Butter, MCT, Coconut, Ghee, Olive. Then I Read the Seed Oil Studies.

I started by adding the butter. I cut two tablespoons from the block and dropped them into the blender with my coffee. The blender was so loud for thirty seconds that I closed the kitchen door.

The result was a pale brown drink with a foamy, shiny layer that caught the morning light. I drank it at the counter before anyone else woke up, and I felt great about it.

I have both a medical and a dental degree. Even so, I ended up drinking butter for breakfast after hearing someone on a podcast explain the science. It made sense to me at the time.

These things always seem to make sense at first. That’s the real problem.

My butter phase lasted about two years. Then I switched to MCT oil, which cost almost as much as the whiskey on the shelf. After that came coconut oil, then ghee, which I thought was an upgrade. Now I use olive oil. Each choice felt reasonable at the time.

Each phase had its own expert, a scientific reason, and a type of fat to avoid. The latest trend has the most talked-about villain so far.

Before all of this, there was a hallway. After three training sessions that day, we would sit on the floor outside our rooms, leaning against the wall. On the youth national team, we shared rooms in a long corridor lined with doors. You could recognize another wrestler from across the room without saying anything. It was the ears that gave us away.

In May, Robert Saleh, in his first year coaching the Tennessee Titans, told reporters that removing every seed oil from the facility had been one of the first changes he made, part of an overhaul of how the team eats [1]. Canola and soybean oil, out of an NFL building.

Recently, more executives have asked me about seed oils than ever before. So I read everything I could find on the topic, including both sides and even the arguments I expected to disagree with.

The biology he describes is real

Paul Saladino is one of the most-followed voices arguing that seed oils are doing serious damage. He’s a physician, and he writes this on his own site: “we STORE these polyunsaturated fats in our cell membranes and mitochondrial membranes” [2].

He’s right about that.

Linoleic acid, the main omega-6 fat in conventional sunflower, corn, soybean, and canola oils, gets built into cell membranes and body fat. A review of 37 studies found that its share of American adipose fatty acids rose from 9.1% in 1959 to 21.5% in 2008 [3]. The review estimated a half-life in fat tissue of about 680 days.

Polyunsaturated fats oxidize more readily than saturated fats. In a laboratory study, peroxidized linoleic acid damaged isolated DNA [4].

In the most recent American dietary survey, foods coded as fats supplied 8% to 13% of people’s linoleic acid. Grains supplied 22% to 35%, meat 15% to 25% [5]. Those are categories of reported food, so oil baked into bread still counts as grain. The survey can’t isolate what came from a bottle. The bottle is the visible part of exposure spread across many foods.

Each of my phases started with a solid scientific explanation. Medium-chain fats are processed differently. Clarified butter removes milk solids. Now, I always ask a practical question: has anyone actually measured what happens to people who eat this?

Someone decided to test it

Saladino’s sharpest claim is about DNA. His words, as written: excess linoleic acid makes fat cells release free fats, and “These free fats induce insulin resistance in the peripheral muscles, causing inflammation and DNA damage” [6].

In 2003, the same group went looking in people. Thirty volunteers across three arms for six weeks, one taking 15 grams of linoleic acid a day against a palmitic acid control, measuring oxidative DNA damage in white blood cells. In the linoleic acid arm, the damage rose 13% from where it started and finished 23% below the control group. Neither difference was statistically significant [7].

Each group had ten people, and the study lasted six weeks. They measured only one marker in white blood cells, not muscle as Saladino’s theory suggests. With those limits, the study found no evidence that extra linoleic acid increased oxidative DNA damage.

The population data point the same way. Among 85,425 UK Biobank adults followed for almost 13 years, the top fifth for plasma omega-6 as a share of total fatty acids had 23% lower all-cause mortality than the bottom fifth [8].

That study also challenged an argument I believed for a year. The group with the highest ratio had 26% higher mortality. Both omega-6 and omega-3 were linked to lower mortality, but the link was stronger for omega-3 [8]. The authors thought the ratio result was probably due to omega-3.

Randomized trials don’t show much. In 19 studies with 6,461 adults followed for one to eight years, increasing omega-6 made little or no difference to deaths or heart problems overall. It did lower total cholesterol and might have reduced heart attacks, but the evidence for that is weak [9].

My own ratio was 3.6, which experts say is good. But that number didn’t tell me if I was getting enough of either fatty acid. I realized I might have been taking the wrong part of my fish oil for ten years.

The two trials that should trouble me

Two randomized trials are central to the main arguments against seed oils. Anyone who thinks this debate is settled should take a close look at them.

The Minnesota Coronary Experiment randomized 9,423 people across six mental hospitals and a nursing home between 1968 and 1973. The intervention replaced saturated fat with corn oil. Cholesterol fell 13.8% among participants measured again after a year or more, with no mortality benefit [10]. People kept leaving the institutions, ending their follow-up. The diet also pushed linoleic acid to 13.2% of calories, well above typical US intake of 5.5% to 6% [5].

The Sydney Diet Heart Study is the harder one. It randomized 458 men, 221 to safflower oil and safflower margarine and 237 to continue their usual diet. 86% had had a heart attack, on average about 11 weeks earlier. More of the intervention group died: 17.6% against 11.8%, a hazard ratio of 1.62, with a confidence interval from 1.00 to 2.64 [11].

I wish I could say the margarine was the reason. Margarine back then contained trans fats, but the exact makeup of this one wasn’t measured. However, the study’s authors considered this and ruled it out: the intervention also removed the usual margarines and shortenings, which were the main sources of trans fats at the time. So, trans fat intake probably went down, not up, and they thought it was unlikely to explain the results [11].

The study had clear limits: it involved men who had recently had heart problems, linoleic acid made up about 15% of their energy, there were several dietary changes, and the original protocol couldn’t be recovered. It was just one trial, in men who were already sick, at much higher intakes than usual. Still, it matters.

Why the evidence disagrees

My training taught me to look at each study and think about what kinds of errors it might have.

Plasma fatty acids depend on diet and metabolism. The UK Biobank authors adjusted for many known differences between participants. They still could not rule out factors they had missed or measured poorly, and they sampled blood once, at the start [8].

Randomization addresses confounding. Cochrane rated most of the clinical-outcome evidence low or very low certainty because of bias and imprecision [9].

Looking at all the studies together, I see two main gaps. The UK Biobank can’t prove cause and effect, and the trials only give rough estimates for real-world outcomes. No one has run a large, long-term trial at typical modern intake levels yet.

What the ears were for

No one planned to talk that night. My roommate brought up weight cutting, and soon everyone joined in, sharing stories about injuries, long hours inside, and the smell that never leaves a gym bag. We said things to each other we’d never say to a coach.

Someone joked that our parents should be prosecuted for signing us up. We all laughed, and while we half-meant it, none of us would have quit.

That’s what the ears meant. When you saw another guy across the room, you knew he’d gone through the same things you had, and you didn’t have to say a word.

I stopped wrestling in my mid-twenties, after my shoulder gave out for the last time. There was no final match or big decision, just a scan and a surgeon giving me practical advice. The training hall kept going every night without me. No one was unkind. What I wasn’t prepared for was how something that had shaped my whole life could just end, with everyone else carrying on while I stood outside.

Then there was nothing.

Nutrition groups offer the same sense of belonging, but without the physical cost. A jar on the counter shows everyone which side you’re on, and no one needs to check your ears.

That’s why the debate never ends. Each position gives you a group identity along with a health rule, and it’s harder to let go of the identity than the rule. I’ve been through this five times myself.

I went through all five phases on my own. Standing at the kitchen counter before anyone else was awake, blending butter into my coffee, I felt like I was part of something.

What I keep in the kitchen

At a work dinner a few weeks ago, a man sitting two seats away put down his fork and turned to me. “Andre, what do you think this was cooked in? Should I worry if it’s seed oils?” He wanted to know if his dinner was safe, and he was asking the doctor at the table.

The practical answer is simpler than the debate makes it seem. In the largest relevant study I found, 221,054 American health professionals were followed for up to 33 years. Replacing 10 grams of butter a day with plant oil was linked to a 17% lower risk of death [12]. This was an observational study, and the swap was modeled, not actually done.

Two of my own phases don’t look so good. Coconut oil raises LDL cholesterol by about 10 mg/dL compared to other vegetable oils, and none of the studies measured heart attacks or deaths [13]. Turning butter into ghee removes water and milk solids, so gram for gram, ghee has more saturated fat. As a percentage of total fat, butter and ghee are only a few points apart [14]. I swapped one for a more concentrated version and thought I was making a smart choice.

Olive oil, which I use now, compares well to butter. In a study of 92,383 people, it didn’t show a significant advantage over other vegetable oils [15].

What I told him

No, don’t worry about it, and eat your dinner.

The longer answer is that the bottle is just a distraction, and the scientific explanation is what convinces you. I went through five versions of this over 15 years, and each one was biochemically accurate. This is the Activate part of the Upward ARC, which is about what you put into your body. It’s also where marketing is strongest and the incentives are hardest to spot.

In one study, twenty people in a metabolic ward ate 508 more calories a day on an ultra-processed diet than on an unprocessed one, gaining about a kilogram in two weeks [16]. The trial didn’t test seed oil or figure out which differences in the diets caused the result. It was the overall eating pattern that changed how much people ate.

So, to answer his specific question: at the amounts people usually eat, there’s no human evidence that seed oils are especially harmful. Replacing butter and other saturated fats with plant oils lowers cholesterol, and studies link that swap to living longer. Whether purposely adding more omega-6 changes lifespan is still an open question.

Try this today

Each phase I went through added another rule. This list is about letting go of some of them.

Don’t treat the ratio as a final answer. In the UK Biobank data, both omega-6 and omega-3 were linked to lower mortality, and the authors believed the ratio was mostly influenced by omega-3. If you don’t eat oily fish often, start there before getting another test.

Stop overthinking and just keep two bottles: extra virgin olive oil for everyday cooking and finishing, and refined canola or high-oleic oil for frying and roasting. The difference between these sensible choices is so small that worrying about it costs you more than picking the wrong one.

Use frying oil only once, throw it out after cooking, and keep the pan below the oil’s smoke point. I do this as a kitchen habit, not because of any proven health outcome.

Ask what would make someone change their mind. For me, it would be a well-designed, independently funded trial at the amounts people actually eat. If I ever call a food poison and can’t answer that question, just stop reading.

Maybe I was just lucky

Throughout all five phases, my blood tests stayed normal. Maybe the type of fat mattered less than I believed. Maybe I was just lucky. I still keep butter in the fridge and use it in normal amounts.

Five times, an expert with a clear explanation convinced me before I checked the evidence myself, and five times I changed my mind later. I don’t regret making those changes.

I still miss that hallway and my wrestling tribe.

Stay healthy.

Andre

PS: I’ve told you my five eras. What was yours? The one you’d rather not admit to. Reply and tell me; I read every message and never share them. And if you know someone with strong opinions about oil who has never read a study on it, send this along. That’s how this newsletter grows, and the only way I want it to.

PPS: If someone forwarded this to you, you can get Under Load, my Sunday edition, here:

https://www.andreheeg.com

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References

[1] Titans’ Robert Saleh sparks nutritional value debate with seed oil ban for players, team-provided meals. (2026, May). Fox News. https://www.foxnews.com/sports/titans-robert-saleh-sparks-nutritional-value-debate-seed-oil-ban-players-team-provided-meals

[2] Saladino, P. (2025, November 10). Don’t read this if you love your bacon. paulsaladinomd.com. https://www.paulsaladinomd.com/psmd-newsletters/dont-read-this-if-you-love-your-bacon

[3] Guyenet, S. J., & Carlson, S. E. (2015). Increase in adipose tissue linoleic acid of US adults in the last half century. Advances in Nutrition, 6(6), 660-664. https://doi.org/10.3945/an.115.009944

[4] de Kok, T. M., ten Vaarwerk, F., Zwingman, I., van Maanen, J. M., & Kleinjans, J. C. (1994). Peroxidation of linoleic, arachidonic and oleic acid in relation to the induction of oxidative DNA damage and cytogenetic effects. Carcinogenesis, 15(7), 1399-1404. https://doi.org/10.1093/carcin/15.7.1399

[5] Momin, S. R., Senn, M. K., Manichaikul, A., Tintle, N. L., Herrington, D. M., Rich, S. S., Kabagambe, E. K., & Wood, A. C. (2023). Dietary sources of linoleic acid (LA) differ by race/ethnicity in adults participating in NHANES between 2017-2018. Nutrients, 15(12), 2779. https://doi.org/10.3390/nu15122779

[6] Saladino, P. (2024, July 28). Seed oils & processed foods: How they’re harming you. paulsaladinomd.com. https://www.paulsaladinomd.com/psmd-newsletters/seed-oils-processed-foods-how-theyre-harming-you

[7] de Kok, T. M. C. M., Zwingman, I., Moonen, E. J., Schilderman, P. A. E. L., Rhijnsburger, E., Haenen, G. R. M. M., & Kleinjans, J. C. S. (2003). Analysis of oxidative DNA damage after human dietary supplementation with linoleic acid. Food and Chemical Toxicology, 41(3), 351-358. https://doi.org/10.1016/S0278-6915(02)00237-5

[8] Zhang, Y., Sun, Y., Yu, Q., Song, S., Brenna, J. T., Shen, Y., & Ye, K. (2024). Higher ratio of plasma omega-6/omega-3 fatty acids is associated with greater risk of all-cause, cancer, and cardiovascular mortality: A population-based cohort study in UK Biobank. eLife, 12, RP90132. https://doi.org/10.7554/eLife.90132

[9] Hooper, L., Al-Khudairy, L., Abdelhamid, A. S., Rees, K., Brainard, J. S., Brown, T. J., Ajabnoor, S. M., O’Brien, A. T., Winstanley, L. E., Donaldson, D. H., Song, F., & Deane, K. H. O. (2018). Omega-6 fats for the primary and secondary prevention of cardiovascular disease. Cochrane Database of Systematic Reviews, 2018(11), CD011094. https://doi.org/10.1002/14651858.CD011094.pub4

[10] Ramsden, C. E., Zamora, D., Majchrzak-Hong, S., Faurot, K. R., Broste, S. K., Frantz, R. P., Davis, J. M., Ringel, A., Suchindran, C. M., & Hibbeln, J. R. (2016). Re-evaluation of the traditional diet-heart hypothesis: Analysis of recovered data from Minnesota Coronary Experiment (1968-73). BMJ, 353, i1246. https://doi.org/10.1136/bmj.i1246

[11] Ramsden, C. E., Zamora, D., Leelarthaepin, B., Majchrzak-Hong, S. F., Faurot, K. R., Suchindran, C. M., Ringel, A., Davis, J. M., & Hibbeln, J. R. (2013). Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: Evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis. BMJ, 346, e8707. https://doi.org/10.1136/bmj.e8707

[12] Zhang, Y., Chadaideh, K. S., Li, Y., Li, Y., Gu, X., Liu, Y., Guasch-Ferré, M., Rimm, E. B., Hu, F. B., Willett, W. C., Stampfer, M. J., & Wang, D. D. (2025). Butter and plant-based oils intake and mortality. JAMA Internal Medicine, 185(5), 549-560. https://doi.org/10.1001/jamainternmed.2025.0205

[13] Neelakantan, N., Seah, J. Y. H., & van Dam, R. M. (2020). The effect of coconut oil consumption on cardiovascular risk factors: A systematic review and meta-analysis of clinical trials. Circulation, 141(10), 803-814. https://doi.org/10.1161/CIRCULATIONAHA.119.043052

[14] U.S. Department of Agriculture, Agricultural Research Service. (2019). FoodData Central: Butter, salted (FDC 173410); Butter, clarified (ghee) (FDC 171314).

https://fdc.nal.usda.gov

[15] Guasch-Ferré, M., Li, Y., Willett, W. C., Sun, Q., Sampson, L., Salas-Salvadó, J., Martínez-González, M. A., Stampfer, M. J., & Hu, F. B. (2022). Consumption of olive oil and risk of total and cause-specific mortality among U.S. adults. Journal of the American College of Cardiology, 79(2), 101-112. https://doi.org/10.1016/j.jacc.2021.10.041

[16] Hall, K. D., Ayuketah, A., Brychta, R., Cai, H., Cassimatis, T., Chen, K. Y., Chung, S. T., Costa, E., Courville, A., Darcey, V., Fletcher, L. A., Forde, C. G., Gharib, A. M., Guo, J., Howard, R., Joseph, P. V., McGehee, S., Ouwerkerk, R., Raisinger, K., … Zhou, M. (2019). Ultra-processed diets cause excess calorie intake and weight gain: An inpatient randomized controlled trial of ad libitum food intake. Cell Metabolism, 30(1), 67-77.e3. https://doi.org/10.1016/j.cmet.2019.05.008