Update Dec 2021: Upon looking into this subject deeper, I have adjusted my stance on these oils slightly as the bulk of nutrition research points to these oils having a beneficial effect to health. However, there may be some aspects of these oils to be concerned about and some context where they will contribute to poor health outcomes. Such as in the context of ultra-processed foods where they are combined with various refined grain flours and sugars, or when they are highly processed as described below vs an organic, cold pressed version of said oils for example. Some articles exploring this subject can be found here (1,2)
If you were to ask me some of my key pieces of nutrition advice, one answer I would give is to avoid ultra processed foods containing what are called industrial seed oils. Almost by default, that one (seemingly simple) strategy forces you to be consuming mainly whole foods, reduces your sugar intake and glycemic load, and removes virtually all ultra-processed food-like products.
By following this strategy, you will also start to become aware of the prevalence of these industrial oils in our food system, and why our population may be so collectively sick. This article aims to explore how these seed oils, often touted as “healthy”, infiltrated our food system, and could actually be a main driver of poor metabolic health, insulin resistance and a wide variety of health conditions and chronic diseases.
What are Industrial Seed Oils (aka Vegetable Oils)?
These oils are relatively new to the human diet. They are generally highly processed, nutrient poor, and calorie dense. They are deeply ingrained in our food system, used in virtually all ultra-processed packaged and frozen foods, as well as the vast majority of restaurants. When you start to bring the consumption of these oils into your awareness, you will find they are almost impossible to avoid unless you are cooking your own whole food meals.
These oils have largely flown under the radar in regards to their impacts on our health. I have heard plenty of people indicate they are avoiding sugar and trying to reduce their sugar consumption. But I have never once heard anyone in my personal life say they are intentionally trying to cut back on or avoid these oils.
So, which oils are we talking about? The main culprits include:
The majority of these oils are derived from destructive monocrop agriculture, and are from the top genetically modified crops (corn, soy, cottonseed, and canola). As staples in the ultra-processed food industry, they also help make the food monopoly of Big Food, Big Seed, Big Ag, and Fertilizer companies thrive and persist. When those industries are thriving, so are widespread chronic health problems, environmental destruction, political and scientific corruption, extreme economic burden, and even social injustice, poverty, and racism.
Alongside refined grains and sugar, our Western society’s consumption of these oils have skyrocketed over the last several decades. Consumption of soybean oil for example has jumped from 4 pounds per year to 26 pound per year, per person.(1)
Most of the fats consumed in our Westernized food supply come from these highly processed oils that are cheap to produce - using high pressure, high heat, and chemicals for extraction, deodorization, and color, and then cooked using high heats (like in a deep fryer). It is rare to come across a minimally processed version of these oils in the vast amount of food items that contain them.
This basically ensures that the delicate fats in these oils are void of protective antioxidants, loaded with distorted, unnatural fat molecules, harmful free radical molecules, are oxidized or rancid, and are generally unfit for human consumption by the time they hit your lips. Remember this the next time you want to opt for that deep fried food item. The distorted and damaged fats in these oils provide nutrient void calories that promote obesity, excess oxidative stress, cell mutations, excess inflammation, and can have negative impacts on how your cells function and communicate.
The Questionable History of Industrial Seed Oils
These oils, and their ubiquity in the food industry, also have a fascinating history. The introduction of these oils in the food supply began in the early 1900’s when Proctor and Gamble developed a way to make cottonseed oil (then classified as a toxic byproduct) into an “edible” fat, resulting in what is known today as Crisco.
Others, like the popular canola oil, also started out as industrial chemicals, used to lubricate machinery (YUMMY).
Wait, I thought these oils were healthy?
These oils also currently enjoy the title of “heart healthy” fats. As part of their effort to popularize their new product, Proctor & Gamble gave a hefty financial donation to the American Heart Association (AHA). This led to a full medical endorsement of these “heart healthy oils” and the dietary recommendations to consume more of them in place of animal fats. Like a perfect storm, this coincided with the work of a man named Ancel Keys and his theory on the development of heart disease called the diet-heart hypothesis- that saturated fats and cholesterol cause heart disease- which may be not be the case in all circumstances. (1,2)
Ancel Keys was the man people turned to for dietary advice on preventing heart disease after his appearance in a CBS documentary in 1958. His nutritional prowess came from his design of the K-ration, which were pocket sized, ready to eat meals sent to troops in WWII. After the war he was hired to study the problem of rising heart attack rates by the Minnesota public health department. Using his extreme confidence and charisma, he sold himself as a heart disease specialist despite not being a cardiologist or an MD. I don’t believe that means he couldn’t have been a highly knowledgeable and positive contributor to the subject, but unfortunately his expertise was sold to the public using a mix of questionable science, deception, and fear.
In his famous “Six Countries Study” Keys used sloppy statistical work to conclude that the countries where the people ate the most animal fat, people died of heart disease more often, and rightfully was lambasted by his peers. One thing he forgot to mention in his infamous study was that 3 of the countries (Canada, USA, Australia) had the highest levels of margarine consumption. He also excluded available data from 16 other countries that when included showed a very poor relationship between total fat intake and heart disease. Rather than modifying his hypothesis, he vengefully pushed his ego driven agenda even harder, wanting the public to think he had single-handedly discovered the cause of heart disease.
A real kicker is that in his laboratory and human experiments Key’s didn’t even use animal fats! He used hydrogenated industrial seed oils (margarine), which were loaded with unnatural, distorted trans fats (which are now mostly banned in foods). Much of the news reports you have heard about the hazards of saturated fats and cholesterol are supported in large part by studies using hydrogenated industrial seed oils, full of unnatural molecules, not resembling anything found in butter, steak, or any natural food. Because those hydrogenated oils contain saturated fats, Key’s and the food industry were then able to put an anti-saturated fat spin on the findings, and animal fats (containing healthy saturated fats and cholesterol) took the blame for heart disease. (4)
Producers of margarine and industrial seed oils had then found their perfect spokesperson. If the public thought animal fats and butter would “clog their arteries“ then they could be persuaded to buy more margarine and industrial seed oils (found in their convenient, ultra-processed, hyper palatable food products). Successful marketing campaigns followed, and people began to opt for these oils and food-like products while shunning natural whole foods like meat, eggs and other animal products. Grocery store shelves started to become loaded with cheap, highly processed, quick, convenient, ready to eat foods and thus many of the issues with the modern food and agriculture systems were born and remain prevalent to this day.
The American Heart Association (who are dependent on large financial donations from the vegetable oil industry), American Medical Association, American Diabetes Association, American Cancer Society, and the American College of Cardiologists all jumped on the Ancel Keys bandwagon, endorsing his hypothesis. This powerful list of endorsements led to most doctors being convinced that natural fats from animals, that humans have been consuming forever, were actually heart attacks on a plate; and that highly processed margarine and industrial seed oils were the healthier choice.
You may be wondering how all those organizations could potentially have gotten things so wrong, and the answers are long winded and beyond the scope of this short article. For a deep dive on this fascinating, controversial and disturbing history, read The Big Fat Surprise by Nina Teicholz, and books by authors such as Gary Taubes, Dr Mark Hyman, Michael Pollan, and Dr. Cate Shanahan (I will note that some of these authors have controversial nutrition viewpoints, but the history aspect is interesting none the less).
The heart healthy labelling of these oils is because there is evidence that they lower LDL cholesterol- often touted as “bad” cholesterol, and considered to be the key player in heart disease. That topic, however, is nuanced and continues to be debated. There is still much to learn and discover on this controversial topic, but do you really think that natural foods that humans have been consuming for thousands of years are likely driving our epidemic of modern diseases like heart disease? Is it possible they were made the scapegoat for ultra-processed food companies to manipulate us into buying their plant-based food like products?
Keys’ hypothesis has persisted despite being strongly criticized the entirety of its existence, with contradictory data even being suppressed. Just look at these conclusions from suppressed research and this other meta-analysis:
“Available evidence from randomized controlled trials shows that replacement of saturated fat in the diet with linoleic acid (vegetable oils) effectively lowers serum cholesterol but does not support the hypothesis that this translates to a lower risk of death from coronary heart disease or all causes. Findings from the Minnesota Coronary Experiment add to growing evidence that incomplete publication has contributed to overestimation of the benefits of replacing saturated fat with vegetable oils rich in linoleic acid.”
“In this cohort, substituting dietary linoleic acid (vegetable oils) in place of saturated fats increased the risks of death from all causes, coronary heart disease, and cardiovascular disease. An updated meta-analysis of linoleic acid intervention trials showed no evidence of cardiovascular benefit. These findings could have important implications for worldwide dietary advice to substitute linoleic acid, or PUFAs in general, for saturated fats.”
The combination of the “low-fat, anti-cholesterol” campaign, and the vegetable oil industry slithering its way into our food supply on that campaigns back, has flooded our grocery store shelves and restaurants with these oils. Unlike their poor health counterparts refined sugars and grains, these oils have largely been able to avoid the public spotlight in regards to disease and poor health.
The replacement of traditional, natural fats that have sustained humans for thousands of years, with industrial seed oils has arguably been a public health flop when it comes to preventing and combating our modern metabolic diseases. Some health experts even make a compelling case that these oils may be the main driver of our poor metabolic health epidemic.
I am just scratching the surface on the subject of industrial seed oils here, and I strongly encourage anyone reading this to explore the subject further if you are skeptical of the impact these oils have on human health. Better yet, experience for yourself what it's like to have a vegetable oil free diet! Here is a 3 part article to help provide further perspective (5, 6, 7).