Are Vegetable and Seed Oils “Toxic”?!

From TikTok trends to bestselling publications, vegetable oils—also known as “seed oils”—are a hot topic these days. To be fair, discussions around the benefits of vegetable oils have been ongoing since their debut in the market.

More recently, with the rise of the carnivore diet, the backlash against vegetable oils has surged on social media. Perhaps you’ve seen posts describing these cooking oils as “toxic sludge,” “motor oil,” “the hateful eight,” and “the leading cause of chronic disease that remains unrecognized.”

The argument against vegetable oils generally follows this line of reasoning…

Animal fats have been a staple for humans for millennia. In contrast, vegetable fats emerged in the last century when profit-driven companies sought a way to market cheap-to-produce foods to unsuspecting buyers.

Another point raised: Much like margarine, vegetable oils were promoted as healthier substitutes for butter, yet critics claim these oils pose a worse risk than butter, increasing susceptibility to obesity, anxiety, depression, ulcerative colitis, and other issues.

Conversely, other professionals argue that vegetable oils are not harmful and may even offer health benefits—and are definitely preferable to butter.

So, who is correct?

Like numerous nutrition discussions, the reality is too complex to be condensed into a meme.

In this article, we’ll assist you in distinguishing scientific facts from pseudoscientific claims so you can make knowledgeable choices about the oils you decide to incorporate into your diet.

What Are Vegetable Oils?

Often referred to as “seed oils,” vegetable oils originate, as you might guess, from plant seeds. The most prevalent varieties you’ll encounter in a standard grocery store include:

• Canola oil
• Corn oil
• Safflower oil
• Sesame oil
• Sunflower oil
• Soybean oil
• Grapeseed oil

By the way, if you believe there are several oils absent from that list, it’s likely due to those oils being sourced from non-seed plants (like olive, avocado, palm, or coconut oil, which all derive from fruits and aren’t classified as vegetable or seed oils).

How Are Vegetable Oils Processed?

Non-vegetable oils—such as olive and avocado oil—come from naturally fatty foods. In fact, olives are so rich in oil that you could theoretically produce your own olive oil at home. (Simply search for “how to make olive oil from scratch,” and you’ll discover numerous videos detailing the process.)

Most vegetable oils, however, cannot be compared, as they primarily originate from foods with a relatively low fat content to start with.

For instance: A cup of green olives contains approximately 20 grams of fat, while a cup of corn contains just 2 grams.

Consequently, manufacturers have to engage in an elaborate multi-step procedure to extract this minimal amount of oil from these low-fat foods. The steps include:

• Crushing: A machine exerts high pressure to extract oil from the seeds.
• Refining: The seeds are heated with a solvent, like hexane, to pull out more oil.
• Deodorizing: To achieve a neutral flavor and eliminate undesirable compounds, the extracted oil is then heated at 400 F (204 C) for several hours.

During this process, beneficial polyphenols and other stabilizing nutrients are diminished, and small amounts of unsaturated fats are converted into trans fatty acids (also known as partially hydrogenated fat).

(Interesting tidbit: This transformation also occurs during deep frying. When vegetable oils are heated in a restaurant fryer for extended periods, the trans fat level of the oil rises.)

Labeling these processed oils as “toxic” might be an overstatement. However, nutrition scientists largely concur that trans fats should be limited in our diets, and in 2018, the Food and Drug Administration prohibited manufacturers from adding trans fats to processed foods.

What Cooking Oils Should You Eat?

At PN, we’ve