traditional diet (including coconut products) and had very low rates of chronic diseases including diabetes and heart disease (6). However, these studies highlight the importance of thinking outside of the square when looking at population-based (epidemiological) studies: the people of Kitava also had a low total fat intake of 21% energy (well, low by Western standards anyway), consumed a whole food diet (of fruit, vegetables, fish and coconut), had low BMIs, were active in their work as horticulturalists, and drank no alcohol.
In my opinion, there is certainly no health benefit to be had from adding coconut oil to your diet. If you do cook with fat or oil, it’s a good choice as it’s very stable and resists oxidation at high temperatures, but I’d only add the minimum amount required, and I certainly wouldn’t go eating it by the spoonful!
(This post was inspired by the recently-released New Zealand Heart Foundation’s evidence paper titled ‘Coconut Oil and The Heart’, which is the best summary of the available evidence I’ve seen. You can read it here.)
1. Eyres, Laurence. Coconut Oil and The Heart. 2014 Sep; Accessed November 26 2014. Available at: http://www.heartfoundation.org.nz/uploads/Evidence_paper_coconut_August_2014.pdf
2. Joint FAO/WHO Expert Consultation on Fats and Fatty Acids in Human Nutrition. Fats and fatty acids in human nutrition: report of an export consultation. Rome: Food and Agriculture Organization of the United Nations; 2010.
3. Effects of dietary coconut oil, butter and safflower oil on plasma lipids, lipoproteins and lathosterol levels. Publ Online 25 August 1998 Doi101038sjejcn1600621 [Internet]. 1998 Aug 25 [cited 2014 Nov 26];52(9). Available from: http://www.nature.com/ejcn/journal/v52/n9/abs/1600621a.html
4. Fisher EA, Blum CB, Zannis VI, Breslow JL. Independent effects of dietary saturated fat and cholesterol on plasma lipids, lipoproteins, and apolipoprotein E. J Lipid Res. 1983 Aug 1;24(8):1039–48.
5. Reiser R, Probstfield JL, Silvers A, Scott LW, Shorney ML, Wood RD, et al. Plasma lipid and lipoprotein response of humans to beef fat, coconut oil and safflower oil. Am J Clin Nutr. 1985 Aug 1;42(2):190–7.
6. Lindeberg S, Nilsson-Ehle P, Vessby B. Lipoprotein composition and serum cholesterol ester fatty acids in nonwesternized melanesians. Lipids. 1996 Feb 1;31(2):153–8.