Vegetable Oils: The “Refining” of Our Health
Caveman Doctor recently read an article recommending vegetable oils for cancer patients to help them achieve “good health”. This website recommended safflower oil, soybean oil, and Canola oil, among several other vegetables oils. This confused Caveman Doctor for several reasons, as the only oil he has ever seen came from animal meat and when he crushed macadamia nuts and avocados over a rock with his club. He has never seen any oil come from vegetables or seeds and was really confused. Where do these oils come from and how are they even made?
Vegetable Oils 101:
The history of vegetable oils can be traced back to several moments in history that stand out, and my favorite involves Rudolf Diesel. He designed his highly sophisticated diesel engine to run on peanut oil. Can we replace this diesel engine with the highly sophisticated human body and achieve the same results as Rudolf?
Oils are essentially fats that are liquid at room temperature, with few exceptions. Coconut oil, for example, is usually a mixture of liquid and solid at room temperature due to its high melting point (imagine if ice melted at 76 degrees instead of 32, it would often remain solid at room temperature). While many people assume that all oils are made of unsaturated fatty acids, coconut, palm oil, ghee, and several other are actually made of saturated fat. However, at room temperature, saturated fats are usually solid due to their more stable molecular structure (so stable that their melting point is higher than room temperature, whereas unsaturated fats are less stable molecularly and become liquid at room temperature). This is all due to the number of unbound carbons on the backbone of the fat (think more unbound carbons = more unsaturated = more often liquid at room temperature).
The Emergence of Vegetable Oils in Fast Food Restaurants
McDonalds used to fry its french fries with tallow (beef fat), lard (pork fat), or palm oil, which are all saturated fats. While they are solid at room temperature, they melt quickly in a heated pan or fryer. You may be wondering why most fast food joints nowadays have replaced these cooking oils with peanut and canola oil, as well as a plethora of other vegetable oils that french fries soak and sizzle in.
These oils can be traced back to the 1980s, when the Center for Science in the Public Interest (CSPI) led an assault on McDonalds for using lard and saturated fats to cook their fries, as it was apparently wreaking havoc on our health, similar to the reasons why your doctor has likely suggested a low-fat diet to you. There was of course no evidence to support this, but nowadays a smear campaign can often work much better than proof and the truth. Thus, fast food chains were forced to replace these “harmful” fats with “healthy” partially hydrogenated oil (like Crisco and margarine). At the time, CSPI even labeled Burger King’s switch to partially hydrogenated oil as “a great boon to American’s arteries.” It’s important to know that these partially hydrogenated oils are full of trans-fats and that these oils are a modern invention and rarely occur in nature. I like to think of them as “Frankenfats”, as they are a well-intentioned but disastrous invention.
So, by maligning saturated fats that fast food chains were using and ushering in the usage of partially hydrogenated oils, trans-fats increased throughout our society1. I think we all know how “healthy” trans-fats are as there has been a push to make them illegal in some cities. Studies (with actual data, not merely a smear campaign) show that replacing saturated fat with trans-fat decreases HDL (good cholesterol) and results in blood vessel damage2. This, of course, is rather ironic since the trans-fats were used to replace the “heart-damaging” effects of saturated fats and provide that “boon” to our arteries. To add insult to injury (literally), consumption of trans fats causes stress and inflammation on our bodies, elevating IL-6, CRP3 and the inflammatory pathways that we are consistently trying to keep low by limiting chronic stress, as previously discussed here and here. To summarize, CSPI and other groups waged a media campaign against naturally occurring fats and replaced them with Frankenfats that are worse for our bodies. Oh, the efforts and good intentions of you modern men…
Just as saturated fats were wrongly replaced with inflammatory trans-fats, leading to more health risks, this trend continues as we have ultimately gone from saturated fats to polyunsaturated vegetable oils. While many praise the health benefits of vegetables oils, few even know what vegetable oils are or how they are made. Consuming trans-fats can result in a slew of health issues as discussed above; however, replacing them with vegetable oil may even be worse! In fact, studies in mice have shown that switching to corn oil, a common vegetable oil, actually results in increased colon cancer in comparison to trans fats. In fact, corn and other vegetable oils high in linoleic acid are often used in animal studies to cause cancer4,5, which I briefly discussed when reviewing the benefits of CLA. When polyunsaturated fats replaced saturated fats in a randomized controlled trial in humans, the rate of cancer actually rose6. How can this be possible if so many health organizations are promoting their consumption? Before we can even answer this question, we need to take a look at how vegetable oils are made.
Is Olive Oil a Polyunsaturated Vegetable Oil?
No! Olive oil is a mostly monounsaturated fat, and as you will read below, is made by an entirely different process than vegetable oil. Like olive oil, there are some oils that contain mostly monounsaturated fatty acids (different from polyunsaturated fatty acids (PUFAs) in that they only have one carbon atom on their backbone that can be attacked by free radicals and oxidized as opposed to polyunsaturated fats, which have many). This gets a little complicated and organic chemistry heavy, but bear with me: a simple way to think about this is that all fats have a chain of carbon atoms as their backbone. Now imagine, like your spine, there is a whole chain of these carbon atoms that can be bound or unbound by a hydrogen atom. Each carbon atom is a vertebra and if the vertebra has a hydrogen atom attached, there is less room for a free-radical to come in and attack. As a result, the free-radical passes by, looking for an unprotected (and unbound) vertebra, or in this case.
Along these lines, saturated fats have no unexposed weak points for this roaming free-radical to attack:
Monounsaturated (mono=one) have a single double bond with exposed carbons on each side:
Finally, PUFAs (poly=many) have many sites that can be attacked by free radicals:
Some common sources of monounsaturated fat (with percentages of monounsaturated fat in parentheses):
1. Macadamia oil: 85%
2. Olive Oil: 75%
3. Avocado Oil: 70%
4. Tallow (beef fat): 50%
5. Lard (pork fat): 40%
Another frequently used cooking oil by caveman eaters is coconut oil, which is mostly saturated fat. Its backbone is totally bound by hydrogens (saturated), and as a result it is very stable, solid at room temperature, and very resistant to free-radical damage during cooking.
The Industrial Process of Making Vegetable Oils: Chemical Refinement
Converting a vegetable or plant-based food into oil is a complicated chemical process, as the oil is not simply squeezed out of the vegetable as many would have you believe.
First and foremost, the process generally starts with a polyunsaturated fat source which, as describes above has many free carbons that are defenseless against heat damage and free radical attack. The final product is one of the many common vegetable oils, including:
1. Rapeseed oil (or based on the original process in Canada: Canola)
2. Peanut oil
3. Soybean oil
4. Sunflower oil
5. Corn oil
Intense chemical and mechanical manipulation of the vegetable source, removing many of the natural elements (including nutrients) is required to produce these unnatural oils. This also renders them damaged and defenseless against oxidation.
Step 1: Pressing
The first step in refinement involves extracting the small amount of oil from the plant-based source. This usually involves taking seeds (often genetically engineered to be immune to pesticides), crushing them, heating them to high temperatures, pressing them, and finally, bathing them in a hexane bath and other solvents made from crude petroleum. Petroleum! The oil is then separated from the seed residue and phosphate is added. The residue that is collected is often used as animal feed (hopefully no animals or animal products that we are consuming…).
Step 2: Neutralization, Bleaching, and Deodorization
After reading the title of this section, please be advised we are still discussing vegetable oil and have not switched to cleaning laundry. If you recall from the boring descriptions of the backbone of fats, PUFAs are somewhat defenseless against free-radical damage. Well, step 1, with all of its heating, pressing and chemicals, leaves the vegetable with significant oxidized damage that actually leaves the oil with a foul odor and unwanted color. This substance then undergoes a process called bleaching, which, just like when you bleach your socks, removes unwanted colors. The final process involves steaming the oils with extremely high temperatures, often over 500º F – much higher than the smoke point of nearly all of these oils – in order to remove residual substances that cause an unwanted taste or odor. This is appropriately called deodorization. Call me crazy, but anything that needs to be deodorized before eating doesn’t sound healthy to me.
While all the steps appear damaging and unhealthy for the oils (neutralization, bleaching, etc.), this last step of deodorization and heating in the process may be the most damaging of all as it severely weakness the fatty acids, leaving them less structurally sound as the high heat carries with it a hefty dose of free radicals. These free radicals wreak havoc on the structure of the fats and are very oxidizing.
However, the demise of your health doesn’t stop here, as many refined vegetable oil contain added butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA)7, both of which have been shown to cause bladder and thyroid cancer in animals8.
The Final Product:
While the health implications are quite obvious just from the process of making vegetable oil, it actually gets worse. The destruction of the backbone of the oil leaves it oxidized and further weakened to defense against future oxidation and free-radical damage during storage and cooking. This is why the shelf life of vegetable oils is so short; they often go rancid after only 6 months of sitting in your cupboard. Of note, olive oil also goes rancid after 6 months as well, but coconut oil (with its very stable structure) can fight off free-radicals and oxidation and stay good for a year or two. Walnut and sesame oil (which I hope none of you use, or at least please don’t use it with heat but only drizzle it on foods if you MUST use it) can go rancid in as little as 2 months.
To add more insult to injury, most antioxidants that would help us fight possible free radical damage, like vitamin E, are destroyed by this extreme process. Oil that is produced the old fashioned way, such as coconut, olive, and macadamia oil avoid having their antioxidants and vitamin content destroyed. In fact when macadamia nuts, which contain an ample amount of antioxidants9, are made into macadamia oil, it remain relatively full of the antioxidants 10.
Note that virgin olive oil is produced through more physical means and not the chemical treatment described above. However, both refined olive oil and pomace oil (a type of olive oil) undergo chemical treatment. Unrefined, virgin, and organic coconut oil avoid chemical processing as well. However, you can still find some chemically altered coconut oil, which is known as RBD (refined, bleached, and deodorized). Stay away from these.
When applying simple caveman logic to the non-animal oils above, we can imagine it is possible to get oil from an olive, avocado, or macadamia nut by crushing it with a club over a rock. However, this is not possible with soybeans or corn. In fact, soybeans are not even edible unless they undergo processing so even if available, the caveman couldn’t have eaten them.
1. Throw away your vegetable oils or donate them to your local lab where they run cancer experiments on animals.
2. Replace them with macadamia, avocado, olive, and coconut oil and grass-fed butter.
3. Never cook with unstable vegetable oils and PUFAs as they can become full of oxidative free radicals that damage your body.
4. Eat foods rich in antioxidants to help fight inflammation and avoid sources that actually introduce free radicals into our bodies, like vegetable oils.
5. Keep the bleaching to your gym socks and bottom of your bathtubs and avoid foods that need to be bleached and deodorized before they can be eaten.
Oils Caveman Doctor Never Uses:
1. Rapeseed oil
2. Canola oil
3. Peanut oil
4. Soybean oil
5. Sunflower oil
6. Corn oil
7. Safflower oil
8. Grape seed oil
9. Sesame Oil
Oils Caveman Doctor Uses:
1. Macadamia oil (his favorite!)
2. Coconut oil
3. Avocado oil
4. Olive oil (to garnish, not cook with)
5. Grass-fed butter
6. Tallow or lard (less frequently)
7. Palm oil
The process of producing vegetable oils through neutralization, bleaching, and deodorizing clearly is not natural and likely not safe for your body. The final chemical product of vegetable oil quickly goes rancid with its short shelf-life, is defenseless against free-radical attack, is stripped of its healthy antioxidants, and often contains cancerous chemicals and compounds. These oils were never around in Caveman Doctor’s time and never stood in his way to optimal health. He hopes they don’t stand in your way, either.
1. Stender S, Dyerberg J, Astrup A. High Levels of Industrially Produced Trans Fat in Popular Fast Foods. New England Journal of Medicine. 2006;354(15):1650-1652.
2. de Roos NM, Schouten EG, Scheek LM, van Tol A, Katan MB. Replacement of dietary saturated fat with trans fat reduces serum paraoxonase activity in healthy men and women. Metabolism. 2002;51(12):1534-1537.
3. Lopez-Garcia E, Schulze MB, Meigs JB, et al. Consumption of Trans Fatty Acids Is Related to Plasma Biomarkers of Inflammation and Endothelial Dysfunction. J Nutr. March 1, 2005 2005;135(3):562-566.
4. Kritchevsky D. Diet and cancer. CA: A Cancer Journal for Clinicians. 1991;41(6):328-333.
5. Carroll K. Dietary fats and cancer. Am J Clin Nutr. April 1, 1991 1991;53(4):1064S-1067S.
6. Lee Pearce M, Dayton S. Incidence of Cancer in Men on a Diet High in Polyunsaturated Fat. . The Lancet. 1971;297(7697):464-467.
7. Wyatt D. Simultaneous analysis of BHA, TBHQ, BHT and propyl gallate by gas chromatography as extracted from refined vegetable oil. Journal of the American Oil Chemists’ Society. 1981;58(10):917-920.
8. Ito N, Fukushima S, Tsuda H. Carcinogenicity and Modification of the Carcinogenic Response by bha, Bht, and Other Antioxidants. Critical Reviews in Toxicology. 1985;15(2):109-150.
9. Quinn L, Tang H. Antioxidant properties of phenolic compounds in macadamia nuts. Journal of the American Oil Chemists’ Society. 1996;73(11):1585-1588.
10. Marisa M W. Functional lipid characteristics, oxidative stability, and antioxidant activity of macadamia nut (Macadamia integrifolia) cultivars. Food Chemistry. 2010;121(4):1103-1108.
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