Canola oil is a vegetable oil found in countless varieties of foods. Many people have eliminated canola oil from their diets due to concerns about its health effects and manufacturing technique.
However, you should still consider whether it is ideal to use or avoid canola oil. This article tells you if canola oil is lucky for you.
What is canola oil?
Canola (Brassica napus L.) is an oil seed crop produced by crossing plants.
Scientists in Canada have developed an edible version of the canola plant, which, in itself, hosts toxic compounds called erucic acid and glucosinolate. The name “canola” comes from “Canada” and “ola”, which means oil.
Although the canola plant looks similar to the canola plant, it contains several nutrients and its oils are safe for human consumption.
Since the canola plant was created, plant growers have developed a variety of varieties that have improved seed quality and brought an explosion to canola oil production.
Most canola crops are genetically modified (GMO) to improve oil quality and increase plant tolerance to herbicides (1). In fact, over 90% of canola crops grown in the United States are GMO.
The canola plant is used to make canola oil and canola dinners, which are commonly used as creature food. Canola oil can also be used as a fuel option in contrast to diesel and part of materials made with plasticizers, such as tires.
How Canola Can It Be Made?
There are many steps in the process of producing canola oil. As demonstrated by the Canadian Canola Council, these interactions include the accompanying advances (3):
Clean the seeds. Radish seeds are isolated and cleaned to eliminate pollutants, for example, plant stems and soil.
Seed Conditioning and Flaking
Seed conditioning and peeling: Seeds are first heated to about 95 ℉ (35 ℃), then “peeled” by a roller mill to break up the seed cell walls.
The bean flakes are cooked by a series of stoves heated by steam. Typically, this heating process lasts for 15-20 minutes at a temperature of 176–221℉ (80°–105°C).
Next, the ripe canola seed flakes are pressed in a series of screw presses or expellers. This action removes 50–60% of the oil from the flakes, leaving the remainder to be extracted by other means.
The remaining seed fragments, which contain 18-20% oil, are then broken down using a chemical called hexane to obtain the residual oil.
Hexane is then separated from the canola flour by heating it a third time at 203–239℉ (95–115°C) by exposure to steam.
Processing the oil.
The extracted oil is purified by various methods, such as steam distillation, exposure to phosphoric acid, and filtration through acid-activated clay.
In addition, canola oil is made into margarine and shortening through a hydrogenation process, a further process in which molecular hydrogen is pumped into the oil to change its chemical structure.
This process makes the oil solid at room temperature and extends shelf life but also creates artificial trans fats, which are different from naturally occurring trans fats found in foods such as dairy and meat products.
Artificial trans fats are harmful to health and have been widely associated with heart disease, prompting many countries to ban their use in food products
Like most other oils, canola is not a good source of nutrients. One tablespoon (15ml) of canola oil provides:
- Calories: 124
- Vitamin E: 12% of the Reference Daily Intake (RDI)
- Vitamin K: 12% of the RDI
Apart from vitamins E and K, canola oil does not contain vitamins and minerals.
Fatty acid composition
Canola is often touted as one of the healthiest oils due to its low level of saturated fat. The following is a breakdown of the fatty acids of canola oil:
- Saturated fat: 7%
- Monounsaturated fat: 64%
- Polyunsaturated fat: 28%
The polyunsaturated fats in canola oil include 21% linoleic acid — more commonly known as omega-6 fatty acids — and 11% alpha-linolenic acid (ALA), a type of omega-3 fatty acid that comes from plant sources.
Many people, especially those on a plant-based diet, rely on sources of ALA to increase levels of the omega-3 fats DHA and EPA, which are essential for heart and brain health.
Although your body can convert ALA into DHA and EPA, research shows that this process is very inefficient. However, ALA has several benefits, as it may reduce the risk of fractures and protect against heart disease and type 2 diabetes.
It is important to note that the heating methods used during rapeseed production, as well as high heat cooking methods such as frying, negatively impact polyunsaturated fats such as ALA.
In addition, canola oil can contain up to 4.2% trans fat, but levels vary widely and are usually much lower.
Artificial trans fats are harmful even in small amounts, prompting the World Health Organization (WHO) to call for a global elimination of artificial trans fats in the diet by 2023.
Canola is the second largest oil crop in the world. Its use in food continues to grow (13).
As canola has become one of the most popular sources of fat in the commercial food industry, concerns about its impact on health have increased.
High in Omega-6 fat
One of the advantages of canola oil is that it is high in omega-6 fats. Like omega-3 fats, omega-6 fats are essential for health and for carrying out important functions in your body.
However, modern diets tend to be very high in omega-6 — found in many processed foods — and low in omega-3 from whole foods, causing an imbalance that leads to increased inflammation.
While the ratio of intake of the healthiest omega-6 and omega-3 fats is 1:1, the typical Western diet is estimated to be around 15:1.
This imbalance is linked to a number of chronic conditions, such as Alzheimer’s disease, obesity, and heart disease.
The omega-6 to omega-3 ratio of canola oil is 2:1, which may seem disproportionate.
However, because canola oil is found in so many foods and is richer in omega-6 than omega-3, it is considered a major source of omega-6 in the diet.
To create a more balanced ratio, you should replace processed foods rich in canola and other oils with whole natural sources of omega-3s, such as fatty fish.
GMO foods have been genetically engineered to introduce or eliminate certain qualities. For example, crops in high demand, such as corn and canola, have been genetically engineered to be more resistant to herbicides and pests.
Although many scientists believe that GMO foods are safe, there are many concerns about their potential impact on the environment, public health, crop contamination, property rights, and food safety.
More than 90% of the canola crop in the United States and Canada is genetically modified.
Although GMO foods have been approved for human consumption for decades, there is little data on their potential health risks, leading many to avoid them.
Producing canola oil involves high heat and exposure to chemicals.
Considered a chemically purified oil, canola goes through stages – such as bleaching and deodorizing – that involve chemical treatments.
In fact, refined oils, including canola, soybean, corn, and palm oil, are known as refined, bleached, and deodorized (RBD) oils.
Distillation greatly reduces the nutrients in the oil, such as essential fatty acids, antioxidants, and vitamins.
Although unrefined chilled rapeseed oil exists, most rapeseeds on the market are very refined and lack the antioxidants found in crude oil like extra virgin olive oil.
Can it harm your health?
Although canola oil is one of the most widely used oils in the food industry, there is little long-term research on its effects on health.
In addition, many studies on the purported health benefits are sponsored by the rapeseed industry.
That said, some evidence suggests that canola oil can have a negative impact on health.
Several animal studies have linked canola oil to increased inflammation and oxidative stress.
Oxidative stress refers to an imbalance between harmful free radicals – which can cause inflammation – and antioxidants, which prevent or slow down free radical damage.
In one study, rats fed a diet of 10 percent canola oil had decreased levels of several antioxidants and increased levels of “bad” LDL cholesterol, compared to rats fed soybean oil.
In addition, the canola oil diet significantly shortens lifespan and causes a marked increase in blood pressure.
Another recent study in mice showed that compounds formed during heating canola oil increase several inflammatory markers.
Impact on memory
Animal studies have also shown that canola oil can have a negative impact on memory.
A study in mice found that chronic exposure to a canola-rich diet resulted in significant memory impairment and substantial weight gain.
In a one-year human study, 180 seniors were randomly assigned to a control diet rich in refined oils, including canola, or a diet that replaced all refined oils with 20-30ml of extra virgin olive oil per day.
In particular, those in the olive oil group experienced improvements in brain function.
Impact on heart health
While canola oil is promoted as a heart-healthy fat, several studies refute this claim.
In a 2018 study, 2,071 adults reported how often they used certain types of fat for cooking.
Among participants who were overweight or obese, those who typically used canola oil for cooking were more likely to develop metabolic syndrome than those who rarely or never used it.
Metabolic syndrome is a collection of conditions — high blood sugar, excess belly fat, high blood pressure, and high cholesterol or triglyceride levels — that occur together, increasing the risk of heart disease.
The findings of the 2018 study contrast with an industry-funded review that linked canola oil intake to beneficial effects on heart disease risk factors, such as total cholesterol and levels of “bad” LDL cholesterol.
It’s important to note that many studies showing the heart health benefits of canola oil have used refined or unheated canola oil instead of the refined types commonly used for high heat cooking.
Additionally, although many health organizations encourage replacing saturated fats with unsaturated vegetable oils such as canola, it’s not clear whether this benefits heart health.
In an analysis of 458 men, those who replaced saturated fat with unsaturated vegetable oils had lower levels of “bad” LDL cholesterol, but significantly higher rates of death, heart disease, and coronary heart disease than the control group.
In addition, a recent review concluded that replacing saturated fats with vegetable oils is unlikely to reduce heart disease, heart disease deaths, or overall mortality. More research is needed on canola oil and heart health.
Alternative cooking oil
It is clear that more research is needed to fully understand the impact of canola oil on health.
Meanwhile, many other oils provide health benefits that are widely supported by scientific evidence.
These oils are heat resistant and can replace canola oil for a variety of cooking methods, such as sauteing.
Keep in mind that saturated fats such as coconut oil are the best choice when using high heat cooking methods, such as frying, as they are less prone to oxidation.
Olive oil is rich in anti-inflammatory compounds, including antioxidant polyphenols, which can prevent heart disease and mental decline
Coconut oil is one of the best oils for cooking over high heat and can help increase the “good” HDL cholesterol.
Avocado oil is heat-resistant and contains antioxidant carotenoids and polyphenols, which may benefit heart health
The following oils should be reserved for salad dressings and other uses that do not involve heat:
Studies show that flaxseed oil can help lower blood pressure and reduce inflammation
Walnut oil has a rich spicy taste and has been shown to reduce high blood sugar and cholesterol levels
Flaxseed oil is highly nutritious and has a nutty flavor that is perfect for salad dressings
Canola oil is a seed oil that is widely used in cooking and food processing. There have been mixed and inconsistent findings in canola oil research.
While some studies link it to improved health, many suggest it causes inflammation and impairs memory and the heart.
Until larger, better-quality research becomes available, it may be best to choose an oil that has been shown to be healthy, such as extra virgin olive oil.