Is Canola Oil Healthy?

【增篇】 What is the most nutritious food for seniors?

Leafy green vegetables, such as spinach and kale, provide important vitamins, minerals, and antioxidants. Berries, like blueberries and strawberries, are rich in antioxidants and fiber. Fatty fish, such as salmon and sardines, are high in omega-3 fatty acids for brain health. Other nutritious foods for seniors include whole grains, lean proteins, low-fat dairy, and a variety of fruits and vegetables.

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.

What 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 (3Trusted Source).

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?
T

here 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 (5Trusted Source, 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, 7Trusted Source).
SUMMARY

Canola 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 (8Trusted Source):

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.

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 (10Trusted Source).

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. Still, ALA has some benefits of its own, as it may help your body regulate blood sugar levels and lower your risk of complications of type 2 diabetes (11Trusted Source, 12Trusted Source).

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.

Canola oil is rich in vitamins E and K, and contains twice as much omega 6 as omega 3 fatty acids. It is not a good oil for frying, however.
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.

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 15:1 (14Trusted Source).

The omega-6 to omega-3 ratio of canola oil is 2:1, which may not seem particularly disproportionate (Trusted Source 10Trusted Source).

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.

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 (18).

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 (19).

Over 90% of canola crops in the United States and Canada are genetically engineered (3Trusted Source).

While GMO foods have been approved for human consumption for decades, little data exists on their long-term safety for human health and the environment, leading many people to avoid them (18, 19, 20).

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 (21Trusted Source).

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 (22Trusted Source, 23Trusted Source, 24Trusted Source).
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.

For the most part, canola oil is highly refined and GMO. It is also a source of omega-6 fats, which could contribute to inflammation if heavily consumed.

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.
What’s more, some studies on its supposed health benefits are sponsored by the canola industry (25Trusted Source).

This is not true of all studies, however. An independent 2021 study found that canola oil improved the lipid profile in women with PCOS (26Trusted Source).
That said, some evidence suggests that canola oil may negatively impact health.

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 (27Trusted Source).
Plus, the canola oil diet significantly decreased lifespan and led to sizable increases in blood pressure (28Trusted Source).

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 (29Trusted Source).

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 (30Trusted Source).

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 (31Trusted Source).

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 (Trusted Source 32Trusted Source).

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 (33Trusted Source, 34, 35Trusted Source, 36Trusted Source, 37Trusted Source).

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 (38Trusted Source, 39Trusted Source).

Some 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.

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.

The following oils should be reserved for salad dressings and other uses that don’t involve heat:

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

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 extra virgin olive oil — instead.

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