Q: What’s the best oil to use for cooking? I’ve heard I shouldn’t cook with extra virgin olive oil. What’s the healthiest oil?
I regularly recommend extra virgin olive oil as a nutritious and versatile cooking oil. It’s my go-to oil when sautéing or roasting vegetables (you can cook with it!), dressing salads and, sometimes, baking.
Olive oil, the principal fat in the well-studied Mediterranean diet, is an excellent source of heart-healthy monounsaturated fats, along with protective plant compounds that have antioxidant and anti-inflammatory properties.
But that doesn’t mean it’s the only bottle of cooking oil in my pantry. When deciding which oil to use, I consider how well it holds up to heat, its nutritional properties and the flavour it imparts to foods.
Cooking and smoke point
It’s often thought that extra virgin olive oil’s “smoke point” makes it unsuitable for cooking and baking. Not true.
The smoke point of a cooking oil refers to the temperature at which it starts to burn and smoke. When an oil is overheated, beneficial nutrients and phytochemicals are degraded and potentially harmful free radicals can be formed.
Olive oil (extra virgin and regular) has a relatively high smoke point, between 365 F and 410 F (185 C to 210 C). Stovetop cooking and oven roasting are typically done between 250 F and 400 F (120 C to 205 C).
Research also suggests that extra virgin oil is more stable at high heats than other cooking oils. Olive oil’s fat composition and antioxidant content are thought to protect it from breaking down.
Other oils that have a high smoke point, 400 F (205 C) and higher, include avocado, peanut, canola, grapeseed, sunflower and safflower oils.
Healthy fats, vitamin E, omega-3s
Cooking oils contain a mix of unsaturated fats, but will contain predominantly monounsaturated fats (e.g. olive, avocado, canola and peanut oils) or polyunsaturated fats (e.g. grapeseed, sunflower, safflower, walnut and flaxseed oils). The exception is coconut oil, which contains mostly saturated fat (82.5 per cent).
In 2017, after a comprehensive evidence review, the American Heart Association concluded that reducing saturated fat and replacing it with polyunsaturated or monounsaturated fats help reduce the risk of cardiovascular disease.
Both unsaturated fats help lower LDL (bad) cholesterol in the bloodstream. Diets high in unsaturated fats may also improve how the body uses insulin.
Some cooking oils are outstanding sources of vitamin E, an antioxidant that protects cells, especially brain cells, from damage caused by harmful free radicals. Several studies have associated higher vitamin E intakes from diet with a lower risk of Alzheimer’s disease.
Vitamin E also supports a healthy immune system by protecting immune cells from free radical damage.
Adults need 15 milligrams of vitamin E each day. Top sources include sunflower oil (5.6 mg a tablespoon), safflower oil (4.6 mg a tablespoon) and grapeseed oil (4 mg a tablespoon). Olive, canola and peanut oils have 2 mg a tablespoon.
Canola, walnut and flax oils are excellent sources of alpha linolenic acid (ALA), an anti-inflammatory omega-3 fatty acid. One tablespoon of walnut oil and canola oil supply 1,280 and 1,400 mg, respectively; one teaspoon of flax oil delivers 2,420 mg. Women require 1,100 mg of ALA a day; men require 1,600.
Flax and walnut oils have a low smoke point; use them in salad dressings, smoothies or drizzling over cooked foods.
Which cooking oil I use will also depend on what I’m making. For stir-fries, curries and certain baked goods, where I don’t want a pronounced flavour, I’ll choose a neutral-tasting oil. Grapeseed, peanut, canola, sunflower and safflower oils have very little flavour.
If I’m making a vinaigrette, I’ll choose extra virgin olive oil for its fruity, grassy flavour. Sometimes I add walnut oil to impart a nutty taste. I’ll also use sesame oil to add flavour to sautéed vegetables.
Extra virgin olive oil, grapeseed oil (or sunflower oil) and peanut oil are staples in my pantry, but I also stock walnut and sesame oils. And you’ll also find a jar of unrefined coconut oil, which I use to make granola.
Leslie Beck, a Toronto-based private practice dietitian, is director of food and nutrition at Medcan. Follow her on Twitter @LeslieBeckRD
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