Vegetable Oils Are Dangerous to Health

For many decades, health authorities have extolled the alleged virtues of vegetable oils, at the same time that they’ve been denigrating meat. Vegetable oils, they tell us, are full of “healthy” polyunsaturated fat, unlike meat, full of allegedly artery-clogging saturated fat. In reality, vegetable oils are dangerous to health, and furthermore, they’re not even really vegetable oils, but industrial seed oils.

What are vegetable oils?

To understand why vegetable oils are dangerous to health, we need to understand what they are. The term “vegetable” is a misnomer in this case and implies a degree of health and safety that they simply don’t have. How could something made of “vegetables” be unhealthy?

Common vegetable oils include the following:

  • corn
  • soybean
  • canola
  • sunflower
  • peanut
  • cottonseed
  • safflower

These oils have a few things in common. One is that they have only been in use for a short while in terms of human history, since the technology to extract these oils didn’t exist until the 19th century. Two, they come from sources that are intrinsically low in oil (except for peanut oil), which explains why they were not used, or even for the most part why they didn’t even exist, until recently.

Vegetable oils are better called industrial seed oils, since they’re made from seeds, not vegetables, and require an industrial process to make them in any volume. Oils that people have commonly used for a long time, such as olive oil, are not industrial seed oils and come from, in the case of olive oil, a fruit with a high fat content the oils of which are relatively easily extracted.

The manufacturing process for vegetable oils involves pressing at high pressure, and extracting more oil using solvents such as hexane, a volatile hydrocarbon similar to gasoline. The oils are then refined by heating to a high temperature and adding sodium hydroxide (lye), and finally, degummed, bleached, and deodorized.

Without knowing anything else about it, I already know that I don’t want this industrial substance in my body, much less in the massive quantities most people consume.

Chemically, vegetable oils are characterized by a high amount of polyunsaturated fats; for example, corn oil contains about

  •  saturated fat, 13%
  • monounsaturated fat, 28%
  • polyunsaturated fat, 55%
  • trans fats, 0.3%

In this case, the polyunsaturated fats and trans fats are the most health-damaging, because they are almost entirely composed of omega-6 fatty acids.

While omega-6 fatty acids are not intrinsically dangerous, the dose makes the poison, and virtually everyone in the Western world consumes far too much of these. An unbalanced ratio of omega-6 to omega-3 fatty acids contributes to a multitude of the diseases of civilization, including cancer, heart disease, and diabetes. While people living in a more natural state and eating whole, unprocessed foods may ingest a ratio of omega-6 to omega-3 fats of 2:1 or even 1:1, ratios in the modern world are typically over 15:1 and even up to 50:1.

Industrial seed oils are behind much of our modern epidemic of the diseases of civilization.

Vegetable oils may cause heart disease and raise death rates

The lipid hypothesis of heart disease, sometimes called the diet-heart hypothesis, holds that dietary saturated fat and high blood cholesterol cause coronary heart disease. Since the beginnings of that idea, mainstream health authorities have urged people to use vegetable oils in order to replace saturated fat with polyunsaturated fat, in the hope that this would reduce the incidence of heart disease. How has that worked out?

A recently published re-analysis of data from the Minnesota Coronary Experiment found that polyunsaturated fats did indeed lower serum cholesterol. Problem is, each 30 mg/dL reduction in cholesterol was associated with a 22% increased risk of death.

The same group re-analyzed the data from the Sydney Diet Heart Study and found that the intervention group that had replaced saturated fat with vegetable oils had a death rate from all causes that was 62% higher than the control group, and 70% higher for cardiovascular disease.

These were randomized controlled studies, which can show causation, as opposed to epidemiological studies, which cannot, and only show association. In epidemiological studies that show an association between intake of polyunsaturated fats and less heart disease, that association could very well be due to the healthy user effect.

Knowing this, deliberately consuming more polyunsaturated fats in the form of industrial seed oils seems positively dangerous to health.

Vegetable oils cause cancer

In animal experiments it’s long been known that corn oil reliably increases cancer rates. For example, mice that were fed a diet high in corn oil had double the incidence of cancer.

Dietary corn oil promotes tumors in rats by impeding apoptosis, or programmed cell suicide, in cancer cells.

In humans, we have the Israeli paradox.

Diet and disease–the Israeli paradox: possible dangers of a high omega-6 polyunsaturated fatty acid diet

Israel has one of the highest dietary polyunsaturated/saturated fat ratios in the world; the consumption of omega-6 polyunsaturated fatty acids (PUFA) is about 8% higher than in the USA, and 10-12% higher than in most European countries. In fact, Israeli Jews may be regarded as a population-based dietary experiment of the effect of a high omega-6 PUFA diet, a diet that until recently was widely recommended. Despite such national habits, there is paradoxically a high prevalence of cardiovascular diseases, hypertension, non-insulin-dependent diabetes mellitus and obesity-all diseases that are associated with hyperinsulinemia (HI) and insulin resistance (IR), and grouped together as the insulin resistance syndrome or syndrome X. There is also an increased cancer incidence and mortality rate, especially in women, compared with western countries. Studies suggest that high omega-6 linoleic acid consumption might aggravate HI and IR, in addition to being a substrate for lipid peroxidation and free radical formation. Thus, rather than being beneficial, high omega-6 PUFA diets may have some long-term side effects, within the cluster of hyperinsulinemia, atherosclerosis and tumorigenesis.

For health authorities, a paradox is a situation in which their cherished beliefs are contradicted by data. In this case, the “paradox” is easily resolved: vegetable oils can kill you.

Vegetable oils cause liver damage

Excessive alcohol intake is well known to cause liver damage and cirrhosis. What’s less known is that, in experimental animals, alcohol alone won’t cause liver damage. Something else is required, and one of those things is linoleic acid, the main polyunsaturated fatty acid found in vegetable oils. Dietary linoleic acid is required for development of experimentally induced alcoholic liver injury. Animals that were fed tallow and given high amounts of alcohol showed no liver damage. Beef fat prevents alcoholic liver disease in rats.

Non-alcoholic fatty liver disease (NAFLD) is strongly associated with obesity and insulin resistance, and has been increasing by leaps and bounds. Humans with NAFLD have a higher ratio of omega-6 to omega-3 polyunsaturated fats in their livers, which is the result of high consumption of omega-6 fats and low consumption of omega-3 fats.

Coinciding with the increased consumption of vegetable oils over the past few decades, not only has there been an increase in NAFLD, but other inflammatory conditions, such as cardiovascular disease, obesity, inflammatory bowel disease, rheumatoid arthritis, and Alzheimer’s disease.

How do industrial seed oils manage to cause all these diseases? To my mind, one of the most important factors may be that they rapidly induce damage to mitochondria, the powerhouses of cells. They also increase the release of inflammatory cytokines.

Processed foods are loaded with industrial seed oils

Image result for salad dressing ingredient label

Here’s the ingredient label from a bottle (plastic of course) of salad dressing. The most abundant ingredient is vegetable oil, and you don’t even know whether it’s soybean or canola oil, not that it makes a lot of difference. Also note high-fructose corn syrup, sugar, and various chemical ingredients. Now, go ahead and pour this concoction on your healthy salad, as millions do, and you’ve just made it unhealthy.

Image result for corn chips ingredients label


Corn chips: second ingredient is vegetable oil.

Fast food is cooked in vegetable oils. In general, almost any can or bag of processed food you look at lists vegetable oil as an ingredient.

Conclusion / Solution

As we’ve seen above, vegetable oils, aka industrial seed oils, can cause heart disease, cancer, and a host of other maladies.

And, in general, food companies have contaminated a whole host of foods with the stuff. What’s the answer? How can we avoid this garbage “food”?

Eat whole, unprocessed food. That means meat, fish, dairy products, fruits and vegetables, nuts. Don’t eat anything that comes in a manufactured bag or box, or anything that has been through an industrial process.

If you need oil for salads or other foods, use olive oil, a healthy fat that has been used for thousands of years.

However, for cooking at higher heat, use lard, tallow, butter, ghee, or coconut oil. Make sure these are pure and not hydrogenated.

PS: If you need to lose weight and you want to save yourself years of poor results due to bad information, I’ve put everything in a simple guide for you.

 The World’s Simplest Fat-Loss Plan.



Leave a Comment:

Matevž says July 12, 2017

Nice article, as always!

Slight typo: “Do understand why vegetable oils…”

    P. D. Mangan says July 12, 2017

    Thanks, I’ll fix that.

Bill says July 12, 2017

Full of good information clearly expressed as usual PD.
Again Thanks !

Thomas says July 12, 2017

I’d been ignoring my liquid condiments up until now, just never thought of it. After looking at the back of each jar, they’re almost all gone now. Well, fortunately, things like Caesar dressing have been around for a long time, and hopefully can be made healthily from scratch.

Bill says July 12, 2017

PD, slightly off topic but very relavant & interesting. Credit Swiss Bank has issued a report for it’s investors on the health affects of industrial oils and carbs. Written with a view to advising what will be growing markets in the future an what will decline.

Dr Malcolm Kendrick in the UK commenst on this issue here :

    Nick says July 12, 2017

    Yeah, those fad-following Swiss bankers! That’s pretty amazing. It’s nearly 2 years old, is there any update to report, I wonder?

      Bill says July 13, 2017

      Yes Nick, almost 2 years old and I had not heard a whisper about till today when I found that post by Dr Malcolm Kendrick.

      The report is predicting out to 2030 which is still a good ways off.

      I suspect it’s being an international bank which is the ‘reason’ why Credit Swisse published this report. They want & need to know what businesses will thrive or not thrive, in the future in order to know what investments and loans etc, will be best.

      On the basis of that report I suspect they may have moved their investment portfolio away from Pharmaceutical companies selling statins and away from loans to grain companies…

Ole says July 12, 2017

It is the slow poisoning of an entire global population. So sad….

Nick says July 12, 2017

Another interesting article, thanks Dennis. My dear mother got us on margarine in the 70’s, not because of supposed health concerns, but because it was CHEAPER than butter. My dad never liked it and continued using butter, but I developed a taste for it, and used it into my adulthood in lieu of butter. My wife also developed a taste for it somehow, and so we used it together.

Now we’re off it and on to proper butter, but we hardly ever use it, since we’re off toast. And I was never one to use it on bread much, at least living here in Germany these last dozen years, the bread capital of the world. I would always say that the bread’s so good here it doesn’t need butter. Now, when I have an occasional nibble of it, it’s as a butter or fat / sauce delivery vehicle.

My sister & I also grew up on corn oil at home. Again for the same reason: Mom grew up extremely frugally, a post-depression farm girl. Wonder how much damage that all did.

Peter says July 13, 2017

Fantastic article, I am a medical student and they definitely don’t teach this in class so I guess I will teach it myself.

People like you are why I am still confident that we can get the right information to the right people who need it. We need young men who are fit, healthy and full of testosterone.

    P. D. Mangan says July 13, 2017

    Thanks, Peter!

Chris in Minneapolis says July 15, 2017

Absolutely. Simple dressings can be made very quickly from olive oil, vinegar and whatever spices you would like to add. Homemade dressings taste far better than the processed junk.

Most “health store” dressings are also full of bad oil…but it’s organic!!

ConantheContrarian says July 18, 2017

Is palm oil bad? At one time in my life, I was allergic to dairy products, so I swore off butter and used “healthy” margarines as a substitute. Although my allergy has almost disappeared, I still like to use margarine. Is Palm Oil bad too. I notice that it is not on the list above, so I thought that I would ask.

    P. D. Mangan says July 18, 2017

    Hi Conan – Although I’ve read bad things about palm oil, it contains only 9% omega-6 polyunsaturated fats, which makes it healthy in my book.

      ConantheContrarian says July 19, 2017

      What about grape seed oil. Because it comes from a seed, is it processed the same way as the other industrial oils?

        P. D. Mangan says July 19, 2017

        Turns out, to my surprise, that grape seed oil is not so healthy. It is, in fact, an industrial seed oil.

          ConantheContrarian says July 27, 2017

          I was looking at the ingredients of some food — I cannot remember what it was — and I saw that the product had expeller pressed safflower oil. So if it is expeller pressed, it might be good, but then the omega fats come into play. What is the verdict on that situation?

          P. D. Mangan says July 27, 2017

          No, expeller pressed won’t make much difference because the main issue is the omega-6 fats in the oil itself.

guest says July 25, 2017

Economist Karl Denninger also noted:

“There are no good “vegetable” oils. Some are worse than others but none are good. Some nut based oils (e.g. coconut) are perhaps better, but were talking in relative terms, not absolutes. Unsaturated oils are not shelf-stable without chemical modification — that’s what “unsaturated” means, that there are open chemical bond sites on the hydrocarbon chain. Hydrogenated oils (if that word appears anywhere on the label) are trans-fats and the safe amount of them in your diet is zero. All plant-based oils are high in Omega-6 and while you do need some small amount of them in their natural form they are pro-inflammatory and thus promote heart disease. Note that historically the balance of Omega-3 (mostly in animal flesh) and Omega-6 (mostly in plants) was about 1:1. Concentrating the amount of Omega-6 oils by processing plants into oils has dramatically increased the ratio to, in most people, 10:1 or more!

The pharmaceutical industry is well aware of point this and has been for decades. In fact all of the OTC NSAIDS (Ibuprofin, aspirin, etc) work by reducing the metabolism of Omega-6 fatty acids into inflammatory compounds.

Let that sink in for a minute or two: Both your doctor and the pharmaceutical industry know, as a matter of scientific fact, that consuming these oils fuels inflammation because the method of action of some of the most-widely used over-the-counter drugs is to reduce that metabolic process.”

That’s why aspirin helps!

And theres more:

“Alarmingly, an assessment of industry-sponsored RCTs showed the median increase in life expectancy for selected participants in secondary prevention trials who adhered to taking statins every day for several years was a mere four days.”

From The cholesterol and calorie hypotheses are both dead — it is time to focus on the real culprit: insulin resistance

Again found via the Market Ticker, where Karl Denninger further adds:

“Now tell me folks — would you agree to take a drug after a heart attack if (1) you knew it would cost you some amount of money — any amount of money — and (2) that the expected improvement in your survival time was four days if you took it every day for several years?

No, you would not — and you know it.

Yet not only the drug industry but your doctor have made billions of dollars selling you these drugs without telling you that the expected improvement in your life is four whole ****ing days.

Knowingly failing to disclose a material fact that would have changed your decision had you known it for the purpose of making a profit at your expense has a name: FRAUD. It is not a mistake, it is a crime.”

Daniel Antinora says July 25, 2017

“While omega-6 fatty acids are not intrinsically dangerous, the dose makes the poison, and virtually everyone in the Western world consumes far too much of these. An unbalanced ratio of omega-6 to omega-3 fatty acids contributes to a multitude of the diseases of civilization, including cancer, heart disease, and diabetes. While people living in a more natural state and eating whole, unprocessed foods may ingest a ratio of omega-6 to omega-3 fats of 2:1 or even 1:1, ratios in the modern world are typically over 15:1 and even up to 50:1.”

So… Since I’m a hard gainer and it’s hard for me to sit 30-40lbs above my natural weight like I like to do…

Let’s just say I have to eat a lot of junk food (burgers and fries can get me the 4,000 calories a day I need)….

If I just down enough fish oil and check my levels (assuming it’s actually the ratio that’s the problem) I’m good right? I have to make a tradeoff somewhere because I just can’t force myself to enough clean food to get the necessary calorie intake.

    P. D. Mangan says July 26, 2017

    Hi Daniel – Fish oil can partially mitigate a high consumption of omega-6 fatty acids. An article, Healthy intakes of n−3 and n−6 fatty acids: estimations considering worldwide diversity, states:

    With caveats inherent for ecologic, nutrient disappearance analyses, a healthy dietary allowance for n−3 LCFAs for current US diets was estimated at 3.5 g/d for a 2000-kcal diet. This allowance for n−3 LCFAs can likely be reduced to one-tenth of that amount by consuming fewer n−6 fats.

    So, given average US consumption of omega-6 fats, 3.5 g/d of omega-3 fats is a healthy level. That’s a lot, something like equivalent to 3 tsp of cod liver oil (which is about what I take in a week). If someone ingests little omega-6, then only a tenth that amount is needed, which is why I say that reducing the amount of omega-6 is the most important thing to do.

Jimmy says July 30, 2017

The oils you mention as safe tend to have a strong flavor, so not always so desirable in cooking. What other oils are safe? Avocado? Nut oils? Also how does cooking affect the safety of oils?

    P. D. Mangan says July 30, 2017

    Avocado oil is safe. Nut oils like walnut oil have fairly high levels of omega-6. Extra light olive oil, which is to say, not extra virgin olive oil, is lighter in taste and may be useful in cooking.

R. says August 7, 2017

What about olive oil made from pomace?

    P. D. Mangan says August 8, 2017

    Afraid I don’t know anything about that. Olive oil generally is good.

      R. says August 9, 2017

      I looked it up in the meantime. Not sure what it is chemically, but it’s extracted the same way most oils mentioned in this post are, through use of solvents and heating.

      There were some recalls and bans at times, as incorrect refining can introduce toxic substances food safety agencies pay close attention to.

        Bill says August 9, 2017

        R, I had never heard of pomace oil. But there you are. That’s your answer. Industrial oils are new and not made in people friendly ways, using toxic chemicals. They are cheap & nasty.

oil boy says September 6, 2017

I just reread this and the part about liver disease blew my mind! Tallow versus linoleic acid. I notice there are two listings on wiki’s vegetable oils table I guess omega 3 and 6 versions. What’s going on there?

I see that avocado oil is another option, especially for cooking because of its high smoke point and that it’s extracted from the fruit not chemically pulled out of parts of the fruit that don’t have no business being extracted from.

I guess us alcoholics need to find good oils.

    oil boy says September 6, 2017

    I guess my follow up would be what about ALA in fish oil?

Exercise Prevents Cancer - Rogue Health and Fitness says September 18, 2017

[…] fed a high-fat diet – which we know usually consists of large amounts of seed oils and sugar – become obese, with large amounts of adipose (fat) tissue, and extracts of this […]

eah says December 8, 2017

“If you need oil for salads or other foods, use olive oil,…”

For salads I make what I consider to be a classic vinaigrette: two parts olive oil, one half part rapeseed oil, one half part linseed oil (better omega 3/omega 6 ratio), one part vinegar, plus salt, pepper, and simple prepared mustard to taste.

James says July 22, 2018

I believe this article is mostly correct. However, cold-pressed sunflower oil may be OK when in combination with other oils according to this article:
on Parent Essential Oils by Dr. Robert Rowen and his wife who is also an MD

James says July 22, 2018

Someone wrote about rapeseed oil, also known as canola oil. Canola oil is not good for brain health. See

Q says November 8, 2018

Thank you for the article.

How bad is peanut oil compared w canola? Is it made via roughly the same process?

    P. D. Mangan says November 8, 2018

    Good question. Peanut oil is high in omega-6, but since it’s naturally high, may not require the extensive processing that seed oils need. Canola oil appears to have other bad qualities besides high o-6. If I had to choose, peanut would be better. But you’d be better off with animal fats or olive and coconut oils.

rowie says November 21, 2018

lol, sodium benzoate in a salad dressing…
In my country we have a producer of saladspreads for your sandwich, they also contain sodium benzoate, after contacting them, never heard from them again.

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