Warning: This oil comes with potentially damaging side effects due to either the ingredient it's made from or the manufacturing process used to extract it. Because these negative effects overshadow the potential benefits, I do not recommend this oil for therapeutic use. Always be aware of the potential side effects of any herbal oil before using.
Canola oil is widely promoted as the "healthiest salad and cooking oil available to consumers."1 However, this information is rather flawed, as canola oil and similar highly processed cooking oils have untold dangers to your health. Before I discuss why canola oil is bad for you, as well as give my personal recommendations for the best cooking oil, I want to mention the flawed information that conventional medicine and the food industry wants you to believe.
What Is Canola Oil?
Referred to as the healthiest cooking oil available on the market by its makers, canola oil is low in saturated fat, high in monounsaturated fatty acid (MUFA), and polyunsaturated fat (PUFA) like omega-3 fatty acids.2 The oil is produced from pressed canola seed, which are harvested from pods obtained from the canola plant.
Although they look the same on the outside, canola is actually not rapeseed. In the late 1960s, scientists used traditional plant breeding methods to remove rapeseed's undesirable traits, mainly erucic acid and glucosinolates.
Canola was not developed using biotechnology, but much of it grown in the United States and Canada today has been genetically modified to make it too tolerant to some herbicides.3 In fact, 90 percent or more of all U.S.-grown corn, soybeans, and canola are either Roundup Ready or Bt tolerant (GE pesticides and herbicides).
Uses of Canola Oil
Canola oil is a common ingredient in food products, such as mayonnaise, salad dressings, and margarine.
Plant-sourced oils like canola oil, once processed, can also be used industrially to formulate lubricants, oils, fuels, soaps, paints, plastics, cosmetics, and ink. Canola and wheat are also used for the production of ethanol, a component of gasohol (gasoline and ethanol). Canola seeds can also be used as biodiesel.4
Some reports show that canola oil, along with soybean oil, is used as active ingredients in pesticide products due to their high effectiveness in eliminating insects.5
Composition of Canola Oil
Canola oil is praised by the mainstream food industry due to its fatty acid content:6
• Saturated fat — Canola oil contains about 7 percent – half the amount found in corn oil, olive oil, and soybean oil.
• Monounsaturated fatty acids — This is the most abundant fat in canola oil. The MUFA oleic acid makes up 61 percent of canola oil.
• Polyunsaturated fatty acid — Compared to palm oil and olive oil, canola oil has a higher amount of PUFA. It has a ratio of omega-6 fat (linoleic acid) and omega-3 fat (alpha-linolenic acid) of 2:1.
Benefits of Canola Oil
From fat-rich traditional diets, there has been a shift to non-fat or low-fat diets due to research conducted on the connection of saturated fat to heart disease. In 1953, Dr. Ancel Keys published a paper that became the basis for scientific support for the negative view on cholesterol.
Oils rich in saturated fat have been vilified, and canola oil as well as other vegetable oils have been praised and became the standard recommendation for cooking due to their low saturated fat content. Another reason why canola oil is in high demand is its high amounts of monounsaturated oleic acid.
According to studies done on oleic acid, this fat is just as effective as polyunsaturated omega-3 fat in lowering plasma cholesterol levels.7 Supporters of canola oil also regard the oil as a good source of omega-3 fats, which most Americans are deficient in.8
How to Make Canola Oil
Unfortunately, details you're told by vegetable oil manufacturers about canola oil's production and benefits are wrong. Canola oil was created through the hybridization of rapeseed oil, an oil used for industrial purposes. Rapeseed oil came from the plant known as "rape," from a Latin word meaning "turnip." Along with cruciferous vegetables, rape is a domesticated crop belonging to the Brassicaceae family.9
Although rapeseed oil is composed of 60 percent monounsaturated fat, it was inedible because of two dangerous substances:10
• Erucic acid — a type of fatty acid that is associated with Keshan's disease, characterized by fibrotic lesions of the heart
• Glucosinolates — bitter compounds that negatively affected the taste of rapeseed oil
To turn rapeseed oil into an edible product, Canadian manufacturers used genetic manipulation that involved seed splitting, to formulate seeds that had lower levels of erucic acid and glucosinolates. Canola oil, also known as "low erucic acid rapeseed (LEAR)" or "Canadian oil, low acid," was formed.11
The derivation of canola oil from seeds involved a combination of high temperature processes. Hexane is added to extract oil from the seeds, causing minute amounts of the dangerous gas byproduct to appear in cooking oils. Other methods included in canola oil processing are refining, bleaching, degumming, and the addition of several chemicals.
The omega-3 fat in canola oil is highly susceptible to heat damage. When canola oil is exposed to heat, its omega-3s become rancid and foul-smelling. Manufacturers then deodorize the oil, which converts omega-3 fat into trans fat – the highly dangerous fat responsible for heart disease.12
Is Canola Oil Safe?
Although the food industry says it is, canola oil is not safe. In spite of its "generally recognized as safe" (GRAS) status, no long-term human safety studies have been conducted on canola oil. Animal studies, however, contradict some of the health claims for canola oil.
In a Canadian research done in 1997, piglets fed with milk replacement with canola oil had signs of vitamin E deficiency, even if the replacement contained sufficient amounts of the nutrient. Deficiency in vitamin E can be dangerous, as it can lead to free radical damage and cardiovascular problems.
A year later, the researchers found that the piglets fed canola oil had reduced platelet count and an increase in platelet size. The results were reconfirmed in another study in the following year. In another animal test conducted, rats ended up with high blood pressure and an increased risk for stroke and a shortened lifespan when canola oil became their primary source of fat.
Later studies found that the possible cause for this is that the sterol compounds in canola oil caused the cell membrane to become more rigid and contributed to the shorter lifespan of the lab animals. It is important to take note that these studies were made prior to the introduction of GE canola oil. This means you face not only the dangers of canola oil discovered in these studies, but also the potential hazards of genetically modified vegetable oils.
Side Effects of Canola Oil
What really happens when you use canola oil in your food? Canola oil and other heated vegetable oils are some of the worst ingredients to add to your food. Eating foods with canola oil will only distort your omega-6 to omega-3 ratio, which is ideally around 1:1. That canola oil can provide ideal amounts of omega-3 fats is a huge misconception.
Anytime you cook food with oils like canola oil, you run the risk of damaging its fat supply. Canola oil is not stable enough to resist heat damage and will introduce oxidized cholesterol and even more trans fat into your body when heated. This puts you at risk for cancer and cardiovascular diseases.
Canola oil is even more dangerous when hydrogenated, which is common in processed foods. Manufacturers hydrogenate the oil because it prolongs processed food shelf life.13 Consuming these foods expose you to even higher levels of trans fat.
Apart from canola oil being beneficial to your health, another myth is that saturated fat is bad for you. Ancel Keys' research was actually manipulated, as he selectively analyzed data from seven countries rather than comparing all data from 22 studies available to him at the time. Majority of the data actually disproved his theory. Saturated fat does not cause heart disease and is, in fact, an important part of a healthy diet.
One of the best options out there is coconut oil, which I personally use. It is the best choice for cooking at it is resistant to heat damage, unlike canola oil and other vegetable oils. Coconut oil also carries beneficial fat like lauric acid, which provides antiviral, antibacterial, and anti-protozoa properties.
Another beneficial oil I recommend is olive oil. However, it should not be used for cooking, as it is highly sensitive to heat damage. Olive oil is best used cold in salads.