Back in October 2024, Robert F. Kennedy Jr. criticized seed oils in a post on X, pushing for fast-food establishments like McDonald’s to switch back to frying their food in beef tallow. He wrote that “seed oils are one of the driving causes of the obesity epidemic,” and that Americans are being “unknowingly poisoned” when they go out to eat.
Kennedy isn’t alone. Some influencers on TikTok have taken to the app to post about the dangers of seed oils like canola, sunflower, safflower, and soybean oils.
But how accurate are Kennedy’s and influencers’ claims about seed oils?
“Seed oils are a part of a healthy balanced diet,” says Lauri Wright, director of nutrition programs and professor of nutrition at the University of South Florida. “We use them in moderation as a substitute for saturated fats and trans fats.”
Wright says we don’t have to worry about consuming seed oils in moderation, and that these oils are beneficial for our health.
What are seed oils?
Seed oils are extracted from ground seeds put through a heating process. Common seed oils used in cooking and frying are:
- Safflower
- Soybean
- Sunflower
- Canola
- Vegetable, which can include a mix of seed oils
- Corn
- Cottonseed
- Grape-seed
- Peanut
- Rice bran
Should you avoid seed oils?
Overall, Wright says seed oils—especially canola oil, derived from rapeseeds—can be very healthy. She places canola oil at the top of the list as the healthiest seed oil, followed by sunflower, soybean, corn, and safflower.
“They’re still hands down a much more healthful choice than a saturated fat like butter or coconut oil,” she says.
The controversy about seed oils stems from multiple points, one of them being the processing of seed oils, which some claim strips them of their nutrients and leads to a less healthy product.
“It’s true that some highly refined oils may lose some nutrients during processing, but it doesn’t mean that they become harmful,” Wright says. “Just because it's processed doesn’t mean it’s turning a good oil into a bad product. It still is retaining its healthful benefits.”
If you are concerned about the processing of seed oils, Wright recommends looking for oils that are cold-pressed, which helps to retain all phytosterols—natural plant compounds that can help lower cholesterol levels—and vitamin E, which boosts antioxidant activity to help fight cancer, aging, and diseases.
RFK Jr. and others have also raised concerns about seed oils releasing toxins, because the fatty acid linolenic acid, found in omega-6s, could potentially be converted into another fatty acid called arachidonic acid, which can promote inflammation, blood clotting, and the constriction of blood vessels, according to Harvard Health. However, Harvard reports that the body converts very little linolenic acid into arachidonic acid, even with high amounts of linolenic acid in the diet.
Other concerns about seed oils surround studies linking seed oils and omega-6 fatty acids to inflammation and chronic disease, but Wright points out that’s because of their use in frying, fast foods, and ultra-processed foods. She says the issue is the cooking method and the foods that seed oils are found in—not the oils themselves.
“You’re just taking it out of context. The problem really is the ultra-processed foods,” Wright says. “It’s not the potato, it’s the french fries.”
Wright says seed oils contain a blend of omega-3 and omega-6 polyunsaturated fatty acids. There is robust evidence behind omega-3s’ health benefits, like boosting the health of the brain, eyes, and heart, yet the American Heart Association reports that most Americans do not eat enough in their diets, but eat roughly 14 to 25 times more omega-6 fatty acids than omega-3 fatty acids.
Wright says that omega-6 fatty acids are a healthy fat to include in your diet, but getting more of a balance is important to reap the benefits of omega-3s, which is why eating more omega-3-rich foods is key. But it is rare to get an imbalance of omega-3s and omega-6s when eating seed oils, she adds, especially considering the oils contain a blend of the two.
In fact, studies have shown that omega-6 fatty acids have no impact on inflammation.
Often those on social media or with public platforms speaking out against seed oils are interpreting these studies incorrectly, Wright says, and they often don’t have the right backgrounds to interpret the science properly.
“It is popular to demonize one particular food. You really have to look at the overall foods and diet,” Wright says.
“I applaud the focus on more healthful diets, but I think we need to be careful about vilifying a certain food or food group,” she adds, “and focus on the overall diet patterns and what truly are the cause and effect versus these inaccurate correlations.”
Health benefits of seed oils
Wright wants people to know that not only should you not worry about avoiding seed oils, but they can also be a healthy addition to your diet.
Studies have shown that omega-6 fatty acids, found in seed oils, can actually help lower cardiovascular disease risk. The American Heart Association (AHA) encourages people to include seed oils full of polyunsaturated omega-6 fatty acids because the body cannot produce them on its own, and for their ability to help lower bad (LDL) cholesterol and boost good (HDL) cholesterol, which can help reduce your risk of heart disease and stroke.
“Hands down, they lower the risk of cardiovascular disease,” Wright says.
Here are ways the AHA recommends using seed oils in cooking (while avoiding deep frying):
- Make your own salad dressings, marinades, dips, and sauces.
- Grill, stir-fry, bake, or roast foods.
- Coat pans to keep food from sticking.
- Lightly drizzle on foods for flavor.
- Substitute for butter, stick margarine, or solid fats.
“We want to show [people] the power of what you can eat so you can prevent and manage diseases,” Wright says. “We want to spread the positive message of the power of nutrition.”
For more on nutrition:
- This nutrition expert avoids a so-called health food at all costs: he says you’re better going full fat instead
- Michelle Obama on the health belief she shares with RFK Jr: ‘It became a partisan issue’
- This gastroenterologist says probiotics are ‘a waste of money.’ Here’s what you should be doing instead
- Just one simple dietary change could help you fight back against cancer and heart disease
