Canola oil is a vegetable-based oil found in countless foods. Many people have cut canola oil out of their diet due to concerns over its health effects and production methods.
You may still wonder whether it’s best to use or avoid canola oil.
This article tells you whether canola oil is good or bad for you.
Share on PinterestChamilleWhite/Getty ImagesWhat is canola oil?
Canola (Brassica napus L.) is an oilseed crop that was created in Canada through crossbreeding of the rapeseed plant. The name “canola” comes from “Canada” and “ola,” denoting oil.
Ever since the canola plant was created, plant breeders have developed many varieties that improved seed quality and led to a boom in canola oil manufacturing.
Most canola crops are genetically modified (GMO) to improve oil quality and increase plant tolerance to herbicides (1, 2).
In fact, over 90% of the canola crops grown in the United States are genetically modified for herbicide resistance, according to an older 2011 study (3).
Canola crops are used to create canola oil and canola meal, which is commonly used as animal feed.
Canola oil can also be used as a fuel alternative to diesel and a component of items made with plasticizers, such as tires.
How is it made?
There are many steps in the canola oil manufacturing process.
According to the Canola Council of Canada, this process involves the following steps (4):
In addition, canola oil made into margarine and shortening goes through hydrogenation, a further process in which molecules of hydrogen are 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 trans fats. Most of the trans fats that people eat today come from partially hydrogenated oils. A smaller proportion comes from “natural” trans fats found in foods like dairy and meat products (5, 6).
Overall, this has meant an increase in the amount of trans fats being consumed. “Industrial” trans fats created through oil processing are harmful to health and have been widely linked to heart disease, prompting many countries, including the US in 2018, to ban their use in food products.
There is not enough evidence to say whether naturally-occuring trans fats from animal sources carry the same risks (6, 7).
SummaryCanola oil is a vegetable oil derived from the canola plant. Canola seed processing involves synthetic chemicals that help extract the oil.
Nutrient content
Canola is a good source of vitamins E and K. One tablespoon (15 ml) of canola oil delivers (8):
- Calories: 124
- Vitamin E: 16% of the DV
- Vitamin K: 8% of the DV
Aside from vitamins E and K, canola oil is devoid of vitamins and minerals.
Fatty acid composition
Canola is often touted as one of the healthiest oils due to its low level of saturated fat.
Here is the fatty acid breakdown of canola oil (9):
- Saturated fat: 7%
- Monounsaturated fat: 64%
- Polyunsaturated fat: 28%
The polyunsaturated fats in canola oil include linoleic acid — more commonly known as omega-6 fatty acid — and alpha-linolenic acid (ALA), a type of omega-3 fatty acid derived from plant sources.
Canola oil typically contains twice as much omega-6 as omega-3, which some consider to be a desirable ratio for human health (10).
Many people, especially those following plant-based diets, depend on sources of ALA to boost levels of the omega-3 fats DHA and EPA, which are critical for heart and brain health.
Though your body can convert ALA into DHA and EPA, research shows that this process is highly inefficient (11).
Still, ALA has some benefits of its own, as it may help your body lower total cholesterol, LDL ‘bad’ cholesterol, triglycerides and blood pressure which are all linked to lowering risk of cardiovascular disease (11, 12).
It’s important to note that the heating methods used during canola manufacturing, as well as high-heat cooking methods like frying, negatively impact polyunsaturated fats like ALA.
SummaryCanola oil is rich in vitamins E and K, and contains twice as much omega 6 as omega 3 fatty acids. Although it has a high smoke point, using it for frying can reduce the content of the heart-healthy omega-3 fat ALA.
Potential downsides
According to the Canola Council of Canada, Canada is the world’s top exporter of canola oil. Most of this oil is sold to the United States (13).
As canola has become one of the most popular fat sources in the commercial food industry, concerns have grown over its health impact.
Major source of omega-6 fats
Like omega-3 fats, omega-6 fats are essential to health and perform important functions in your body.
However, modern diets tend to be extremely high in omega-6s — found in many refined foods — and low in omega-3s from whole foods, causing an imbalance that leads to increased inflammation.
While the most healthy ratio of omega-6 to omega-3 fat intake is 1:1, the typical Western diet is estimated to be around 20:1 (14).
This imbalance is linked to a number of chronic conditions, such as Alzheimer’s disease, obesity, and heart disease (15, 16, 17, 18).
The omega-6 to omega-3 ratio of canola oil is 2:1, which may not seem particularly disproportionate (10).
Yet, because canola oil is found in so many foods and is higher in omega-6s than omega-3s, it’s thought to be a major source of dietary omega-6 (19).
In order to create a more balanced ratio, you should replace processed foods rich in canola with natural, whole-food sources of omega-3, such as fatty fish.
Mostly GMO
GMO foods have had their genetic material engineered to introduce or eliminate certain qualities (20).
For example, high-demand crops, such as corn and canola, have been genetically engineered to be more resistant to herbicides and pests.
Although many regulators deem GMO foods safe, concerns abound over their potential impact on the environment, public health, crop contamination, property rights, and food safety (21).
Over 90% of canola crops in the United States and Canada are genetically engineered (3).
While GMO foods have been approved for human consumption for decades, and there has not been any direct safety hazards reported from GMO use, the topic remains controversial, and therefore including GMO foods in the diet is up to individual preference (20, 21, 22).
Highly refined
Canola oil production involves high heat and exposure to chemicals.
Considered a chemically refined oil, canola goes through stages — such as bleaching and deodorizing — that involve chemical treatment (23).
In fact, refined oils — including canola, soy, corn, and palm oils — are known as refined, bleached, and deodorized (RBD) oils.
Refining markedly decreases nutrients in oils, such as essential fatty acids, antioxidants, and vitamins (24, 25, 26).
All industrial plant oils are processed this way, unless an oil says cold pressed, expeller pressed, or extra virgin. This includes olive oil and coconut oil.
If you are worried about GMO or the processing, it’s extremely easy to find organic cold pressed versions of all these oils including canola oil. However, these versions of the oil are not suitable for high-heat cooking as they typically have lower smoke points.
SummaryCanola oil that is most commonly found in grocery store shelves is highly refined and a GMO. It is also a source of omega-6 fats found abundantly in ultra-processed foods, which could contribute to inflammation if heavily consumed.
Can it harm health?
Although canola oil is one of the most widely used oils in the food industry, comparatively few long-term studies exist on its health impacts.
This is not true of all studies, however. An independent 2021 study found that canola oil improved the lipid profile and insulin sensitivity in women with PCOS (27).
The high unsaturated fat content in canola oil may protect against inflammation, microbial infection, or cancer, as well as other benefits (28).
Other studies have found evidence that canola oil may:
- reduce cardiometabolic risk factors (29)
- delay heart disease progression (30)
- promote a modest reduction in body weight (31)
That said, some evidence suggests that canola oil may negatively impact health.
Increased inflammation
Several animal studies link canola oil to increased inflammation and oxidative stress. Though animal studies alone are not strong enough to make a case for negative health implications for humans, these are still worth noting.
Oxidative stress refers to an imbalance between harmful free radicals — which can cause inflammation — and antioxidants, which prevent or slow free radical damage.
A recent rat study demonstrated that compounds formed during the heating of canola oil increased certain inflammatory markers (32).
Plus, in another rat study, the canola oil diet significantly decreased lifespan and led to sizable increases in blood pressure, when compared to a soybean oil diet (33).
Impact on memory
Animal studies also indicate that canola oil may negatively impact memory.
A study in mice found that chronic exposure to a canola-rich diet resulted in significant harm to memory and substantial increases in body weight (34).
In a yearlong human study, 180 older adults were randomly assigned to either a control diet rich in refined oils — including canola — or a diet which replaced all refined oils with 20–30 ml of extra virgin olive oil per day.
Notably, those in the olive oil group experienced improved brain function (35).
Impact on heart health
While canola oil is promoted as a heart-healthy fat, some studies dispute this claim.
In a small 2020 study, participants cooked with only olive oil or canola oil for six weeks. Those who consumed only olive oil had significantly lower blood levels of interleukine-6, a substance that promotes heart inflammation. There were no significant improvements after six weeks among those eating only canola oil (36).
The findings of the 2020 study contrasted with a 2013 industry-funded review that linked canola oil intake to beneficial effects on heart disease risk factors, such as total cholesterol and “bad” LDL cholesterol levels (37).
It’s important to note that many of the studies suggesting heart-health benefits for canola oil use less refined canola oil or unheated canola oil — not the refined type commonly used for high-heat cooking (38).
On the other hand, a recent research review suggests that cooking with canola oil instead of butter or margarine can reduce the risk of dying from cardiovascular disease or diabetes. A different review found that consuming canola oil may lower total cholesterol and “bad” LDL cholesterol, especially for older adults (30, 39).
More research is needed on canola oil and heart health.
SummarySome studies suggest that canola oil may increase inflammation and negatively impact memory and heart health. However, other research reports positive effects on health including the possibility that it might lower LDL cholesterol.
Alternative cooking oils
It’s clear that more research is needed to fully understand how canola oil impacts health.
In the meantime, many other oils provide health benefits that are thoroughly backed by scientific evidence.
The following oils are heat-stable and can replace canola oil for various cooking methods, such as sautéing.
Keep in mind that saturated fats like coconut oil are the best choice when using high-heat cooking methods — such as frying — as they’re least prone to oxidation.
- Olive oil. Olive oil is rich in anti-inflammatory compounds, including polyphenol antioxidants, which may prevent heart disease and mental decline (40).
- Avocado oil. Avocado oil is heat-resistant and contains carotenoid and polyphenol antioxidants, which may benefit heart health (41).
- Coconut oil. Coconut oil is a good oil for high-heat cooking and may help increase “good” HDL cholesterol, though its high saturated fat content can also promote increase in “bad” LDL cholesterol, so it should be used in moderation (42).
The following oils should be reserved for salad dressings and other uses that don’t involve heat:
- Flaxseed oil. Studies show that flaxseed oil may help reduce blood pressure and decrease inflammation (43).
- Walnut oil. Walnut oil has a rich, nutty taste and has been shown to reduce high blood sugar and cholesterol levels (44, 45).
- Hempseed oil. Hempseed oil is highly nutritious and has a nutty flavor perfect for topping salads (46).
There are many effective replacements for canola oil. Heat-tolerant oils — such as coconut and olive oils — can be used for cooking, while flaxseed, walnut, and hempseed oils can be utilized in recipes that don’t involve heat.
The bottom line
Canola oil is a seed oil widely used in cooking and food processing.
There are many conflicting and inconsistent findings in canola oil research. While some animal studies suggest it causes inflammation and harms your memory and heart, there is much evidence that canola oil is beneficial for human health.
Until larger, better-quality studies are available, consider choosing oils that have been proven healthy — such as olive oil — instead.