Historically, rapeseed oil was used as a heating, lighting, and lubrication oil. In fact, Canadian rapeseed production grew out of the critical shortage of rapeseed oil that followed the World War II blockade of European and Asian sources in the early 1940’s. The oil was urgently needed as a lubricant for the rapidly increasing number of marine engines in naval and merchant ships. Rapeseed oil was not a food.
Rapeseed oil was not widely consumed because 30 to 60% of its fats are in the form of erucic acid. Erucic acid is a toxin that causes myocardial lipidosis (fatty degeneration of the heart) and damages the heart muscle in animals. As a result, the government monitors and limits the erucic acid content in our food. In the 1970s, using a variety of hybridizing techniques, researchers created a variety of rapeseed with a low erucic acid content. This variety, canola oil, was brought to market as a very healthy oil choice because it has a good omega 6:3 ratio. Very quickly, the “health food community” adopted canola as the oil of choice.
As a result, today – even though the erucic content of canola is minimal – many are eating significant amounts of canola. In New Zealand, the No Observable Effect Level (NOEL) set for erucic acid is about 500 mg for an average adult. The estimated average intake of erucic acid was estimated to be about 25% of the NOEL and, given the lack of proof of harm in humans, the high safety margins in setting NOELs, and the average amount of erucic acid consumed, New Zealand views canola as very safe. The U.S. estimates that if 50% of the oils consumed were canola containing the highest allowed amount of erucic acid (2%; most oils tested contain much, much less), an adult will get 600 mg of erucic acid per day. This means that a person consuming canola frequently does have the potential of reaching or exceeding the NOEL safety limits.
On the TQI Diet, our goal is to eat foods that are good for us. While canola oil in the amounts generally consumed may or may not cause damage, there is absolutely no evidence that erucic acid is good for us. As a result, the TQI Diet recommends avoiding canola. One of PCC’s nutritionists takes the opposite position: “When shoppers tell me that canola contains a toxin called erucic acid, I always reply that today’s canola contains less than 2 percent of this controversial fatty acid that also is found in kale and broccoli — so it can’t be that bad for you!”
First off, there is absolute agreement that erucic acid is a toxin. That is why the government monitors and limits the amount of erucic acid present in our food. Second, neither kale leaves nor broccoli flowers contain erucic acid. All members of the mustard family produce some erucic acid in their seeds. However, they do not produce erucic acid throughout the plant. One study compared the erucic acid content in broccoli flowers, sprouts, and seeds. To reach the NOEL limit for erucic acid, a person would have to eat about 150 pounds of broccoli flowers per day.(Fn.1.) In another study, kale leaves were found not to have detectable levels of erucic acid. So, it simply does not follow that because broccoli and kale are good for you, erucic acid is as well.
And there are additional reasons to limit canola oil in your diet:
Today, most canola oil on the market is genetically modified to be herbicide resistant. This raises the potential that modifying the plant may change how it expresses its gene for erucic acid in unpredictable ways. This problem seemingly can be avoided by only using either organic or Non-GMO Project Verified. However, this unfortunately does not really work: Some of the varieties of canola today are herbicide resistant not through genetic modification but through the use of mutagenesis: These herbicide tolerant varieties are not classified as genetically modified.
The food industry is well aware that consumers are trying to avoid foods with manipulated genes. Increasingly, the industry is turning to techniques that alter the genes of the plant but that can pass a non-GMO project verification. To do this, they sterilize plants with toxic chemicals, insert desired genes from soil bacteria, and then restore the fertility of the plant. While this technique does involve genetic modification, the ultimate plant comes from “naturally” bred parent and as a result is not considered GM.(Fn. 2.) However, this is not the type of food most consumers opposed to genetic modification want to be eating.
A great deal of the commercial grade canola oil on the market is hexane extracted, bleached with clay, and deodorized at high temperatures that likely damages or destroys the omega-3 fats in the oil. The damage done to omega-3 fats in production is then aggravated by the fact that many varieties of canola have been hybridized to produce very low amounts of omega-3 fats. Of course, most of canola’s health benefits are because it purportedly is rich in omega-3 fats. However, given how it is grown and processed we may well not be getting much in the way of omega-3 fats from the canola oils we are eating.
My conclusion: Olive oil has a long history of use by humans. There are fabulous, well-made olive oils available to us. There are hundreds of studies showing that olive oil has positive health effects. So, given the checkered and questionable history of canola, I strongly urge people to make olive oil their primary dietary fat and to avoid canola oil as much as possible.
Fn.1 Broccoli sprouts and seeds (and presumably kale seeds) do provide significant amounts of erucic acid. Three ounces of broccoli sprouts provide about 320 mg of erucic acid, so it might be wise to avoid sprouting seeds from plants in the mustard family. Three ounces of broccoli seeds contain over 12,000 mg of erucic acid – likely the reason that we do not use broccoli seed oil.
Fn.2 Although not considered GM, in some systems these modified plants are classified as “plants with novel traits.”
P.S. Most of the information in this blog comes from publications of the Canola Council.
Photo: “Rapeseed field” by Skånska Matupplevelser
NOTE: You are welcome to use my blog’s original images and content for non-commercial purposes but only if if you attribute the work to me (Kathy Abascal) and link back to the blog. This work is licensed under a Creative Commons Attribution-Noncommercial 3.0 United States License.
TQIDiet 
How is modifying a plant to add soil bacteria genes “not considered GM”? Who is claiming this?
If the process stopped at the point of adding soil bacteria genes to a plant, that would be considered genetic modification. However, when they restore fertility to a modified plant and that plant goes on to “naturally” produce offspring, that is not considered modification. Tricky stuff, isn’t it, but quite common. There is more on this in the blog on high oleic oils
Thinking about this, I need to look into whether this technique actually would pass the GM verification process, so more to follow on that. According to the Canola Association, it is not classified as genetically modified in countries that require labeling – and I would assume they know.
I contacted the GM project for more information on whether canola modified in this manner might be certified as non-GM or not:
The initial response from the GM verification representative was ” Mutagenesis as a technology for creating new plant varieties is currently being reviewed by our Standard Committee. Pending recommendation from the committee, we are not advancing the verification process for any products with ingredients that come from plants grown from mutagenically altered seeds.”
While this sounds as if mutagentic products cannot be verified, the language troubled me so I wrote back: “If you are “not advancing the verification process” for mutagenic products, does that mean that they cannot be certified?
How do you know that any given canola oil submitted for certification is or is not derived from a mutagenic ancestor plant?
Do you have the capacity to detect herbicide resistant genes in products submitted to you? Do you employ methods that will?”
I sent this message three times to the GM project. It was neither acknowledged nor answered.
I then sent the message to the Regional Office of Whole Foods (WF uses the GM verification) hoping they could get more detailed information for us. The message was neither acknowledged nor answered.
To me this means that the GM verification project is not able to unequivocally avoid certifying plants. So even if organic or GM verified, I will avoid canola as I am not confident that these certifications preclude that the oil has soil genes in it.
Thank you for this research, Kathy. Good advice.
I am so confused about broccoli, broccoli sprouts, and mustard. How much of the bad erucic acid is in each?
The good in broccoli will far outweigh the small amount of erucic acid it contains. Broccoli sprouts have a bit more, but not a lot, and tend to be consumed in small amounts so they are fine as well. Broccoli seeds and oils made from them should be avoided: “The erucic acid content of broccoli florets, sprouts, and seeds was found to be about 0.8, 320, and 12100 mg/100 g, respectively. Using the erucic acid limit established for canola oil in the U.S.A. and Canada as a guideline, the estimated dietary intake of erucic acid from florets and sprouts was considered of little consequence, whereas in seeds a relatively small amount (about 35 g/wk) equaled our calculated exposure limit for erucic acid.”
It is much harder to get reliable information on prepared mustard but it is certain that mustard oil contains too much erucic acid. As for prepared yellow mustard, one study found 4 grams of erucic acid in about 350 grams (1000mg/100g), more than in broccoli sprouts but less than in broccoli seeds, so being moderate with your intake of mustard makes sense, although on occasion antioxidants etc. in the mustard may counterbalance. And, of course, make sure your mustard is not made with canola or other oil adding yet more erucic acid.
Kathy, Thank you for this valuable information. Georgia Day
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While I agree canola is not a desirable oil for several of the reasons mentioned in the article (GMO, pressing technique), I do not agree that Erucic acid is one of these reasons. My main reason for being hesitant to vilify erucic acid is because diets of people in China and India are high in mustard oils (which contain high levels of erucic acid). These diets following eating traditions that trace back thousands of years, without any evidence of the heart problems you describe that appeared in trials with animals. I believe there were several studies post 1970 era that proved rats (subjects of the studies on erucic acid back in the 70’s) do not metabolize fats and oils very well, thus were the primary reason for the heart issues. Udo Erasmus has a chapter in his book dedicated to this topic, “Fats that Heal, Fats that Kill,” that is very informative. Also, there appear to be beneficial effects of erucic acid that are not mentioned in the article – see Lorenzo’s Oil, which contains 20 % erucic acid. .
The fact that some diets include oils high in erucic acid does not prove that this toxin is healthful. That would take exhaustive research that simply has not been done. The point being made is that we have EVOO that is far healthier and would do well to avoid the heavily manipulated increasingly engineered canola now present in most processed foods. The fact that erucic acid may be beneficial in a particular illness is irrelevant here: There are many toxins used medicinally, none of which you would want to be part of your daily diet.
and how do we know which olive oils are really virgin and are a good olive oil?
Best way: Read my latest post on choosing a good olive oil: https://tqidiet.wordpress.com/2016/01/18/choosing-the-right-olive-oil/#more-481 Kathy