Coconut fat, oil, and CVD

Fats make up less than 25% of the total energy expenditure among Sri Lankans. Studies done more than 20–30 years ago have shown that coconut fats constitute about 80% or more of the total fat intake of Sri Lankans [1].

Over 95% of coconut oil is fat, and the fat content of scraped coconut is around 34% and of coconut milk around 24%. It is also true that around 92% of the coconut fat is saturated fat. However, the saturated fats in coconut and palm-kernel, oil also called “tropical oils”, differ from saturated fats in animal fats. Over 50% of the fats in coconut are medium chain triglycerides that are formed from fatty acids of chain length 8:0 to 14:0. When digested in the small intestine, these fats yield saturated medium chain free fatty acids and monoglycerides such as lauric acid (12:0). Of these, it is primarily the 14:0 fatty acids that are thought to be atherogenic. Coconut oil is the highest natural source of lauric acid. Lauric acid and its derivative monolaurin constitute around 50% of coconut fat-derived lipid .

Virgin coconut oil when fed to rats is reported to lower lipid levels in serum and tissues, and LDL oxidation. This property of virgin coconut oil is attributed to the biologically active polyphenol components present in the oil.

What of other benefits that may accrue from eating coconut oil? Many readers may not be aware of the close similarity among the medium chain triglycerides in coconut fats, human breast milk and the secretion of sebaceous glands, all rich in lauric acid. Monolaurin and even lauric acid have been shown to be bactericidal, par- ticularly against Helicobacter pylori, Vibrio cholerae, Salmonella typhi, Shigella sonnei and enterotoxigenic Escherichia coli [22].

In the absence of convincing evidence against the continued use of coconut fats in relation to atherosclerosis and ischaemic heart disease, one has to ask whether the recom- mendation of the Asian Heart Assoication issued in 1996, “An intake of 400g/day of fruit, vegetables and legumes, mustard or soybean oil (25 g/day) instead of hydrogenated fat, coconut oil or butter, in conjunction with moderate physical activity (1255 kJ/day), cessation of tobacco consumption and moderation of alcohol intake may be an effective package of remedies for pre- vention of coronary artery disease in Asians” is valid in toto [25]. (This was in 1996)

Finally, one is left with the question—given the importance of coconut not only as a major dietary component in our diet but also because of its export potential, why is it that there has been little or no investment in research in Sri Lanka on the health effects of coconut products?

(CMJ Article about Coconut Fat Vol 51, No 2, June 2006)


Recent reviews

The Effect of Coconut Oil Consumption on Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis of Clinical Trials

Coconut oil is high in saturated fat and may, therefore, raise serum cholesterol concentrations, but beneficial effects on other cardiovascular risk factors have also been suggested. Therefore, we conducted a systematic review of the effect of coconut oil consumption on blood lipids and other cardiovascular risk factors compared with other cooking oils using data from clinical trials. 

Effects of Oils and Solid Fats on Blood Lipids: A Systematic Review and Network Meta-Analysis

The aim of this network meta-analysis (NMA) is to compare the effects of different oils/solid fats on blood lipids. Safflower, sunflower, rapeseed, flaxseed, corn, olive, soybean, palm, and coconut oil as well beef fat were more effective in reducing LDL-C (-0.42 to -0.23 mmol/l) as compared with butter. Results: 16 articles were included in the meta-analysis. Results were available from all trials on blood lipids, 8 trials on body weight, 5 trials on percentage body fat, 4 trials on waist circumference, 4 trials on fasting plasma glucose, and 5 trials on C-reactive protein. Coconut oil consumption significantly increased LDL-cholesterol by 10.47 mg/dL (95% CI: 3.01, 17.94; I2 = 84%, N=16) and HDL-cholesterol by 4.00 mg/dL (95% CI: 2.26, 5.73; I2 = 72%, N=16) as compared with nontropical vegetable oils. These effects remained significant after excluding nonrandomized trials, or trials of poor quality (Jadad score <3). Coconut oil consumption did not significantly affect markers of glycemia, inflammation, and adiposity as compared with nontropical vegetable oils. Conclusions: Coconut oil consumption results in significantly higher LDL-cholesterol than nontropical vegetable oils. This should inform choices about coconut oil consumption.

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