Over the last few years, you might have heard about how seed oils are “toxic,” causing inflammation, and basically ruining our health. And I get it—some oils are super processed, and we don’t want that in our beautiful, nourishing food. But how bad are they? And which ones are harmful? Is canola the same as sesame oil?  

Which Seed Oils Are Causing All This Drama?

Not all seed oils are being lumped into the controversy. The ones at the center of the debate include canola, soybean, corn, sunflower, safflower, cottonseed, grapeseed, and rice bran oils. These oils are often used in ultra-processed foods and fried fast food because they’re cheap, have a long shelf life, and hold up well under high heat. 

Some people call these the “hateful eight,” blaming them for everything from inflammation to obesity. Canola oil, for example, is bad for the environment and does cause inflammation in the body, whether you use organic oil or not. But before we go throwing out all our oils, let’s take a closer look at what’s really going on.

What Does Science Actually Say About Seed Oils?

“The real first issue is balance,” says Leona West Fox CN, CH, FMCHC. “When we get way more omega-6s than omega-3s (like the typical 15:1 ratio in a Western diet vs. the more ideal 3:1 or even 1:1), it can nudge the body toward a more pro-inflammatory state.” She says that  while seed oils often get the blame, grain-fed meats and dairy are also big contributors. “That said, people eating a healthy plant-based diet are typically getting more omega-3s and aren’t consuming those animal-based omega-6 sources anyway.”

The seed oils under attack are high in omega-6 fatty acids, and some believe that these fats promote chronic inflammation, which could lead to diseases like heart disease and diabetes. But here’s the thing—scientific research doesn’t back that up.

A study published in the American Journal of Clinical Nutrition found that increasing omega-6 intake while maintaining a good balance of omega-3s does not increase inflammation. In fact, the American Heart Association still recommends seed oils as part of a heart-healthy diet because they help reduce bad cholesterol levels.

The problem isn’t necessarily seed oils themselves—it’s like West Fox says, that many people eat too many processed foods loaded with these oils, while not getting enough omega-3-rich foods like flaxseeds, walnuts, and hemp seeds.

Not All Seed Oils Are Created Equal

There’s a huge difference between organic, cold-pressed seed oils and the highly refined, industrialized versions used in fast food. Take sesame oil, for example. It’s a staple in Asian cuisine and has been used for centuries. Studies show it has powerful antioxidant properties and can even help lower blood pressure and improve blood sugar control.

Sunflower oil, especially the high-oleic variety, is rich in vitamin E and heart-healthy monounsaturated fats. And then there’s avocado oil—technically not a seed oil, but often lumped into the conversation—which has been shown to support cardiovascular health.

The real issue is refined vs. unrefined oils. Highly refined oils go through chemical processing and bleaching, which can strip away beneficial compounds and leave behind trace amounts of processing chemicals. But if you’re using organic, cold-pressed versions, you’re getting the nutrients and healthy fats without the junk.

What About Fast Food?

One of the biggest talking points in the anti-seed oil movement is that fast food restaurants should switch back to using beef tallow or other animal fats instead of seed oils. Some restaurants are even making the switch—Steak ‘n Shake recently announced that it’s frying its food in beef tallow again, and Sweetgreen is phasing out seed oils in favor of olive oil. The truth is, as Americans, we eat far too much saturated fat as it is already, and beef tallow is absolutely not the answer. It is steeped in cruelty and is awful for human health. Dr. Neal Barnard explains the science here.

But focusing only on the oil in fast food misses the bigger problem: fast food itself. Even if McDonald’s switched to cooking in tallow, that wouldn’t magically make a Big Mac healthy. The bigger issues are the artificial additives, low-quality meat, excessive sodium, and overall lack of whole, nourishing ingredients. Making fresh quality food is the answer, not swapping one bad fat for another.

Should You Cut Out Seed Oils?

If you feel better avoiding seed oils, go for it! But if you’re using organic sesame, sunflower, or avocado oil in your home cooking, there’s no need to panic. The key is choosing high-quality, minimally processed oils and maintaining a balanced diet with plenty of whole plant-based foods.

West Fox says the bottom line is this: Omega-6s are essential. The focus should be on quality, processing, and keeping them in balance with omega-3s. And for someone eating plant-based, it’s more about “which oils you’re using, how they’re made, and how you’re cooking with them.”

Prioritize fresh, unprocessed foods, avoid ultra-processed junk, and make sure your fat sources are coming from whole, healthy ingredients. That’s the real secret to glowing health. You can get healthy omega fats in ground flax seeds, chia seeds, hemp seeds, and walnuts. They’re easy to add to smoothies, baked goods, atop cereal, non-dairy yogurt, salads and bowls.

And when using oils, keep this breakdown in mind:

Best for high heat

• Avocado oil
• Refined coconut oil

Best for low heat/raw

• Extra virgin olive oil
• Cold-pressed sesame
• Unrefined sunflower

Avoid heating

• Flaxseed oil
• Walnut oil