Canola oil is a cooking oil made from the seeds of a plant that Canadian scientists bred specifically to be safe for eating. It comes from rapeseed, a crop in the same family as broccoli and mustard, but standard rapeseed oil contained compounds that made it unsuitable as food. In the 1960s and 1970s, plant breeders in Saskatchewan and Manitoba used traditional cross-breeding to create new varieties with those problematic compounds stripped down to safe levels. The name “canola” is short for “Canadian oil.”
Why Rapeseed Oil Needed a Makeover
Rapeseed had been grown for centuries, mostly as an industrial lubricant rather than a food. The oil from traditional rapeseed contained high levels of erucic acid, a long-chain fatty acid that raised concerns about heart health in animal studies. It also contained sulfur compounds called glucosinolates, which in small amounts give vegetables like radishes and mustard their sharp bite but in high concentrations cause problems for both humans and livestock.
These two issues made rapeseed a dead end as a food crop. The oil wasn’t safe for cooking, and the leftover meal after pressing couldn’t be widely used as animal feed either. Traditional rapeseed meal could only make up about 8 to 10 percent of livestock feed before the glucosinolates started causing health problems in the animals. Canada, with vast agricultural land and a short growing season that suited rapeseed well, had strong economic motivation to turn the crop into something more useful.
How Canadian Breeders Solved the Problem
The fix didn’t involve genetic engineering in the modern sense. Plant breeders used traditional cross-pollination, selecting plants with naturally lower levels of erucic acid and glucosinolates, then breeding those together over successive generations. By the early 1970s, they had varieties that produced oil with less than 2 percent erucic acid (down from around 30 to 50 percent in conventional rapeseed) and meal with glucosinolate levels below 30 micromoles per gram. These “double zero” cultivars, zero for erucic acid and zero for glucosinolates, became what we now call canola.
The U.S. Food and Drug Administration formally defines canola oil as refined oil from specific varieties of Brassica napus or Brassica campestris containing no more than 2 percent erucic acid. That threshold is a legal requirement for anything sold as canola oil in the United States.
The low-glucosinolate meal turned out to be a major economic win on its own. Canola meal can replace soybean meal at up to 20 percent of livestock feed without harming animal growth, more than double what traditional rapeseed meal allowed. This made the entire crop more profitable: farmers could sell both the oil and the leftover meal.
What’s Actually in Canola Oil
Canola oil’s fat profile is one of the reasons it became so popular so quickly. The average composition breaks down to about 62 percent oleic acid (the same monounsaturated fat that makes olive oil famous), 19 percent linoleic acid (an omega-6 fat), 9 percent linolenic acid (an omega-3 fat), and only 7 percent saturated fat. That saturated fat content is among the lowest of any common cooking oil.
The omega-6 to omega-3 ratio of roughly 2:1 is also notable. Most Western diets are heavy on omega-6 fats and light on omega-3s, so canola oil offers a more balanced profile than corn oil, soybean oil, or sunflower oil. It won’t replace fatty fish as an omega-3 source, but as a baseline cooking fat, it tips the balance in a favorable direction.
Effects on Heart Health
A large meta-analysis of controlled clinical trials found that canola oil significantly lowered total cholesterol, LDL (“bad”) cholesterol, and several other markers of cardiovascular risk compared to other edible oils. The reductions held up even when canola oil was compared head-to-head with oils that already have strong health reputations. Against olive oil, canola oil produced lower total cholesterol and LDL cholesterol. Against sunflower oil, it improved LDL levels and the ratio of LDL to HDL cholesterol. Against saturated fats like butter or palm oil, the improvements were even larger.
The dose-response analysis suggested the greatest cardiovascular benefit came from replacing about 15 percent of total daily calories with canola oil. For someone eating 2,000 calories a day, that works out to roughly 2.5 tablespoons.
How Canola Oil Is Made
Most commercial canola oil goes through solvent extraction. The seeds are crushed and slightly heated, then mixed with a chemical solvent (hexane) that pulls the oil out of the seed material. After extraction, the oil is refined in several steps: water and organic acid remove gums and free fatty acids, filtering strips out color compounds, and steam distillation removes odors and off-flavors. The result is a neutral-tasting, pale yellow oil.
Cold-pressed canola oil also exists, though it’s less common and more expensive. It skips the solvent step, relying on mechanical pressure alone. Cold-pressed versions retain more of the plant’s natural flavor and some additional minor nutrients, but they have a lower smoke point and shorter shelf life than the refined version.
Cooking With Canola Oil
Refined canola oil has a smoke point of about 400°F (204°C), which puts it comfortably in the range for sautéing, stir-frying, and most oven roasting. Its neutral flavor makes it a versatile choice when you don’t want the oil to compete with other ingredients. It works well in baking, salad dressings, and deep frying.
The plant itself is now one of the world’s most important oilseed crops. Canada remains the largest producer and exporter, but canola is grown across North America, Europe, and Australia. What started as a regional agricultural project to make an inedible industrial oil safe for the dinner table became one of the most widely consumed cooking oils on the planet within a few decades.