Is high-oleic sunflower oil healthy?
Increasingly used in packaged foods, this fat is beneficial compared to other seed oils, yet also has drawbacks.
As the seed oil debate rages on, you may hear people or companies pitching high-oleic sunflower oil as a solution. It’s been dubbed a “better for you” culinary oil compared to regular sunflower oil and other industrial seed oils (such as soybean, corn, canola, cottonseed, safflower, and grapeseed), since its fatty acid profile is more similar to olive oil and avocado oil.
Increasingly, brands are adopting high-oleic sunflower oil as the fat source in packaged foods like cereals, crackers, protein shakes, chips, and condiments like salad dressings, and some restaurants use it for deep-frying. That's because it’s more stable and less likely to degrade into harmful compounds when heated compared to other seed oils, and it’s typically more affordable than olive or avocado oil.
Get more deep-dives like this delivered to your inbox
Sign up to make sure you see our latest articles, as well as recipes and discounts
While it technically falls under the “seed oil” umbrella, high-oleic sunflower oil doesn’t have the key characteristic that seed oil detractors rage against: high levels of unstable omega-6 polyunsaturated fats. Is it perfect? No. But this does highlight that not all seed oils are the same.
Here, we look at the potential benefits and downsides of high-oleic sunflower oil so you can make a choice you feel comfortable with when grocery shopping and eating out.
What is high-oleic sunflower oil?
High-oleic sunflower oil is a plant oil derived from sunflower seeds that have been bred through means like selective breeding (not genetic modification) to be ≥80% oleic acid (a monounsaturated fat) and lower in linoleic acid (an omega-6 polyunsaturated fat).
Since it’s extracted from the seeds—rather than the pulp or fruit—of a plant, high-oleic sunflower oil is a seed oil. However, it differs significantly from other seed oils in terms of its fatty acid profile—especially its much higher monounsaturated fat and lower omega-6 content. Compare it to conventional sunflower oil or soybean oil.
| Oil type | Monounsaturated fatty acids | Omega-6 polyunsaturated fatty acids (linoleic acid) | Saturated fatty acids |
|---|---|---|---|
| High-oleic sunflower oil | 82 percent | 9 percent | 9 percent |
| Conventional sunflower oil | 21 percent | 68 percent | 11 percent |
| Conventional soybean oil | 22 to 30 percent | 50 percent | 12 to 15 percent |
Overall, high-oleic sunflower oil has a fatty acid profile closer to extra virgin olive oil (up to 83 percent monounsaturated fat) and avocado oil (up to 70 percent monounsaturated fat). Conventional sunflower oil is similar to other seed oils, such as safflower, corn, and soybean oils, due to its higher omega-6 polyunsaturated fatty acid content.
Monounsaturated fats resist oxidation better than polyunsaturated fats, and they offer cardiovascular and other metabolic health benefits—as such, high-oleic sunflower oil is often considered a better seed oil option. A rising preference for healthy oils in processed foods is one reason the sunflower oil industry is projected to grow almost 50%, from $13.4 billion in 2023 to $19.6 billion by 2030.
How is high-oleic sunflower oil made?
Production of high-oleic sunflower oil closely resembles that of other seed oils. Unlike the fairly simple production process of something like extra-virgin olive oil—in which olives are ground into a paste, fruit solids are separated from the oil in a centrifuge, and the finished oil is filtered, all with minimal heat exposure—making seed oils involves significant processing, refinement, and heat exposure. The process goes something like this:
- Extraction: Producers crush or press sunflower seeds and extract the oil. They mix the crushed seeds with a chemical solvent like hexane to release the remaining oils (unless it’s an organic oil, since USDA organic standards prohibit hexane extraction; organic HO sunflower oils are typically expeller- or cold-pressed).
- Refinement: Manufacturers may “wash” the oil with a solution of citric acid and centrifuges it to remove unwanted compounds like phospholipids, free fatty acids, and trace metals, which can create “off” flavors and colors or lead to early spoilage.
- Bleaching: Processors heat the oil up to 230°F and mix it with a bleaching clay to remove additional unwanted compounds—such as color pigments (like carotenoids and chlorophylls) and heavy metals—that can increase the rate of oxidation.
- Deodorizing: Manufacturers treat the oil with steam distillation, at temperatures reaching up to 464°F, to remove other impurities like pesticides, protein fragments, and free fatty acids, leaving it flavorless and odorless.
While the end result is sunflower oil with a neutral taste and a high smoke point (around 450°F for refined, high-oleic sunflower oil; varies by brand and refining), this process also removes healthy compounds such as polyphenols, sterols, squalene, and tocopherols (which have vitamin E activity). Small amounts of potentially harmful byproducts may also be generated via this type of processing, which we’ll cover later.
What are high-oleic sunflower oil’s benefits?
High-oleic sunflower oil's molecular composition gives it advantages over conventional seed oils in two key areas: enhanced stability during cooking and storage, and potential heart health benefits. Here's how these benefits break down.
It’s more stable and less prone to oxidation
Most of high-oleic sunflower oil’s benefits over other seed oils are because it has a higher proportion of monounsaturated fatty acids versus polyunsaturated fatty acids. Monounsaturated fats are more stable than polyunsaturated fats.
This comes down to molecular structure: Monounsaturated fats have just one double bond between the carbon atoms in their fatty acid chain, while polyunsaturated fats have two or more double bonds. The more double bonds present, the less stable the fatty acid molecules, and the more likely they are to degrade or oxidize when exposed to oxygen, light, or heat.
Research shows that when polyunsaturated fat-rich seed oils are exposed to high temperatures or stored at room temperature for prolonged periods, they are more likely than monounsaturated fats to generate compounds with cell- and DNA-damaging and inflammatory properties.
In a 2024 study, researchers compared the oxidative stability of conventional and high-oleic sunflower oils by evaluating their induction period (IP). This is the time it takes for a heated oil to begin breaking down and generating potentially harmful oxidation products. At 248°F, high-oleic sunflower oil had a superior IP compared to other oils:
- High-oleic sunflower oil: 11.8 hours
- Conventional sunflower oil: 2.6 hours
- Soybean oil: 1 to 7 hours
- Canola oil: 3 to 5 hours
Because of its enhanced oxidative stability, compared to polyunsaturated fat-rich seed oils, high-oleic sunflower oil is less likely to accumulate potentially harmful compounds during high-heat steps of oil production, such as deodorization, during high-heat cooking and food processing applications such as frying, and when sitting on store shelves for an extended period of time. This is why you’re increasingly seeing high-oleic sunflower oil used as an ingredient in shelf-stable products like protein shakes, cereals, and crackers, and it’s why some restaurants have proudly announced the switch to high-oleic sunflower oil in their deep fryers.
It may offer cardiovascular benefits
In some situations, high-oleic sunflower oil may support cardiovascular health.
In a 2005 study, people who ate a diet with 20 percent of total calories coming from monounsaturated fat in the form of high-oleic sunflower oil for 10 weeks had lower levels of LDL cholesterol, triglycerides, and a clotting protein compared to those who consumed a comparable amount of saturated fat. And a 2010 study found that replacing 13 percent of people’s daily calories from carbohydrates with monounsaturated fats from high-oleic sunflower oil led to higher levels of beneficial HDL cholesterol and lower levels of the inflammatory marker C-reactive protein. However, the study didn't test the effects of any other monounsaturated fat-rich oils—like olive or avocado oil—to see the relative benefits of each.
When compared to saturated fatty acids, research suggests that oleic acid may improve the function of blood vessels when inflammation is present, protect against insulin resistance in the heart and blood vessels, and help reduce the formation of atherosclerotic plaque buildup.
In 2018, the FDA decided there was enough scientific evidence to allow companies to use the qualified health claim that daily intake of 1.5 tablespoons of high-oleic acid oils (with more than 70 percent oleic acid) could reduce the risk of coronary heart disease. To achieve this effect, these oils should be used in place of saturated fats and without increasing total daily calories. (Note: Olive oil also qualifies as a high-oleic acid oil, so these perks aren’t unique to high-oleic sunflower oil.)
Finally, a tablespoon of high-oleic sunflower oil has about 38 percent (5.75 mg) of the recommended dietary intake of vitamin E. Some research shows vitamin E prevents the oxidation of LDL cholesterol particles, which is thought to be a key step in initiating atherosclerotic plaque buildup. However, the oil’s overall antioxidant profile is less diverse and potent compared to something like extra-virgin olive oil.
What are high-oleic sunflower oil’s potential downsides?
The biggest downsides of high-oleic sunflower oil stem from the fact that most of it undergoes intensive processing.
It may contain harmful fatty acid esters
While processing generally aims to remove unwanted compounds, side reactions can occur due to high heat exposure, particularly during deodorization. This can lead to the formation of potentially harmful compounds such as fatty acid esters (like 2-MCPDE, 3-MCPDE, and GE). When digested, these fatty acid esters convert to their free forms, some of which have been classified as possible and probable carcinogens to humans by the International Agency for Research on Cancer (IARC).
Researchers are investigating ways to upgrade current oil processing methods, some of which have been shown to reduce the formation of these fatty acid esters in high-oleic sunflower oil by 48 to 70 percent. However, it is unclear if and when these upgrades will be adopted. Keep in mind: Fatty acid esters aren’t unique to high-oleic sunflower oil. Refined palm, corn, hazelnut, and coconut oil may be even more susceptible to their formation.
It lacks meaningful nutrients
Industrial processing also strips sunflower oil of many beneficial compounds with antioxidant and cholesterol-lowering properties, such as polyphenols, sterols, squalene, and tocopherols (compounds with vitamin E activity). Much of this happens during the high-heat deodorization step. This is one reason high-oleic sunflower oil can’t compete with extra-virgin olive oil in terms of overall health benefits, despite having a similar concentration of monounsaturated fatty acids.
In fact, a 2001 crossover study in postmenopausal women found that a 28-day diet enriched with high-oleic sunflower oil led to higher blood levels of lipid peroxides and thromboxane B2 compared to a diet enriched with extra-virgin olive oil. Lipid peroxides can drive oxidative stress (including the oxidation of LDL), while thromboxane B2 promotes blood vessel constriction and platelet stickiness. Researchers attribute these differences to olive oil’s rich supply of polyphenols and other bioactive compounds, and to its slightly lower levels of omega-6 polyunsaturated fats. So, while high-oleic sunflower oil may offer advantages over saturated fats, it appears less protective—and potentially harmful—compared to extra-virgin olive oil.
Repeat use increases harmful compounds
While high-oleic sunflower oil is a better choice compared to other seed oils for high-heat cooking methods like deep frying, it’s not immune to accumulation of potentially harmful compounds when the same oil is used repeatedly—as occurs in restaurant deep fryers. In a 2023 study, high-oleic sunflower oil used to fry several batches of shrimp over 24 hours accumulated large amounts of lipid oxidation products, primarily aldehydes. Using it for single frying applications at home would likely be less problematic.
Manufacturers use hexane for extraction
Finally, there’s concern about the use of chemical solvents like hexane during the extraction of non-organic oils. However, the health concerns of hexane are likely overblown. Experts estimate that hexane-extracted oils contain only about 0.8 milligrams of residual hexane per kilogram of oil (about 0.8 parts per million), far less than the levels to which pollutants like gasoline fumes expose us. However, hexane can contribute to environmental contamination when inappropriately disposed of.
Does it contribute to excessive omega-6 intake in Western diets?
One big argument against seed oils is that they contribute to excessive intake of omega-6 fats relative to omega-3 fats in our diets, and this imbalance drives inflammation. But that’s not the case for high-oleic sunflower oil. By definition, high-oleic sunflower oil is high in the monounsaturated fat oleic acid and relatively low in the omega-6 polyunsaturated fat linoleic acid. It even has fewer omega-6 fats compared to some varieties of extra-virgin olive oil.
If you’re consuming high amounts of processed or deep-fried foods that contain other common seed oils, however, you may be ingesting high levels of omega-6 fats, which could be crowding out healthier fat sources. While research is mixed on how directly an elevated omega-6 to omega-3 ratio impacts inflammation, we do know that incorporating more minimally processed foods and fat sources (such as fatty fish, nuts, seeds, avocados, and extra-virgin olive oil) and avoiding highly processed and deep-fried foods can help curb inflammation.
What’s the final verdict?
In the context of an otherwise nutrient-dense, high-quality diet containing varied fat sources, eating food prepared with high-oleic sunflower oil now and then is unlikely to cause harm. And, depending on what you’re using it to replace, it may offer some health benefits.
When it replaces seed oils rich in omega-6 polyunsaturated fats, high-oleic sunflower oil may improve the stability and health profile of packaged and fried foods, and reduce the intake of problematic lipid oxidation products. When it’s used as a cooking oil to replace saturated fats, it may support a healthier lipid profile and overall cardiovascular health.
However, despite being a superior pick compared to other seed oils, high-oleic sunflower oil is still highly processed, stripping it of beneficial polyphenol antioxidants and promoting the formation of potentially harmful compounds like fatty acid esters. So, you don’t want to use it in place of a minimally processed, antioxidant-rich oil like extra-virgin olive oil for home cooking.
Bottom line: While we wouldn’t call it a health food, high-oleic sunflower oil is a “less bad,” affordable choice that helps nudge the overall quality of our food supply in the right direction.
Take control of your health with expert guidance
Levels pairs real-time glucose data and comprehensive lab testing with clinician analysis and personalized support—everything you need to turn insights into real health improvements. Click here to get started with Levels.
