If you’ve spent any time on health and wellness TikTok or Instagram, you’ve probably heard people warning you to toss your seed oils immediately—or else.
Influencers claim they’re toxic, inflammatory, and even to blame for America’s obesity crisis. But is there any science behind the fear mongering?
We asked dietitians to fact-check some of the most viral claims about seed oils and help you make informed choices.
Claim #1: Seed Oils Are “Toxic” and Cause Inflammation
You might have heard that seed oils—like sunflower, soybean, safflower, or corn oil—are harmful because they’re full of “toxins” that cause inflammation. But according to MyFitnessPal dietitian Brookell White, this idea doesn’t hold up.
“Seed oils are getting a bad rap,” she says. “They’re high in omega-6 polyunsaturated fats, which are actually essential—we need them for brain development, metabolism, and overall growth (1).”
While it’s true that omega-6 fats can lead to the formation of arachidonic acid, a compound linked to inflammation, your body only converts a small amount. In fact, studies show that diets high in omega-6 fatty acids can help lower cholesterol and improve heart health (5) .
What’s more likely to drive inflammation? Ultra-processed foods that happen to contain seed oils, along with added sugars, sodium, and saturated fat. “There’s strong evidence that reducing ultra-processed food supports better health,” says White (2). “But that doesn’t mean seed oils used in home cooking or whole foods are the problem.”
Claim #2: Seed Oils Were Invented as Industrial Products
Yes, this family of oils has industrial uses. But that doesn’t mean they don’t belong in your kitchen.
White explains that seed oils were originally extracted using a mechanical screw press, an innovation from the 1880s that made oil production more efficient (6).
Today, these oils are used not only in food, but also in eco-friendly products like soaps and cosmetics. That’s not a red flag—it’s actually a benefit for sustainability (7).
What about chemical processing? Some people worry about the use of solvents like hexane during refining. But White emphasizes that any residue in the final oil is minimal and regulated.
The bigger issue, she says, is what happens when seed oils are overheated and reused repeatedly (ahem, like in deep fryers at restaurants) because that can lead to oxidation and harmful compounds (5).
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Claim #3: Seed Oils Are Responsible for the Rise in Obesity
This one sounds simple, but the truth is far more complicated.
“While seed oils are often blamed for rising obesity rates, other factors likely play a bigger role,” says Lauren Cuda, a dietitian with MyFitnessPal. “Diets high in ultra-processed foods—many of which contain seed oils—are associated with poor health outcomes, but not just because of the oils. These foods are also high in calories, added sugars, and low in fiber and nutrients (8).”
In other words, it’s not the canola oil in your homemade vinaigrette. The problem is the combination of low-nutrient, high-calorie packaged foods that may contribute to weight gain.
When people reduce seed oils, it’s often part of a broader dietary change that includes eating fewer processed foods. That’s what drives the weight loss results people sometimes get from eliminating seed oils. It’s not cutting oils alone that does the trick.
Claim #4: Seed Oils Are Full of “Oxidized” Fats That Destroy Your Cells
Seed oils contain polyunsaturated fats (PUFAs), which can be sensitive to heat, light, and air. But that doesn’t mean they’re destroying your cells (9), (3).
“The idea that seed oils are harmful because of oxidation is misleading,” says MyFitnessPal dietitian Katherine Basbaum. “They also contain antioxidants like vitamin E, which help prevent oxidative stress in the body. In fact, eating these oils in appropriate amounts may actually help protect your cells,” she adds (10).
Basbaum recommends keeping your oils in a cool, dark place. And when cooking, don’t heat them beyond their smoke point. But used properly, these oils don’t pose the oxidative risk some online voices suggest (11).
Claim #5: Fats Like Butter, Ghee, Beef Tallow, or Coconut Oil Are Always Healthier
This claim often comes with the idea that “natural” fats are better than “processed” ones. But when it comes to your heart health, saturated fat content matters more than social media trends.
“Fats like butter, ghee, beef tallow, and coconut oil are all high in saturated fat,” says Basbaum. “And excess saturated fat has been linked to increased risk of heart disease and higher mortality (12).”
On the other hand, unsaturated fats—like those found in olive, avocado, and canola oil—have been shown to decrease heart disease risk (13).
That doesn’t mean you can never cook with butter or enjoy coconut oil in a recipe. But making unsaturated fats your default choice for daily cooking supports long-term health.
And remember: no single ingredient makes or breaks your diet. “Health is about your overall eating pattern,” Basbaum says. “That means aiming for more fiber, fruits, and veggies, and less added sugar, sodium, and saturated fat—while still enjoying the foods you love.”
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Frequently Asked Questions (FAQs)
Cooking oils derived from the seeds of plants. The most common are canola oil, corn oil, cottonseed, grapeseed oil, soybean oil, sunflower oil, safflower oil, rice bran oil, and peanut oil (14).
No. Olive oil It comes from the fruit of the olive tree, specifically the flesh and pulp, rather than from seeds (15).
There is no single “healthiest” oil. The healthiest oil for you in a specific situation depends on things like the cooking method you’ll be using and your personal health goals.
According to the company’s website, the restaurant fries its “hand-breaded chicken exclusively in fully refined, heat-processed peanut oil (16).” For the most up to date information, you can also check the ingredient list of your meals whenever eating out to determine if specific food items contain seed oils.
Studies in healthy adults do not suggest that these oils cause inflammation. In fact, they may be linked to reduced inflammation (18).
Yes, most seed oils are processed and refined. Oils that are cold-pressed or expeller-pressed are extracted without chemicals, so these oils are less processed and refined than those extracted with chemical solvents (19).
Yes. Also known as rapeseed oil, canola oil comes from seeds.
Not directly. “One recent study followed 200,000 adults for more than 3 decades and found worse health outcomes with butter consumption than plant-based oils,” notes Melissa Jaeger (20).
The Bottom Line
These oils may be a social media scapegoat, but the science tells a different story. They’re a source of essential fats your body needs and aren’t inherently harmful. The real health risks come from ultra-processed foods—not the oils themselves.
While it’s smart to be mindful of how you store and cook with oils, there’s no need to fear seed oils in your salad dressing or stir-fry. Instead of falling for viral nutrition myths, focus on your overall dietary pattern: more whole foods, fewer ultra-processed ones, and a balanced mix of healthy fats.
Wondering how much fat you’re really eating? Download the MyFitnessPal app to track stay on top of your nutrition and make progress toward your health goals.
The post Dietitians Fact Check 5 Claims Made About Seed Oils appeared first on MyFitnessPal Blog.
