Canola oil has been receiving a lot of flack lately. Maybe you’ve heard the chatter about how this oil is inflammatory, toxic, bad for heart health, used as an industrial lubricant, or rancid. So, are the dangers of canola oil just now being exposed, or is canola oil being senselessly demonized? Let’s talk about it.
In this post, we will delve into the many claims made against canola oil and address the research surrounding these topics to determine if these claims are supported. The studies and papers that I reviewed while researching these topics are linked throughout the post if you’re interested in reading more.
Common Claims About Canola Oil
Claim: “Canola oil is inflammatory, and chronic inflammation is the leading contributor of many ailments that Americans face.”
Is this true?
While it is true that chronic inflammation is a huge health issue, especially in America, canola oil is not one of the sources of this inflammation. In fact, canola oil been shown to be anti-inflammatory.
The reason this myth is circulating is because canola oil is high in omega-6 fatty acids. Previously, it was thought that we needed to decrease our ratio of omega-6’s to omega-3’s in order to reduce inflammation caused by omega-6’s. However, newer research shows us that omega-6’s actually do not cause inflammation and are actually anti-inflammatory. (Also see here and here for supporting studies.) (PS – canola oil is also high in omega-3’s!) So no need to worry about this oil causing inflammation.
Claim: “Canola oil contains erucic acid, which is is harmful to heart health.”
Is this true?
Canola oil was developed through the crossbreeding of another type of oil – rapeseed oil. Rapeseed oil is known to have high levels of erucic acid. But the canola oil that is available for culinary use today has been selectively bred to be low in erucic acid, with average level of 0.01% in oilseed products, according to a 2017 study. In fact, erucic acid content in culinary canola oil is something that is strictly regulated; its fatty acid profile must be less than 2% erucic acid to be sold as “canola oil.”
High erucic acid rapeseed (HEAR) oil is still grown, but only for industrial use. (We’ll get into what that means with the next claim.) But you’re certainly not going to find HEAR oil at your local grocery store.
Claim: “Canola oil is used as an industrial lubricant, so we shouldn’t be putting it in our bodies.”
Is this true?
As mentioned above, HEAR oil and culinary canola oil have key differences that are strictly regulated. HEAR oil has a non-culinary purpose – it is commonly used as an industrial lubricant. With rapeseed oil’s high heat stability properties, it makes for a great option in the chemical and motor industries. It’s high monounsaturated fatty acid content and lubricity makes it an ideal candidate for environmentally friendly lubricants.
So essentially, rapeseed oil (HEAR oil) is what is often being used for industrial purposes, not culinary canola oil. Not to mention that just because something is used for an alternative purpose doesn’t mean it’s inherently unsafe to consume. That’s certainly not a good argument against the safety of canola oil….
Claim: “Hexane is produced during the extraction process, so canola oil contains hexane, which is toxic to humans.”
Is this true?
Hexane is indeed used in the production of canola oil to extract the maximum amount of oil from the seed after mechanical pressing. Hexane is a known volatile solvent with very low toxicity, meaning it doesn’t take much to ingest too much of it. However, what this claim fails to address is that the hexane used during extraction is then removed via a process called desolventization. This leaves only trace amounts of hexane behind in the oil, such trace amounts that it has not been shown to negatively impact human health. In fact, only about 2% of hexane ingestion has been shown to come from food sources. The majority of human exposure to hexane is from gasoline fumes. So if you’re truly worried about hexane exposure, I would start by looking at those non-food sources.
If the idea of trace amounts of hexane in your canola oil still freaks you out, there are other canola options available. You can find what’s called cold-pressed canola oil on the market nowadays. These are not treated with heat and don’t require the extraction process, eliminating the use of hexane altogether. This process can also help preserve fatty acid profile and bioactive compounds. This oil is usually labeled as “cold-pressed,” “unrefined,” “virgin,” etc. However, even these oils are often adulterated through processes such as undisclosed blending, which mixes the cold-pressed oil with traditionally processed oil. In this case, it can be helpful to purchase oil from reputable sources that have been verified to meet certain quality standards.
In general, the trace amounts of remaining hexane in traditionally extracted canola oil is generally regarded as safe by the FDA and appears to be negligible with regards to its impact on human health.
Claim: “Canola oil is rancid by the time you buy it from the grocery store.”
Is this true?
I just want to quash this claim right here and now, because I think it’s utterly ridiculous. Canola oil is shelf stable for 1-2 years. How it is stored (time, temperature, air, light) impacts how long the oil will last before turning rancid. It’s very clear that those who are claiming canola oil is rancid when you buy it have never actually been around truly rancid oil. When oil is rancid, you know. The smell alone would immediately alert you to its rancidity, but also the taste if you actually used it.
One of the benefits of using canola oil is its moderately high smoke point compared to other cooking oils, at upwards of 400° F. An oil’s smoke point is the temperature at which it will start to smoke, and subsequently lose some of its nutritional value and develop an unpleasant taste. So using oils with higher smoke points for high-heat cooking methods is a good idea.
Important Note: Any oil will start to degrade with continued high-temperature heat exposure. A common example of this is reusing oil for commercial deep-frying. (This is commonly done in foodservice establishments that deep fry food.) When oil is reused, it becomes oxidized and rancid, decreasing its nutritional value and even increasing levels of trans fat. Therefore, I generally recommend staying away from deep-fried foods, especially when eating out. It’s important to note that this will happen with any oil that is subject to continued high-temperature heat exposure, not just canola oil.
Benefits of Canola Oil
After going through the various claims against canola oil, let’s talk about the benefits.
Canola oil, like many vegetable oils, is low in saturated fat and high in mono- and polyunsaturated fatty acids (MUFAs and PUFAs). Therefore, replacing things such as butter, coconut oil, or palm oil with canola oil can help to lower LDL cholesterol and reduce heart disease risk.
As mentioned above, canola oil also has a moderately high smoke point compared to other cooking oils. This makes it easier to cook with at higher temperatures and lowers risk of heating to a point where nutritional value is decreased and oil becomes rancid.
It’s also important to mention that canola oil is relatively inexpensive and widely available, making it a great option for cooking oil. (I want to note that, due to its low cost, canola is often used in highly processed foods. This tends to give it a bad rap, but does not mean that canola oil is unhealthy.)
Because of all of the known benefits, I recommend using canola oil for things like stir-frying or roasting. It’s a cost-effective, nutritious, and versatile option!
Oils to Limit
Rather than avoiding canola oil, I encourage people to limit the below oils instead. Of course, I believe that all foods can fit into a healthy diet. However, limiting these oils whenever you can is a good idea.
For some reason, coconut oil has become known as a “healthy” oil option in recent years. However, this oil is extremely high in saturated fat. Therefore, I recommend using it in moderation.
Palm Oil/Palm Kernel Oil
Not only are palm oils detrimental to the environment, but are very high in saturated fat, especially palm kernel oil. Unfortunately, palm oil is currently present in a lot of foods in our food system. However, I recommend trying to consume it in moderation when possible.
Partially Hydrogenated Oil
Lastly, and most importantly, I recommend completely avoiding anything with partially hydrogenated oil, if possible. (My clients know that this is the one thing I recommend avoiding entirely.) This is because of the known risk of trans fats. Several decades ago, trans fats were found to increase LDL (bad) cholesterol and decrease HDL (good) cholesterol, greatly increasing risk for heart disease. Though many efforts have been made to rid our food system of trans fats, some products may still have it. Some examples of these foods are shortening, commercial baked goods, nondairy creamer, frozen or refrigerated dough, and fried foods (as mentioned above).
Canola oil and the surrounding industry has been heavily researched over the last century. And the overwhelming majority of this research shows us that canola oil is not only safe, but beneficial for overall long-term health. It’s a nutrient-dense, versatile option that’s inexpensive and widely available.
With all of the nutrition misinformation circulating the internet these days, I always recommend speaking to a medical professional, specifically a dietitian, when it comes to nutrition questions. It can be hard to differentiate someone who knows what they’re talking about from someone who doesn’t. Looking for medical credentials is always a good idea.