Written by
Louise W Lu, PhD, MPH, BMLS
Reviewed by
Alexandra V Goldberg, Registered Dietitian
A friend of mine recently asked: “I have breast cancer, and someone told me the cooking oil I use might actually make it worse because of something called linoleic acid. Is that true? Is there any oil that’s safer?”
Great question—and one more people should be asking.
Many common cooking oils—like sunflower, soybean, and corn oil—are high in linoleic acid. It’s a fatty acid our bodies need. But some new research suggests that in triple-negative breast cancer, too much linoleic acid might trigger certain signals in the body that make the cancer grow faster.
That doesn’t mean linoleic acid is bad for everyone. But for people with certain health conditions, the oil you use every day could actually matter more than you think.
In this post, we’ll walk you through which oils are high in linoleic acid, which ones are more balanced, and who should pay closer attention. By the end, you’ll feel more confident about what’s in your kitchen—and what’s going into your body.
Jump to Sections:
- 01｜What Is Linoleic Acid, and Why Is It in So Many Oils?
- 02｜What Does Linoleic Acid Actually Do in the Body?
- 03｜Linoleic Acid & Triple-Negative Breast Cancer: What New Research Shows
- 04｜Which Cooking Oils Are High in Linoleic Acid?
- 05｜How Should High-Risk Groups Balance Omega-6 and Omega-3?
- Final Thoughts｜How Should We Think About Linoleic Acid?
01｜What Is Linoleic Acid, and Why Is It in So Many Oils?
You’ve probably heard of omega-3—the “good fat” in fish oil that’s praised for its health benefits. But linoleic acid? Not so much.
Linoleic acid is an omega-6 fatty acid, and it shows up in many everyday cooking oils like sunflower, corn, soybean, and even some salad dressings. It’s not some exotic chemical—it’s something we all eat, usually without realizing it.
And here’s the thing: your body needs it. Linoleic acid helps keep your skin healthy, supports your immune system, and plays a role in how your cells function. It’s what scientists call an “essential fatty acid,” meaning we can’t make it ourselves—we have to get it from food.
Then, why do media headlines say linoleic acid is “bad” and we should avoid it?
The real question isn’t whether linoleic acid is “good” or “bad.” It’s whether we’re getting the right amount, and in the right balance with other fats in our diet.
02｜Does It Promote Inflammation? What It Actually Does in the Body
Linoleic acid isn’t the villain—it’s actually a fatty acid your body needs. It helps regulate your immune response and supports tissue repair.
When you get sick or injured, your body triggers inflammation as a defense signal. Linoleic acid gets converted into molecules like prostaglandins and leukotrienes, which help widen blood vessels, call in immune cells, and kickstart repair. Redness, heat, and swelling? That’s your body doing its job.
This kind of short-term inflammation is protective—like firefighters rushing in when the alarm goes off. It’s not a bad thing.
The trouble starts when there’s too much linoleic acid in the diet. Excess omega-6 fats can fuel chronic low-grade inflammation—a subtle internal fire that may affect blood vessels, blood sugar, immune health, and possibly even promote the growth of certain tumors.
Linoleic acid is part of the omega-6 family. But its cousins—the omega-3 fats found in fish oil (EPA, DHA)—help balance things out and reduce inflammation. So it’s not about cutting one fat out—it’s about the balance.
Bottom line: linoleic acid plays a useful role. The problem is too much, and too little balance with omega-3s.
03｜What Does New Research Say About Linoleic Acid and Triple-Negative Breast Cancer?
Recently, a new study made a surprising connection between linoleic acid and one of the most aggressive types of breast cancer—triple-negative breast cancer.
Published in 2024 by researchers at Weill Cornell Medicine (source), the study found that linoleic acid binds to a protein called FABP5 (Fatty Acid Binding Protein 5), which is present in high levels in triple-negative breast cancer cells.
This binding activates a powerful cell growth pathway known as mTORC1. You can think of it like a cellular “accelerator” that speeds up tumor growth when triggered.
The researchers also ran animal studies. Mice were fed two different diets with identical calories and protein, but:
- One group had high linoleic acid (e.g. safflower oil)
- The other had high omega-3 fats (e.g. fish oil, flaxseed oil)
The results? Tumors grew faster and larger in the high linoleic acid group. Mice fed omega-3 fats had significantly slower tumor growth, and in some cases, tumors barely developed at all.
Even more compelling, the researchers found elevated linoleic acid and FABP5 levels in the blood of triple-negative breast cancer patients, lending more credibility to this link.
But let’s be clear: this doesn’t mean linoleic acid causes cancer or that cooking oils should be avoided altogether. What it does mean is that in specific cases—like patients with high FABP5 or this cancer subtype—linoleic acid intake might play a role in disease progression.
This opens the door to more personalized dietary guidance, where a patient’s biology could determine the kind of fats that are best—or safest—to consume.
04｜Which Cooking Oils Are High in Linoleic Acid?
We often hear people say “eat less linoleic acid”—but how much is actually in the oils we use every day? Which oils are high, which are low, and how should we choose?
Here’s a quick breakdown:
- Very high in linoleic acid (60–75%): Safflower oil, sunflower oil, corn oil, grapeseed oil, wheat germ oil
- Moderate content (35–55%): Traditional peanut oil, sesame oil, soybean oil, walnut oil
- Lower content (10–25%): Canola (low-erucic rapeseed), rice bran oil, pumpkin seed oil
- Very low (<10%): Olive oil, tea seed oil, avocado oil
Note: Oils high in linoleic acid aren’t “bad oils.” But if you’re prone to inflammation, acne, or are at higher risk for certain conditions (like triple-negative breast cancer), it’s wise to moderate total intake.
For example:
If you fry eggs in soybean oil in the morning, grab a stir-fried lunch with mixed vegetable oil, and sauté with sunflower oil at night—that’s potentially twice the recommended daily linoleic acid already.
But here’s the good news—
You can cut back without sacrificing flavor: switch to oils with lower linoleic acid for cooking, like canola, olive, avocado, or rice bran oil. Easy swaps, big difference.
05｜Who Should Be Cautious with Linoleic Acid?
Not everyone needs to fear linoleic acid.
If you're underweight, have low inflammation levels, or need immune support, moderate intake of linoleic acid is usually fine.
But you may want to reduce linoleic acid if you:
- Have chronic inflammation or autoimmune issues
- Struggle with acne, eczema, or inflammatory skin conditions
- Have hormone-related issues, especially triple-negative breast cancer or a high risk
- Eat lots of processed or deep-fried foods
This doesn’t mean linoleic acid is “bad.” It’s about how much you eat and how well it balances with other fats.
A smarter approach includes:
- Adding more omega-3-rich foods like flaxseed, walnuts, and oily fish
-
Supplementing with high-purity omega-3 fish oil to reduce inflammation and balance omega-6 intake
👉 Check out our recommended omega-3 fish oils - Rotating your oils—don’t stick to one
- Cooking with oils lower in linoleic acid, like high-oleic canola, tea seed, or avocado oil
Remember:
One of the key reasons we recommend high-purity omega-3 is to balance out excessive omega-6 intake. That ratio matters—for your metabolism, inflammation, and long-term health.
Final Thoughts｜How Should We Think About Linoleic Acid?
Linoleic acid isn’t a “bad fat”—but too much of it, with too little omega-3, can throw your body off balance. For people at higher breast cancer risk, choosing lower-linoleic oils and adding high-purity omega-3 is a smart move.
