Template:Two other uses In agriculture, canola is a trademarked quality description of a group of cultivars of rapeseed variants from which low erucic acid rapeseed oil and low glucosinolate meal are obtained. Also known as "LEAR" oil (for Low Erucic Acid Rapeseed), Canola was initially bred in Canada by Keith Downey and Baldur Stefansson in the 1970s.
Once considered a specialty crop in Canada, canola has evolved into a major North American cash crop. Canada and the United States produce between 7 and 10 million metric tons (tonnes) of canola seed per year. Annual Canadian exports total 3 to 4 million metric tons of the seed, 700,000 metric tons of canola oil and 1 million metric tons of canola meal. The United States is a net consumer of canola oil. The major customers of canola seed are Japan, Mexico, China and Pakistan, while the bulk of canola oil and meal goes to the United States, with smaller amounts shipped to Taiwan, Mexico, China, and Europe. World production of rapeseed oil in the 2002–2003 season was about 14 million metric tons. 
Canola was developed through conventional plant breeding from rapeseed, an oilseed plant with roots in ancient civilization. The word "rape" in rapeseed comes from the Latin word "rapum," meaning turnip. Turnip, rutabaga, cabbage, Brussels sprouts, mustard and many other vegetables are related to the two canola species commonly grown: Brassica napus and Brassica rapa. The negative associations with the word "rape" in North America resulted in the more marketing-friendly name "Canola", but also to distinguish it from regular rapeseed oil, which has much higher erucic acid content.
Hundreds of years ago, Asians and Europeans used rapeseed oil in lamps. As time progressed, people employed it as a cooking oil and added it to foods. Its use was limited until the development of steam power, when machinists found rapeseed oil clung to water- and steam-washed metal surfaces better than other lubricants. World War II saw high demand for the oil as a lubricant for the rapidly increasing number of steam engines in naval and merchant ships. When the war blocked European and Asian sources of rapeseed oil, a critical shortage developed and Canada began to expand its limited rapeseed production.
After the war, demand declined sharply and farmers began to look for other uses for the plant and its products. Edible rapeseed oil extracts were first put on the market in 1956–1957, but these suffered from several unacceptable characteristics. Rapeseed oil had a distinctive taste and a disagreeable greenish colour due to the presence of chlorophyll. It also contained a high concentration of erucic acid. Experiments on animals have pointed to the possibility that erucic acid, consumed in large quantities, may cause heart damage, though Indian researchers have published findings that contradict these conclusions. Feed meal from the rapeseed plant was not particularly appealing to livestock, due to high levels of sharp-tasting compounds called glucosinolates.
Rapeseed had been grown in Canada (mainly Saskatchewan) since 1936 . Canadian plant breeders took up the challenge to improve the quality of the plant. In 1968, Dr. Baldur Stefansson of the University of Manitoba used selective breeding to develop a low erucic acid variety of rapeseed. In 1974 another variety was produced with both a low erucic acid content and a low level of glucosinolates; this was dubbed Canola, from Canadian Oil Low Acid.
A variety developed in 1998 is considered to be the most disease- and drought-resistant variety of Canola to date. Recent varieties such as this have been produced by gene splicing techniques.
Canola could emerge as a crop in Central Oregon. An Oregon State University researcher has determined that growing winter canola for hybrid seed now appears possible. Canola is the highest producing oil-seed crop, but the state prohibits it from being grown in Deschutes, Jefferson and Crook counties because it may attract bees away from specialty seed crops such as carrots which require bees for pollination.
Canola oil has been touted as a healthy oil due to its low saturated fat and high monounsaturated oil content—the latter almost 60%—and beneficial omega-3 fatty acids profile. The Canola Council of Canada states it is completely safe and is the healthiest of all commonly used cooking oils. Traditional rapeseed oil contains higher amounts of erucic acid and glucosinolates, both of which were deemed undesirable for human consumption by the United States Food and Drug Administration (FDA). Erucic acid is implicated with cancer and rancidity and glucosinolates are goitrogenic. Canola oil reduces them to very low levels—0.5 to 1% for erucic acid—which is below the 2 percent limit set by the USDA. 
For many years, rapeseed oil was used for human consumption in Canada. Although the undesirable effects of glucosinolates and erucic acid were known, they were deemed an acceptable risk versus the many health benefits of rapeseed oil. Nonetheless, researchers attempted and were able to develop fully "double-zero" varieties by the 1980s without significant levels of those two compounds.
Nonetheless, the oil generated controversy. In March 1996 John Thomas published an article, "Blindness, Mad Cow Disease and Canola Oil", in Perceptions magazine, implicating Canola oil with glaucoma and the Mad Cow Disease.  This article was taken up, condensed and widely circulated in a story via emails. The industry and many health professionals condemn this as an email hoax and condemn its claims as being wholly unsubstantiated.
In Nexus Magazine, Volume 9, Number 5 (Aug–Sept 2002), contrarian dietitians Sally Fallon and Mary G. Enig, published an article, called "The Great Con-ola", questioning the industry's marketing claims, stating that Canola oil 'has a number of undesirable health effects when used as the main source of dietary fats'. Their article cites independent studies done from the late 1970s to 1990s, which show animals fed on a pure Canola oil-based diet suffer from vitamin E deficiency, a decrease in blood platelet count, an increase in platelet size, and shortened life-spans.
The authors state "Furthermore, it seems to retard growth, which is why the FDA does not allow the use of canola oil in infant formula" with terse citation to Federal Register 1985. However, an article from The Journal of Nutrition explains this same citation differently: "The use of canola oil in infant formulas is not permitted because infants fed formula might consume higher amounts of 22:1(n-9) than would be provided in usual mixed diets and because of the lack of data about infants fed diets containing canola oil.". The "22:1(n-9)" mentioned by the FDA here is another name for euric acid. So although levels below the 2 percent limit set by the USDA in Canola are permitted in the diet of adults the FDA does not permit these amounts in an infants diet.
The authors state that omega-3s in canola oil are transformed into trans fats during the deodorisation process, citing a single University of Florida study published in 1994 which found trans fat content to be as high as 4.6% in a sample of soy and canola oils purchased in the U.S. 
- Today about 75% of the Canola crops planted in Alberta, Manitoba, and Saskatchewan are GM (genetically modified food) herbicide-tolerant varieties.
- "Canola oil (19 grams – about 1 ½ tablespoons per day) may reduce the risk of coronary heart disease due to its unsaturated fat content, according to supportive but not conclusive research. Canola oil should replace a similar amount of saturated fat in the diet without increasing calories." 
- Canola oil is a promising source for manufacturing biodiesel, a renewable alternative to fossil fuels.
- The main price-discovery mechanism for worldwide canola trade is the Winnipeg Commodity Exchange canola futures contract. Rapeseed is traded on the Euronext exchange.
- Low Erucic Acid Rapeseed (Lear) Oil Derived From Canola
- Swathing and Harvesting Canola
- The Canola Council of Canada
- Northern Canola
- Canola Production
- North Dakota State University picture comparing canola oil fatty acid content with other oils.
- The U.S. Canola Association's (USCA's)