The Great Con-ola
By Sally Fallon and Mary G. Enig, PhD
Canola oil is "widely recognized as the healthiest salad and cooking oil available to consumers." It was developed through hybridization of rape seed. Rape seed oil is toxic because it contains significant amounts of a poisonous substance called erucic acid. 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. This is what the food industry says about canola oil.
Canola oil is a poisonous substance, an industrial oil that does not belong in the body. 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 is what detractors say about canola oil.
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?
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.
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 percent monounsaturated fatty acids (compared to about 70 percent 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, Canadian plant breeders came up with a variety of rapeseed that produced a monounsaturated oil low in 22-carbon erucic acid and high in 18-carbon oleic acid.
The new oil referred to as LEAR oil, for Low Erucic Acid Rapeseed, was slow to catch on in the US. In 1986, Cargill announced the sale of LEAR oil seed to US farmers and provided LEAR oil processing at its Riverside, North Dakota plant but prices dropped and farmers took a hit.
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. The animal studies carried out over the past twenty years suggest that when rapeseed oil is used in impoverished human diets, without adequately saturated fats from ghee, coconut oil or lard, then the deleterious effects are magnified.
In the context of healthy traditional diets that include saturated fats, rapeseed oil, and in particular erucic acid in rapeseed oil, does not pose a problem. In fact, erucic acid is helpful in the treatment of the wasting disease adrenoleukodystrophy and was the magic ingredient in Lorenzo's oil.
High levels of omega-3 fatty acids, present in unprocessed rapeseed oil, don't pose a problem either when the diet is high in saturates. A 1998 study indicates that diets with adequate saturated fats help the body convert omega-3 fatty acids into the long-chain versions EPA and DHA, which is what the body wants to do with most of the 18-carbon omega-3s.21 Conversion is reduced by 40-50 percent in diets lacking in saturated fats and high in omega-6 fatty acids from commercial vegetable oils (particularly soybean oil). In the animal studies on canola oil, dietary saturated fats mitigated the harmful effects of omega-3s.
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. Once again, a lack of saturates in the diet may explain the association, because the lungs can't work without adequate saturated fats.
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.
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. Although the Canadian government lists the trans content of canola at a minimal 0.2 percent, research at the University of Florida at Gainesville, found trans levels as high as 4.6 percent in commercial liquid oil. The consumer has no clue about the presence of trans fatty acids in canola oil because they are not listed on the label.
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.
THE MYTH OF MONOUNSATURATES
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.
But most of the omega-3s in canola oil are transformed into trans fats during the deodorization process; and research continues to prove that the saturates are necessary and highly protective.
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? Obviously monounsaturated fatty acids are not harmful in moderate amounts in the context of a traditional diet, but what about in the context of the modern diet, where the health-conscious community is relying on monounsaturated fats almost exclusively? 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.
Even the dogma that monounsaturated fatty acids are good for the heart is at risk. According to a 1998 report, mice fed a diet containing monounsaturated fats were more likely to develop atherosclerosis than mice fed a diet containing saturated fat. In fact, the mice fed monounsaturated fats were even more prone to heart disease than those fed polyunsaturated fatty acids.
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 - pay-ola for the food companies and con-ola for the public.
The above opinionated views and information serves to educated and informed consumer . The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. It should not replaced professional advise and consultation. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions
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