Everything You Need to Know about Cooking Oils

by | Jun 16, 2015 | Last updated Feb 15, 2022

Whether we realize it or not, cooking oils play a large part in all of our diets. From coating the bottom of a pan to topping some of our favorite foods, cooking oils are present in most of the food we eat (especially if it’s processed).
But with the plethora of options available — olive and canola and coconut, oh my! — it can be tough to navigate the cooking oil market. We’ve broken down a bit about cooking oils, which oils you should be using, and what to use them for.
All cooking oils are categorized as fats. Fats get a bad rap but fat is a major energy source for our bodies and is necessary for certain bodily functions, including absorbing vitamins and minerals and building cell membranes. It’s also essential for blood clotting, muscle movement, and inflammation. The takeaway? Fats can be good for your body, so don’t eliminate them from your diet entirely. Focus on choosing ‘good’ fats and consuming them in moderate amounts.
Cooking oils are a great way to add healthy fats to your diet, but not all cooking oils are created equal. All cooking oils have around the same amount of calories per tablespoon (about 120), but their nutritional contents can differ vastly. (Pro tip: If you can’t find your measuring spoons, 1 tablespoon of oil is about the size of a poker chip.) The best oils for cooking have a high smoke point. Oil’s smoke point is the temperature at which it begins to smoke, break down, and lose its taste and nutritional quality.
High-heat all stars
High-heat cooking includes pan frying, sauteing, grilling, and pan-roasting. The high-heat provides a sear while a lower level heat finishes the cooking. Anything above 375°F is considered high-heat cooking.
Avocado oil is full of monounsaturated fat, which has been shown to reduce “bad” cholesterol and boost “good” cholesterol, which can reduce risk of heart disease. Avocado’s high potassium and lutein content may help promote normal blood pressure and help control inflammatory stress. Avocado oil has one of the highest smoke points — 520 degrees — making it great for high-heat cooking including grilling, pan roasting, sauteing, and baking. If you’re in a no-cook kind of mood, drizzle on top of your salad to increase the amount of beneficial nutrients your body can absorb from salad greens.
Peanut oil, another oil with a high monounsaturated fat content, has also been shown to lower cholesterol and reduce risk of heart disease. In addition, peanut oil contains resveratrol, a substance that has been linked with reduced risk of cardiovascular disease as well as reduced cancer risk. Peanut oil also has a neutral flavor and high smoke point, making it great for high-heat cooking.
Medium-heat cooking includes simmering and reductions, and can be used to cook food all the way through or to finish foods that began in high-heat cooking. Medium heat ranges from 325°F to 374°F. Medium/Low heat ranges from 250°F to 324°F and is good for slow cooking things like lean meats, stews, stocks, and reductions.
While health-gurus and wellness bloggers swear by coconut oil, organizations such as the American Heart Association recommend limiting the amount of saturated fat (like that found in coconut oil) in your diet. While recent studies have found no link between saturated fats and heart disease, limiting saturated fat intake is still recommended. But this doesn’t mean you need to discard coconut oil all together. Coconut oil is able to withstand fairly high-heats (up to 350 degrees Fahrenheit for unrefined varieties) and could raise your “good” cholesterol, improve insulin sensitivity in type 2 diabetics, and be beneficial for weight loss.
Low-heat, high-flavor
Olive oil
Olive oil, another monounsaturated fat, is high in antioxidants called polyphenols that have been linked to heart health. The type of fats found in olive oil have also been shown to normalize blood clotting and benefit insulin levels in type 2 diabetics. The best type of olive oil is expeller or cold-pressed, meaning it has not been exposed to any chemical solvents in the process of creating the oil. Because of olive oil’s low smoke point, it is best to use it as a salad dressing, topping for veggies, or for cooking with low-heat.
Flaxseed oil
Fresh flaxseed oil has a clear, uniform, gold-yellow color free of cloudiness and has a light, nutty aroma. Flaxseed oil has a crisp, nutty flavor and a low-smoke point, making it a perfect topping for dishes looking for a little extra flavor. Use as a salad dressing or dip for bread. Flaxseed oil has been known to reduce blood pressure, reduce risk of skin cancer, treat depression, and reduce risk of liver disease.
Vegetable oils
The name vegetable oil is somewhat misleading as there are no oils created using vegetables. Vegetable oils (most of which are made from seeds, not vegetables) are created by extracting the oil out of rapeseeds (canola), cottonseeds, sunflower seeds, safflower seeds, and soybeans.
Because it’s difficult to extract oil from a cottonseed or a rapeseed (unlike naturally oily olives), the creation of these oils normally necessitates the use of high-heat and chemical solvents, including hexane. (If you’d like to see how mass-produced canola oil is made, check out this video from the Discovery Channel.) Why does this matter? When vegetable oils are heated, they can become oxidized, meaning there has been a breakdown of the oil’s chemical make-up. Excessive oxidation in the human body can damage cell membranes and other structures including cellular proteins, lipids, and DNA.
What does this mean in real talk? Oxidation can contribute to deterioration of the eye lens, inflammation of the joints, damage to nerve cells in the brain, acceleration of the aging process, and increased risk of heart disease.
Of course, this is not to say that if you eat vegetable oil you will go blind. But when other alternatives offer such great health benefits, why not choose a less oxidized option? If you are going to opt for vegetable oil, choose a cold-pressed variety, which does not apply as much heat as normal processing and uses no chemical solvents (for more tips on how to keep your vegetable oil from oxidizing, click here).
Most importantly, remember that moderation is key. Oils are a great way to add healthy fats to your diet, but just because they’re deemed healthy doesn’t mean you should go overboard. Use it to saute, measure a tablespoon for salad dressing, or coat meats before baking. Experiment and find a variety that you like — have fun with it!