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French Fries Tallow Fries

French Fries are the Least Healthy Fast Food, But Not Tallow Fries

Fried Food Expert Warns Seed Oils Break Down into Potent Toxins

One of the most humble world-renown experts I’ve ever met might be Dr. Martin Grootveld,  Professor of Bioanalytical Chemistry and Chemical Pathology, author of over 200 journal articles, and holder of many prestigious awards and grants. Dr. Grootveld studies molecular fingerprints of toxins in our food supply, mostly toxins that form during cooking with seed oils. The technique he uses to conduct this research, proton nuclear magnetic resonance, enables him to identify toxins with long and short half-lives.

Counter to what you might think, catching the short-lived toxins is actually more important than catching the ones that live longer. The reason? Short-lived toxins disappear more quickly because they react with other molecules more quickly, which gives our bodies little time to metabolically deactivate them, making them more dangerous.

His research has shown that foods cooked with seed oils contain the very same toxins that you inhale while smoking cigarettes.

Cigarette smoking causes heart attacks by damaging arteries. The process is called atherosclerosis. Cigarette smoke contains several compounds known to cause atherosclerosis, called aldehydes, specifically acrolein, crotonaldehyde, butyraldehyde, hexanal, and malonaldehyde. Dr. Grootveld’s research has consistently shown that French fries, also contain these very same chemicals at high concentrations when the frying oil is high in polyunsaturates.

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The Trans Fat Ban Made Fries More Toxic

In 2004, with the publicity around trans fats, restaurants wanted to clean up their image a little bit. So in 2007, KFC and other chains started using seed oils in their fryers instead of hydrogenated oil, which was actually less toxic. Most fast food chains followed suit, including McDonald’s, in 2008. The official trans fat ban went into effect as of 2018 in the USA. And other countries did the same.

Seed oils used in most restaurant fryers around the world are now high in polyunsaturated fats, the kind that Dr. Grootveld says is the worst thing we could possibly use in a deep fryer.

It’s not just Dr. G. His findings have been repeated, replicated, and ratified by multiple other research laboratories worldwide, so it’s now accepted as truth.

hateful eight oils
Click Here to Learn How These Oils Make Us Fat

But remember the toxicologists’ axiom, the dose makes the poison.

Techniques for sniffing out toxins are now so good that we can find them in just about everything. In fact, one of the worst, acrolein, is universally present in cooked foods, including vegetables. So it’s important to know how much of these toxins you eat when you chow down a side of fries cooked in seed oil.

Dr. Grootveld explains that the answer changes depending on how many rounds of cooking the seed oil in the fryer endures. At first, there are fewer toxins. But after a few rounds of use, and keep in mind deep fryer oils are usually used for multiple rounds a day, for multiple days, the concentration of these toxins goes much higher.

How much higher?

Dr. Grootveld says enough that a 5-ounce serving of fries would exceed the WHO tolerable daily limit by a factor of 3. A dinner of fish and chips could easily exceed that limit 10 times or more. And keep in mind this is just one of the many kinds of toxins identified in fries cooked in seed oils, there are hundreds of others. Dr. Grootveld himself expresses a reserved form of outrage even in his scientific publications, demanding that previous scientific reports focusing on the beneficial health effects of seed oils “should be revisited.” I agree. Particularly since the authors of the pro-seed oil articles typically deny that important seed-oil-derived toxins exist.

Frying in seed oils generates toxic compounds
Frying in seed oils generates “highly significant amounts” of these “highly toxic” compounds. They’re not in the seeds you eat, so eating corn, soy and sunflower seeds is ok as long as they’re not prepared using seed oils. For more information about seed oil induced weight gain, you can watch my video presentation. 

The Smoking Habit You Didn’t Know You Had

It’s interesting that when we compare French fries to cigarettes, we find a convenient symmetry. Dr. Grootveld estimates the average five-ounce serving of fries “aldehyde contents are not dissimilar to those arising from the smoking of a (daily) allocation of 25 tobacco cigarettes.” Oddly enough a large order of McDonald’s fries contains 20-25 fries. So for each French fry you eat, you can imagine that you just smoked a single cigarette. If you cook at home using a seed oil for high-heat shallow pan frying, after 90 minutes your food contains identical toxins at similarly high concentrations.

The reason these oils hit us with such a serious toxicity problem is a matter of organic chemistry. These oils are high in polyunsaturated fatty acids. And polyunsaturated fatty acids (PUFA for short) and unstable. In chemist’s terms, “polyunsaturated fatty acids (PUFAs) are much more susceptible to thermally-induced oxidation” also known simply as ‘burning.’ It’s inescapable when you cook with unstable fatty acids. These PUFAs deteriorate without visible smoking, so the fact that they have a high smoke point is actually a detriment in this regard. Research shows foods cooked in this kind of oil “produce the highest levels of hazardous LOPs [shorthand for a variety of toxic compounds] during frying episodes, which repetitively escalate with the unfortunately common reuse of such frying media.” [quotes taken from this article]

When you go to the website dedicated to the Seven Countries Study, which is the ultimate source of information used to convince doctors that saturated fat is unhealthy, you won’t find much about the role of cigarettes. You will see plenty of statements asserting that cholesterol is the major cause of heart attacks. Click here to read the full article on what you’re doctor should know about cholesterol, but doesn’t.

Tallow Fries Are Way Healthier

Back in 1980, Mcdonalds’ fries were cooked in Tallow. Tallow comes from beef, so it’s full of saturated fat. Dr. Grootvelds says that the idea to swap out tallow and use seed oils instead has had incredibly harmful effects. He explains ” Contrastingly, saturated fatty acids (SFAs) are extremely resistant to peroxidation, and hence SFA-laden frying media such as coconut oil and animal fat (lard) generate little or no LOPs when exposed to authentic or laboratory-simulated high-temperature frying practices

Why is Seed Oil So Different From Tallow?

It’s just basic organic chemistry. Due to the fact that tallow is high in saturated fat and low in PUFA, it has fantastic thermal stability. You can heat tallow over and over, and the fatty acids just don’t break down. They’re inherently, structurally stable. You can see evidence of their stability in the fact that they are solid at room temperature. This is a reflection of their internal chemistry.

So if you want fries, but don’t want fried arteries, use tallow. There are a few restaurants that actually use tallow, and more popping up every day. You can also buy tallow and make your own. Recipe here.

Resource for finding restaurants that use healthy fats. (The OutBack Steakhouse is ON the list!)

With over two decades of clinical experience and expertise in genetic and biochemical research, Dr. Cate can help you to reverse metabolic disease and reshape your body.

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This Post Has 8 Comments

  1. This has to be an oversight:
    The tallow fries recipe calls for frying in peanut or canola oil!
    For the fries:
    5 pounds potatoes, Russet or Kennebec
    Peanut or canola oil, for frying
    Rendered beef fat
    Flakey sea salt
    Chili flakes
    Grated parmesan
    Chopped Italian parsley

    1. Thank you for bringing it up! I selected this recipe because it says peanut or canola, so just choose the peanut and skip the canola.

      The sad fact is so many recipes include a Hateful 8 we often need to substitute. There are easy substitutions we can learn to make and here is a lesson on that principle.

  2. Very interesting and scary. But doesn’t cigarette smoke damage the lungs mainly? Are the toxins just as harmful when ingested instead of inhaled? The article does not make it clear on this point.

    1. Cigarette smoke damages the lungs and it gets into your arteries, where it can cause atherosclerosis. It also promotes multiple cancers.
      Both seed oils and cigarettes are terrible.
      But seed oils are overall worse due to the fact that even when non-oxidized in the diet they can oxidize in your body.
      Good question. 🙂

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