Seed Oils Aren’t Killing People: But the BS Around Them Might Be

An epidemiologist’s guide to why your tallow-fueled fear of seed oils is pseudoscience dressed in PubMed.

Let’s get one thing clear up front: I’m not a nutritionist or dietician. I’m an epidemiologist.

That matters here because the seed oil discourse, like much of modern food panic, isn’t being driven by nutrition science or dietetics. It’s being driven by storytelling grifters. Specifically, they sell stories about molecules. “Toxic” ones. “Oxidized” ones. The kinds that sound scary under a microscope and even scarier when someone like Paul Saladino explains them while standing shirtless in a grocery store shouting “broccoli is bullshit” while holding a head of broccoli in one hand and a slab of raw liver in the other¹.

In that world, linoleic acid, the omega-6 fatty acid found in seed oils like soybean, sunflower, and canola oil, isn’t just a nutrient. It’s a villain. The theory goes something like this: linoleic acid oxidizes. Oxidized molecules damage cells. Damaged cells mean inflammation. Inflammation means heart disease. QED: seed oils are poison.

It’s a theory that sounds sciencey. It invokes real molecules. It even includes links to PubMed. But here’s the thing: none of it holds up when you look at actual outcome data. And in epidemiology and health practice, outcome data is the whole point. If oxidized linoleic acid were really the primary driver of coronary heart disease, we’d see it in clinical trials. In cohort studies. In populations. But we don’t.

What we do see is this: people who consume more linoleic acid have lower LDL cholesterol, better cardiometabolic profiles, and a reduced risk of cardiovascular death^2,3. We see randomized trials where replacing saturated fat with polyunsaturated fat leads to fewer heart attacks, not more. We see decades of converging evidence being waved away by influencers who think “oxidized” means “toxic” in all contexts, and that a rat study from the 90s is the last word on dietary science.

This post is meant to takedown the claims themselves and the entire rhetorical ecosystem that lets bad ideas thrive. It’s a defense of outcome data, of nuance, and of the basic idea that if something’s going to be called harmful, it should have to actually, measurably harm people.

The Mechanistic Mirage

Paul Saladino isn’t just wrong, he’s confidently wrong, which is how you get 100,000 Instagram likes while citing biochemistry like it’s a Ouija board.

Here’s the basic arc of his argument:

1. Seed oils are rich in linoleic acid.

2. Linoleic acid is unstable and can oxidize.

3. Oxidized linoleic acid damages cells, “breaks” fat tissue, causes insulin resistance, DNA damage, inflammation, and—just for good measure—chronic disease.

4. Therefore: seed oils are “the most important lever” in chronic disease prevention, and should be eliminated entirely.

This is textbook mechanism-first thinking. It’s how you go from a test tube study to a grocery list. But in epidemiology, and really in all of science, plausibility isn’t proof. If you can’t show it in outcome data, it’s not causality.

Let’s break this down.

Mechanistic Claim: “Seed oils break fat cells and cause insulin resistance.”

There’s a version of this hypothesis that shows up in rodent studies: feed mice 50% of their calories as linoleic acid, and weird things happen to their adipose tissue. But that’s not a human diet. That’s a toxicological stress test.

Meanwhile, in actual humans:

· Increased linoleic acid intake does not raise inflammatory cytokines.

· It does not increase insulin resistance.

· In fact, in people with metabolic syndrome, it’s been shown to improve insulin sensitivity and lower triglycerides ⁴.

So, unless he thinks humans have the biology of a diabetic mouse on an all-soybean-oil diet, the mechanism doesn’t apply.

Mechanistic Claim: “Oxidized linoleic acid drives atherosclerosis and heart disease.”

Yes, linoleic acid can oxidize. So can every polyunsaturated fat. So can saturated fats in the wrong contexts. The question is: does it matter in humans at real-world intakes? And the answer is no.

RCTs, cohort studies, and umbrella reviews all show that:

· Higher linoleic acid intake = lower cardiovascular risk.

· People with higher circulating levels of LA have lower risk of coronary heart disease,stroke, and type 2 diabetes ⁵.

· Oxidation products like 9-HODE are found in plaques, but they are byproducts, not causes. They go up in disease because disease increases oxidative stress. That’s correlation, not causation.

What Saladino has done is take a true statement (“oxidized lipids exist”) and perform rhetorical jiu-jitsu to turn it into a dietary mandate. That’s not science. That’s storytelling.

Mechanistic Claim: “Humans aren’t meant to eat this much linoleic acid.”

This is the “ancestral purity” argument dressed in biochemistry. He cites the Hadza and Maasai consuming 2–3% of calories from LA, and contrasts this with modern intakes around 6–8%.

Uh, two things:

1. The Hadza and Maasai’s health outcomes don’t generalize to industrial societies. Romanticizing subsistence diets while ignoring overall nutrition quality, time spent active, life expectancy, and infection burden is intellectually dishonest.

2. Modern cohort data shows that people eating more LA (up to ~10% of calories) have better outcomes. Their hearts last longer. Their pancreases work better. Their mortality is lower ⁴.

And again: show us the human data where higher LA intake causes harm. Not rat models. Not “mechanisms.” Actual people. Actual outcomes. Saladino never does. He can’t. Because it doesn’t exist^2,6.

What the Outcome Data Actually Says

Let’s put the mechanisms down for a moment. No more lipid peroxidation cascades or mitochondrial dysfunction. Just data on actual people telling us about real-world outcomes.

If linoleic acid were as toxic as the supplement-peddling seed oil warriors claim, we wouldn’t need to infer it from rat livers or cell cultures. We’d see it in population-level harm. Higher LA intake would mean more heart attacks. More diabetes. Worse lipid panels. Higher all-cause mortality.

But that’s not what we see.

Cardiovascular Disease

Across dozens of cohort studies and randomized trials, linoleic acid intake is either neutral or inversely associated with cardiovascular disease.

• The Mozaffarian et al. meta-analysis pooled over 13,000 participants from randomized trials and found that replacing saturated fat with polyunsaturated fat (mostly LA) led to a 19% reduction in coronary events.

• Jackson et al. (2024) and others confirm: higher circulating LA is linked to lower risk of coronary heart disease, myocardial infarction, and cardiovascular death (using circulating LA as a reliable biomarker of long-term intake).

• Voon et al. (2024) showed in an umbrella review that LA-rich oils improve lipid profiles by lowering LDL and triglycerides in both healthy and high-risk populations.

This isn’t controversial among cardiologists. It’s just inconvenient for people trying to sell you beef tallow and Instagram detox kits.

Inflammation and Oxidative Stress

A core pillar of the seed oil narrative is that linoleic acid is “pro-inflammatory.” That it fuels chronic inflammation through oxidized metabolites like 9-HODE.

This has been tested. Repeatedly. In actual humans.

• A 2012 meta-analysis of 15 RCTs found no increase in CRP, IL-6, TNF-α, or any other inflammatory cytokine with higher LA intake⁴.

• No rise in oxidative stress markers like isoprostanes either.

• A 2021 update by Calder et al. reaffirmed: LA is not pro-inflammatory at real-world dietary intakes⁶.

In fact, in some studies, people with higher LA intake show lower inflammatory markers, especially when it replaces saturated fat⁴.

So where’s the harm? There isn’t any. Not unless you count the harm done to Saladino’s credibility.

Metabolic and All-Cause Outcomes

• Linoleic acid is also associated with lower incidence of type 2 diabetes in large prospective studies².

• Body composition improves in older adults and women with higher unsaturated fat intake^3,4.

• And all-cause mortality? Again, lower in people consuming more LA.

In other words: if this is the poison we’re supposed to fear, it’s doing a remarkably bad job of killing us.

What the Evidence Doesn’t Show

There is no modern RCT or meta-analysis in a human population that demonstrates:

• Increased cardiovascular risk from seed oils,

• Increased inflammation from dietary linoleic acid, or

• Any plausible level of intake where LA becomes pathologically “pro-oxidative.”

The few trials that ever suggested harm, like the Sydney Diet Heart Study and Minnesota Coronary Experiment, are⁷:

• Riddled with methodological flaws, including high dropout rates, trans fat confounding, and unblinded interventions,

• And regularly contradicted by meta-analyses of more rigorous modern trials ^8,9.

But, they bank on you not checking or knowing this. Or worse, they know you will, and they’re confident you’ll get overwhelmed by the biochemistry jargon and give up before getting to the part where the data disagrees with them.

Fear Is the Product

If you’re wondering how we got here, to the point where a fatty acid that lowers LDL became “the most important lever” in avoiding chronic disease, it’s worth zooming out.

This isn’t just about linoleic acid. It never was. Seed oils are just the latest toxin du jour, filling the slot once held by gluten, then carbs, then lectins, then oxalates. There always has to be something. Because wellness grifts need a villain.

Paul Saladino didn’t build a multimillion-dollar brand on nuanced takes about dietary patterns. He built it on outrage porn, certitude, and enemy molecules. And the brilliance of the seed oil narrative is that it has just enough biochemical garnish to look legitimate while being entirely undermined by human outcome data.

Let’s be blunt: fear is the product. The supplements, the ebooks, the workshops, they’re just the delivery mechanisms for the fear.

The Credibility Theater Playbook

This ecosystem runs on a simple formula:

1. Start with a mechanism – “Look, linoleic acid oxidizes!”

2. Invoke an ancient diet – “Our ancestors didn’t eat this!”

3. Cite an old or irrelevant paper – Bonus points for something from the 1960s.

4. Ignore RCTs or meta-analyses – Outcome data gets in the way.

5. Sell a corrective – “Avoid seed oils by buying this $35 beef tallow.”

There’s not an ounce of skepticism. It’s scientific cosplay, dressing up biochemical cherry-picking as expertise, then monetizing the fear it creates.

Why It Spreads

Seed oil panic is optimized for the internet:

• Mechanisms are sticky. “Oxidized linoleic acid causes inflammation” is easier to grasp (and fear) than “no significant increase in CRP across 15 RCTs.”

• Outcome data is slow and messy. It needs nuance, sample sizes, effect sizes, confidence intervals. It doesn’t go viral.

• Fear feels empowering. Telling people “You’re being poisoned and here’s how to stop it” creates agency, even if it’s fake.

And unlike science, which updates, grifter narratives just pivot. If it’s not seed oils, it’ll be something else. A new molecule, a new “ancestral mismatch,” a new supplement line. The toxin du jour will change. The business model won’t.

The Real Harm

This kind of thing would be mildly funny if it weren’t pulling attention away from real nutrition problems:

• Ultra-processed diets that overload on calories and underdeliver on nutrients.

• Structural food insecurity, where people don’t have the luxury of worrying about oil oxidation.

• Actual cardiometabolic risk factors like sedentary lifestyles, smoking, and poor sleep that get ignored in favor of purity spirals about mayonnaise.

Seed oils aren’t killing people. But the distraction from real health interventions? That might be.

The Real Villain

Seed oils didn’t cause the rise in heart disease. They didn’t break your metabolism. They didn’t poison your fat cells or oxidize your mitochondria. What they did was become a convenient scapegoat in a story that sells better than science.

If you want to eat fewer processed foods, great. If you want to swap canola oil for olive oil, knock yourself out. But don’t confuse aesthetic preference with evidence. Don’t fall for scientific theater dressed up as ancestral wisdom. And don’t let people who sell beef supplements convince you that PubMed links are the same as clinical outcomes.

In epidemiology, we have a rule: trust the data, not the drama. It might not sell detox kits, but it’ll actually make you healthier.

Citations

1. Seed Oils & Processed Foods: How They’re Harming You – Paul Saladino, MD. Accessed April 24, 2025. https://www.paulsaladinomd.co/psmd-newsletters/seed-oils-processed-foods-how-theyre-harming-you

2. Jackson KH, Harris WS, Belury MA, Kris-Etherton PM, Calder PC. Beneficial effects of linoleic acid on cardiometabolic health: an update. Lipids Health Dis. 2024;23(1):296. doi:10.1186/s12944-024-02246-2

3. Voon PT, Ng CM, Ng YT, et al. Health Effects of Various Edible Vegetable Oils: An Umbrella Review. Adv Nutr. 2024;15(9):100276. doi:10.1016/j.advnut.2024.100276

4. Petersen KS, Messina M, Flickinger B. Health Implications of Linoleic Acid and Seed Oil Intake. Nutr Today.:10.1097/NT.0000000000000746. doi:10.1097/NT.0000000000000746

5. Data Support Health Benefits of Seed Oils High in Unsaturated Fatty Acids. SNI Global. Accessed April 24, 2025. https://sniglobal.org/new-manuscript-reinforces-scientific-consensus-on-the-health-benefits-of-seed-oils/

6. Djuricic I, Calder PC. Beneficial Outcomes of Omega-6 and Omega-3 Polyunsaturated Fatty Acids on Human Health: An Update for 2021. Nutrients. 2021;13(7):2421. doi:10.3390/nu13072421

7. DiNicolantonio JJ, O’Keefe JH. Omega-6 vegetable oils as a driver of coronary heart disease: the oxidized linoleic acid hypothesis. Open Heart. 2018;5(2):e000898. doi:10.1136/openhrt-2018-000898

8. Mozaffarian D, Micha R, Wallace S. Effects on Coronary Heart Disease of Increasing Polyunsaturated Fat in Place of Saturated Fat: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. PLOS Med. 2010;7(3):e1000252. doi:10.1371/journal.pmed.1000252

9. Petersen KS, Maki KC, Calder PC, et al. Perspective on the health effects of unsaturated fatty acids and commonly consumed plant oils high in unsaturated fat. Br J Nutr. 2024;132(8):1039-1050. doi:10.1017/S0007114524002459