Is canola oil a healthy choice?

One of my Clients recently asked me if canola oil was a healthy oil to use, as it's often seen in recipes by celebrity chefs such as Hugh Fearnley-Whittingstall and is touted as being good for us due to the levels of Omega 3 which it contains.

On the surface, it seems like a healthy option for use on salads and in cooking, but the research on Canola oil is not so clear-cut.

The following article from the Weston-Price Foundation helps to shed some light on the issue...

Canola oil was developed through hybridization of rape seed. Rape seed oil is toxic because it contains significant amounts of a poisonous substance called erucic acid.

The food industry maintains that Canola oil contains only trace amounts of erucic acid and its unique fatty acid profile, rich in oleic acid and low in saturated fats, makes it particularly beneficial for the prevention of heart disease. It also contains significant amounts of omega-3 fatty acids, also shown to have health benefits.

Critics of Canola oil state that it is a poisonous substance, an industrial oil that does not belong in the body. It contains hemagglutinins and toxic cyanide-containing glycocides; in addition, it causes mad cow disease, blindness, nervous disorders, clumping of blood cells and depression of the immune system.

How is the consumer to sort out the conflicting claims about canola oil?

Is canola oil a dream come true or a deadly poison?

And why has canola captured so large a share of the oils used in processed foods?

Hidden History

Let’s start with some history. The time period is the mid-1980s and the food industry has a problem. In collusion with the American Heart Association, numerous government agencies and departments of nutrition at major universities, the industry had been promoting polyunsaturated oils as a heart-healthy alternative to “artery-clogging” saturated fats.

Unfortunately, it had become increasingly clear that polyunsaturated oils, particularly corn oil and soybean oil, cause numerous health problems, including and especially cancer.

The industry was in a bind. It could not continue using large amounts of liquid polyunsaturated oils and make health claims about them in the face of mounting evidence of their dangers. Nor could manufacturers return to using traditional healthy saturates–butter, lard, tallow, palm oil and coconut oil – without causing an uproar. Besides, these fats cost too much for the cut-throat profit margins in the industry.

The solution was to embrace the use of monounsaturated oils, such as olive oil. Studies had shown that olive oil has a “better” effect than polyunsaturated oils on cholesterol levels and other blood parameters. Besides, Ancel Keys and other promoters of the diet-heart idea had popularized the notion that the Mediterranean diet–rich in olive oil and conjuring up images of a carefree existence on sun-drenched islands – protected against heart disease and ensured a long and healthy life. (See The truth about saturated fat under my health articles).

The National Heart, Lung and Blood Institute (NHLBI) sponsored the First Colloquium on Monounsaturates in Philadelphia. The meeting was chaired by Scott Grundy, a prolific writer and apologist for the notion that cholesterol and animal fats cause heart disease. Representatives from the edible oil industry, including Unilever, were in attendance.

The Second Colloquium on Monounsaturates took place in Bethesda, Maryland, early in 1987. Dr. Grundy was joined by Claude Lenfant, head of the NHLBI, and speakers included Fred Mattson, who had spent many years at Proctor and Gamble, and the Dutch scientist Martign Katan, who would later publish research on the problems with trans fatty acids. It was at this time that articles extolling the virtues of olive oil began to appear in the popular press.

Promotion of olive oil, which had a long history of use, seemed more scientifically sound to the health-conscious consumer than the promotion of corn and soy oil, which could only be extracted with modern stainless steel presses. The problem for the industry was that there was not enough olive oil in the world to meet its needs. And, like butter and other traditional fats, olive oil was too expensive to use in most processed foods. The industry needed a less expensive monounsaturated oil.

Rapeseed oil was a monounsaturated oil that had been used extensively in many parts of the world, notably in China, Japan and India. It contains almost 60% monounsaturated fatty acids (compared to about 70% in olive oil).

Unfortunately, about two-thirds of the mono-unsaturated fatty acids in rapeseed oil are erucic acid, a 22-carbon monounsaturated fatty acid that had been associated with Keshan’s disease, characterized by fibrotic lesions of the heart. In the late 1970s, using a technique of genetic manipulation involving seed splitting, 2 Canadian plant breeders came up with a variety of rapeseed that produced a monounsaturated oil low in erucic acid and high in oleic acid.

The new oil referred to as LEAR oil, for Low Erucic Acid Rapeseed, was slow to catch on in the US.

Marketing LEAR

Before LEAR oil could be promoted as a healthy alternative to polyunsaturated oils, it needed a new name. Neither “rape” nor “lear” could be expected to invoke a healthy image for the new “Cinderella” crop.

In 1978, the industry settled on “canola,” for “Canadian oil,” since most of the new rapeseed at that time was grown in Canada. “Canola” also sounded like “can do” and “payola,” both positive phrases in marketing lingo. However, the new name did not come into widespread use until the early 1990s.

An initial challenge for the Canola Council of Canada was the fact that rapeseed was never given GRAS (Generally Recognized as Safe) status by the US Food and Drug Administration. A change in regulation would be necessary before canola could be marketed in the US. Just how this was done has not been revealed, but GRAS status was granted in 1985, for which, it is rumored, the Canadian government spent $50 million to obtain.

Since canola was aimed at the growing numbers of health-conscious consumers, rather than the junk food market, it required more subtle marketing techniques than television advertising. The industry had managed to manipulate the science to make a perfect match with canola oil–very low in saturated fat and rich in monounsaturates.

In addition, canola oil contains about 10% omega-3 fatty acids, the most recent discovery of establishment nutritionists. Most Americans are deficient in omega-3 fatty acids, which had been shown to be beneficial to the heart and immune system. The challenge was to market this dream-come-true fatty acid profile in a way that would appeal to educated consumers.

Canola oil began to appear in the recipes of cutting edge health books, such as those by Andrew Weil and Barry Sears. The technique was to extol the virtues of the Mediterranean diet and olive oil in the text, and then call for “olive oil or canola oil” in the recipes. One informant in the publishing industry told us that since the mid 1990s, major publishers would not accept cookbooks unless they included canola in the recipes.

In 1997, Harper Collins engaged Dr. Artemis Simopoulos to write a cookbook featuring the health benefits of omega-3 fatty acids. Dr. Simopoulos was a pediatrician who had served for nine years as chair of the Nutritional Coordinating Committee of the National Institutes of Health before becoming president of the Center for Genetics, Nutrition and Health.

She had published several papers on omega-3 fatty acids, calling attention to their disappearance from the food supply due to the industrialization of agriculture. Her most famous paper, published in 1992 in the American Journal of Clinical Nutrition, compared omega-3 levels in supermarket eggs from hens raised on corn with eggs from hens allowed to roam and eat a more varied diet. The more natural eggs contained twenty times more omega-3 than supermarket eggs.

Simopoulos’s The Omega Plan came out in 1998 and was reissued as The Omega Diet in 1999. The book discusses the virtues of monounsaturated and omega-3 fatty acids in the Mediterranean diet. Since unprocessed canola oil contains not only lots of monounsaturated fatty acids, but also a significant amount of omega-3, it shows up in most of the book’s recipes.

Simopoulos claims that the Mediterranean diet is low in saturated fat and recommends lean meat and lowfat yoghurt and milk as part of her regime. [N.B. when I studied Nutrition in college, I had several fellow students who came from the Med area who maintained that this is a completey false view of what Mediterraneans really eat...!!]

The canola industry’s approach – scientific conferences, promotion to upscale consumers through books like The Omega Diet and articles in the health section of newspapers and magazines–was successful. By the late 1990s, canola use had soared, and not just in the US. Today China, Japan, Europe, Mexico, Bangladesh and Pakistan all buy significant amounts.

Canola does well in arid environments such as Australia and the Canadian plains, where it has become a major cash crop. It is the oil of choice in gourmet and health food markets like Whole Foods markets, and shows up in many supermarket items as well. It is a commonly used oil in sterol-containing margarines and spreads recommended for cholesterol lowering. Use of hydrogenated canola oil for frying is increasing, especially in restaurants.

Dangers overstated?

Glycosides or glycosinolates (compounds that produce sugars on hydrolysis) are found in most members of the brassica family, including broccoli, kale, cabbage and mustard greens. They contain sulphur (not arsenic), which is what gives mustard and cruciferous vegetables their pungent flavor. These compounds are goitrogenic and must be neutralized by cooking or fermentation.

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.

Like all fats and oils, rapeseed oil has industrial uses. It can be used as an insecticide, a lubricant, a fuel and in soap, synthetic rubber and ink. Like flax oil and walnut oil, it can be used to make varnish. Traditional fats like coconut oil, olive oil and tallow also have industrial uses, but that does not make them dangerous for human consumption.

The Weston Price Foundation have had reports of allergies to canola, and internet articles describe a variety of symptoms – tremors, shaking, palsy, lack of coordination, slurred speech, memory problems, blurred vision, problems with urination, numbness and tingling in the extremities, and heart arrhythmias that cleared up on discontinuance of canola.

None of this has been reported in the medical journals, however. Writing for the Washington Post, Professor Robert L. Wolke (www. professorscience.net) chastises the publishers of these reports as spreading “hysterical urban legends about bizarre diseases. The industry actually profits from such wild claims, because they are wrong and easily dismissed.

Nevertheless, consumers do have reason to be cautious about the establishment’s favorite oil, now showing up in an increasing number of products.

The Studies

Says Wolke: “I found no research studies indicating that today’s low-erucic-acid canola oil, as distinguished from ordinary rapeseed oil, is harmful to humans.” That’s because, even though canola oil now has Generally Recognized as Safe (GRAS) status, no long-term studies on humans have been done.

Animal studies on Low Erucic Acid Rapeseed oil were performed when the oil was first developed and have continued to the present. The results challenge not only the health claims made for canola oil, but also the theoretical underpinnings of the diet-heart hypothesis.

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 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 LEAR study were mixed. Rats genetically selected to be prone to heart lesions developed more lesions on the LEAR 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 LEAR and flax oil might be the culprit.

But rats genetically selected to be resistant to heart lesions showed no significant difference between the four oils tested and LEAR 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 LEAR and other oils on the incidence of heart lesions. They found that saturated fats (palmitic and stearic acids) were protective against heart lesions but that high levels of omega-3 fatty acids correlated with high levels of lesions. They found a lesser correlation with heart lesions and erucic acid.

In 1982, the same research group published a paper that looked at the interaction of saturated fats with LEAR 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.”

Finally, studies carried out at the Health Research and Toxicology Research Divisions in Ottawa, Canada discovered that rats bred to have high blood pressure and proneness to stroke had shortened life-spans when fed canola oil as the sole source of fat. The results of a later study suggested that the culprit was the sterol compounds in the oil, which “make the cell membrane more rigid” and contribute to the shortened life-span of the animals.18

These studies all point in the same direction–that canola oil is definitely not healthy for the cardiovascular system. Like rapeseed oil, its predecessor, canola oil is associated with fibrotic lesions of the heart. It also causes vitamin E deficiency, undesirable changes in the blood platelets and shortened life-span in stroke-prone rats when it was the only oil in the animals’ diet.

Furthermore, it seems to retard growth, which is why the FDA does not allow the use of canola oil in infant formula. When saturated fats are added to the diet, the undesirable effects of canola oil are 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.

Rapeseed oil in traditional diets

Rapeseed oil has been used in China, Japan and India for thousands of years. In areas where there is a selenium deficiency, use of rapeseed oil has been associated with a high incidence of fibrotic lesions of the heart, called Keshan’s disease.

A 1995 Wall Street Journal article reported that use of rapeseed oil in cooking was associated with greatly increased rates of lung cancer in the women breathing the fumes.  In India, rapeseed oil has been used as a cooking oil for thousands of years, but only recently have Indian housewives been cajoled into the belief that saturated butter and ghee should be avoided. Many now use vanispati, an imitation ghee made of partially hydrogenated soybean oil.

Processing

Rapeseed has been used as a source of oil since ancient times because it is easily extracted from the seed. Interestingly, the seeds were first cooked before the oil is extracted. In China and India, rapeseed oil was provided by thousands of peddlers operating small stone presses that press out the oil at low temperatures. What the merchant then sells to the housewife is absolutely fresh.

Modern oil processing is a different thing entirely. The oil is removed by a combination of high temperature mechanical pressing and solvent extraction. Traces of the solvent (usually hexane) remain in the oil, even after considerable refining. Like all modern vegetable oils, canola oil goes through the process of caustic refining, bleaching and degumming – all of which involve high temperatures or chemicals of questionable safety.

And because canola oil is high in omega-3 fatty acids, which easily become rancid and foul-smelling when subjected to oxygen and high temperatures, it must be deodorized. The standard deodorization process removes a large portion of the omega-3 fatty acids by turning them into trans fatty acids.

A large portion of canola oil used in processed food has been hardened through the hydrogenation process, which introduces levels of trans fatty acids into the final product as high as 40 percent. In fact, canola oil hydrogenates beautifully, better than corn oil or soybean oil, because modern hydrogenation methods hydrogenate omega-3 fatty acids preferentially and canola oil is very high in omega-3s. Higher levels of trans mean longer shelf life for processed foods, a crisper texture in cookies and crackers–and more dangers of chronic disease for the consumer.

Consumer acceptance of canola oil represents one in a series of victories for the food processing industry, which has as its goal the replacement of all traditional foods with imitation foods made out of products derived from corn, wheat, soybeans and oil seeds. Canola oil came to the rescue when the promotion of polyunsaturated corn and soybean oils had become more and more untenable. Scientists could endorse canola oil in good conscience because it was a “heart-healthy” oil, low in saturated fat, high in monounsaturates and a good source of omega-3 fatty acids.

At least it can be said that canola oil is a good source of monounsaturated fat–like olive oil–and therefore not harmful. . . Or is it? 

There are indications that monounsaturated fats in excess and as the major type of fat can be a problem. Overabundance of oleic acid (the type of monounsaturated fatty acid in olive and canola oil) creates imbalances on the cellular level that can inhibit prostaglandin production. In one study, higher monounsaturated fat consumption was associated with an increased risk of breast cancer.

This means that the type of diet recommended in books like The Omega Diet–low in protective saturates, bolstered with high levels of omega-3 fatty acids and relying on monounsaturated fatty acids, whether from olive or canola oil, for the majority of fat calories–may actually contribute to heart disease. Such diets have been presented with great marketing finesse, but we need to recognize them for what they are–payola for the food companies and con-ola for the public.

Genetically modified rapeseed

The first seed oil to be created through genetic manipulation, canola is also the focus of a variety of genetic engineering (GMO) projects in which genetic material from other species is inserted into the seeds in order to magnify certain traits in the resultant plant.

Herbicide-resistant GMO canola now comprises a large portion of the total canola crop. Apologists point to endorsement by the FDA and the American Dietetic Association that GMO canola is nutritionally and environmentally safe and claim that the GMO variety means less spraying of herbicides, less chemical runoff and a boon to farmers.

Genetic engineers are involved in projects to make canola oil “even more nutritious,” by further reducing the amount of saturates in the fatty acid profile and raising the levels of monounsaturates. This, they claim, will make it possible to reduce the amount of trans fats in the processed oil, presumably because levels of omega-3 fatty acids, which need to be deodorized, will also be lowered. Should the genetic engineers be successful, it might be possible to create a diet in which the vast majority of fatty acids is monounsaturated, something that does not exist in any traditional diet anywhere in the world.

For references and the original article which appeared in the 2002 issue of Wise Traditions in Food, Farming and the Healing Arts, the quarterly magazine of the Weston A. Price Foundation please see:

http://www.westonaprice.org/health-topics/the-great-con-ola/