Coconut Oil and Heart Health: Fact or Fiction?

Abstract

hat coconut oil contributes to cardiovascular disease would appear noncontroversial because its saturated fat content increases plasma low-density lipoprotein (LDL) cholesterol concentration. 1 Cholesterol-rich LDL is a major cause of atherosclerosis because it delivers its cholesterol load to the arterial wall and causes obstruction and inflammation.Nonetheless, coconut oil has been accorded much attention in the popular media as a potentially beneficial food product.In fact, a survey in 2016 found that 72% of Americans viewed coconut oil as a healthy food. 2 This represents a remarkable success in marketing by the coconut oil and related industries calling coconut oil a natural, healthful product, despite its known action to increase LDL cholesterol, an established cause of atherosclerosis and cardiovascular events.A systematic review, published in 2016, identified 7 trials that tested the effect of coconut oil on LDL cholesterol.In these trials, coconut oil was compared with oils that had a high content of unsaturated fats.3 Significant detrimental effects were found in 6 of them.The present study by Neelakantan, Seah, and van Dam 4 is an important advance over this systematic review in that it includes a total of 17 published trials, takes a quantitative rather than a descriptive approach, and includes a range of outcomes relevant to assessing cardiovascular and metabolic health.This meta-analysis found that coconut oil significantly increased plasma LDL cholesterol and high-density lipoprotein (HDL) cholesterol, and had no effect on triglycerides, body weight, body fat, and markers of glycemia and inflammation in comparison with nontropical vegetable oils.Overall, this meta-analysis is rigorously conducted and reported, putting the results in the context of cardiovascular disease prevention.Coconut oil is composed mainly of the saturated fatty acid, lauric acid (12 carbon atoms), but also of other long-chain saturated fatty acids, myristic (14 carbon atoms) and palmitic acids (16 carbon atoms).5 Mensink performed a comprehensive systematic review with meta-regression of each of these fatty acids on plasma LDL cholesterol and other lipoproteins.1 Mensink's review considered all sources of lauric, myristic, and palmitic acids, not only from coconut oil, but also in other foods such as dairy fat, palm kernel, and palm oil.All these saturated fatty acids increased LDL cholesterol.Lauric acid, the most prevalent fatty acid in coconut oil, had a significant linear effect on LDL cholesterol.Mensink used carbohydrate as the direct comparator nutrient for the fatty acids.His approach found even more of an effect on LDL cholesterol of these saturated fatty acids in comparison with mono-and polyunsaturated fatty acids, combining the 2 estimates (coconut oil minus carbohydrate) + (carbohydrate minus unsaturated fats).This is a practical way to illustrate the dietary application of the present meta-analysis, because