By Christine Mallar
Every once in a while a customer comes into the store and asks about Canola Oil, as they have read a lot of scary things on the internet about it. Many sites online claim that Canola Oil “is a poisonous substance, an industrial oil that does not belong in the body. They claim that it contains “the infamous chemical warfare agent mustard gas,” hemagglutinins and toxic cyanide-containing glycocides; it causes mad cow disease, blindness, nervous disorders, clumping of blood cells and depression of the immune system”. This same information is copied and pasted to many sites, and though even organic Canola Oil is definitely not our favorite oil (especially when used exclusively in anyone’s diet), these are distortions that should be cleared up for those who are trying to educate themselves about nutrition. Of course, one of the major problems we have with Canola oil is it’s largely a GMO crop that can cross pollinate with other members of the brassica family (broccoli, cabbage, brussels, kale, mustard, etc) damaging these crops (especially organic crops which cannot contain GMO material) and the livelihood of the farmers that grow them. Our discussion here focuses on the safety of Canola oil in pet foods, not to advocate for or against it, just for the sake of objectivity we want to address the truths vs. the fear-mongering.
Canola Oil was created from an oil called Rapeseed, a member of the brassica family. About two-thirds of the mono-unsaturated fatty acids in rapeseed oil are erucic acid, a monounsaturated fatty acid that has been associated with fibrotic lesions of the heart. In the 70′s when the association between Rapeseed and heart damage came to light, Canadian plant breeders created a variety of this plant with oil that is very low in erucic acid which was originally named LEAR oil (Low Erucic Acid Rapeseed) and later renamed Canola Oil (named for Canadian Oil, as most of the rapeseed at the time was grown in Canada).
Although rapeseed is a member of the brassica or mustard family, it is NOT the source of mustard gas used in chemical warfare. Chemically, “Mustard gas” has absolutely no relationship to mustard oil or any other mustard plant. It received its name because of the yellowish color of the gas and the sulfur odor.
Hemagglutinins, substances that promote blood clotting and depress growth, are found in the protein portion of the seed, although traces may show up in the oil. And canola oil was not the cause of the mad cow epidemic in Britain, although feeding of canola oil may make cattle more susceptible to certain diseases.
As far as it being an “industrial oil that doesn’t belong in the body”: ¨Flax Oil and Walnut Oils can be made into varnish, but this doesn’t make them toxic.¨Mary G. Enig, Ph.D., Director Nutritional Sciences Division Enig Associates, Inc. says, “The statement suggesting that because it is used as an industrial oil it is therefore not edible is not valid. Flax oil is also used as an industrial oil for paint and linoleum, etc. But when it is prepared as a food it is edible. Most oils have been used at one time or another as industrial products. In my opinion, one of the most edible oils is coconut oil, which is used for many industrial products, especially for soaps and cosmetics. Olive oil apparently has been used to make soap for as long as it has been used as a food oil”.
The first published studies on the new oil were performed in 1978 at the Unilever research facility in the Netherlands. The industry was naturally interested to know whether the new LEAR oil (Canola) caused heart lesions in test animals. In earlier studies, animals fed high-erucic-acid rape seed oil showed growth retardation and undesirable changes in various organs, especially the heart, a discovery that touched off the so-called “erucic acid crisis” and spurred plant geneticists to develop new versions of the seed.
The results of the Canola study were mixed. Rats genetically selected to be prone to heart lesions developed more lesions on the canola oil and the flax oil, than those on olive oil or sunflower oil, leading researchers to speculate that the omega-3 fatty acids (not erucic acid) in Canola and flax oil might be the culprit (emphasis mine). But rats genetically selected to be resistant to heart lesions showed no significant difference between the four oils tested. Canola oil did not cause heart problems in mice, in contrast to high-erucic oil which induced severe cardiac necrosis.
In 1979, researchers at the Canadian Institute for Food Science and Technology pooled the results of 23 experiments involving rats at four independent laboratories. All looked at the effects of Canola and other oils on the incidence of heart lesions. They found that saturated fats were protective against heart lesions but that high levels of omega-3 fatty acids correlated with high levels of lesions.
In 1982, the same research group published a paper that looked at the interaction of saturated fats with Canola oil and soybean oil. When saturated fats in the form of cocoa butter were added to the diets, the rats in both groups had better growth and a significant lowering of heart lesions. Said the authors: “These results support the hypothesis that myocardial lesions in male rats are related to the balance of dietary fatty acids and not to cardiotoxic contaminants in the oils.”
These and several other studies all point in the same direction, that Canola Oil, when fed as the exclusive fat in a diet, has some negative effects on the heart, changes in growth rates, vitamin E deficiency (this is the case with any omega 3 oil such as fish oil – additional vit E must be supplemented), and negative changes in platelets. When saturated fats are added to the diet, the undesirable effects of canola oil are largely mitigated. Most interesting of all is the fact that many studies show that the problems with canola oil are not related to the content of erucic acid, but more with the high levels of omega-3 fatty acids and low levels of saturated fats.
Those very concerned with the presence of Canola in their pets’ food could supplement the diet with Coconut Oil, an extremely beneficial medium chain fatty acid. Pets can eat up to 1 tsp per 10 lbs of body weight, but start slowly with smaller amounts.
A more in depth discussion of this issue can be found at:
http://articles.mercola.com/sites/articles/archive/2002/08/14/con-ola1.aspx (Part one)
http://articles.mercola.com/sites/articles/archive/2002/08/17/con-ola2.aspx (part two)
Some of the text in this document (especially in the research section) was taken directly from these articles. Please see these articles for References citing the studies mentioned.