While the skeptical cardiologist was wandering around in ketoland, he acquired a large jar of extra virgin coconut oil for the purpose of boosting his fat consumption. He stirred spoonfuls of the solid waxy substance into his coffee and applied it to various and sundry skin rashes.
Coconut oil (CO) is a microcosm of the dietary confusion present in the U.S. On one hand a CO Google search yields a plethora of glowing testimonials to diverse benefits: Wellness Mama lists “101 Uses for Coconut Oil,” Authority Nutrition lists “10 Proven Health Benefits.”
On the other hand, the American Heart Association (AHA) and the USDA’s Dietary Guidelines For Americans warn us to avoid consuming coconut oil because it contains about 90% saturated fat (SFA) which is a higher percentage than butter (about 64% saturated fat), beef fat (40%), or even lard (also 40%) and thus contributes to heart disease.
In many respects, the vilification of coconut oil by federal dietary guidelines and the AHA resembles the inappropriate attack on dairy fat and is emblematic of the whole misguided war on dietary fat.
The problem with this simplistic message is that the kind of saturated fat in CO differs markedly from both dairy SFAs and beef SFAs and, like dairy fat, appears to have a beneficial effect on blood lipids, weight, and cardiovascular health.
Misguided Dietary Fat Recommendations
The AHA guidelines, for example, recommend cooking oils that have less saturated fat such as canola and corn oil. They advise, in general, to “choose oils with less than 4 grams of saturated fat per tablespoon.”
Canola and corn oil, the products of extensive factory processing techniques, contain mostly mono or polyunsaturated fats which have been deemed “heart-healthy” on the flimsiest of evidence.
The most recent data we have on replacing saturated fat in the diet with polyunsaturated fat comes from the Minnesota Coronary Experiment performed from 1968 to 1973, but published last month in the BMJ, (don’t get me started on why these data were “buried” for decades).
Data from this study, which substituted liquid corn in place of the usual hospital cooking fats, and corn oil margarine in place of butter and added corn oil to numerous food items, showed no overall benefit in reducing mortality. In fact, individuals over age 65 were more likely to die from cardiovascular disease if they got the corn oil diet.
Very Brief (But Seemingly Unavoidable) Digression Into Organic Chemistry Featuring Obscure But Intriguing Chemical Names and Numbers to 5.0 Significant Digits
Saturated fats are divided into various types based on the number of carbon atoms in the molecule. Depending on length, they differ markedly in their metabolism, absorption and effects on lipid profiles.
The major SFA in coconut oil, lauric acid, has a 12 carbon chain and is thus considered a medium chain fatty acid (MCFA). Take a look at the complex mixture of saturated fatty acids present in virgin coconut oil and note lauric acid (green) and palmitic acid (red):
|Fatty acid profile
|C16 : 1
|C18 : 1n9c
|C18 : 1n9t
|C18 : 2n6c
|C18 : 2n6t
|C18 : 3n6g
|C18 : 3n3a
|C20 : 1n9
Palmitic acid, a long chain FA with 16 carbon atoms, makes up only 7% of coconut oil, but is the major SFA in dairy and beef fat. When consumed in isolation, it raises the LDL or bad cholesterol and the ration of LDL to HDL, and thus has been labeled as unhealthy. Of course, as pointed out here we don’t consume either palmitic acid or lauric acid in isolation; we consume them in the complex milieu of other fats, antioxidants, proteins and carbohydrates that we call food.
Medium chain fatty acids, and especially lauric acid, do a really good job of raising the good HDL cholesterol and lowering the ratio of LDL to HDL, changes which should boost heart health.
Detailed Explanation of Differential Long and Medium Chain Fatty Acid Absorption and Metabolism (Feel Free to Skip)
Looking closely at the metabolism of MCSFAs we find:
” MCFAs are rapidly absorbed in the intestines even without catalyzation by the pancreatic lipase enzyme. LCFAs, on the other hand, required pancreatic lipase for absorption. They are carried by the lymph to the systemic circulation in chylomicrons and eventually reach the liver where they either undergo beta oxidation, biosynthesis to cholesterol, or are repackaged as triglycerides. MCFAs are carried by the portal vein to the liver where they are rapidly oxidized to energy. Unlike LCFAs, MCFAs do not enter the cholesterol cycle and they are not deposited in fat depots.”
Benefits of Coconut Oil, Cardiovascular and Otherwise
If you’d like to read a lot of hype and mumbo-jumbo about the benefits of coconut oil, I suggest you start at coconutoil.com and take a look at this graphic:
After a little reading, you will be ready to smear coconut oil all over your body and consume heaping spoonfuls thrice daily.
Be careful, though, you may end up like German nudist August Englehard who believed “that since the coconut grew high up in the tree, closest to God and closest to the sun, it was godlike, And since it had hair and looked like a human head, he thought it came closest to being a man. According to his rather crackpot theory, to be a cocovore was to be a theophage — or eater of God.”
My favorite article on the potentially atherogenic effects of coconut oil is entitled “Atherogenic of Not? (What therefore causes atherosclerosis?) published in the Philippine Journal of Cardiology in 2003:
The author, a prominent Phillipino cardiologist inserted the Phillipines (note my big red arrow) data into the famous Ancel Keys graph which plots heart disease mortality rate versus percent calories from fat.
The data point of the Phillipines, where coconut oil is the predominant cooking oil, totally disrupts the relationship between dietary fat and heart disease.
Of course, scientists now know that these kinds of correlations prove nothing, but they were the basis for guiding Americans to low fat, high carbohydrate manufactured monstrosities.
Coconut Oil: The Bottom Line
After all is said and done, it would appear that coconut oil, despite coming from a vegetable, resembles dairy fat in many ways.
It is more likely than not that coconut oil, like dairy fat, reduces your chances of obesity and heart disease, especially when compared to the typical American diet of highly processed and high carbohydrate foods.
Although containing lots of saturated fat, the SFAs in coconut oil are drastically different from other dietary sources of SFA. The medium chain fatty acids like lauric acid which make up the coconut are absorbed and metabolized differently from long chain fatty acids found in animal fat.
The only explanation for dietary guidelines advising against coconut oil and dairy fat is the need to stay “on message” and simplify food choices for consumers, thus continuing the vilification of all saturated fats.
Substituting corn oil (or other vegetable oils with lots of linoleic acid) for foods containing saturated fats does not lower risk of heart disease and may promote atherosclerotic outcomes like heart attack and stroke.
I doubt that few if any of the miraculous CO benefits hyped at coconutoil.com and elsewhere are real but if it helps your skin or your scalp, your digestion or your taste buds, feel free to consume ad lib and don’t worry about any adverse effects on your coronary arteries or your heart.
For those seeking more information.
This graph is from the BMJ paper which also included a meta-analysis of all randomized studies substituting linoleic acid for saturated fat. The data do not favor substituting corn oil for saturated fat