Fat is an essential part of your diet, but there are healthy and unhealthy types of fats. This fact carries over to the category of cooking oils, which are made up entirely of fat. To find out which cooking oils are the healthiest, INSIDER consulted two registered dietitians and a chef from a health-focused restaurant. Here's what they had to say:
Healthy cooking oils are high in unsaturated fat, while unhealthy oils have saturated or trans fat
Kris Sollid, RD and senior director of nutrition communications at the International Food Information Council Foundation, explained that all cooking oils contain a blend of different types of saturated and unsaturated fats.
"While some cooking oils are higher in certain types of fat, no oil contains only one type," said Sollid. "A cooking oil is considered healthy if it is high in unsaturated fat. Cooking oils that are considered less healthy typically are high in saturated or trans fat."
Canola, olive, and soybean oil have great blends of heart-healthy unsaturated fats
Sollid listed canola, olive, and soybean oil as examples of healthy cooking oils due to their "excellent blends of heart-healthy fats."
"Olive oil is known for its high monounsaturated fat (MUFA) content, but it also contains a small amount of alpha-linolenic acid (ALA), an especially beneficial type of polyunsaturated (PUFA) omega-3 fat," said Sollid. He told INSIDER that monounsaturated fatty acids decrease LDL cholesterol and are considered to be more heart-healthy than saturated fat.
"Canola oil is also a great source of MUFA," said Sollid. "Compared to olive oil, canola oil contains less MUFA, but less saturated fat and more ALA omega-3 fats. Canola oil has the least saturated and the most ALA omega-3 fats of the common cooking oils." He explained that alpha-linolenic acid (ALA) is the plant form of omega-3 fatty acids and can be found in flaxseed, walnuts and canola and soybean oil.
Lastly, soybean oil (commonly labeled "vegetable oil") contains less MUFA than olive oil, but more PUFA and ALA omega-3 fats. "Polyunsaturated fatty acids (e.g., omega-3 and omega-6) can improve our health by helping to reduce total and LDL cholesterol, which is great for cardiovascular health," Sollid told INSIDER.
While common vegetable and nut oils contain small amounts of trans fats, they're still considered healthier than butter
Sollid told INSIDER that while common vegetable and nut oils contain trans fatty acids, the amount is so insignificant that they're not required to be listed on food labels.
"The heart-healthy benefits of cooking oils far outweigh any concerns about trans fat content," said Sollid. "For context, cooking oils have less trans fat than butter or other animal products that have naturally occurring trans fat."
This health-conscious chef chooses cooking oils based on what he's making
For Matt Aita, executive chef of The Little Beet Table (a vegetable-forward, gluten-free restaurant with locations in New York City and Chicago), choosing the best cooking oil comes down to how it's being used.
Aita recommended cooking with avocado oil as it's "high in monounsaturated fatty acids and can promote healthy cholesterol levels while enhancing absorption of some nutrients." He added that its high smoke point makes it a good choice for cooking (though recent research suggests that smoke point isn't an accurate predictor for cooking performance). Canola oil was also recommended for higher heat preparations as it's "low in saturated fat and has a higher smoke point than olive oil."
For cold preparations (cooking without heat), chef Aita recommends flaxseed and olive oil
While some oils are great for high-temperature applications like deep frying, some have delicate flavors and taste great cold (though they can still be used for cooking). "Flaxseed oil has the potential to reduce arthritis symptoms, but I suggest only using it for cold preparations," said Aita. (More research is needed to learn more about flaxseed oil's relationship to arthritis symptoms).
Olive oil has a variety of no-heat applications, including infusing it to make herb oils. "You can use [olive oil] in many different preparations: to dress a crudo or for something as simple as a vinaigrette for potato salad or watermelon salad," said Aita.
Oils like coconut and palm should be used in moderation
On the not-so-healthy side of things, Aita listed coconut, palm, and anything labeled as partially hydrogenated.
"These [oils] are often high in saturated fats and don't have the extra nutrition benefits, so I recommend using them in moderation," said Aita.
Sollid added that "eating partially hydrogenated oils can raise your total and LDL cholesterol (the 'bad' kind you want to keep low) and blood triglycerides, which increases your risk of heart disease."
One RD considers soybean and canola oil less-healthy options compared to avocado and olive oil
Pegah Jalali, MS, RD, and dietitian at Middleberg Nutrition, listed avocado and olive oil as healthier cooking oil options. Canola and soybean oils, on the other hand, were described as "inferior" because of the type of fat they contain.
"Canola and soybean oils are higher in omega-6 fats which are chemically less stable than other types of fat," Jalali explained. "This means they break down easily into metabolites that are inflammatory. The typical American diet is very high in omega-6 fats, which even though our body needs in small amounts is not desirable in large amounts."