In a little over 100 years, we went from heart disease being a rare condition in the early 1900s, to being the leading cause of death in humans. Why?
Preface:
When writing this, I knew seed oils are bad for a few months, but the majority of sources I follow have never really explained why or how we got here. What I learned while researching for this article truly made my jaw drop to the floor, and I encourage you to read the whole thing to receive the entire picture. What you choose to do with seed oils after reading this is up to you, but at least you will be informed.
In 2019, scientist William Osman figured out how to make use of a common waste product: saw dust. Osman decided to use sawdust as a food filler ingredient as part of a research project, which started with the rice crispy treat. Interestingly enough, he concluded that the amount of saw dust he could add to rice crispy treats without consumers noticing is 15%. FIFTEEN PERCENT!
While this is clever and disgusting at the same time, it is miniscule in comparison to the greatest bait and switch in our global food supply over the last 100 years, creating a $100 BILLION dollar industry.
While this is clever and disgusting at the same time, it is miniscule in comparison to the greatest bait and switch in our global food supply over the last 100 years, creating a $100 BILLION dollar industry. As a result, we have switched out a very common type of food, eaten for thousands of years in favor of something foreign to the human diet: replacing animal fats with seed (vegetable) oils.
I often talk about the dangers of seed oils on social media and how I believe my previously excessive consumption of seed oils was a major contributor to the two large endometriomas on my ovary (one the size of a lime, one the size of a grape) and the onset of symptoms of polycystic ovarian syndrome (PCOS).

What are seed oils?
- The simple, most basic answer: seed oils are processed oils industrially extracted from genetically modified crops
For most of human history, we consumed 0 grams of vegetable/seed oils. Now, we consume, on average, a whopping 80 grams (6 tablespoons) PER DAY, making it the single greatest change to human nutrition in history.
Speaking of history, let’s take a look:
Unfortunately, this garbage is in almost everything: your chips, your oat milk lattes, fake meat products, many store bought hummus brands, salad dressings, dips, and likely 90%+ of your groceries.. even on what you think is just ‘roasted cashews’ you will likely find canola or some type of seed oil.
Now we’ve gone over the history, what are the seed oils I’m talking about?
Seed Oils to Avoid:
- Canola Oil (or as I like to call it, caNOla oil)
- Sunflower (Seed) Oil
- Safflower Oil
- Palm Oil
- Rice Bran Oil
- Cottonseed Oil
- Linseed Oil
- Corn Oil
- Sesame Oil
- Rapeseed Oil
All of the above seed oils contain high amounts of Polyunsaturated Fatty Acids (PUFAs). PUFAs are extremely unstable, break down very easily and form a wide variety of toxins when exposed to chemical stress such as high heat, high pressure, metals and bleaching agents- all of which happen to these vegetable oils in the refining and manufacturing process.
When we consume these rancid, oxidized, toxic oils, they promote free radical reactions in our body that damage our mitochondria , enzymes, hormone receptors, and even our DNA.
Scientists are beginning to find that mitochondrial dysfunction may play a central role in the development of many diseases including heart disease and Alzheimer’s. Not surprising, considering the heart and brain require massive amounts of energy to work properly. And as we know, the mitochondria is the powerhouse of the cell and creates ATP, a substance present in all living cells that provides energy for metabolic processes and is involved in making RNA. It is also well known that mitochondria are dysfunctional in patients with obesity and diabetes.
Yet, with all of this data, it is extremely alarming that seed oils are still being promoted as the healthier option today.
How are seed oils even manufactured?
A long industrial process is dedicated to ripping oil out of these seeds and our bodies were never meant to consume polyunsaturated fats in such high amounts. Even Dr. Cate Shanahan, nutritionist for the LA Lakers removed vegetable oils from the players’ diet.
Process to make them:
- 1. Chemical extraction via petroleum based solvent (or hexane)
- 2. Acid wash process (heated to 80°C = 176°F) High Heat = oxidation
- 3. Neutralization process (heated to 95°C = 203°F) High Heat = oxidation
- 4. Bleaching process (heated to 110°C = 230°F) High Heat = oxidation
- 5. Deodorants (heated to 260°C = 500°F) = trans fats → need to use chemical to deodorize because they’ve oxidized so much from the above process that they are colorless and smell awful if consumed as is
- 6. Color enhancement
In the refining process, all of the beneficial compounds are stripped away, leaving you with basically toxic sludge. I personally took the below screengrab from a ‘how canola oil is made’ youtube video from Discovery. It’s real.
Did you know?
- It takes 2,800 sunflower seeds to make 5 tablespoons of sunflower oil.
- 98 ears of corn to make 5 tablespoons of corn oil.
- 625 grapes to make 5 tablespoons of grapeseed oil.
- 40 cups of rice to make 5 tablespoons of rice bran oil.
Now let’s go into oxidation, which we briefly discussed above.
What does it mean to oxidize?
To oxidize means to react with oxygen. This is how metals rust. Oxidation changes the structure and properties of fats for the worst.
Light, exposure to oxygen, and especially heat ALL speed up oxidation. When PUFAs oxidize in seed oils, they produce oxidation products that give these fats a bad flavor, and these oxidation byproducts are toxic. For example, the toxic aldehydes in seed oils are one of the byproducts of PUFA oxidation.
Seed oils also oxidize in your body, creating toxic oxidation byproducts such as an aldehyde 4-HNE, which is in fact, considered to be the most toxic aldehyde according to the NIH. This compound has been associated with aging, heart disease, diabetes and Alzheimer’s.
Between the years of 1959 and 2008, the increase of PUFAs in subcutaneous tissue, i.e. adipose tissue, i.e. the fat cells in our bodies, has increased 2.5x from 9.1% to 21.5%. This parallels an increase in chronic lifestyle diseases and is considered a reliable marker because it has a half life of 2 years. Yes- THE TOXIC COMPOUNDS IN THESE SEED OILS CAN LIVE IN THE FAT TISSUE IN YOUR BODY FOR TWO YEARS.
Professor of Bioanalytical Chemistry in the UK, Martin Grootveld, received press from the Independent when he suggested that vegetable oils are not a healthy cooking oil, contradicting advice from the NHS. His research showed that meals fried in seed oils contain 100-200x more aldehydes than the daily limit set by the WHO.
After significant studies on animals, it has been confirmed that animals with cells that oxidize easily do not live as long as those with cells that do not. What data do we have on humans, vegetable oils, and lifespan? Let’s take a closer look:
Dr. Robert Frantz spoke with Malcolm Gladwell and revealed “the Basement Tapes,” concerning his father, Ivan Frantz who devoted his life to studying heart disease. He was very meticulous in his experiments studying the role of cholesterol and blood lipids in heart attacks.
Back in the 1960s, Ivan Frantz conducted a controlled 5-year long study that would shed light on what actually happens when people cut out saturated fats and eat polyunsaturated vegetable oils/fats instead. This was called the Minnesota Coronary Survey, which took many years to set up and had over 9,000 research subjects in institutions. The patients in the study would pick one of two trays, which looked completely identical, but one tray was food cooked with vegetable oil and everything low fat, and the other had everything cooked in saturated fat. This is likely one of the most rigorous diet trials ever conducted.
The results?
The patients who ate the low fat, vegetable (seed) oil diet, did end up with lower cholesterol than the people who ate food cooked with animal fats, BUT the vegetable oil subjects did not live longer, which made ‘no sense.’ They were eating the kind of diet that everyone believed would make you healthier and live longer. The subjects who were over 65 and had been on the diet for more than a year: the more their cholesterol was lowered, the higher the risk of an adverse outcome (death).
There is no good evidence that reducing saturated fat makes you live longer. The best clinical trials on this subject actually reach the opposite conclusion.
Besides these chilling facts and correlations between seed consumption and heart disease (the #1 cause of death in humans), let’s talk about what seed oils do to the rest of the body.
Seed oils also act like estrogen: they decrease testosterone levels in men, potentially shrink testicles, and lower sperm quality. Estrogen overload is also dangerous for women too, which is a risk factor for breast cancer.
Seed oils cause bloating, intestinal inflammation, and gut dysbiosis and anxiety.
From a cosmetic standpoint: cellulite was rare before the 1970s- the same decade seed oils became prominent in western diets. According to the LA Lakers’ nutritionist I mentioned earlier, Dr. Cate Shanahan states vegetable oils spread out your fat, making it have a more liquid like texture, thus being prone to cellulite. The PUFAs polymerize inside your fat tissue, meaning they turn into a hard, plastic-like substance, which is visible as cellulite. It also damages your collagen (the most abundant protein in the body). To fix it, you need to detoxify your body from these PUFAs, eat more saturated fat, take vitamin E (in healthy quantities), liquid collagen, and sauna if you can. Normal fat should be compacted and have a healthy amount of collagen, which keeps skin smooth and dimple free.
This is a lot of information to take in. If you’re like me, and made it this far, it’s likely that your jaw is dropping. So to sum it all up, seed oils rich in PUFAs replaced saturated fats, which our ancestors had eaten for thousands of years. The consumption and monetization of these seed oils + removal of these saturated fats happen to correlate with rates of obesity, diabetes, Alzheimer’s, and you guessed it, heart disease: the #1 leading cause of death in humans.
Just like with the sawdust like in William Osman’s rice crispy treats, seed oils are hiding in your food, hard to notice. If someone swapped the sugar in your coffee to stevia or honey, you would notice, but you would likely not notice if someone swapped butter for seed oils in your meal until you realize how your body feels from it.
Finally, you will often find marketing materials on labels that say ‘organic’ or ‘vegan,’ but that does not give it a pass. Before I learned all of this, I had a refrigerator full of this trash that was labeled as ‘healthy’ with a USDA organic stamp. It is so important to see beyond marketing and read your ingredients.
Is there a way to function without seed oils at home? YES, absolutely. Check out my grocery guide which includes an elaboration on the below, but I always stress to go back to basics as much as you can, scan your labels, and try to cook more than you eat at restaurants or do take-out. When you’re at a restaurant, ask for your food to be cooked in butter rather than oil. Do the best you can to make informed decisions.
Safe Fats to cook with:
- 1. Butter
- 2. Ghee
- 3. Tallow
- 4. Lard
- 5. Avocado Oil (has to say 100%)
- 6. Coconut Oil
- 7. Extra Virgin Olive Oil
Here is a cheat sheet if you ever need any guidance!
Do yourself and your family a favor: go through your kitchen, get rid of these seed oils and go back to basics. Control what you can control at home.
Please share this post: when it comes to seed oils, ignorance is NOT bliss!
Preach, Meg. We’ve cut seed oils from our family’s diet and the difference has been night and day. No more inflammation and bloating post-meals.
My mother and grandparents told us this growing up. I should have believed their wisdom. They grew up in Ireland close to nature and intuitively understood. The fact that I didn’t listen shows the power of the propaganda coming from big corporations and their media allies. Thanks Meg!! My mother and grandparents would be singing your praises! Keep it coming! I hear you!
These “vegetable” oils were designed to lubricate machinery, and not mankind. Subtract the seed oils before they subtract you!