A quick search of the internet will reveal an astonishing number of diseases and conditions for which coconut oil is claimed to be helpful. Some of the touted benefits include improving weight loss, possibly through increased fat burning, reducing hunger and reducing belly fat; treating bowel diseases such as irritable bowel syndrome and Crohn’s disease; increasing energy; reducing symptoms of chronic fatigue syndrome; killing harmful bacteria, viruses and fungi; healing wounds; boosting brain function in Alzheimer’s Disease; treating Parkinson’s disease; treating diabetes; protecting skin, hair and dental health; lowering cholesterol; and improving heart health (1,2,3). The ability to positively affect even just a few of these conditions would indeed make coconut oil a superfood. Unfortunately, the vast majority of these claims come from personal accounts or uncontrolled human or animal studies looking at one isolated component of coconut oil. Consequently, there is very little solid scientific evidence to support any health-promoting effects of coconut oil (3). Let’s look more closely now at coconut oil and heart heath.
Proponents of coconut oil like to point out that people such as the Veddas, the last indigenous tribe of Sri Lanka, whose diet centers around eating coconuts, fruits, yams, and the occasional game shot with bows and arrows, appear to have low incidence of heart disease. A study from 1980 found that the Veddas had a low rate of high blood pressure (3.8%) and blood cholesterol and triglycerides were at similar levels to those of the general population of Sri Lanka (23). There are many reasons why the Veddas might enjoy good heart health. First of all, their coconut intake is in the form of whole coconut, a food that is metabolized in the body very differently than the extracted oil. Whole coconut flesh contains soluble and insoluble fiber and protein along with antioxidants and phytonutrients which together act to restrain the digestion of the coconut flesh and its release of fats into the bloodstream. In addition, the animal-based component of the diet of the Veddas is extremely low and their lifestyle is very high in physical activity. For people like the Veddas, coconut fat is likely their only cardiovascular risk in an otherwise very healthy lifestyle. On the contrary, eating generous amounts of the extracted oil from a coconut is a whole different kettle of fish (1,4).
What do we know about coconut oil? Coconut oil is about 90% saturated fat, an extremely high amount even when compared to butter which is 64% saturated fat and palm oil with 50% saturated fat. In comparison, non-tropical oils contain much lower amounts – 6% saturated fat in safflower oil, 8% in corn oil, 11% in sunflower oil and 14% in olive oil (5).
A common argument in favour of coconut oil is its large component of a type of saturated fatty acid called medium-chain fatty acid (MCFA). MCFAs are generally absorbed through the portal vein and then sent to the liver where they are distributed for use as a quick energy source rather than being stored in fat and muscle tissue as happens to longer-chain fatty acids (LCFAs) (6). It has been hypothesized that the MCFAs in coconut oil would not raise LDL-cholesterol and may even be heart healthy. Indeed, some studies of MCTs (Medium Chain Triglycerides) find that they raise LDL-cholesterol only by about the same amount as does olive oil but not as high as do LCFAs. However, MCTs are products made up of 100% MCFAs and they are a vastly different proposition than coconut oil (7). In fact, a large proportion of the fat in coconut oil is lauric acid, classified as an MCFA, but not acting at all like other MCFAs in their digestion. It turns out that lauric acid is absorbed and transported in the same way as LCFAs and, because lauric acid makes up 50% of the total fatty acids of coconut oil, this has a substantial affect on the consequences of ingesting coconut oil. Additionally, two other major fatty acids in coconut oil are myristic acid and palmitic acid. They make up another 25% of the fat in coconut oil and are true LCFAs that are treated as such by the body. Consequently, the majority of the fats in coconut oil initiate increases in cholesterol blood levels and thus promote the development of heart disease (8).
How important is cholesterol level in elevating heart disease risk? In 2017 the European Atherosclerosis Society completed an astoundingly extensive review of current clinical and genetic evidence regarding the association between LDL-cholesterol and atherosclerotic cardiovascular disease. This comprehensive analysis encompassed over 200 different studies including controlled, randomized trials along with prospective cohort studies, genetic studies and Mendelian randomization studies. These studies involved more than 2 million participants with over 20 million person-years of follow-up. The conclusion of this study is as follows, “Consistent evidence from numerous and multiple different types of clinical and genetic studies unequivocally establishes that LDL-cholesterol causes atherosclerotic cardiovascular disease.” (9) In addition, a meta-analysis encompassing 170,000 participants, enrolled in 27 statin trials, demonstrated that the risk of coronary heart disease is reduced by about 20% for every 1 mmol/L reduction in LDL-cholesterol (24).
STUDY: THE EFFECT OF COCONUT OIL CONSUMPTION ON CARDIOVASCULAR RISK FACTORS: A SYSTEMATIC REVIEW AND META-ANALYSIS OF CLINICAL TRIALS (8)
This month, January, 2020, a meta-analysis was published that investigated the effect of coconut oil on cholesterol levels. This study reviewed and re-analyzed seventeen clinical trials comprising 730 participants to examine the effects of coconut oil consumption as compared to other tropical and non-tropical vegetable oils on cardiovascular risk factors. The studies included in this meta-analysis were controlled clinical trials with a minimum intervention of 2 weeks to allow blood lipid concentrations to stabilize. Daily amounts of coconut oil varied among the studies but were within the range of 10 to 20% of daily energy intake (about 2 to 3 tablespoonsful).
Study Results: Coconut compared to Non-Tropical Vegetable Oils (including canola, corn, olive, safflower, soybean and sunflower oil)
Consuming 2 to 3 tablespoons of coconut oil daily significantly increased…
– total cholesterol by 14.69 mg/dl
– LDL-cholesterol by 8.6% (10.47 mg/dl)
– HDL-cholesterol by 7.8% (4 mg/dl)
…as compared to increases from non-tropical vegetable oils
Coconut oil did not change blood concentrations of triglycerides compared to non-tropical oils
These increases translate into a 6% greater risk of major vascular events and a 5.4% greater risk of death from coronary heart disease.
Coconut oil had no significant effect on…
Percentage body fat
Fasting plasma glucose
Study Results: Coconut Oil compared to Palm Oil
Consuming 2 to 3 tablespoons of coconut oil daily significantly increased…
– Total cholesterol by 25.57 mg/dl
– LDL-cholesterol by 11% (20.50 mg /dl)
– HDL-cholesterol by 5% (2.83 mg/dl)
…as compared to increases from palm oil
Coconut oil increased blood concentrations of triglycerides by about the same amount as does palm oil
Is the rise in HDL-cholesterol from coconut oil a positive sign?
Though high HDL-cholesterol has been linked with less cardiovascular disease, it is not the driving force behind heart disease protection. An offshoot of the Framingham Study monitored cholesterol levels and cardiovascular disease risk for 3,590 participants and concluded that high LDL and/or high TG (triglycerides) are the lipid components predictive of heart disease risk regardless of the HDL level (10). There is increasing evidence that it is the quality and not the quantity of HDL that is important. High functioning HDL particles have the ability to remove cholesterol from the body as waste and to normalize artery wall endothelial function thereby reducing oxidation and inflammation. However, in a state of chronic inflammation such as occurs in cardiovascular disease, atherosclerosis, metabolic disorder, chronic renal disease, diabetes or arthritis, the HDL is not functioning well. Transport of cholesterol out of the body by HDL is interrupted and the HDL particles actually support oxidation of cholesterol and fuel the inflammatory process. (11,12,13). The association of high HDL with less cardiovascular disease stems from healthy people whose HDL is working well.
This finding has been corroborated in numerous ways. For example, people who genetically have lifelong high HDL levels do not have a lower risk of heart attack (14). Drugs such as torcetrapib, administered to increase HDL levels, have not been shown to have any effect on atherosclerotic plaques in the carotid or coronary arteries nor have they shown any improvement in cardiovascular outcomes. In fact torcetrapib actually increased cardiovascular events and total mortality, leading to its discontinuation (11,15,16,17,18). Another drug, niacin, increases HDL by up to 25%, but two large randomized controlled trials have shown that niacin does not decrease the incidence of cardiovascular events and may also have significant adverse effects (19).
The takeaways from this study
Coconut oil is not a healthy oil for the human cardiovascular system.
Coconut oil has no effect on C-reactive protein which means it doesn’t reduce inflammation.
Coconut oil has no effect on body weight.
Coconut oil has no effect on blood sugar levels.
WHO (World Health Organization) and the Canadian dietary guidelines endorse a maximum daily intake of saturated fat for healthy people of 10% of daily calories (20). The American Heart Association recommends a reduced amount at 5 to 6% of daily calories for those with heart disease or aiming to prevent heart disease (21).
One tablespoonful of coconut oil contains about 15 gm of saturated fat which would provide 135 calories or approximately 7% of daily calorie intake (5).
Think about it…one tablespoonful of coconut oil alone contains close to the daily maximum of saturated fat consumption recommended for best cardiovascular health.
Anyone who is eating animal-based foods, where most of our dietary saturated fat resides, will be ingesting other saturated fats. A constructive and attainable goal is to eliminate consumption of coconut oil completely and thus remove a major source of saturated fat from the diet.
Limited sporadic use of coconut oil for taste or texture in cooking will not likely have a significant detrimental effect.
In 2016, Americans were surveyed on their views of coconut oil and 72% of them considered coconut oil a healthy food (22). This is a potent reminder of the power of food producers and the media that broadcasts the health claims for foods such as coconut oil. It is time to spread the word that coconut oil increases harmful LDL-cholesterol, an established cause of cardiovascular disease.
3 Lockyer, S., Stanner, S. Facts Behind the Headlines: Coconut oil – a nutty idea? Nutrition Bulletin – British Nutrition Foundation February 2016; 41 (1): 42-54.
6 St-Onge, M.-P., Jones, P.J.H. Physiological Effects of Medium-Chain Triglycerides: Potential Agents in the Prevention of Obesity. The Journal of Nutrition. March, 2002; 132(3): 329-332.
7 St-Onge, M.-P., Bosarge, A., Goree, L. L.T., Darnell, B. Medium Chain Triglyceride Oil Consumption as Part of a Weight Loss Diet Does Not Lead to an Adverse Metabolic Profile When Compared to Olive Oil. J Am Coll Nutr. 2008 Oct; 27(5): 547–552.
8 Neelakantan N, Seah JYH, van Dam RM. The Effect of Coconut Oil Consumption on Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis of Clinical Trials. Circulation. Published online January 13, 2020.
9 Ference, B.A., Ginsberg, H.N., Graham, I. et al. Low-density lipoproteins cause atherosclerotic cardiovascular disease. Evidence from genetic, epidemiologic, and clinical studies. A consensus statement from the European Atherosclerosis Society Consensus Panel. Eur Heart J April 4, 2017.
10 Bartlett, J., Predazzi, I.M., Williams, S.M., et al. Is isolated low high-density lipoprotein cholesterol a cardiovascular disease risk factor? New insights from the Framingham Offspring Study. Circ Cardiovasc Qual Outcomes. Published online May 10, 2016.
11 März, W., Kleber, M.E., Scharnagl, H., Speer, T., Zewinger, S. et al. HDL cholesterol: reappraisal of its clinical relevance. Clin Res Cardiol. 2017 Sep; 106(9): 663-675.
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13 Nicholls, S.J., Lundman, P., Harmer, J.A., Cutri, B., Griffiths, K.A., Rye, K.A., Barter, P.J., Celermajer, D.S. Consumption of saturated fat impairs the anti-inflammatory properties of high-density lipoproteins and endothelial function. J Am Coll Cardiol. 2006 Aug 15; 48(4):715-720.
14 Voight, B.F., Peloso, G.M., Orho-Melander, M., Frikke-Schmidt, R. et al. Plasma HDL cholesterol and risk of myocardial infarction: a mendelian randomisation study. Lancet. 2012 Aug 11; 380(9841): 572–580.
15 Barter, P.J., Caulfield, M. Effects of Torcetrapid in Patients at high risk for coronary events. N Engl J Med 2007 Nov 22; 357 (21); 2109-1222
16 Clark, R.W., Sutfin, T.A., Ruggeri, R.B., Willauer, A.T. et al. Raising high-density lipoprotein in humans through inhibition of cholesteryl ester transfer protein: an initial multidose study of torcetrapib. Arteriosclerosis, Thrombosis, and Vascular Biology January, 2004; 24 (3): 490–497.
17 Lloyd-Jones, D.M. Niacin and HDL – Time to Face Facts. N Engl J Med July 2014; 371(3).
18 Barter, P. Lessons learned from the Investigation of Lipid Level Management to Understand its Impact in Atherosclerotic Events (ILLUMINATE) trial. Am J Cardiol. 2009 Nov 16; 104(10 Suppl):10E-5E.
19 Mani, P., Rohatgi, A. Niacin Therapy, HDL Cholesterol, and Cardiovascular Disease: Is the HDL Hypothesis Defunct? Curr Atheroscler Rep. 2015 Aug; 17(8):43.
22 Sacks, F.M. Coconut Oil and Heart Health: Fact or Fiction? Circulation. Jan. 13,2020; http://doi.org/10.1161/CIRCULATIONAHA.119.044687.
24 Ference, B., Mahajan, N. The Role of Early LDL Lowering to Prevent the Onset of Atherosclerotic Disease. Curr Atheroscler Rep. 2013 Apr;15(4):312. doi: 10.1007/s11883-013-0312-1.
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