What Oil Should I Use (Cooking)?

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Today's post is written by student Tanya Ruscheinski (with my input). Tanya will be starting to train as a dietitian next year. Thank you Tanya!

Meal planning and deciding between Roma or hothouse tomatoes takes up enough of your time during the week (who are we kidding, the family has to eat on the weekends too!), deciding which cooking oil to use shouldn’t take up more of it. But with all the options out there on the grocery shelves, how do you know which one to pick up?

Actually, there’s no one-size-fits-all solution here, as you’ll soon find out. This is because different cooking oils have different chemical and nutritional properties that make them best suited to certain types of use. That being said, some are generally better suited for cooking than others, and the good news is that they have all been broken down here into their best uses. So read on, budding oil connoisseur.

Cooking oils, also referred to as vegetable oils, are obtained from plant sources and contain heart-healthy mono- and polyunsaturated fats, as well as vitamins E and K and certain other beneficial minerals. This is in contrast to animal fats, such as butter or lard, as well as hydrogenated vegetable oils including shortening, which are high in saturated fats. Although the satisfying go-to choice for many, these fats are less healthy and have been linked to a higher risk of heart disease later in life.

Smoke Point

Among cooking oils, the most important thing to consider when choosing which one to use is its smoke point. An oil’s smoke point - as you might have already deduced - is the temperature at which an oil begins to burn and smoke. 

An oil that has been heated past its smoke point will affect the flavour of your food, but it will also degrade many of the oil’s nutrients and release free radicals that, when consumed, our bodies must then work to eliminate. Since this should be avoided, you want to choose an oil that will withstand your cooking heat. Here’s how they compare:

  • Corn, peanut, (refined) safflower, soybean, and (refined) sunflower oilsall have a high smoke point around 450°F and are good for cooking at high heat. Avocado oil has an even higher smoke point at 520°F, and is a fantastic choice for all cooking purposes from stir-frying and roasting to drizzling on salads. Pomace and light olive oils- refined versions of extra virgin olive oil – also have high smoke points and are safe for cooking, unlike their extra virgin counterparts.
  • Almond, canola, sesame, coconut, walnut, grapeseed, and virgin olive oilshave medium-high smoke points (between 350°F and 420°F) and can generally be used for cooking so long as the heat isn’t too high.
  • Flaxseed, hemp, and extra virgin olive oils have smoke points below 350°F and should not be used for cooking. Try adding them to salad dressings, in homemade dips and pesto, or drizzled on top of soups or popcorn instead.


Beyond the smoke point – if you want to start getting fancy – you may want to consider the flavour profiles of your cooking oil. For example, avocado, peanut, almond, walnut, and flaxseed oils have a nutty flavour and are perfect if you want to balance out a fruity or sweet flavour. Strawberry and feta spinach salad with almond oil dressing anyone?

If you want your oil to just serve as a means of cooking and not impart any extra flavours, canola, corn, safflower, sunflower, and grapeseed oils are all great options. In contrast, soybean and sesame oil have strong robust flavours and are great for salad dressings that pack a flavour punch.

Types of Fat (and What's Healthy)

Finally, lets bust out a little science and look at the chemical makeup of different cooking oils (and why it matters!). Interestingly, coconut oil contains the highest proportion of saturated fat out of all the cooking oils – even more than butter or lard! - making up between 80% to 90% of its fat content (which is why it’s solid at room temperature). While saturated fat raises LDL (bad) cholesterol levels, coconut oil also appears to raise HDL (good) cholesterol levels, too, not to mention the other vitamins and minerals it provides. That being said, while coconut oil is more nutritious than butter (and makes for a wicked Thai curry), it’s best not to use it as your only go-to cooking oil.

In contrast to coconut oil, the rest of the cooking oils contain a very low amount of saturated fat and instead have high levels of unsaturated fat. There are two types of unsaturated fat, monounsaturated and polyunsaturated. In turn, there are two types of polyunsaturated fats:  omega-3 and omega-6 fatty acids.   

Monounsaturated fat is a healthy choice. Almond, avocado, safflower, and olive oil contain predominantly monounsaturated fats like omega-9 oleic fatty acids.

Currently our understanding is that you want to maximize your omega-3 compared to your omega-6 fat intake. That's why we recommend eating lots of fatty fish and take an omega-3 supplement (either fish oil or algae-based). Omega-6 fatty acids are highest in sunflower, corn, grapeseed, walnut, and hemp seed oils. Omega-3 fatty acids dominate in flaxseed oil, and are notably high in hemp seed oil.

Tips for Storing Oils

No matter which oil you choose, you need to make sure you store it properly to maximize its shelf life. Heat and light can destroy oil’s delicate antioxidants and eventually cause spoilage. Store your cooking oils in a cool, dark place to help maintain freshness. The exceptions here are hempseed and flaxseed oil, which are ultra-delicate and should be stored in the fridge.

Kristen's Bottom Line

So, what oil should you use? I recommend avocado oil for high heat cooking (e.g. sautéing, stir-frying) and olive oil for low heat cooking. For salads, choose an oil that matches with your flavour profile - olive oil, avocado, flax, hemp, etc. Oh, and eat your nuts, seeds, fish, and avocados as healthy fats. 

Looking for healthy recipes? Check out my recipe page

Photo credit: Photo by Roberta Sorge on Unsplash