Warning: Vegetable Oils Unfit for Human Consumption

By Mallory Nowak, NTP
Estimated Reading Time: 6 minutes 30 seconds

Though most everything we consume is ‘Generally Recognized As Safe’ by the FDA, much of what modern humans eat is simply unfit for human consumption.

Industrial seed oils, more commonly and deceivingly referred to as vegetable oils, are one such substance. Most often, these oils are not derived from vegetables but from the seeds of plants we would otherwise not ingest. Canola, cottonseed, safflower, corn and soybean oils are amongst the most popular. With an abundance of time-honored, species-appropriate fats available to us, when and why did we develop a preference for these highly processed oils?

Researchers in the 1960’s and 1970’s were eager to find what was clogging American arteries in the nation’s latest epidemic: heart disease. Saturated fat—thick, dense and solid at room temperature—was a seemingly obvious suspect. Saturated fat was put in the hot seat and hastily named the villain. Hence, the introduction of “heart-healthy” vegetable oils ensued.  These seemingly new-and-improved oils were liquid at room temperature and contained essential fatty acids. They must be superior, right?! 

However, vegetable oils are not easily cold- or expeller-pressed the way olive, coconut and palm oils are. They are not a byproduct of rendered-down animal fats the way lard, tallow, or duck fat is. No—in order to extract oil from these plants and seeds, high heat, chemical solvents and industrial methods are often employed.

The problem is the “high heat, chemical solvents and industrial methods” bit. These vegetable oils consist primarily of polyunsaturated fatty acids, or PUFAs. One often overlooked property of PUFAs is that they are extremely fragile, making them prone to damage when exposed to heat, light and air. These volatile oils are not to be cooked with, but taken as a dietary supplement or used as an ingredient in cold applications such as salad dressings. This explains why quality PUFAs (such as hemp, flax and fish oils) are cold- or expeller-pressed, stored in tinted bottles and refrigerated.

Sadly, most vegetable oils are oxidized before even hitting the grocery store shelves. In fact, canola oil is so damaged that it must be deodorized to mask its rancid stench! Watch how canola oil is made here, taking note that this video is actually promoting canola oil. The blatant damage these fragile oils endure throughout their extensive processing is cause for concern, especially considering the average person’s intake. 

Luckily, there are safe alternatives for high-heat cooking: saturated fats. Compared to PUFAs, saturated fats are able to withstand significantly more heat, light and air. Prior to the demonization of saturated fats, cooking with lard or beef tallow was normal. In fact, beef tallow filled McDonalds’ deep fryers up until 1990! The vilification of saturated fats and subsequent endorsement of vegetable oils has greatly contributed to the modern health issues we are plagued with today. Let’s get specific.

Free Radical Damage

Damaged oils contain harmful free radicals—that’s right: those pesky, antioxidant-stealing antagonists responsible for premature aging, macular degeneration, cell damage and other forms of physiological decline. Trust me: our bodies have more important roles for antioxidants than the busy-work of scavenging free radicals from vegetable oils! 

We can counteract free radical damage by consuming antioxidant-rich foods or supplements. Antioxidants include Vitamins A, C, and E, carotenoids, zinc, selenium and glutathione. Foods high in antioxidants include dark leafy vegetables, berries, citrus fruits, nuts and seeds, eggs, liver, oysters and orange-hued fruits and vegetables. 


Omega-3 and omega-6 fatty acids have some opposing roles in the body, the former being anti-inflammatory and the latter being pro-inflammatory. Vegetable oils happen to be a potent source of omega-6s. While most experts consider a 1:1 ratio ideal, the average US citizen consumes a 1:20 ratio in favor of inflammatory omega-6s! This discrepancy is largely due to frequent consumption of vegetable oils. 

We can improve our omega-3:omega-6 fatty acid ratios by increasing our intake of omega-3s through foods and supplements (fatty fish, nuts and seeds, fish oil, flax seed oil and algae oil) while decreasing our intake of omega-6s (especially vegetable oils!). 

Gallbladder Issues & Nutrient Deficiencies

Bile, produced in the liver and stored in the gallbladder, ensures that we are able to digest fat and absorb fat-soluble nutrients. Healthy bile requires regular consumption of healthy fats. 

When replacing healthy fats with unrecognizable vegetable oils, bile can get old, thick and viscous. This is known as “biliary sludge” and it can lead to the formation of gallstones. In turn, the gallbladder can lose its ability to efficiently contract, resulting in biliary stasis and/or gallbladder attacks. Beyond painful gallbladder issues, insufficient bile and poor gallbladder function can lead to deficiencies in fat-soluble nutrients like CoQ10 and Vitamins A, D, E and K. 

One can improve the health of their bile by consuming healthy fats, adequate fiber, choleretics and cholagogues. Choleretics are foods which stimulate the production of bile and cholagogues are foods which stimulate the release of bile. These foods should be consumed cautiously by individuals with active gallbladder dysfunction. Individuals who have had their gallbladder removed may find supplemental ox bile to be a helpful digestive aid.

These cheap, toxic oils have replaced traditional fats in nearly every US kitchen, restaurant and ingredient list. In fact, they are so prevalent it is hard to find prepared foods without them! 

While it may seem intuitive to believe that solid fats clog arteries and that liquid fats do not, this is simply not the case. Human metabolism is much more complex than that! The misconception that saturated fats cause heart disease is based on unsubstantiated, poorly-constructed, popularized science. This misinformation made its way into the US Dietary Guidelines, the American Heart Association and nutrition education programs across the US.  

Fortunately, modern science is now disproving many of these mainstream theories. Unfortunately, it’s hard to rewrite the books. This means your healthcare providers and educators could still be endorsing harmful vegetable oils. 

The takeaway message? Bad science goes mainstream all the time! Prestigious entities share misinformation on a daily basis—not because they are malicious, but because they are misguided. It is important that we learn from quality science rather than popularized science. 

To receive a free chart I’ve created with appropriate cooking temperatures for various fats, please click here.

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