Canola Oil Dangers: Why Canola Oil Is Bad For you According to Evidence
Canola oil is a vegetable oil that may not be as good for you as you think. Canola oil has been promoted for its health benefits because it is low in saturated fats. However, some evidence points to the fact that canola oil may have hidden dangers to your health.
Many people claim that canola oil is bad for you because it is made from GMO crops and is highly refined. There is some scientific evidence that canola oil is bad for your health because an increased intake of canola oil is linked to inflammation, heart disease, impaired memory function, and stroke.
In this article, you will find out if claims about canola oil dangers are founded. You will also find out if this oil is safe to use for cooking, frying, or in salads.
What is Canola Oil?
Canola oil is made from crushing seeds from a plant which is a variety of the rapeseed plant.
Pure rapeseed oil isn’t suitable for consumption as it contains high amounts of toxic compounds called erucic acid and glucosinolates. So, scientists in Canada developed an edible version of the rapeseed plant. This plant was called canola and its name comes from “Canada” and “ola” meaning oil. The oil from the rapeseed plant is low in saturated fats and high in monounsaturated and polyunsaturated fats. (1)
Canola belongs to the Brassicaceae family which is the same family as mustard, rapeseed, kale, cabbage, and broccoli. Although the rapeseed plant can be developed naturally by cross-breeding, most of the world’s production of canola oil is produced from genetically engineered crops. (2)
Genetically modified rapeseed plants are designed to be resistant to many herbicides and weed killers.
There are quite a few steps in the canola oil manufacturing process:
- Initially the canola seeds are cleaned and cooked.
- The cooked canola seeds are then mechanically pressed to extract much of the oil.
- The oil from the remaining canola meal is extracted using a solvent called hexane.
- The oil is refined using different ways such as steaming, filtration or exposure to phosphoric acid.
Researchers found that the refining process removes most of the vitamin E and the carotenoids (plant pigments) from the oil. During the refining process trans fats can develop in the canola oil. Trans fats have been linked to various chronic diseases such as heart disease and cancer. (1)
Canola oil vs. rapeseed oil
What is the difference between rapeseed oil and canola oil? Rapeseed oil and canola oil that are used in cooking are one and the same thing. Canola oil is also called low erucic acid rapeseed oil.
Because rapeseed oil or canola oil has mainly been produced using GMO crops and is highly refined, many people choose to stay away from canola oil. At the end of this article, you will find out some great and healthy alternatives to canola oil if you want to avoid its dangers.
Why Some People Believe Canola Oil is Healthy
One of the reasons why some people promote the use of canola oil is that it is high in unsaturated fats. For example, doctors from the Mayo Clinic say that canola oil is good for you because it has a high proportion of monounsaturated fat. They say that the oil from the rapeseed plant is generally recognized as safe by the U.S. Food and Drug Administration. (3)
Another reason why canola oil is said to be healthy is that it contains phytosterols that help to reduce cholesterol levels in the body. (4)
Canola Oil Nutrition
According to the United States Department of Agriculture, 1 tablespoon of canola oil contains 120 calories. (5)
Studies have shown that cold-pressed canola oil contains good levels of vitamins E and K. However, it is good to remember that refined canola oil is usually devoid of vitamins. (1, 6)
Fatty acids in canola oil
The main reason why people say that canola oil is healthy is that it contains low levels of saturated fat and high levels of unsaturated fats.
According to the USDA, canola oil contains 7% saturated fat, 64% monounsaturated fat and 28% polyunsaturated fat. (5)
Canola oil is also a good source of omega-6 and omega-3 fatty acids (in the form of alpha-linolenic acid). Studies have shown that canola oil contains about 20% linoleic acids. These are commonly known as omega-6 fatty acids. (7)
Even though omega-6 and omega-3 fatty acids are healthy for you, too much omega-6 can lead to inflammation. This is one of the reasons why many people avoid canola oil in their diet. Western diets tend to be high in omega-6 and low in omega-3. Many scientists have linked this imbalance to the increase of chronic diseases such as heart disease, cancer, and autoimmune conditions. (8, 9)
Why Canola Oil is Bad for You
On the face of it, canola oil may seem like a healthy oil because it contains mostly monounsaturated and polyunsaturated fats. However, there are many reasons why people look for canola oil alternatives.
Researchers from Harvard T.H. Chan report that canola oil may be bad for you because canola oil can contain solvents, trans fats, and too much omega-6. Compared to soybean oil and walnut oil, canola oil may have similar trans fats content. (10)
At the end of the article you will find good alternatives to canola oil that are not associated with the dangers of canola oil.
Canola Oil and its Health Risks – Dangers of Canola Oil
Let’s look in more detail at scientific research on the reasons why many say that canola oil is not good for you.
GMO and herbicides
One of the biggest concerns when it comes to potential health risks of canola oil is the fact that it is mainly produced using genetically modified crops.
Even though many countries allow the use of GM crops, many people prefer to stay away from these types of foods. One of the reasons for this is that there are no long-term studies on their potential health risks. Many scientists voice concern that more research needs to be done on the safety of GM crops. (11)
Another potential danger of GM crops such as canola is the overuse of herbicides such as glyphosate.
Some varieties of canola have been genetically modified to be resistant to the herbicide glyphosate. This had led to concerns due to the overuse of glyphosate weed killer that farmers can liberally spray on canola crops without harming them. Glyphosate is a known carcinogen and may be responsible for birth defects in humans. (12, 13)
Find out more about this cancer-causing chemical and why you should always buy non-GMO foods.
High in omega-6 fatty acids
One concern over the increased use of canola oil is that it can create an imbalance of omega-6 and omega-3 fatty acids.
Researchers have found that a diet rich in omega-6 fatty acids can cause a number of health concerns. Some studies indicate that the ratio of omega-6 to omega-3 should be 1:1, however the ratio in diets in some countries could be as high as 20:1. This creates inflammation in the body and can have a negative impact on health. (14)
Too much omega-6 has been linked to obesity, cancer, heart disease, Alzheimer’s disease, and certain mood disorders. (15, 16)
Regularly taking omega-3 supplements is one way to help address health problems related to inflammation.
Chemical solvents
One of the reasons why canola oil is unhealthy is that solvent residue can be found in the refined oil.
To extract as much of the oil from canola seeds as possible, canola seed paste is heated with the solvent hexane and then bleached. Researchers have found that small amounts of hexane are leftover in the final product. Although scientists say there is no risk to health, many people choose to look for healthier alternatives to canola oil. (10)
Although these levels of chemicals may not make canola oil toxic, you may prefer to look for organic oils such as extra virgin olive oil or avocado oil.
Highly refined oil
The fact that most canola oils sold in supermarkets are highly refined using heat and chemicals makes many people doubt if canola oil is really safe.
To create a light-colored vegetable oil with no flavor, manufacturers heat canola seeds to a high temperature. Solvents are used to extract the oil. The extracted oil is then bleached and deodorized to create a usable oil. (1)
Studies have shown that refined oils contain extremely low levels of nutrients such as essential fatty acids, antioxidants, and vitamins. (17)
Trans fats
Canola oil can be bad for you because small amounts of trans fats may develop during the refining process.
Trans fats found in oils such as canola oil can lead to heart disease and increase your risk of stroke. Even small amounts of trans fats (also called partially hydrogenated oils) can be detrimental to your heart health. (18)
The high heat temperatures used to process canola oil results in turning some healthy polyunsaturated fats into dangerous trans fats. (19)
The World Health Organization has recommended all trans fats to be eliminated from food sources by the year 2023. (20)
Canola Oil May Increase Inflammation
One of the reasons not to consume or cook with canola oil is that it can raise inflammatory markers in your body.
One study on the effects of canola oil on rats found that the high content of linoleic acid increases inflammation. Rats who consumed oils such as canola oil and soybean oil showed more signs of oxidative stress. (21)
Other studies on animal subjects found that canola oil reduced the number of antioxidants in the body. The resulting increase in inflammation increased the risk of cardiovascular disease. (22)
Canola oil is among the many inflammatory foods that you should avoid on a healthy diet. Learn more about the best foods to consume to reduce inflammation.
Canola Oil Can Impact on Memory Function
Consuming refined canola oil can be bad for your cognitive function due to its inflammatory actions.
One 2017 study on animal subjects found that canola oil has a negative impact on brain health. Increasing levels of canola oil in the diet resulted in memory impairment and cognitive decline. (23)
A study involving elderly patients found that consuming extra virgin olive oil was better for your brain health than canola oil or other vegetable oils. (24)
Find out about some of the best foods that help to boost your brain power and may delay the development of cognitive impairment.
Canola Oil Could Be Bad for Your Heart
The reason that canola oil is touted as being good for your health is due to having high levels of unsaturated fats. However, recent research has found that canola oil may not be as beneficial for your heart as once thought.
The journal Nutrients reported on a 2018 study on the effects of different cooking oils and metabolic syndrome. The research found that overweight or obese participants who usually used canola oil for cooking had more chances to have metabolic syndrome than those who hardly or never used it. (25)
According to the Mayo Clinic “metabolic syndrome is a cluster of conditions that occur together, increasing your risk of heart disease, stroke and type 2 diabetes. These conditions include increased blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol or triglyceride levels”
Cooking with olive oil seemed to be the best type of oil with cardio-protective properties.
Interestingly, there is some scientific research pointing to the fact that just replacing saturated fats with unsaturated oils may not reduce the risk of coronary heart disease. (26)
Some studies contradict these studies about the dangers of canola oil on your heart health. For example, a review of published research into the heart-benefits of canola oil found positive results. However, it is good to know that the review was funded by the Canola Council of Canada. (27)
Although there are conflicting reports on the dangers of canola oil, more research needs to be carried out. One study on the benefits of replacing olive oil with canola oil (rapeseed oil) for its heart benefits couldn’t recommend canola oil as a suitable replacement. (28)
Is Cold Pressed Canola Oil Good For You?
You may be able to find unrefined cold pressed canola oil which could be slightly better for you than the refined oil. The unrefined canola oil contains more nutrients than the refined oil. However it’s good to remember that the cold pressed canola oil is still made from genetically modified rapeseed plant. The cold pressed canola oil is still high in omega 6 fatty acids and will have many of the associated risks related to canola oil.
Best Canola Oil Substitutes
Even though cold-pressed canola oil may have some health benefits, there are many better oils to use in cooking.
When looking for healthier alternatives to canola oil, it’s important to pick the best oil depending on your cooking method. For cooking with high heat, it’s important to choose an oil with a high smoke point. For salad dressings, you can use a more delicate oil with a nutty taste.
Olive oil
The British Journal of Nutrition reported that olive oil has many health benefits in protecting you against chronic disease. Olive oil helps to lower blood pressure, inflammation, and has cardio-protective properties. Some studies have also found a link between olive oil consumption and a lower risk of certain types of cancer. (29)
Learn more about the proven health benefits of extra virgin olive oil in this article.
Avocado oil
Avocado oil is good for cooking at high temperatures. Avocado oil is rich in polyunsaturated and monounsaturated fatty acids and can help to keep your heart healthy. Avocado oil also has a unique chemical structure that helps to enhance antioxidants capacity. (30)
Learn more about the many benefits of avocado oil and how to use this versatile oil in cooking and on your skin.
Coconut oil
Although high in saturated fats, coconut oil contains lauric acid which can help increase levels of “good” cholesterol in your blood. Coconut oil is also good for cooking with, as the saturated fat content protects the oil from oxidation at high temperatures. (31, 32)
Many recent studies have shown that there are many health benefits to coconut oil and that not all saturated fats are equal. Coconut oil contains medium chain saturated fatty acids, or medium chain triglycerides (MCTs). Research has found that the body metabolizes MCTs differently from long-chain fatty acids, and in fact, MCTs have a protective effect on cardio health. (33)
Find out how to cook with coconut oil and how to incorporate coconut oil into your diet.
Flaxseed oil
Flaxseed oil is not suitable for cooking with. However, its nutty flavor and abundance of plant-based omega-3 fatty acids make this a tasty and healthy alternative to canola oil. Studies have shown that flaxseed oil is good for your heart, is anti-inflammatory, and can help lower your risk of cancer. (34)
Learn more about the many benefits of flaxseeds and how to use flaxseed oil to keep your skin looking wonderful.
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