Confused about seed oils? Everything you need to know from health benefits to cooking options. – UCHealth Today

If you’ve been confused about which oil to use when you cook, sauté, broil and bake, you’re not alone.

A stroll down the grocery store aisle offers consumers dozens of choices ranging from the tried-and-true vegetable and canola oil to scores of olive oils, as well as ones a little off the beaten track like hemp, avocado, sunflower and flax.

So, which oils provide the best punch up for flavor and nutrition when making healthy and good-tasting recipes?

For answers, UCHealth Today spoke with Rebecca Kerber, clinical dietitian and certified diabetes care and education specialist at the UCHealth Diabetes and Medical Nutrition Therapy in Colorado Springs.

Why has there been a growing interest in different types of cooking oils?

“The past few decades have seen an explosion of choices when it comes to what we eat and how we eat,” Kerber said. “And that includes a fundamental kitchen staple: cooking oil.”

Recently, certain types of vegetable oils, also known as seed oils, have been getting a bad rap as the subject of online news stories – something Kerber disagrees with.

“There is a lot of online nutrition information that contains so many falsehoods. If anything, we know that fear sells, and that is true for what we eat. When I read about so-called experts touting a certain ‘miracle’ food that is really good for you or blaming a certain food like a particular seed oil that they say is really bad, that’s a red flag. Seed oils are just one component of what should be a well-balanced and nutritious diet.”

What is a seed oil?

A seed oil is a cooking oil named after the plant, vegetable, seed or nut that the oil came from, for instance, corn, canola, sunflower or peanut.

Why are they called seed oils?

Manufacturers name the oil after the seed or plant from which the oil is derived.

What is the difference between a seed oil and a vegetable oil?

Generally, these labels are used interchangeably. To be precise, all seed oils are vegetable oils, but not all vegetable oils are seed oils. For instance, oil from olives, avocados and coconuts are vegetable oils but not seed oils, as their oil is derived from the vegetable/fruit itself and not a seed, she said.

Still, using the term “seed oil” as opposed to vegetable oil is, in many respects, a marketing and business decision that manufacturers made over the past several years in efforts to re-brand the cooking oil industry as more heart-healthy.

How are these oils derived?

The oils are extracted from the plant or seed through either a mechanical or chemical process that includes bleaching, refining and heating.

What did people use to cook with before today’s choices of oils?

Up until about 25 years ago, saturated fats (solid at room temperature) were the go-to for most cooking needs. Think bacon grease, lard and margarine.

“Public awareness and growing medical research showing that trans fats were not safe and contributed to heart disease, contributed to a push toward other oil alternatives,” Kerber said.

But that’s not to say that certain oils haven’t been around for centuries for instance, ancient Egyptians cooked with olive oil and many cultures used plant and seed oils in cooking.

“Cooking with oils is not a new concept, though it’s more popular and easily available nowadays with so many to choose from.”

Why are we hearing so much about seed oils now? 

There are several reasons why seed oils are a hot topic, Kerber said. The trend to eat healthier foods has increased interest in oils such as avocado and flax, as well as our understanding of trans and saturated fats and how they elevate our risks for heart disease and strokes.

Explain the different types of fats and how they relate to cooking oil. 

Kerber said if we put fat on a spectrum of beneficial to harmful when it comes to heart health, the rankings from worst to best are:

• Trans fat in the form of partially hydrogenated oil is the worst for our bodies. Rarely used today but once quite common in food and used in margarine, trans fat was formed through a manufacturing process that converted vegetable oil into solid fat at room temperature.
• Saturated fat comes from dairy and animal sources like bacon, red meat and chicken and is solid at room temperature.
• Poly and monounsaturated fat is the best fat for our body and includes all seed/vegetable oils and oils from fish, nuts, avocados, peanuts and other nut butters. Oil from these foods is liquid at room temperature.

Why are some people saying we shouldn’t eat certain seed oils?

Kerber said seed oils are getting an undeserved bad rap because some of them have a higher ratio of Omega-6 as opposed to Omega-3. Both are versions of unsaturated fats that our body needs: Omega-6 is contained in corn and sunflower oil, while Omega-3 can be found in flaxseed and canola oil.

“Both of these fats, in moderation, are important for our health. Unfortunately, some articles like to pit them against each other, as if one is good, then the other must be bad. Omega 3 has more anti-inflammatory benefits than Omega 6, but that does not mean Omega 6 fatty acid is bad for you, it is just not as beneficial as Omega 3.” 

Is there such a thing as a ‘good’ seed oil and a ‘bad’ seed oil? 

There is not necessarily a good or bad seed oil. Kerber is more concerned about what type of food you’re eating rather than the specific oil you’re cooking it with.

“If the oil is one of the ingredients in a packaged, premade meal full of lots of sugar and sodium, those are things we worry about more than the type of seed oil it contains.” 

Are there certain oils I should avoid?

Again, Kerber is not as concerned about the type of oil you’re using as much as what you are using it for. She takes a more nuanced, common-sense approach to “rules” around food.

“When someone asks me what foods they should avoid, I tell them anything they don’t like and anything they’re allergic to.”

Looking at the nutritional values of oils and fats in general, she typically wants her patients to use unsaturated fats or ones that are liquid at room temperature, which includes all seed and vegetable oils, as they help lower cholesterol and reduce the risk of heart attack and stroke.

Oils that are solid at room temperature that come from saturated fat, such as bacon grease, lard, butter and coconut oil, should be used more sparingly for specific recipes as they contribute to higher cholesterol and increase the risk of heart attack and stroke.

Coconut oil is a saturated fat. Should I avoid cooking with coconut oil? 

“It was very popular for a while, about 10 years ago, but since it is a saturated fat, I would treat it the same way I do butter. Use sparingly and try using unsaturated fats like olive oil instead.”

Is palm oil in the same (saturated fat) category as coconut oil?

“Yes, since palm oil is solid at room temperature, it, too, should be used sparingly, if at all.”

Another important reason to avoid palm oil is that its use has contributed to deforestation through the proliferation of oil palm plantations in certain parts of the world, she said.

Are there health risks associated with other seed oils?

According to Kerber, the main health risk of seed oils is their “caloric density” at nine calories per gram (stacked up against protein and carbohydrates which are just four calories per gram.)

“Calories add up if you have a diet high in any type of fat, including these oils,” she said.

“Not specific to seed oil, we need to watch out and be mindful about how much oil and fat we are taking in, whether we are cooking with oil in general or having salad dressings comprised of oil. This does not mean we should avoid fat altogether, though. Our bodies need fat, but a high-fat diet is certainly not something I’d recommend for most people.”

Do seed oils put us at a higher risk for cancer and cardiovascular heart disease? 

No. Seed oils reduce the risk for cancer and cardiovascular heart disease.

Does all packaged food contain seed oils? 

A lot of packaged foods do contain oils, as they are a common ingredient in manufactured food; but again, Kerber said it’s not necessarily the oil that is the problem, but the high amount of sugar and sodium as compared with low amounts of protein and fiber in these products.

Are seed oils high in saturated fat?

They are not. Seed oils are liquid at room temperature, so they are low in saturated fat.

Are there good fats contained in these oils? 

“As I mentioned, Omega 3 and Omega 6 are ‘good’ fats in vegetable and seed oils, and both are part of a healthy diet.”

Are there any reasons not to use seed oils?

“The only reasons I would tell someone not to use these oils is if you don’t like the taste of them, or if you are following a calorie-restrictive diet and limiting fat intake for medical reasons with the oversight of a dietitian. In these cases, you could try air frying or cooking in water.”

Have fast food restaurants changed the oils they use, and why?

About 10 years ago, there was a big push in the United States to eliminate trans fat in restaurants and manufactured food, and in 2015, the U.S. Food and Drug Administration gave food-makers until 2018 to eliminate them from the food supply.

“We know that trans fat, even at low amounts, contributes to heart disease. Most restaurants, but not all, have eliminated trans fat, and margarine is now made with olive oil, flax oil, or sunflower oil.”

What oil should I use for cooking?

It depends on what you’re cooking and your access to different oils, she said.

While olive oil could be deemed a more beneficial choice than canola oil, the higher costs may put it out of some people’s price range.

“You can cook just fine with either. Many people must make tough choices at the grocery store. I would rather have people buy what they can afford and have less stress financially. Again, it’s as or more important what you’re cooking in the oil, as opposed to the oil itself.”

What does the ‘smoke point’ of an oil mean?

The smoke point of an oil is the temperature at which it starts to burn and smoke.

If you are sauteing or roasting food for a longer period of time and at a temperature over 400 degrees, you are going to want an oil with a higher smoke point such as canola, avocado, sesame, extra virgin oil, safflower or peanut oil, she said, as opposed to ones with a lower smoke point such as walnut oil, flax oil, palm oil, or a cold pressed olive oil, which she likes to use in dressings.

Speaking of olive oil, which one should I buy?

“No particular olive oil is healthier than another,” she said.

Cold-pressed olive oil shouldn’t be used for cooking as it has a low smoke point and instead, should be used for dressings and marinades. Purified extra virgin oil is the one to reach for when cooking. 

What oil should I use if I want to adopt the Mediterranean diet?

Olive oil is traditionally the primary oil used in the Mediterranean diet, but other seed oils will provide similar benefits. Oils from fatty fish, nuts and seeds are also a staple in the Mediterranean diet.

Should I use different oils for different types of foods?

If you’re not cooking at high heats when reaching an oil’s smoke point could be an issue, she suggests picking the oil that best suits your taste buds.

“Cook with whatever oil you like that is going to enhance the flavor profile of your meal. Seed oils are a great way to boost the enjoyment of food in a healthy way. As an example, using sesame seed oil in a stir fry with broccoli and other vegetables is not only heart smart, but delicious.”

Do seed oils boost our immune system?

“No one single food does that. But overall, having a well-balanced diet high in unsaturated fat, that includes seed oils, can help us accomplish that.”

What oil do you mostly cook with?

“I mainly cook with olive oil, as it has a good balance of those healthy Omega 6 and Omega 3 unsaturated fats that we talked about earlier. It has a neutral flavor, it cooks well with everything, and it’s more cost-effective than avocado oil, which is another very healthy choice.”

How should I introduce seed oils into my diet?

Take small steps, she said. For instance, try swapping out butter for eggs with oil; make homemade dressings and marinades instead of store-bought ones that may be loaded with sugar and salt; reach for seeds, avocados and nuts that contain healthy oils as opposed to chips.

“Think about what you cook, what you like to eat and how much you can budget for groceries. Make a list when you head to the store to help you select healthy foods that taste good and that you enjoy making for yourself, family and friends.”