Are Seed Oils Bad for You? Here's What the Science Shows

Seed oils like canola and sunflower oil are commonly used in processed foods like baked goods. Now, some wellness influencers say they’re avoiding seed oils, claiming that the omega-6 fatty acids in these oils are toxic and inflammatory.

Robert F. Kennedy, Jr., the Trump administration’snominee to run the Department of Health and Human Services, also blamed seed oils as one of the “driving causes of the obesity epidemic” in arecent Instagram post.

Social media users often refer to seed oils as the “Hateful Eight.” This group includes canola (rapeseed), corn, soybean, sunflower, cottonseed,safflower, grapeseed, and rice bran oils.Anti-seed oil influencers often post videos from grocery stores, encouraging followers to avoid any item with these oils.

But for many people, it’s hard to avoid seed oils. These oils are prevalent in the U.S. food supply, especially in processed foods, which make up 60% of the typical American diet.Common items like chips, popcorn, and bread often list sunflower or soybean oil on their ingredient labels.

“Many ultra-processed foods are lower in nutrient density, but the oil itself has really been demonized,”Judy D. Simon MS, RD, CD, a registered dietitian nutritionist at the University of Washington Medical Center, told Verywell.

McDonald’s cooks its fries in a canola oil blend, but RFK Jr. has advocated for a return to beef tallow, which was used until 1990.“This switch was made because saturated animal fats were thought to be unhealthy,” Kennedy said in an Instagram post. Consuming excessivesaturated fatcan raise levels of “bad” cholesterol, increasing the risk of heart disease and stroke.

Even if you skip fast food altogether, steering clear of seed oils can be difficult. But do you even need to avoid seed oils to maintain a healthy diet?

Saturated vs. Unsaturated Fats

What Are the Health Benefits of Seed Oils?

Dietary fats and oils contain a mixture of healthy fats—polyunsaturated and monounsaturated—and less healthy saturated fats.Polyunsaturated fats include omega-3s and omega-6s. Fatty fish contain more omega-3s, while seed oils contain more omega-6s.

TheDietary Guidelines for Americansrecommend reducing saturated fats in favor of unsaturated fats.The American Heart Association also recommends consuming monounsaturated and polyunsaturated fats, like those fromseed oils, nuts, and tofu, instead of saturated or trans fats.

“Research has shown us over the years that consumption of these polyunsaturated types of fats has actually been correlated with a lower risk of mortality from cardiovascular disease and cancer, and so they’ve had positive health benefits,” Simon said.

Contrary to claims on social media, studies have shown that dietary intake of linoleic acid, the primary omega-6 in seed oil, does not increase inflammatory markers in the blood.Linoleic acidmay actually help lower heart disease risk.

Oxidation is another reason some people decide to avoid seed oils. Heat and light can cause the unsaturated fatty acids to oxidize and produce free radicals.Unsaturated fatty acids, especially linoleic acid, oxidize quicker than saturated fats.

Omega-3s and Omega-6s May Reduce Overall Cancer Risk, Study Finds

Is Beef Tallow Healthier Than Seed Oils Though?

Seed oils, like all fats, provide 9 calories per gram, while protein and carbohydrate sources provide 4 calories per gram.

“Excessive consumption of calorie-dense foods, including those containing seed oils, can contribute to a caloric surplus and, subsequently, weight gain,” Derocha said. However, the evidence does not support blaming seed oils alone.

“Much of the criticism of seed oils stems from their widespread use in ultra-processed foods, like fried snacks, baked goods, and fast food, which are high in calories, low in nutrients, and easy to overconsume. It is the overall dietary pattern, not the presence of seed oils, that contributes to weight gain,” Derocha said.

Using beef tallow, as RFK Jr. has suggested, is also an option. Beef tallow is a type of rendered fat made from cooking down fatty tissues from cows.It mostly contains saturated and monounsaturated fatty acids and only a small amount of polyunsaturated fats.

Seed oils are low in saturated fats. One tablespoon of canola oil contains less than 1 gram of saturated fat, and the same amount of sunflower oil has 1.36 g, but one tablespoon of beef tallow has over 6 grams of saturated fat.In other words, 3 tbsp of beef tallow would almost reach the recommended 20g of saturated fat per day.The American Heart Association recommends keeping daily saturated fats even lower, at no more than 13 g.

“Tallow is more heat-stable due to its high saturated fat content, which resists oxidation during frying,” Derocha said. “While oxidation is less of a problem, the higher saturated fat content may not align with heart-health guidelines if consumed in large amounts over time.”

People who want to avoid seed oils have other choices, like olive, avocado, and peanut oils that have a higher monounsaturated fat content.However, these oils often cost more than seed oils.

What Does ‘Ultra-Processed Food’ Actually Mean?

What This Means For YouWhile seed oils like canola and sunflower oil have been criticized on social media, research shows they contain beneficial polyunsaturated fats that may support heart health when consumed in moderation. Instead of cutting seed oils entirely, focus on a balanced diet with minimally processed foods and a variety of healthy fats.

What This Means For You

While seed oils like canola and sunflower oil have been criticized on social media, research shows they contain beneficial polyunsaturated fats that may support heart health when consumed in moderation. Instead of cutting seed oils entirely, focus on a balanced diet with minimally processed foods and a variety of healthy fats.

20 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Heart Association.There’s no reason to avoid seed oils and plenty of reasons to eat them.Massachusetts General Hospital.Seed oils: facts & myths.Clapp JE, Niederman SA, Leonard E, Curtis CJ.Changes in serving size, calories, and sodium content in processed foods from 2009 to 2015.Prev Chronic Dis. 2018;15:E33. doi:10.5888/pcd15.170265McDonalds.Snacks & sides FAQs.Healthy UC Davis.Why do I need to include fat in my diet?American Heart Association.Monounsaturated fats.Harvard Health Publishing.No need to avoid healthy omega-6 fats.Department of Health and Human Services Office of Disease Prevention and Health Promotion.Cut down on saturated fat.American Heart Association.Polyunsaturated fats.Su H, Liu R, Chang M, Huang J, Wang X.Dietary linoleic acid intake and blood inflammatory markers: a systematic review and meta-analysis of randomized controlled trials.Food Funct. 2017;8(9):3091-3103. doi:10.1039/C7FO00433HOregon State University.Essential fatty acids.Geng L, Liu K, Zhang H.Lipid oxidation in foods and its implications on proteins.Front Nutr. 2023;10:1192199. doi:10.3389/fnut.2023.1192199Maszewska M, Florowska A, Dłużewska E, Wroniak M, Marciniak-Lukasiak K, Żbikowska A.Oxidative stability of selected edible oils.Molecules. 2018;23(7):1746. doi:10.3390/molecules23071746Merck Manual.Carbohydrates, proteins, and fats(consumer version).U.S. Department of Agriculture.Edible tallow.University of Rochester Medical Center.Fat, beef tallow, 1 tbsp.University of Rochester Medical Center.Oil, vegetable, sunflower, high oleic (70% and over), 1 tbsp.University of Rochester Medical Center.Vegetable oil, canola, 1 tbsp.American Heart Association.Saturated fat.Harvard T.H. Chan School of Public Health.Types of fat.

20 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Heart Association.There’s no reason to avoid seed oils and plenty of reasons to eat them.Massachusetts General Hospital.Seed oils: facts & myths.Clapp JE, Niederman SA, Leonard E, Curtis CJ.Changes in serving size, calories, and sodium content in processed foods from 2009 to 2015.Prev Chronic Dis. 2018;15:E33. doi:10.5888/pcd15.170265McDonalds.Snacks & sides FAQs.Healthy UC Davis.Why do I need to include fat in my diet?American Heart Association.Monounsaturated fats.Harvard Health Publishing.No need to avoid healthy omega-6 fats.Department of Health and Human Services Office of Disease Prevention and Health Promotion.Cut down on saturated fat.American Heart Association.Polyunsaturated fats.Su H, Liu R, Chang M, Huang J, Wang X.Dietary linoleic acid intake and blood inflammatory markers: a systematic review and meta-analysis of randomized controlled trials.Food Funct. 2017;8(9):3091-3103. doi:10.1039/C7FO00433HOregon State University.Essential fatty acids.Geng L, Liu K, Zhang H.Lipid oxidation in foods and its implications on proteins.Front Nutr. 2023;10:1192199. doi:10.3389/fnut.2023.1192199Maszewska M, Florowska A, Dłużewska E, Wroniak M, Marciniak-Lukasiak K, Żbikowska A.Oxidative stability of selected edible oils.Molecules. 2018;23(7):1746. doi:10.3390/molecules23071746Merck Manual.Carbohydrates, proteins, and fats(consumer version).U.S. Department of Agriculture.Edible tallow.University of Rochester Medical Center.Fat, beef tallow, 1 tbsp.University of Rochester Medical Center.Oil, vegetable, sunflower, high oleic (70% and over), 1 tbsp.University of Rochester Medical Center.Vegetable oil, canola, 1 tbsp.American Heart Association.Saturated fat.Harvard T.H. Chan School of Public Health.Types of fat.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

American Heart Association.There’s no reason to avoid seed oils and plenty of reasons to eat them.Massachusetts General Hospital.Seed oils: facts & myths.Clapp JE, Niederman SA, Leonard E, Curtis CJ.Changes in serving size, calories, and sodium content in processed foods from 2009 to 2015.Prev Chronic Dis. 2018;15:E33. doi:10.5888/pcd15.170265McDonalds.Snacks & sides FAQs.Healthy UC Davis.Why do I need to include fat in my diet?American Heart Association.Monounsaturated fats.Harvard Health Publishing.No need to avoid healthy omega-6 fats.Department of Health and Human Services Office of Disease Prevention and Health Promotion.Cut down on saturated fat.American Heart Association.Polyunsaturated fats.Su H, Liu R, Chang M, Huang J, Wang X.Dietary linoleic acid intake and blood inflammatory markers: a systematic review and meta-analysis of randomized controlled trials.Food Funct. 2017;8(9):3091-3103. doi:10.1039/C7FO00433HOregon State University.Essential fatty acids.Geng L, Liu K, Zhang H.Lipid oxidation in foods and its implications on proteins.Front Nutr. 2023;10:1192199. doi:10.3389/fnut.2023.1192199Maszewska M, Florowska A, Dłużewska E, Wroniak M, Marciniak-Lukasiak K, Żbikowska A.Oxidative stability of selected edible oils.Molecules. 2018;23(7):1746. doi:10.3390/molecules23071746Merck Manual.Carbohydrates, proteins, and fats(consumer version).U.S. Department of Agriculture.Edible tallow.University of Rochester Medical Center.Fat, beef tallow, 1 tbsp.University of Rochester Medical Center.Oil, vegetable, sunflower, high oleic (70% and over), 1 tbsp.University of Rochester Medical Center.Vegetable oil, canola, 1 tbsp.American Heart Association.Saturated fat.Harvard T.H. Chan School of Public Health.Types of fat.

American Heart Association.There’s no reason to avoid seed oils and plenty of reasons to eat them.

Massachusetts General Hospital.Seed oils: facts & myths.

Clapp JE, Niederman SA, Leonard E, Curtis CJ.Changes in serving size, calories, and sodium content in processed foods from 2009 to 2015.Prev Chronic Dis. 2018;15:E33. doi:10.5888/pcd15.170265

McDonalds.Snacks & sides FAQs.

Healthy UC Davis.Why do I need to include fat in my diet?

American Heart Association.Monounsaturated fats.

Harvard Health Publishing.No need to avoid healthy omega-6 fats.

Department of Health and Human Services Office of Disease Prevention and Health Promotion.Cut down on saturated fat.

American Heart Association.Polyunsaturated fats.

Su H, Liu R, Chang M, Huang J, Wang X.Dietary linoleic acid intake and blood inflammatory markers: a systematic review and meta-analysis of randomized controlled trials.Food Funct. 2017;8(9):3091-3103. doi:10.1039/C7FO00433H

Oregon State University.Essential fatty acids.

Geng L, Liu K, Zhang H.Lipid oxidation in foods and its implications on proteins.Front Nutr. 2023;10:1192199. doi:10.3389/fnut.2023.1192199

Maszewska M, Florowska A, Dłużewska E, Wroniak M, Marciniak-Lukasiak K, Żbikowska A.Oxidative stability of selected edible oils.Molecules. 2018;23(7):1746. doi:10.3390/molecules23071746

Merck Manual.Carbohydrates, proteins, and fats(consumer version).

U.S. Department of Agriculture.Edible tallow.

University of Rochester Medical Center.Fat, beef tallow, 1 tbsp.

University of Rochester Medical Center.Oil, vegetable, sunflower, high oleic (70% and over), 1 tbsp.

University of Rochester Medical Center.Vegetable oil, canola, 1 tbsp.

American Heart Association.Saturated fat.

Harvard T.H. Chan School of Public Health.Types of fat.

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