Canola is a "double-low" variety
of the rapeseed plant (Brassica napus or Brassica campestris) that was developed
by traditional plant breeding methods in the 1970's. Compared to rapeseed, canola
seed contains a reduced content of two undesirable constituents, erucic acid
Canola oil is extracted from the
seed of the canola plant. It is widely used in salad dressings, margarines and
shortenings and is also suitable for cooking and baking at temperatures below
360oF. The canola seed meal that remains after oil extraction is used in animal
feed, but is not used for human consumption.
Canola oil is very inexpensive compared
to most other vegetable oils. As a cooking oil, it is much cheaper than olive
oil and peanut oil and similar in price to soybean and corn oil. Canola oil
is also much cheaper than other ALA-rich oils like flaxseed and hempseed oil.
Canola is an excellent source of
monounsaturated fat, containing almost as much as olive oil. Monounsaturated
fat is considered beneficial when consumed in the recommended amounts (10-15
% of total calories).
Essential Fatty Acids
Canola oil is a good source of the
polyunsaturated fatty acids linoleic acid (LA, omega-6) and the polyunsaturated
fatty acid alpha-linolenic acid (ALA, omega-3). Polyunsaturated
fatty acids are considered beneficial when consumed in the recommended amounts
(8-10 % of total calories). Unlike saturated and monounsaturated fatty acids,
polyunsaturated fatty acids cannot be produced by the body and must therefore
be acquired from the diet. For this reason, polyunsaturated fatty acids are
also known as essential fatty acids.
Low in Saturated Fat
Canola oil is very low in saturated
fat, which is considered harmful. It is recommended that no more than 10 % of
total calories be acquired from saturated fat.
Canola is a good source of vitamin
E. One tablespoon of canola oil provides approximately 2.9 mg of vitamin E,
which is equivalent to approximately 1/5 of the recommended daily intake.
Canola oil is a good source of phytosterols.
Phytosterols are structural analogs of the cholesterol found in animals and
humans. They are considered beneficial as they interfere with cholesterol metabolism.
Fatty Acid Content of Canola
% of Total Fatty Acids
Amount (g) / Tablespoon*
* 1 tablespoon = 14 g
Canola oil has been shown to reduce
cholesterol levels and inhibit platelet aggregation and may therefore help prevent
cardiovascular disease. Canola oil has also been shown to protect against cardiac
arrhythmias in animal studies. Cardiac arrhythmia refers to a loss of heartbeat
rhythm, which may result in sudden death.
Other Areas of Research
Preliminary studies have demonstrated
that animals fed canola oil gained less weight than animals fed beef fat, suggesting
that canola oil may be a good source of fat for weight-reducing diets. Further
research is necessary to investigate whether canola oil may promote weight loss
Omega-3 fatty acids have been shown
to provide benefits in a number of cardiovascular, immune/inflammatory and neurological
disorders and have also been investigated as potential anti-cancer agents. Some
of the ALA that is consumed in the diet is converted
in the body to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the
two long chain omega-3 fatty acids that are abundant in fish oil. Although fish
oils have been shown be beneficial in the treatment and prevention of several
diseases, it is still unclear whether or not ALA-containing foods provide equal
High monounsaturated fat diets may
be beneficial for controlling glucose levels in people with diabetes.
Safety and Side Effects
Traditional rapeseed is believed
to be unsuitable for human consumption due to its high content of erucic acid.
Erucic acid is a long chain monounsaturated fatty acid that has been shown to
cause heart damage in experimental animals. Whereas traditional rapeseed oil
contains 20-55 % erucic acid, canola oil contains less than 2 % erucic acid
and is therefore considered safe.
When consumed in normal amount with
food, canola oil does not cause any side effects. If large amounts are consumed
without food however, upset stomach and diarrhoea may occur.
Canola and Genetic Modification
Genetically Modified Canola
Canola was developed
from the rapeseed plant through traditional plant breeding methods, not by genetic
modification. In recent years however, several genetically modified canola varieties
have been developed and approved for sale in Canada
and the United States.
These canola varieties include herbicide resistant lines, lines displaying pollination
control systems (male sterility and fertility restoration) and a phytase-expressing
Genetically modified canola oil
is considered to be as safe as unmodified canola oil. Before a genetically modified
food can be produced and sold in Canada or the United States,
it must undergo a thorough environmental, livestock feed and food safety assessment.
It is mandatory that genetically
modified foods be labelled when the composition of the food is modified (eg.
high oleic/low linolenic acid canola oil) or when there are potential safety
concerns associated with its consumption (eg. allergenicity). It is not required
however, that foods derived from plants that were genetically modified to improve
agronomic characteristics, without affecting food composition (eg: herbicide
resistant plants) be labelled as genetically modified.