Coconut Oil Unveiled!
Posted:
2019-12-20
A recent Canadian Broadcasting Corporation’s Marketplace Program provided information about coconut oil’s saturated fat content as this fat has been widely promoted for health and weight loss (See Table 1 for an overview of the saturated, linoleic and linoleic acid fatty acid content of various oils). Marketplace interviewed Dr. St-Onge, the lead researcher for the 2003 randomized crossover study of 24 overweight men who, in random order, consumed prepared diets containing olive oil or medium chain triglyceride (MCT) oil for four weeks (1). Both of the diets had 40% of energy as fat, 15% as protein and 45% as carbohydrates and were identical except for the type of fats included. The MCT-containing diet used an oil for 75% of the dietary fat composed of: 65% MCT oil, 13% olive oil, 7% each of canola and flaxseed oil and 6% coconut oil. In the control diet, 75% of total fat was olive oil. The remainder of the fat came from other foods. Food energy was provided to maintain each individual’s weight. The results showed that energy expenditure was slightly but significantly greater in the MCT oil mixture by 0.04±0.02 kcal/min (P< 0.05) on day 2 but was not significantly different on day 28. There was no significant difference in the loss of whole-body subcutaneous adipose volume. Upper body adipose tissue decreased significantly with MCT oil compared to olive oil consumption (-0.67±0.26 kg and -0.02±0.19 kg, respectively (P<0.05)). Average fat oxidation was not significantly different on day 2 or day 28. The authors speculated that a “diet rich in MCTs results in greater loss of adipose tissue compared with LCTs, perhaps due to increased energy expenditure and fat oxidation observed with MCT intake. Thus, MCTs may be considered as agents that aid in the prevention of obesity or potentially stimulate weight loss ” (1).
St-Onge reported on the Marketplace Program that despite the fact that the study contained only minimal amounts of coconut oil (6% of fat in the MCT group) and coconut oil contains only 15% MCT (or less depending on how C12:0 lauric acid is classified (2)), this study is often used to promote the consumption of coconut oil. She described the situation as coconut oil being perceived as having a health halo and noted that she “would not consume [coconut oil] on a regular basis”.
Table 1. Saturated, Linoleic and Linoleic Acid Fatty Acid Contents of Commonly Consumed Oils (3)
Oils |
Saturated % | Linoleic %
| Linolenic % |
coconut
| 87 | 1.8 | 0 |
butter
| 51 | 2.7 | 0.3 |
lard
| 40 | 10 | 1 |
pumpkin
| 18 | 42 | 0 |
peanut
| 17 | 32 | 0 |
soybean oil
| 16 | 51 | 6.8 |
sesame
| 14 | 41 | 0.3 |
olive
| 14 | 10 | 0.8 |
corn oil
| 13 | 54 | 1.2 |
avocado
| 12 | 13 | 1.0 |
sunflower oil
| 9 | 29 | 0 |
canola oil
| 7 | 19 | 9.1 |
Dietary Reference Intakes Fatty acids are essential nutrients with only small amounts required. Recommended Adequate Intakes for α-linolenic acid (omega-3) are 1.1 g/day adult females and 1.6 g/day adult males, aged 19-50 years. Recommended Adequate Intakes for linoleic acid (omega-6) are 12 g/day adult females and 17 g/day adult males, aged 19-50 years. Fats that have high proportions of saturated fats include coconut oil (87%) and butter (51%) (See Table 1).
While coconut oil is promoted for its ability to raise HDL, saturated fats raise both LDL and HDL. This effect is common among saturated fats and is not unique to coconut oil (5,6). Oils that contain PUFA lower LDL as well as slightly lower HDL (5). Oils containing both omega-3 and omega-6 fatty acids that are the most effective at lowering LDL cholesterol include canola, flax and soybean (5,6).
See Additional PEN Content:
Is a reduced saturated fat diet recommended for primary or secondary cardiovascular disease (CVD) prevention? What effect do tropical oils (palm oil and coconut oil) have on blood lipids?Currently, there is no need for substantial changes for people who consume saturated fats in amounts around 10% of energy (7) and who do not have elevated cardiovascular risk. Individuals with elevated cardiovascular risk should discuss their risk profile with a physician and a dietitian.
See Additional PEN Content:
Are there any health benefits in consuming coconut oil?Should omega-3 fatty acids (fish or plant-based food or supplements) be recommended for the primary or secondary prevention of cardiovascular disease (CVD) in adults?Article Analysis: Cardiovascular Effects of Exchanging Saturated Fat With an Oil High in Linoleic Acid - Not all Vegetable Oils are Created EquallyReferences- St-Onge MP, Ross R, Parsons WD, Jones PJ. Medium-chain triglycerides increase energy expenditure and decrease adiposity in overweight men. Obes Res. 2003 Mar;11(3):395-402. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/12634436
- Dietitians of Canada. What effect do tropical oils (palm oil and coconut oil) have on blood lipids? In: Practice-based evidence in nutrition [PEN]. 2019 Jan 07 [cited 2019 Dec 19]. Available from: http://www.pennutrition.com. Access only by subscription.
- Health Canada. Canadian nutrient file. 2016. Available from: https://food-nutrition.canada.ca/cnf-fce/index-eng.jsp
- Institute of Medicine. Dietary reference intakes: the essential guide to nutrient requirements. The National Academies Press: Washington, DC; 2006. P 122. Available from: https://doi.org/10.17226/11537
- Schwingshackl L, Bogensberger B, Benčič A, Knüppel S, Boeing H, Hoffmann G. Effects of oils and solid fats on blood lipids: a systematic review and network meta-analysis. J Lipid Res. 2018 Sep;59(9):1771-82. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/30006369
- Dietitians of Canada. Is a reduced saturated fat diet recommended for primary or secondary cardiovascular disease (CVD) prevention? In: Practice-based evidence in nutrition [PEN]. 2019 Jan 07 [cited 2019 Dec 19]. Available from: https://www.pennutrition.com/KnowledgePathway.aspx?kpid=2671&pqcatid=146&pqid=25600. Access only by subscription.
- U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015–2020 Dietary
guidelines for Americans. 8th Edition. December 2015. Available from: http://health.gov/dietaryguidelines/2015/guidelines/