All about canola oil

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Canola, or Brassica napus, is one of the most important oilseed crops globally. The name “canola” comes from the words “Canada” and “ola,” meaning oil.

Scientists in Canada created canola through crossbreeding an edible type of rapeseed plant. By crossbreeding, they removed toxic compounds called glucosinolates and erucic acid.

The canola plant looks identical to the rapeseed plant, but it contains different nutrients, and its oil is safe for consumption.

Since scientists created the canola plant, breeders have developed different varieties with improved seed quality. This has led to a massive increase in canola oil manufacturing.

Most canola crops are genetically modified (GM), which improves the quality of the oil and increases the plant’s tolerance to herbicides. GM canola makes up 95% of canola planted in the United States.

According to the Canola Council of Canada, the process for turning canola seed into oil is similar to that of other oilseeds.

Cleaning

The process begins with cleaning the canola seeds thoroughly to remove stems, pods, weed seeds, and other materials that are present from harvesting.

Heating and flaking

Machines then heat and flake the canola seeds before extracting the oil. They raise the temperature slightly in grain dryers to prevent the seed from shattering. They then pass the seeds through rollers to rupture the cell walls and flake the seeds to the ideal thickness.

Cooking

The seeds progress through a series of stacked cookers or heating drums. This process further ruptures the cells and obtains the correct viscosity and moisture level that the upcoming steps require. Cooking also prevents the product from breaking down, which could affect its quality.

Pressing

The heated flakes then progress through a series of expellers or pressers for gentle pressing. This process removes most of the oil and compresses the remaining seed into a solid cake.

Extraction

An extractor then removes the remaining oil from the pressed cakes with a solvent called hexane. The machine then separates the oil and solids and recycles the hexane for further use.

Refining and processing

Processes refine the crude oil to improve its flavor, color, and shelf-life. Water and organic acids remove gums, fatty acids, fine meal particles, and lipids.

A process called bleaching removes color pigments, though it does not use bleach. The process involves passing the oil through a clay filter, and steam distills the oil to remove unpleasant odors.

The manufacturers then package and distribute the canola as cooking oil or process it into a range of consumer products.

According to the U.S. Department of Agriculture’s FoodData Central database, canola oil contains the following.

Per tablespoon:

• 124 calories
• 16% of the recommended daily intake (RDI) of vitamin E
• 9% of the RDI of vitamin K

Fatty acids per tablespoon:

• 14 grams (g) of total fat
• 1.03 g of total saturated fatty acids
• 8.86 g of total monounsaturated fatty acids
• 3.94 g of total polyunsaturated fatty acids

Canola oil does not contain gluten or soy.

Canola oil is a rich source of polyunsaturated fatty acids (PUFAs). These PUFAs include 21% linoleic acid, or omega-6 fatty acid, and 11% alpha-linolenic acid (ALA), which is an omega-3 fatty acid.

Many people, especially when following plant-based diets, depend on ALA sources to increase their levels of the omega-3 fats ​docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). These omega-3 fats are critical for brain health.

However, it is worth noting that the human body converts ALA to DHA and EPA at a low rate, meaning that it is not particularly efficient at increasing levels of these fats.

The heating process that takes place during the manufacture of canola oil, as well as cooking methods such as frying, negatively affect ALA and other polyunsaturated fats.

Canola oil also contains trans fats. According to the World Health Organization (WHO), these can be harmful, even in small amounts.

One 2013 review claims that canola oil is one of the healthiest vegetable oils, as it reduces disease-related factors and improves health. Although the study appears in a peer reviewed journal, it has the support of organizations in the canola oil industry.

A 2016 book claims that many dietitians believe that canola oil should be considered the healthiest edible oil due to its fatty acid composition and other nutrient properties. It also contains a low amount of saturated fat compared with other vegetable oils.

One 2011 study concludes that people who eat more canola oil than other oils rich in saturated fatty acids may experience lipid-lowering effects. The researchers also suggest that canola oil could be considered heart-healthy.

Some research suggests that canola oil may harm health.

Heart health

Although marketers often promote canola oil as a heart-healthy fat and alternative to other oils, some studies regard it as potentially harmful.

One 2018 study suggests that people who use canola oil for cooking may be more likely to have metabolic syndrome.

This study contradicts a review that claims that people who consume canola oil may have fewer heart disease risks, such as high low-density lipoprotein cholesterol levels. This review has funding from organizations in the canola industry.

It is unclear whether canola oil is harmful or beneficial to heart health, so more research is necessary.

Inflammation

Many animal studies have linked canola oil to oxidative stress and increased inflammation.

In a 2020 study involving a large yellow croaker fish, the researchers conclude that a diet with more than 6% dietary rapeseed oil may cause an inflammatory response.

A 2018 study suggests that heating canola oil results in compounds that increase inflammatory markers in rats.

Inflammatory and immune cells are sensitive to change according to a diet’s fatty acid profile.

Memory

A 2017 study involving mice bred to simulate Alzheimer’s disease demonstrates that the chronic consumption of canola oil may have a negative impact on memory.

Before researchers can confirm whether canola oil is harmful or healthy, they need to conduct further studies.

In the meantime, people can choose alternative oils for cooking, including the following:

• Olive oil: This is rich in anti-inflammatory properties and antioxidants, which may help prevent heart disease and cognitive issues.
• Avocado oil: This contains the antioxidants polyphenols and carotenoids, which promote heart health.
• Coconut oil: This may help increase high-density lipoprotein, or “good,” cholesterol. However, coconut oil also contains high amounts of saturated fats.

Scientists in Canada developed canola oil by crossbreeding rapeseed to remove toxins. Manufacturers heat, press, and use solvent extraction to obtain the final product.

Canola oil is a good source of vitamins E and K and contains a variety of fatty acids, including omega-3 and -6 fatty acids.

According to some studies, canola oil may have health benefits, with some industry-supported studies claiming that it is the healthiest oil available.

Conversely, canola oil may also pose certain health risks, including those related to heart health, cognition, and inflammation.

People can choose alternatives to canola oil, such as olive oil, avocado oil, and coconut oil.