Canola oil has a number
of undesirable health effects when used as the main source of dietary
fats, although these side effects can be offset by the intake of saturated
fats.
------------------------------------------------------------------------
Extracted from Nexus Magazine, Volume 9, Number 5 (Aug-Sept 2002)
This is what the food industry says about canola oil:
Canola oil is widely recognised as the healthiest salad and cooking
oil available to consumers. It was developed through hybridisation
of rapeseed. Rapeseed 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 detractors say 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", haemagglutinins and toxic cyanide-containing
glycosides; 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?
THE HIDDEN HISTORY OF CANOLA
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.1
The industry was in a bind. It could not continue using large amounts
of liquid polyunsaturated oils and make healthclaims 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&endash;heart
idea had popularised 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 Dr Claude Lenfant, head of
the NHLBI, and speakers included Dr Fred Mattson, who had spent many
years at Procter & Gamble, and the Dutch scientist Martijn 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 per cent monounsaturated fatty acids (compared
to about 70 per cent in olive oil). Unfortunately, about two-thirds
of the monounsaturated fatty acids in rapeseed oil are erucic acid,
a 22-carbon monounsaturated fatty acid that had been associated with
Keshan's disease, characterised 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 that was 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 oilseed to US farmers and provided LEAR oil processing at
its Riverside, North Dakota, plant, but prices dropped and farmers
took a hit.3
THE LOW-DOWN ON FATTY ACIDS
SATURATED FATTY ACIDS are chains of carbon atoms that have hydrogen
filling every bond. In foods, they normally range in length from four
to 22 carbons. Because of their straight configuration, saturated
fatty acids pack together easily and tend to be solid at room temperature.
Butter, tallow, suet, palm oil and coconut oil are classified as saturated
fats because they contain a preponderance of saturated fatty acids.
Saturated fats are stable and do not become rancid when subjected
to heat, as in cooking.
MONOUNSATURATED FATTY ACIDS are chains of carbon atoms that have one
double bond between two carbons and therefore lack two hydrogens.
Normally they range from 16 to 22 carbons. They have a kink or bend
at the position of the double bond, so the molecules do not pack together
as easily as in saturated fatty acids. Monounsaturated oils tend to
be liquid at room temperature but become solid when refrigerated.
Olive oil, peanut oil, lard, rapeseed and canola oils are classified
as monounsaturated oils. The most common monounsaturated fatty acids
are palmitoleic (16 carbons), oleic (18 carbons) and erucic (22 carbons).
Monounsaturated oils are relatively stable and can be used for cooking.
POLYUNSATURATED FATTY ACIDS have two or more double bonds. As there
is a bend or kink at each double bond, these fatty acids do not pack
together easily and tend to be liquid, even when cold. Polyunsaturated
oils are very fragile. They tend to develop harmful free radicals
when subjected to heat and oxygen, as in cooking or processing. Soybean
oil, safflower oil, sunflower oil and flax oil are polyunsaturated
oils. Omega-6 fatty acids have the first double-bond at the sixth
carbon from the end of the fatty acid chain. The most common omega-6
fatty acid is linoleic acid, which is called an essential fatty acid
(EFA) because your body cannot make it. Omega-3 fatty acids have the
first double bond at the third carbon. The most common omega-3 fatty
acid is the EFA alpha-linolenic acid. The consensus among lipid experts
is that the American diet is too high in omega-6 fatty acids (present
in high amounts in commercial vegetable oils) and lacking in omega-3
fatty acids (which are present in organ meats, wild fish, pasteurised
egg yolks, organic vegetables and flax oil). A surfeit of omega-6
fatty acids and deficiency in omega-3 fatty acids has been shown to
depress immune system function, contribute to weight gain and cause
inflammation.
MARKETING LEAR OIL
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 had never been 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.4 Just
how this was done has not been revealed, but GRAS status was granted
in 1985 - for which, it is rumoured, the Canadian government spent
US$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 per cent 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, HarperCollins engaged Dr Artemis Simopoulos to write a cookbook
featuring the health benefits of omega-3 fatty acids.5 Dr Simopoulos
is a paediatrician 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 industrialisation
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.6 The more natural eggs contained 20 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.7 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 she recommends lean meat and low-fat yoghurt
and milk as part of her regime.
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 United
States. 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 Fresh Fields 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.
SOYBEAN OIL VERSUS RAPESEED OIL IN INDIA
While canola oil is displacing soybean oil in many American processed
foods, soybean oil is displacing traditional rapeseed oil in India.
In her book Stolen Harvest, Indian author Dr Vandana Shiva describes
how American industrially processed soy oil replaced traditional seed
oils in a large part of India. Each region in India has its specific
edible oil used for cooking. In the North and East it is rapeseed
oil, in the West it is peanut oil, in the Deccan it is sesame and
in Kerala it is coconut.
In India, rapeseed or mustard oil was traditionally sold in small
quantities, extracted as needed with a small oil press or ghanis.
Oil processing provided employment for thousands of artisans and ensured
that the housewife had a fresh product. The oil cake was then fed
to cattle (with no apparent negative effects). Mustard oil also served
as mosquito repellent and as a nonpolluting oil in lamps.
Within a few months after the advent of "free trade" for
soybean oil into India, thousands of Indians fell ill with "dropsy"
due to a mysterious adulteration of rapeseed oil. The government banned
the sale of all unpackaged edible oils, thus ensuring an end to all
household and community-level oil processing. Edible oil production
became fully industrialised and local processing became a criminal
act. Thousands of workers were dispossessed of their livelihood and
millions of Indians were dispossessed of a healthy oil. Cheap, highly
processed soy oil immediately replaced rapeseed oil in the markets.
During the crisis, the US Soybean Association pushed for soybean imports
as the "solution". One business publication reported: "US
farmers need big new export markets. India is a perfect match."
Growth was achieved by theft of an important part of the small-scale
local economy.
REASONS TO BE CAUTIOUS ABOUT CANOLA
Reports on the dangers of rapeseed oil are rampant on the Internet,
mostly stemming from an article, "Blindness, Mad Cow Disease
and Canola Oil", by John Thomas, which appeared in Perceptions
magazine, March/April 1996. Some of the claims are ludicrous. Although
rape is a member of the Brassica or mustard family, it is not the
source of mustard gas used in chemical warfare.
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
flavour. These compounds are goitrogenic and must be neutralised by
cooking or fermentation.
As rapeseed meal was high in glycosides, it could not be used in large
amounts for animal feeding. However, plant breeders have been able
to breed out the glycosides as well as the erucic acid from canola
oil.8 The result is a low-glycoside meal that can be used as an animal
feed. In fact, canola meal for animal feed is an important Canadian
export.
Haemagglutinins - 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,9 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.
We 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 (http://www.professorscience.com)
chastises the publishers of these reports as spreading "hysterical
urban legends about bizarre diseases".10 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
favourite oil, which is now showing up in an increasing number of
products.
CANOLA OIL STUDIES
Says Professor 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 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.11 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
rapeseed 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 experimentsinvolving 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.12
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."13
Canadian researchers looked at LEAR oils again in 1997. They found
that piglets fed milk replacement containing canola oil showed signs
of vitamin E deficiency, even though the milk replacement contained
adequate amounts of vitamin E.14 Piglets fed soybean oil&endash;based
milk replacement, fortified with the same amount of vitamin E, did
not show an increased requirement for vitamin E.
Vitamin E protects cell membranes against free radical damage and
is vital to a healthy cardiovascular system. In a 1998 paper, the
same research group reported that piglets fed canola oil suffered
from a decrease in platelet count and an increase in platelet size.15
Bleeding time was longer in piglets fed both canola oil and rapeseed
oil. These changes were mitigated by the addition of saturated fatty
acids from either cocoa butter or coconut oil to the piglets' diet.
These results were confirmed in another study a year later. Canola
oil was found to suppress the normal developmental increase in platelet
count.16
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.17 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.19
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.
USE OF 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.20
The animal studies carried out over the past 20 years suggest that
when rapeseed oil is used in impoverished human diets, without adequate
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 - 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 to 50 per cent 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.22 Once again, a lack of saturates
in the diet may explain the association, because the lungs can't work
without adequate saturated fats.23
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.
GENETICALLY ENGINEERED/ MODIFIED CANOLA
The first seed oil to be created through genetic manipulation, canola
is also the focus of a variety of genetic engineering/modification
(GE/GM) 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 GE canola now comprises a large portion of the
total canola crop. Apologists point to endorsement by the FDA and
the American Dietetic Association that GE canola is nutritionally
and environmentally safe and claim that the GE variety means less
spraying of herbicides, less chemical runoff and a boon to farmers.
Percy Schmeiser, a third-generation Saskatchewan farmer, found out
the hard way that GE canola may not be a boon to farmers. Pollen from
Monsanto's patented GE canola seeds blew onto his land from neighbouring
farms; unlike grains, rape and canola plants spread their pollen on
the wind. Monsanto's "gene police" then invaded his farm
and took seed samples without his permission. Because Schmeiser did
not spray his crop with herbicides, a Canadian court ruled that he
had taken advantage of Monsanto's GE technology. Schmeiser was ordered
to pay $10,000 for licensing fees and up to $75,000 in profits from
his 1998 crop.
Meanwhile, 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 deodorised, 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&emdash;something
that does not exist in any traditional diet anywhere in the world.
(Source: Eric Peters, "Let them eat canola", Washington
Times, April 29, 2002)
TRADITIONAL AND MODERN OIL PROCESSING METHODS
Rapeseed has been used as a source of oil since ancient times because
it is easily extracted from the seed. Interestingly, the seeds were
cooked first before the oil was 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 deodorised. The standard deodorisation 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 per cent, research at the University of Florida at
Gainesville found trans levels as high as 4.6 per cent in commercial
liquid oil.24 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 per cent.25 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.26
THE MYTHS OF MONOUNSATURATES
Consumer acceptance of canola oil represents one in a series of victories
for the food processing industry, which hasas its goal the replacement
of all traditional foods with imitation foods made out of products
derived from corn, wheat, soybeans and oilseeds.
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 deodorisation 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 harmfulÉ 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.27 In one study, higher
monounsaturated fat consumption was associated with an increased risk
of breast cancer.28
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.29 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 recognise them for what they are:
payola for the food companies and "con-ola" for the public.
Endnotes:
1. Enig, M.G. and S.W. Fallon, "The Oiling of America",
http://www.westonaprice.org/oiling.htm. [See also NEXUS Magazine,
vol. 6, nos. 1 and 2.]
2. Downey, R.K., "Genetic Control of Fatty Acid Biosynthesis
in Rapeseed", Journal of the American Oil Chemists' Society,
1964;41:475-478.
3. Journal of the American Oil Chemists' Society, December 1986;63(12):1510.
4. "Canola &endash; a new oilseed from Canada", Journal
of the American Oil Chemists' Society, September 1981:723A-9A.
5. The amount of the advance was $350,000. Personal email communication,
Jo Robinson, co-author of The Omega Diet.
6. Simopoulos, A.P. and N. Salem, Jr, "Egg yolk as a source of
long-chain polyunsaturated fatty acids in infant feeding", American
Journal of Clinical Nutrition, 1992;55.
7. Simopoulos, A.P. and J. Robinson, The Omega Plan, HarperCollins
Publishers, New York, NY, 1998.
8. "Canola &endash; a new oilseed from Canada", op.
cit.
9. Purdey, M., "Educating Rita", Wise Traditions, Spring
2002;3(1):11-18.
10. When we contacted Dr Wolke to provide him with evidence of canola
dangers, he was dismissive.
11. Vles, R.O. and others, "Nutritional Evaluation of Low-Erucic-Acid
Rapeseed Oils", Toxicological Aspects of Food Safety, Archives
of Toxicology, Supplement 1, 1978:23-32.
12. Trenholm, H.L. and others, "An Evaluation of the Relationship
of Dietary Fatty Acids to Incidence of Myocardial Lesions in Male
Rats", Canadian Institute of Food Science Technology Journal,
October 1979;12(4):189-193.
13. Kramer, J.K.G. and others, "Reduction of Myocardial Necrosis
in Male Albino Rats by Manipulation of Dietary Fatty Acid Levels",
Lipids, 1982;17(5):372-382.
14. Sauer, F.D. and others, "Additional vitamin E required in
milk replacer diets that contain canola oil", Nutrition Research,
1997;17(2):259-269.
15. Kramer, J.K. and others, "Hematological and lipid changes
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