Summary
June 11 is Seed Oil Awareness Day. Here’s Why it Matters.
In June 1911, Crisco was introduced to the American public. Made from hydrogenated cottonseed oil and aggressively marketed to women, it launched one of the most radical shifts in dietary history.
This moment marked the beginning of seed oils replacing traditional fats in the American diet. While partially hydrogenated oils like this are no longer commonly used, the shift they triggered—from traditional fats to industrial seed oils—remains deeply relevant today. It was the start of a nutritional experiment that still shapes our food system.
Natural fats like lard, butter, tallow, and coconut oil, used for generations, began to disappear from American kitchens—replaced by highly refined, industrial seed oils—fats that didn’t exist in the human diet before the 20th century.
Today, over a century later, seed oils dominate the modern food supply. And yet, most people have no idea this shift happened—let alone how it may be affecting their health.
From Soap Factory to Supper Table
Procter & Gamble developed Crisco by chemically modifying cottonseed oil through hydrogenation—turning it from lamp fuel into a solid fat that looked like lard. The problem? It wasn’t food. So, they marketed it as a “digestible” alternative to grandma’s cooking fats.
Cottonseed oil wasn’t originally intended for the dinner table—it was an industrial byproduct from the textile industry. Unrefined, it was considered toxic due to compounds like gossypol and was often used in insecticides or burned as lamp fuel. But it was cheap and abundant, and once refined and hydrogenated, it could mimic the appearance of traditional fats.
They told consumers it was the fat of the future— “pure,” “modern,” and perfect for the American housewife. In reality, it was the first major introduction of a chemically altered, ultra-processed fat into the human diet.
Crisco’s success wasn’t built on health—it was built on low cost, clever branding, and high profit margins.
This moment didn’t just introduce a new ingredient. It marked one of the most significant changes in human dietary history: the shift from traditional fats like butter, tallow, and lard to industrial seed oils.
Where Are Seed Oils Hiding Today?
Next time you’re in the grocery store, read the ingredient labels. From the snack aisle to the dairy case and frozen foods, you’ll see seed oils making repeated appearances. Seed oils are now a default fat in the modern food supply:
- Frying oil in nearly all restaurants—regardless of where you dine, they’re commonly used in cooking oils, sauces, and marinades
- Salad dressings, mayonnaise, dips, and condiments
- Packaged snacks like crackers, chips, cookies, bars, and granola
- “Health” products such as plant-based milks, nutrition drinks, protein snacks, and meat substitutes
- Even baby formula, pet food, and skincare
They often appear as “vegetable oil,” which sounds healthy, but this term can be misleading.
Today, the average American now derives approximately 20–30% of daily calories from seed oils, compared to none just over a century ago. For most of human evolutionary history, traditional populations consumed omega-6 and omega-3 PUFAs in close to a 1:1 ratio, with total PUFA consumption rarely much more than approximately 2-3% of calories.
The Omega Imbalance: How Seed Oils Skew Our Fatty Acid Ratio
Seed oils are rich in polyunsaturated fats (PUFAs), particularly omega-6 linoleic acid. By consuming seed oils, people take in far more concentrated omega-6 fats than ever occurred naturally in the human diet.
📌 Just one tablespoon of oil contains the extracted fat from approximately:
- 200 soybeans
- 100 sunflower seeds
- 5,200 rapeseeds
- 13 ears of corn
While omega-6 fats are essential in small amounts, modern diets contain them in excess—while being relatively low in omega-3s, creating a significant fatty acid imbalance.
Over the 20th century, U.S. dietary fat sources shifted from minimally processed animal fats like butter and lard—rich in vitamins A, D, and E—to industrial seed oils from sources like soybean, corn, safflower, sunflower, cottonseed, and canola. This transition reduced the micronutrient density of our fats (due to refining losses of vitamin E and phytosterols) and contributes to an imbalanced omega-6/omega-3 ratio, a topic of ongoing research for its potential role in inflammation.
Research shows that the omega-6/omega-3 ratio in the modern diet has shifted from roughly 1:1 historically to 15:1 or higher today—largely due to the rise of refined seed oils. This imbalance has been linked to chronic inflammation and increased risk of disease,
Further supporting this concern, recent data from the UK Biobank study found that a high omega-6 to omega-3 ratio is associated with increased risks of total mortality, cancer mortality, and cardiovascular disease mortality.
The Oxidative Instability of Seed Oils
Unlike saturated fats, which are found in lard, coconut oil, butter, and tallow, or monounsaturated fats, like those in olive and avocado oil, polyunsaturated fats (PUFAs)—the primary fat in seed oils—have a key structural weakness. They contain multiple double bonds in their carbon chains. The phrase double bond refers to how carbon atoms are linked within a fatty acid molecule. These atoms can be joined by either single or double bonds. When there are no double bonds present, the fatty acid is classified as saturated, meaning each carbon atom is completely bonded with hydrogen atoms.
This hydrogen coverage acts as a shield against oxygen, helping to prevent oxidation. As a result, saturated fats are highly resistant to oxidative damage. In contrast, polyunsaturated fats—abundant in seed oils—contain two or more closely spaced double bonds, making them far more prone to oxidative breakdown. This is why oils made from seeds oxidize and form harmful byproducts more easily than fats like butter, beef tallow, or coconut oil, which are primarily composed of oxidation-resistant saturated fats.
When used in frying, cooking, or food manufacturing, seed oils form harmful byproducts such as aldehydes, trans fats, polycyclic aromatic hydrocarbons (PAHs), hydroxy alkenyls, and polymers at a higher rate than seed oil free options. These byproducts are linked to inflammation and chronic disease, making seed oils particularly problematic in heated applications. One of the most dangerous groups of toxins is the aldehydes—a class of chemicals that includes the pungent formaldehyde used in cadaver preservation, along with several compounds responsible for the harmful and irritating effects of cigarette smoke. The way polyunsaturated fats break down during cooking is surprisingly similar to how skin burns: it all comes down to time and temperature. The longer an oil is heated—and the higher the heat—the more harmful compounds are produced. And the more polyunsaturated fat an oil contains, the more toxins it’s likely to produce when heated. This means the most effective way to minimize exposure to these harmful byproducts is to avoid seed oils altogether and instead choose fats that are made up of more stable fatty acids.
The Science Was Suppressed—Until Recently
It turns out the early randomized controlled trials (RCTs), which influenced dietary guidelines recommending that we decrease saturated fat consumption and swap in seed oils, didn’t tell the full story because key data from those trials was never published or misinterpreted for decades.
Here are a few of the trials (RCTs) that challenged the health claims of seed oils—and were buried for decades.
When NIH researcher Dr. Christopher Ramsden reanalyzed the long-suppressed data from the Sydney Diet Heart Study (2013) and the Minnesota Coronary Experiment (2016), he found that replacing saturated fats with linoleic acid (from corn or safflower oil) lowered cholesterol—but increased mortality.
About ten years ago, NIH researcher Dr. Christopher Ramsden recovered unpublished data from the Minnesota Coronary Experiment and Sydney Diet-Heart Study and concluded:
“Substituting dietary linoleic acid in place of saturated fats increased rates 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.”
Also, as one research group wrote, “[Dietary fat] recommendations were introduced for 220 million US and 56 million UK citizens by 1983, in the absence of supporting evidence from RCTs.”
Despite these reasons for concern, public health guidelines continue to recommend high consumption of polyunsaturated fats.
A recent analysis found that supportive reviews for seed oils have often failed to cite relevant RCTs and exhibit significant citation bias. In fact, 82% of historical reviews favoring seed oils referenced only a single RCT with positive results, ignoring the broader body of evidence.
Most people are surprised to learn that so few RCTs support public health advice to consume large amounts of polyunsaturated fats from seed oils—and that better-designed trials have actually shown high seed oil consumption may be harmful rather than beneficial.
The Industry Influence
The promotion of seed oils is heavily supported by industry funding in scientific journals and popular media.
Many popular articles dismissing concerns about seed oils follow a similar narrative, painting seed oil skepticism as “anti-science” while failing to address these key issues:
- Harmful byproducts formed when heating seed oils
- Unprecedented consumption of seed oils today
- Lack of robust RCTs supporting the safety of high seed oil intake
These articles attempt to create the impression of scientific consensus, yet they often lack substance and fail to address the concerns raised by high-quality, independent research.
Seed Oil Awareness Day: Rethinking Fat Starts Here
Seed Oil Awareness Day is about shining light on one of the biggest dietary changes in human history—and giving people the power to choose what oils they consume through education.
This isn’t about fear mongering. It’s about asking what kind of fat we want on our plates—and giving consumers that choice.
Seed Oil Awareness Day exists to:
- Expose the history of seed oils
- Understand the science of oxidation and PUFA overconsumption
- Promote transparency in our food system
- Empower people to make informed choices
It’s a call to examine what replaced traditional oils and fats in our food—and whether it’s truly better.
What You Can Do Today
🔍 Read labels. Look for seed oils under names like: soybean, sunflower, safflower, cottonseed, vegetable oil, canola, and corn oil, and of course, look for the Seed Oil Free Certified™ seal on qualifying food and consumer products.
🍳 Cook with traditional fats like extra virgin olive oil, ghee, tallow, butter, coconut oil, or avocado oil.
✅ Support brands that are certified free from seed oils:
👉 SeedOilFreeCertified.com/product-finder
📣 Spread the word with #SeedOilAwarenessDay
Let’s Bring Back Better Fats—for Good.
Disclaimer:
The information provided in this blog is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare provider before making any changes to your diet, health routine, or treatment plan.
The Seed Oil Free Alliance is the third-party certifying organization behind the world’s first Seed Oil Free Certified™ Seal. This certification guarantees that products are free from seed oils like soybean, corn, and canola—and have passed rigorous auditing and independent lab testing to verify the purity of added fats and oils. Supporting the Seed Oil Free Alliance in its mission to advance the availability of seed-oil-free food options through trust, transparency, and education is an advisory panel of public health and nutrition experts, led by Dr. Andrew Weil. More information can be found at seedoilfreecertified.com.
