Tuesday, November 19, 2013

Rustless Hearts: Adding 15-20ml of Virgin Coconut Oil to Your Diet May Counter the Oxidative Stress From Partially Oxidized Fats and Keep Your Heart Rust-Free

Could a daily dose of virgin coconut oil really be all it takes to escape the #1 leading cause of death (CDC data) - despite French fries and co?
Originally I wanted to post the results of this study from the Universiti Kebangsaan Malaysia as a short news item in the Facebook News. Then I decided that it may actually be worth to allow you to have a look a the surprisingly pronounced effects the addition (not replacement!) of 3-4 tablespoons of virgin coconut oil had on the in vivo lipid oxidation levels of rodent hearts in the course of this 4 months study at the end of which the researchers did not simply measure the systemic, but the more significant local malondialdehyde (MDA) levels. With the direct analysis of the presence of lipid oxidation production in the heart being a more reliable indicator of whether or not the changes the researchers observed in the study at hand are physically relevant...

Ah, I don't want to give it all away. So let's rather take a look at Subermaniam et al.'s attempt to "to investigate the influence of virgin coconut oil on the malondialdehyde level in the heart tissue of rats fed with heated palm oil." (Subermaniam. 2013)

Palm oil is ubiquitous

I am not sure if you are aware of that, but the regular palm oil (not the red PO with the high carotene and tocotrienol content), with its saturated - unsaturated fatty acid ratio close to one, has become the most widely used "vegetable oil" worldwide. In fact, if the product label says "vegetable oil" and there is a significant amount of saturated fats in a product, it's likely that what you are about to eat contains palm oil, which is easy to process and, with its 1:1 ratio of saturated to unsaturated fats relatively stable.
Rejection points of various oils (Marikkar. 2007; Berger. 2005; Casai. 2010)
Cooking with Virgin Coconut Oil (VCO) - good or bad idea? The answer to this question is not as straight forward as you may think. On the one hand frying the "virgin" oil, will have it lose it's virginity, i.e. most of those molecules that are responsible for the beneficial health effects. On the other hand, a study by Marikkar et al. (2007) shows that these molecules act as a buffer, due to which VCO has a 30% higher rejection point (13h vs. 10h of frying at "only" 180°C; compare to the other oils in the table to the right) than regular coconut oil (CNO) and refined corn oil (CO). After those 13h the concentration of newly formed compounds (TPCs) that have higher polarity such as oxidized triglycerides, diacylglycerides and fatty acids is >25% and downright unhealthy.
Despite being less prone to oxidation, the way the oil is reheated and (ab-)used for deep frying by the food industry can cause changes in the fatty acids composition of palm oil that may have significant health consequences.
"Repeatedly heated oil undergoes changes in physical appearance and a series of chemical reactions such as oxidation, hydrolysis and polymerization that eventually alter the fatty acid composition . Therefore, when the degree of unsaturation in fatty acid is greater, it is more vulnerable to lipid peroxidation (Choe. 2007)." (Subermanian. 2013)
In mouse and man, the ingestion of this chemically altered oil has been found to increase the levels of ,alondialdehyde  (MDA), one of the major end products of lipid peroxidation which causes endothelial damage, vascular inflammation and cell membrane injury (USDA. 2007).

Virgin coconut oil to the rescue?

Studies by Harrison and Ng have shown that the increases in MDA levels in response to the ingestion of oxidated palm oil causes "oxidative stress" and increases in blood pressure that cannot be countered by the ingestion of common antioxidants such as vitamin C and E (Harrison. 2007). Now, Subermaniam et al. were interested, whether the same would be true for the sunsaponifiable components in virgin coconut oil.

SuppVersity Suggested Read: True or false - Eating tons of medium chain triglycerides (MCTs) will make you lean | learn the truth!
In previous studies, these molecules, which are lost when the milk is not extracted under controlled temperature, have been linked to a host of beneficial health effects, e.g.
  • anti-inflammatory and anti-thrombotic properties,
  • the ability to reduce the oxidation of LDL cholesterol, or
  • beneficial effects on the immune factor and cytokine response to endotoxins,
of the increasingly popular medium-chain-triglyceride rich oil from Cocos Nucifera Linn - an oil of which Figure 1 tells you that it has a lower peroxide value than freshly extracted palm oil even after processing and storage.

In view of its already established health benefits, the assumption that virgin coconut oil can ameliorate the pro-oxidative effect of diets that were fortified with 15% pre-heated palm oil, when it is administered to rodents at a daily dose of 1.43 ml/kg of body weight/day by oral gavage does not appear to be too far-fetched.
Figure 1: Left - MDA level in heart tissue after 4 months of feeding with basal diet (control), five times heated palm oil (HPO), basal diet and VCO supplementation (VCO) and five times heated palm oil with VCO supplementation (HPO+VCO; left); right - baseline peroxide value (in mEQO2/kg) of the oils used in the study (Subermaniam. 2013)
The rats stayed on these regular palm oil, pre-heated palm oil, regular palm oil + VCO, pre-heated palm oil + VCO and an unmodified control diet for 4 months. Thereafter, the thirty two rats were sacrificed and their heart tissues were harvested in order to measure the level of lipid oxidation. The results? Well, you just have to look at Figure 1 to see that there was a significant (p < 0.05) decrease in MDA (and peroxide / data not shown) values in the rodents which received the supplemental coconut oil on top of their heated palm oil diets.
Bottom line: It is unquestionably impressive that the effects of what would have been ca. 15-20ml commercially available virgin coconut oil for a human being were so pronounced that the oxidative stability of the lipids in the cells of the rodents on the HPO + VCO ended up being virtually identical to that of the rodents which received the regular chow. I must still warn you not to expect any of the meanwhile literal "Coconut Miracles".

In view of the fact that the benefits of the 'VCO supplement' did not depend on the presence of a "junk food" diet, it is still obvious that the addition of one or another tablespoon of virgin coconut oil may be one of the 1001 pieces of your personal "healthy lifestyle" puzzle - along with a protein- and vegetable-rich whole foods diet, exercise and more than just an occasional night of good night's sleep, of course ;-)

References
  • Berger KG. The use of palm oil in frying. Malaysian Palm Oil Promotion Council. 2005.
  • Casal S, Malheiro R, Sendas A, Oliveira BP, Pereira JA. Olive oil stability under deep-frying conditions. Food Chem Toxicol. 2010 Oct;48(10):2972-9.
  • Choe E, Min DB. Chemistry and reactions of deep-fat frying oils. Journal of Food Science. 2007; 72(5):R77-R86.
  • Harrison DG, Gongora MC, Guzik TJ, Widder J. Oxidative stress and hypertension. Journal of the American Society of Hypertension. 2007; 1(1):30-44.
  • Marikkar et al. Assessment of the stability ofvirgin coconut oil during deep-frying. Cord 2007; 23(1).
  • Ng CY, Kamisah Y, Faizah O, Jubri Z, Qodriyah HM, Jaarin K. Involvement of inflammation and adverse vascular remodelling in the blood pressure raising effect of repeatedly heated palm oil in rats. Int J Vasc Med. 2012;2012:404025.
  • Subermaniam K, et al. Virgin Coconut Oil (VCO) Decreases the Level of Malondialdehyde (MDA) in the Cardiac Tissue of Experimental Sprague-Dawley Rats Fed with Heated Palm Oil. Journal of Medical and Bioengineering. 2014; 3(2).
  • World  Vegetable  &  Marine  oil  Consumption,  World  Statistics, USDA, 2007, pp. 10