A study just published in Food and Function, of the Royal Society of Chemistry, shows once again that the highest amounts of antioxidants in coconut oil are found in virgin coconut oils produced by the wet-milling process. The study was conducted in the Department of Biochemistry at the University of Kerala in India. The study compared a traditionally made virgin coconut oil with refined coconut oil, olive oil, and sunflower oil for effects on antioxidant status. The results revealed that virgin coconut oil improved the antioxidant status compared to other three oil-fed groups. They observed increased activities of catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase in the liver, heart, and kidneys. Virgin coconut oil also prevented oxidative stress, indicated by the decreased formation of lipid peroxidation and protein oxidation. This is perhaps the most exhaustive study to date examining the anti-oxidant activities of traditional, wet-milled virgin coconut oils. The virgin coconut oil used in this study was prepared in the following way:
The solid endosperm of mature coconut (West coast tall variety) was crushed, made in to viscous slurry and squeezed through cheese cloth to obtain coconut milk, which was refrigerated for 48 hours, then subjected to mild heating in a thermostat oven. The obtained Virgin Coconut Oil filtered through cheese cloth was used for the present study.
This is a very low-tech traditional method, referred to as “the wet-milled method” used in tropical cultures. Some cultures do not use the refrigerator to separate the oil from the water, but let it sit overnight allowing a quicker and easier separation. But it is still a low-tech wet-milling process.
The fact that this low-tech traditional method, which includes some low level heat, produces a superior virgin coconut oil to mass-produced machine-made coconut oils has also been documented in previous studies, which also showed higher levels of antioxidants in traditional wet-milled virgin coconut oil. A recent trend for the past few years for producing “virgin” coconut oils is to use centrifuge with mechanical extraction with no heat applied. It had been assumed that “no heat” was better. However, this study confirms a finding in an earlier study that heat actually increases the antioxidant levels in virgin coconut oil:
Heating the coconut milk emulsion at 55 C may enhance the incorporation of these phenolics into the oil; this may be the reason for increased amounts of polyphenols in Virgin Coconut Oil extracted by wet processing.
A study published in 2011 in Sri Lanka also found that wet-milled traditionally-made coconut oils using heat in the process produced higher levels of antioxidants. They noted:
More surprises awaited the research team. The general impression is that cooking at high temperatures would degrade the quality of the oil. However, it is not applicable since coconut oil is thermally stable, it is learnt. “Fortunately, most of the phenolic anti-oxidants present in coconut oil are also thermally highly stable,” he pointed out, explaining that the reason for a greater composition of anti-oxidants is that simmering for a long time at a high temperature dissolved more anti-oxidants into the oil. (Story here.)
It can be concluded, therefore, that machine made “virgin” coconut oils that use no heat, or “virgin” coconut oils that do not use the wet-milling method to extract coconut oil from fresh coconut milk, are not transferring over the antioxidants present in fresh coconut. This would be one clear case where the raw food belief that no foods should be heated clearly has a detrimental effect. Lycopene in tomatoes is another example where “no heat” means less nutrients.
Bringing a traditionally-made virgin coconut oil that is not machine-made is certainly a challenge, however, if one desires wide distribution. It requires a lot of labor. The Tropical Traditions Gold Label brand of Virgin Coconut Oil is the only widely distributed product that is made by traditional methods and employing heat in the process that we are aware of in the U.S. My wife and I brought this product into the market back in 2001, the first virgin coconut oil ever exported from the Philippines, and in 2006 it was tested at a university laboratory and found to have antioxidant levels almost twice as high as the “no heat” virgin coconut oils on the market.
One the biggest factors in oxidative stress is what is called “lipid peroxidation.” Free radicals are formed among polyunsaturated oils that are not shelf stable, and highly prone to oxidation once the oils are removed from the plant source. They make up the majority of the edible oil industry in the U.S. in the form of corn and soybean oils. These two crops are also mostly genetically modified today.
Saturated fats are not prone to lipid oxidation. Once demonized as unhealthy and the cause of high cholesterol and heart disease, science is now confirming the traditional cultural values of our parents’ and grandparents’ generations that not only are saturated fats not unhealthy, but that they are in fact healthy. For one thing, they do not oxidize and cause free radical damage in the body. Traditional saturated fats are coconut oil, palm oil, butter, lard, and beef tallow. The animal sources of saturated fats are best consumed from healthy animals grazed on pasture, as opposed to raised in CAFOs (confined animal feeding operations).
Finally, it should be noted that while this study showed that virgin coconut oils using the wet-milling process had higher levels of antioxidants than refined coconut oils, that this in no way implicates refined coconut oil as unhealthy. Remember, coconut oil is a saturated fat, and the refining process in coconut oil does NOT change the fatty acid structure at all. This study even noted that:
There was no major diﬀerence among the individual fatty acids in Virgin Coconut Oil and Coconut Oil. The amounts of saturated fatty acids in VCO and CO were 91.96% and 90.38% respectively.
There has been a lot of misinformation on the Internet regarding refined coconut oils, casting them in a light as being unhealthy. Often the very ones selling the more expensive virgin coconut oils are the ones trying to condemn the cheaper refined coconut oils. It is true that any hydrogenated oils are unhealthy, including coconut oil, but since coconut oil is over 90% saturated, nobody selling refined coconut oil in the U.S. would go through the extra cost to hydrogenate the tiny amount of polyunsaturated fatty acids in coconut oil. Coconut oil is already shelf stable. We know of no company selling refined coconut oil in the U.S. that has hydrogenated it. It may happen in tropical cultures where they want to change the melting point from 75 degrees to over 100 degrees to keep it solid, but even then they would use it as an ingredient in processed foods, not sell it as an edible oil for cooking.
Some popular bloggers (who themselves sell high-priced “virgin” coconut oils, often erroneously calling them “extra” virgin of which there is no official definition), have accused some of the big box chains of selling bad coconut oil. Nothing could be further from the truth. Refined coconut oils, or even other “virgin” coconut oils that are mass produced by machine and do not use the wet-milling process, are still very good oils, and far better than the polyunsaturated oils that are widely used, many of which are genetically modified (this would include canola oil!) These refined or machine-made coconut oils may not provide the same levels of antioxidants that a traditional virgin coconut oil may supply, but they are in no way unhealthy. They will NOT increase your body’s oxidative stress, and they still contain the very useful medium chain fatty acids that have been proven to support the body’s immune system. So while there are a variety of different grades and quality coconut oils to choose from in the market, NONE of them are unhealthy. Purchasing any coconut oil to use in your daily life is a wise choice, especially if you are replacing unhealthy dietary oils (corn, soy, canola) that are mostly processed from genetically modified seeds, and can cause lipid peroxidation in the body.
Coconut oil: the champion among dietary oils!
About the authors: Unlike many people who write about coconut oil by simply reading about it, Marianita Shilhavy actually grew up on a coconut plantation in the Philippines and in a culture that consumed significant amounts of coconut fat in their diet. She later went on to earn her degree in nutrition and worked as a nutritionist in the Philippines. Brian Shilhavy also lived in the Philippines for several years with Marianita and their 3 children observing firsthand the differences between the diet and health of the younger generation and those of Marianita’s parents’ generation still consuming a traditional diet. This led to years of studying Philippine nutrition and dietary patterns first hand while living in a rural farming community in the Philippines. They are authors of the best-selling book: Virgin Coconut Oil: How it has changed people’s lives and how it can change yours!
Virgin Coconut Oil:
How it has changed people’s lives and how it can change yours!