Seed Oils: The Villain Everyone's Avoiding (But Should You?)

Walk into any health food store right now and you'll see "seed oil free" labels everywhere.

Scroll through social media and you'll see influencers claiming seed oils are toxic poison causing inflammation, heart disease, and every chronic illness known to man.

RFK Jr. is publicly bashing them. Restaurants are bragging about cooking without them. And 20% of Americans are now actively avoiding them.

On the other side, you've got dietitians, the American Heart Association, and decades of research saying seed oils are perfectly fine—even beneficial.

So who's right?

After 13+ years of training clients and watching diet trends explode and implode, here's my take: The truth is somewhere in the middle, and context matters way more than people think.

What Are Seed Oils?

Seed oils (also called vegetable oils) are oils extracted from seeds. The most common ones are:

• Canola oil
• Soybean oil
• Corn oil
• Sunflower oil
• Safflower oil
• Cottonseed oil
• Grapeseed oil

These oils are high in omega-6 fatty acids (specifically linoleic acid) and are used in everything—restaurants, packaged foods, salad dressings, mayonnaise, and more.

They're cheap, neutral-tasting, and have a high smoke point, which makes them perfect for food manufacturers.

Why People Say Seed Oils Are Toxic

The anti-seed oil movement claims these oils are causing chronic disease. Here's their case:

1. High in Omega-6 Fatty Acids

Seed oils are loaded with omega-6 fatty acids. The problem? Modern diets have an omega-6 to omega-3 ratio of about 20:1, when it should be closer to 4:1 or lower.

High omega-6 intake is linked to inflammation, which drives heart disease, obesity, and autoimmune issues.

2. Highly Processed

Seed oils are extracted using industrial processes involving heat, solvents, and chemical refining. Critics say this creates oxidized, damaged fats that are harmful to your body.

Compare that to olive oil or coconut oil, which are minimally processed.

3. Oxidized and Unstable

Polyunsaturated fats (like those in seed oils) are chemically unstable. When exposed to heat, light, or air, they oxidize—creating harmful compounds like aldehydes and lipid peroxides.

These oxidized fats can damage cells and contribute to inflammation.

4. Not Ancestral

Humans didn't eat seed oils until the 1900s. Our ancestors ate animal fats, olive oil, and coconut oil—not industrially processed soybean oil.

Critics argue that our bodies aren't adapted to handle these oils in large amounts.

5. Correlation With Chronic Disease

The rise in seed oil consumption correlates with the rise in obesity, heart disease, and diabetes.

Correlation isn't causation—but it's suspicious.

Why Nutritionists Say Seed Oils Are Fine

Now let's hear the other side. Because mainstream science still says seed oils are safe.

1. They Lower LDL Cholesterol

Studies show that replacing saturated fat (like butter) with polyunsaturated fats (like seed oils) lowers LDL cholesterol, which is linked to reduced heart disease risk.

The American Heart Association recommends seed oils for this reason.

2. Omega-6 Isn't the Problem

Yes, omega-6 can be pro-inflammatory—but only in the absence of omega-3.

The issue isn't omega-6 itself; it's the ratio. If you're getting enough omega-3 (from fish, flaxseed, walnuts), omega-6 isn't harmful.

3. Processing Doesn't Make Them Toxic

Nutritionists argue that the refining process is safe and regulated. The oils aren't "damaged" or "oxidized" when properly stored.

Most of the fear around processing is exaggerated.

4. Population Studies Show No Harm

Large-scale studies haven't shown that seed oil consumption causes chronic disease.

In fact, some studies show that people who consume more polyunsaturated fats have lower rates of heart disease.

5. The Real Problem Is Ultra-Processed Food

Seed oils aren't eaten in isolation. They're in chips, cookies, fast food, and fried junk.

Maybe the problem isn't the oil—it's the food it's in.

The Truth: It's Not Black and White

Here's where I land after digging into the research and watching clients for over a decade:

Seed oils aren't poison. But they're not optimal either.

Here's what actually matters:

1. Context Is Everything

If you're eating seed oils from whole foods or minimally processed sources (like sunflower seeds or walnuts), they're fine.

If you're eating them in fried fast food, chips, and packaged junk, that's a problem—but not because of the oil. It's because the entire food is garbage.

2. The Dose Makes the Poison

A little seed oil in your salad dressing? Not an issue.

Deep-fried food every day? That's excessive omega-6, oxidized fats, and too many calories.

3. Processing Matters

Cold-pressed, unrefined seed oils are better than heavily processed, refined ones.

But let's be real—most seed oils you encounter are refined. That's just how the food industry works.

4. Balance Your Omega-6 and Omega-3

The problem isn't omega-6 itself. It's that most people get way too much omega-6 and not enough omega-3.

Eat fatty fish 2-3x per week, add flaxseeds or chia seeds, and you'll be fine.

5. Focus on What You're Eating, Not Just the Oil

If you're eating whole foods—meat, fish, eggs, vegetables, fruit, rice—you're not getting much seed oil anyway.

If you're eating out 5 days a week and snacking on chips, the seed oil is the least of your problems.

Should You Avoid Seed Oils?

Here's my practical recommendation:

Don't Stress About Trace Amounts

If your salad dressing has canola oil, you're fine. If you eat out once a week, you're fine.

Don't become obsessive.

Cook With Better Oils at Home

Use olive oil, avocado oil, butter, or coconut oil for cooking. They're less processed and more stable at high heat.

This alone will drastically reduce your seed oil intake.

Avoid Deep-Fried Food

Whether it's fried in seed oil or lard, deep-fried food is high in calories, oxidized fats, and generally unhealthy.

Limit it to occasional indulgences.

Eat More Omega-3

Get fatty fish (salmon, mackerel, sardines) 2-3x per week. Add flaxseeds, chia seeds, or walnuts.

This balances out any omega-6 you do consume.

Focus on Whole Foods

If 90% of your diet is whole, unprocessed food, seed oils won't matter.

The people freaking out about seed oils while eating Doritos every night are missing the point.

What I Use and Recommend

Here's what I cook with and tell clients to use:

• Olive oil: Great for salads, low-heat cooking, drizzling
• Avocado oil: High smoke point, good for sautéing
• Butter or ghee: Flavor, nutrients, stable at heat
• Coconut oil: High heat cooking, baking

I don't stress if there's canola oil in a restaurant meal or salad dressing. But I don't buy it for my kitchen.

The Bottom Line

Seed oils aren't the toxic villain they're made out to be. But they're not optimal either.

The real issue is that most people consuming large amounts of seed oils are eating ultra-processed junk food. That's the problem—not the oil itself.

If you want to be healthy:

• Eat whole foods
• Cook with better oils at home (olive, avocado, butter)
• Balance your omega-6 and omega-3
• Don't stress about trace amounts

Seed oils aren't killing you. But they're also not doing you any favors.

CJ Critney is a personal trainer and owner of FYTS Fitness in Westlake Village, California, with 13+ years of experience transforming clients through science-backed training and faith-driven discipline.