Are seed oils bad for you? The truth about seed oils.
Shortly after moving to Boulder 18 years ago, I began running into the gluten-free prophets. At first, I thought, “They’re nuts.” Less than 1% of the population suffers from celiac disease, but it seemed about half the people I was meeting back then called themselves gluten free and rejected proper bread, beer, baklava and the rest of the wheat-anchored treasures that enrich our brief tenure on the planet.
My wife, Annie, and I dreamed of making “I (Heart) Gluten” T-shirts and swanning around town in them.
Many other diets prompt similar reactions. The whole paleo/caveman/keto thing, for example. Juice cleanses. Alkaline diets. With most of them, I concluded their pursuit had little to do with vigor and health; instead, they were just weight-loss gambits dressed up in fancy phrasing.
Now we have the anti-seed oil brigade. The Make America Healthy Again (MAHA) types, in particular, align with the movement, trumpeting the evils of oils made from seeds and urging companies to excise them from products.
My first reaction: “Loons.”
I found the demonization of seed oils so bizarre that I dove into seed-oil research. And then, to my shock, I discovered they’re on to something.
Good news for the natural and organic products industry—while commercial seed oils figure into some formulations, they don’t dominate as they do in conventional grocery. (CANVA)
All oils not created equally
As with so many diets and food restrictions, kernels of truth cling to some of the claims. Seed oils are the most commonly used fats in ultra-processed foods (UPFs). They’re cheap. The main targets in the anti-seed oil campaign are canola, corn, cottonseed, grapeseed, soybean, sunflower, safflower and rice bran oils.
For the seed oil haters, the problem with many of the oils stems—mostly—from the processes used to manufacture the oils, rather than the seeds themselves.
Think manufacturers just press oil out of the seeds and then bottle it? Not with the mass-produced renditions. The steps for turning seeds into refined oil could include:
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Grinding the seeds.
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Heating them.
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Using the solvent hexane to withdraw the oil.
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Heating the seeds again to remove the hexane.
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“Degumming,” which uses water or weak acid to remove different botanical compounds, such as lecithin.
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“Neutralization,” a process involving the addition of sodium hydroxide to remove free fatty acids (FFAs). Getting rid of the sodium hydroxide then requires more refining.
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“Bleaching,” where oil gets heated, mixed with clay or carbon, then filtered.
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“Deodorization,” in which oil gets heated to as high as 500 degrees, under a vacuum.
All of this is done to create a shelf-stable, neutral oil. By the time it’s ready, the oil has been stripped of most of the seeds’ natural compounds. And the combination of high heat and additives interferes with the oils’ health-giving integrity.
Extra virgin olive oil, by comparison, gets pressed and filtered. That’s it.
Does the parade of processing render most seed oils akin to poison? No—and that’s the rub.
I’ve canvassed the research and cannot find evidence for healthy quantities of seed oils, including the mass-produced ones, serving as health demons.
Let’s cover the health claims made by the anti-seed oil people.
Claim: Seed oils cause inflammation because they are high in omega-6 fats, mostly due to linoleic acid.
Fact: Omega-6 fats on their own are not dangerous; in fact, they are necessary. Over-consumption of products with a lot of omega-6 fats can skew the balance between omega-3 and omega-6 fats in unhealthy ways, but that doesn’t mean people should strive to eliminate omega-6 fats from their diets. Also, it turns out that omega-6 fats produce anti-inflammatory molecules. Citation
Claim: Seed oils oxidize when cooked, producing toxins that damage cells.
Fact: It’s true—when seed oils are heated to high temperatures repeatedly for deep-frying. But for sautéing onions or using it in a carrot cake recipe, the claim crumbles. Citation
Claim: Seed oils cause obesity, heart disease, fatty liver and more.
Fact: Seed oils on their own aren’t the culprits here. However, the ultra-processed foods (UPFs) in which they commonly get used stand as true health villains. Citation
Claim: Seed oils and products high in omega-6 fats cause cancer.
Fact: There is no evidence for this. In fact, research shows that healthy intake of seed oils contributes to a lower risk of a range of chronic diseases. Citation
Claim: The linoleic acid found in common seed oils “breaks” mitochondria, making them fragile and disease-prone.
Fact: This is purely speculative, and popular in biohacking circles. However, no studies involving humans consuming normal quantities of the oils has yielded evidence for this. Citation
Despite the lack of proof for seed oils being toxic, the anti-seed oil movement’s momentum has upped sales of saturated fats like tallow. The fast-food chain Steak ’n Shake, in fact, switched to beef tallow for frying. But most medical research has concluded that the saturated fats found in butter and tallow are far more damaging to human health than any unsaturated fat—like those in seed oils.
The campaign’s collateral damage extends beyond newfound reverence for tallow and butter—and to be clear, I enjoy butter quite a bit, and sometimes find tallow tasty. I just don’t think wholesale swapping of seed oils for saturated fats is wise. Also, seed oils that get manufactured through simple methods such as cold pressing and expeller pressing endure none of the steps that go into making industrial seed oils. Like olive oil, they get pressed and filtered. But they’re getting demonized by the shrill anti-seed oil activists.
In addition, some activists have even concluded that raw seeds are dangerous. Seeds contain robust concentrations of omega-6s—and to some of the crusaders anything containing omega-6 fats detracts from health. Yet nearly any health professional would praise seeds as smart components of a good diet.
My takeaway from the anti-seed oil hysteria? The oils, from which nearly all botanical compounds have been stripped, do not contribute toward health. A tablespoon of an industrial safflower oil isn’t unhealthy on its own—but it’s also not boosting human vigor.
Poison? Nope.
The villain is UPFs. According to the Centers for Disease Control and Prevention, between 2021 and 2023 UPFs made up about 55% of the calories among people aged 1 and older. And the numbers are trending higher.
Seed oils figure largely into UPFs. So, for many Americans, seed oils commandeer a significant portion of their diet. Researchers suspect that mass consumption of seed oils through UPFs probably has contributed toward a rise in omega-6 fats, at the expense of omega-3s, in the American diet. While omega-6s are necessary and contribute toward health, they should dwell in balance with omega-3s.
Most of us have close to no idea what goes into the foods we buy in packages, or order at restaurants. I hadn’t thought much about the kinds of oils used in foods, and appreciate the anti-seed oil movement’s spotlighting of manufacturing issues with most mass-market seed oils.
But as so often is the case, it’s gone too far. Seed oils aren’t the problem. Instead, the product devastating human health is UPFs.
Good news for the natural and organic products industry—while commercial seed oils figure into some formulations, they don’t dominate as they do in conventional grocery. Many retailers reject them or at least try to mitigate their presence on shelves. Meanwhile, bottles of cold- and expeller-pressed seed oils retaining their botanical gifts abound in many natural and organic grocery stores. Brands in the industry, too, are more careful than conventional manufacturers about sourcing healthy oils for their chips and cookies.
I’ve rejected most food fads over the years. But the burgeoning crusade against UPFs resonates. Instead of designing a “I (Heart) Gluten” T-shirt, maybe it’s time to come up with something emblazoned with UPF and a skull and crossbones.
