Harvard study finds seed oils healthier than butter
79 comments
·March 19, 2025alexfromapex
mlyle
> This study has a few that we know of:
The International Nut and Dried Fruit Council may or may not be a conflict of interest about seed oils.
NIH and Novo Nordisk wouldn't be.
> I wish we could get studies without any conflicts of interest
You'd need to have a whole lot more public funding of research than we already do, if we're going to have the entire academic world not do any research for industry.
In this case, they didn't produce new data and made a relatively straightforward analysis. So the opportunities for shenanigans when other people can reproduce and evaluate the results are limited.
hollerith
If the anti-seed-oil narrative is correct, then Novo Nordisk would have a conflict of interest because the narrative says that seed oils cause metabolic disease, of which type-2 diabetes is an important one.
mlyle
You're saying that Novo wants to obscure the true causes of metabolic disease to make, decades from now, marginally more from metabolic disease treatments?
There's far more lucrative shenanigans that pay off much sooner :P
manmal
> The International Nut and Dried Fruit Council may or may not be a conflict of interest about seed oils.
Why do you doubt that there’s a conflict there?
mlyle
Seed oils seem to be a tiny, edge portion of their advocacy. It's probably a conflict, but a relatively weak one.
observationist
200 billion was spent in 2024 by the US, broadly, on research in general. I think we need to mandate that publicly funded research be open, doesn't get gamed by politics, clout chasing, or other flawed incentives, and we need to deliberately establish replication protocols. We should be establishing fundamental scientific data with rigorous and thorough standards, but people end up doing sloppy, incoherent, politicized papers that are published on behalf of a person or idea or pre-existing conclusion.
If you did the basic research, then mandated 10 replications for each novel outcome (or whatever, some sort of structured process needs to be created), and then put up replication grants to fund it, you'd filter out the noise. The NIH and Congress and other government entities should have some number of yearly slots for replication grants, so that should the public or some agency have an interest in validating the findings of a paper, they can direct their representatives to pursue it, and so forth.
We have an enormous amount of money, an amazing system of research labs and universities and private corporations in the US, we just need a reliable and intentional system to use those things to best effect.
kolbe
I can think of plausible[1] motives for the NIH and Novo Nordisk that would make it a conflict.
[1] emphasis on "plausible," as opposed to confirmed
mlyle
If you are going to say that anyone who ever takes public health money -or- private industry money is conflicted, then everyone who ever does -any- research for a living is conflicted.
pton_xd
I grew up in a period when eggs went from bad for you to healthy to probably fine in moderation. In the same time period there was a huge push toward low fat diets which were supposed to reduce the risk of heart disease. Then it was low carb diets, then healthy fat diets.
It's unfortunate but now I have little faith in health studies related to food.
CSMastermind
I remember growing up everyone told me that I should be using margarine instead of the butter I preferred.
Years later everyone went crazy banning trans fat.
I'll stick with butter and live with the health consequences (if any).
> It's unfortunate but now I have little faith in health studies related to food.
As someone who was taught the "food pyramid" in school, I'm firmly on the side of trust body builders and 'bro science' not the government.
fkyoureadthedoc
> I'm firmly on the side of trust body builders and 'bro science' not the government
You're in luck. Here's a strong bald man to tell you about seed oils:
guyzero
I find it deeply weird that seed oils have become a culture war topics and a tabula rasa onto which people projects all manner of societal ills.
foxyv
We're deeply wired to avoid and attach to things based on extremely simple heuristics. Avoid the strange man with the pointy stick, attach to the tree that makes tasty fruit, avoid the crocodile pond, attach to the thing that makes women flock to you.
Marketing departments and politicians are very good at using this to their advantage.
rce
Why? My understanding of the argument against seed oils is that they have a high omega 6 to omega 3 ratio, which does not align with historical intake and leads to inflammation. While I'm not a nutritionist, this seems like a perfectly reasonable argument
guyzero
Americans eat 12.51 million metric tons of it a year, so it is clearly not exactly poisonous. And "inflammation" is very vague... most people would be better off just increasing their dietary fiber intake and not worry about swapping one fat for another. It doesn't require thousands of people with no education in the area creating social media content about it.
relaxing
What the fuck is inflammation? That wasn’t part of my 9th grade health class, outside of getting a sprained ankle. How is it suddenly a well known health crisis?
jmye
Omega 3 vs 6 and inflammation has nothing to do with it being a culture war topic or the tabula rasa GP described. Odd, soap-boxy response.
It’s also a straightforward thing to test for, assuming you can define “inflammation” without weird woo-pseudoscience.
PaulHoule
The John Birch society was into weird ideas about health since the 1960s, I had a friend in the 1980s whose parents were Amway distributors and selling supplements who were introducing my family to anti-abortion and school voucher activists.
In Ithaca though we have a population of hypochondriacs who are notoriously left wing.
Alternative ideas about the healthiness of fats have circulated a long time
https://www.amazon.com/Fats-That-Heal-Kill-Cholesterol/dp/09...
is the first one I saw against ‘seed oils’, certainly alternative ideas about the healthiness of cholesterol and saturated fats have been circulating a long time. What is different is the polarization of the post-COVID environment but the polarization is such that you find people who don’t think we are post COVID.
roughly
Naomi Klein’s Doppelgänger is an absolutely brilliant read on why you see this kind of consonance between the fringe left & right (although fringe may not be the right word anymore):
https://bookshop.org/p/books/doppelganger-a-trip-into-the-mi...
guyzero
Ha, poor Naomi Klein getting confused with the other Naomi... I guess it was inevitable she'd write a book about it.
PaulHoule
One of the things that cuts the Democrats off at the knees is that the far left is even hungrier for “change” and “shaking things up” than Trump supporters are and doesn’t get any emotional satisfaction out of supporting the party of “status quo at any cost” other than the behavioral sink of “the enemy of my enemy is my friend.”
European politics is itself in a death spiral of the center left and center right forming an emotionally false coalition whereas the AfD looks emotionally truer by the day.
ceejayoz
People really love the idea of a quick, easy fix; a single solveable problem that explains a vast swath of issues.
like_any_other
Like vitamin C to fix everything that goes wrong on long sea voyages, or removing lead and mercury from diets, avoiding alcohol and thalidomide during pregnancy, abstaining from cigarettes, removing cocaine from Coca Cola, or any number of other additives that are perhaps less clear cut: https://time.com/7210717/food-additives-us-fda-banned-europe...
Avoiding poison is a "quick, easy fix" to the consequences of that poison (or the opposite in the case of vitamin deficiency). Whether there's any reason to believe seed oils are harmful, I have no clue, but the idea that we could be en-masse consuming something harmful has dozens of precedents.
ForTheKidz
> the polarization is such that you find people who don’t think we are post COVID.
What does the phrase "post-covid" even mean in a population with actively circulating covid? I don't think such a concept is even possible at this point.
PaulHoule
Accurately, post a set of cultural changes. Some variant of that virus will be going around until, maybe, there is a severe lockdown because of another virus but that won’t happen for another half-generation at least even if the new virus is The Andromeda Strain.
There is a population of people today though who have internalized the threat of COVID as a core part of their identity such as one of those Ithaca hypochondriacs that doesn’t get invited to parties because the only thing she’s wanted to talk about since 2021 is face masks.
kurthr
But since I stopped eating seed oils I haven't been mauled by a lion. Also, I ate seed oils in middle age and gained a bunch of weight, then I got healthy started exercising, spent money on a trainer and a diet, and stopped eating seed oils in fast food and lost weight!
Pick something almost everyone does and then claim that it is the source of the current great social ill... social media... profit! For bonus points use the phrases "cleanse", "detox", "inflammation", "processed", "all-natural" bereft of meaning.
I mean, it's not like the health effects of an oil would depend on what seed, or what quantity, or how you cook, or what other activities you do, is it?
p.s. all the silicon in your computer was inorganically grown!
sct202
It is especially fitting that another front page topic today is "The Origin of the Pork Taboo"
bediger4000
A lot of the culture war topics seem deeply weird. mRNA vaccines that absolutely do work and are safe somehow get all kinds of things ascribed to them.
Prayer in schools, which has passed out of the Gartner Culture War hype cycle, seems like another one of those head scratchers.
relaxing
Everyone likes God, God wants you to pray. It’s quite easy to whip up opposition to anyone who gets in the way of that.
Although frankly, with the way the propaganda machine is well oiled and constantly running, it’s easy to whip up opposition to anything.
tengbretson
> Participants in the three studies filled out surveys every four years on how often they ate certain foods.
I don't have a dog in this fight, but this data is nearly useless.
jjice
Am I wrong, or do we already know a good diet for the majority of people is? Get a mix of fruits, vegetables, lean meats, grains, and fats in reasonable distribution. That distributions seems to have a pretty flexible range and each person can shift it around a bit. Maybe you skip out of meat and dairy - that works too. Same with taking out a piece of these in any way you want. Oh, and go ahead and break that once and a while and don't think it's a big deal - a day of state fair food won't kill you.
Except for specific cases that are not common (dietary restrictions of all kinds), it seems like you should mostly consume the things you traditionally associate with being "healthy", but also give yourself some wiggle room.
Get your blood work done and see a doctor regularly - if there are no issues, you're probably fine. If you're not, I doubt the reduction of seed oils in your diet would've remedied that.
wanderr
I wish articles like this would engage in a bit of critical analysis of the studies they are reporting on. It's no wonder people are confused as hell about the latest science about what foods are healthy when there are seemingly new contradicting studies coming out all the time and the news about them just parrots the contents of the study with no critical analysis why this new understanding might be better, or worse, than what we had before.
That said, I hope this is right. As someone who is allergic to dairy it would be nice to know that the substitutes I'm consuming aren't significantly worse for me, and it would be great to see more dairy free options for foods although the trend seems to be going in the opposite direction (for example, the amount of "dark" chocolate with milk in it is astounding, and brands that were reliably true dark chocolates have started adding milk too)
zeroonetwothree
Not surprising. I think the argument against seed oils is they are worse than other vegetable oils, not butter. Not sure there is strong evidence for that claim either though.
azinman2
Except those on the crusade (including RFK Jr) want animal fats, like beef tallow, to replace seed oils.
berbec
Wait, I missed this. They're saying we need to replace peanut oil, which I'm not saying is a multivitamin or anything, with lard? Holy crap... Even McDonald's figured out that's something to skip
randomNumber7
No only processed oil. Cold pressed oil like olive oil is healthy.
cantrecallmypwd
The "health and wellness" conspiracy nut influencer fad crowd believes they "know better" than science, which is nothing new. If they say it's "good", probably best to avoid or do the opposite.
aaaioididiid
It’s not explicitly seed oil vs not. It’s the more modern processed oils (of which many seed oils you’ll find are) that you can’t create without modern tech. Olive oil, sesame, etc are fine. People have been using these for thousands of years.
Regardless, the science behind this is so political and complex none of us will get a definitive answer in our lifetimes. RFK jr has just as much of an agenda and the large corps profiting from these oils.
Keep an open mind and try things out. I’ve personally benefited from eating simpler. Nothing overly processed and trying to eat the way my ancestors likely did. Chestertons fence applies just as much to diet and nutrition as it does software.
fkyoureadthedoc
> It’s the more modern processed oils (of which many seed oils you’ll find are) that you can’t create without modern tech.
Such as?
The conclusion of the study mentions a few specific oils for what it's worth.
> ...replace animal fats like butter with nonhydrogenated vegetable oils that are high in unsaturated fats, especially olive, soy, and canola oil.
tengbretson
Taking canola oil as an example– pressed canola oil is too impure and has a nasty stink to it, so in order to be used in food it has to be refined.
This refining usually involves: Extracting it using hexane, degumming with maleic anhydride and/or citric acid, neutralizing with sodium hydroxide, bleaching with clay, activated charcoal, and/or hydrogen peroxide. Then dewaxed with some combination of methyl ethyl ketone, toluene, dipropylene glycol and ethylene glycol, and finally deoderized via steam distillation.
mmastrac
I'm clearly out of the loop on this, how did seed oils become a big news topic? I've seen random posts on Reddit and now this.
streptomycin
There's always a new villain to explain why people are so fat, because people don't want to accept the obvious answer. Previous villain was corn syrup, you hear about that less these days. New villain is seed oils. Similar lack of evidence for either being worse than their "healthy" alternative (normal sugar or other fats). Check back in 5 years and there will be another villain.
aggie
I've seen it discussed on Twitter for a while, mostly on the right. As best I can tell it is related to a general trend toward distrust of big agriculture, big pharma, big institutions in general as seed oils are painted as a product of that whereas animal fats are a "retvrn" type of diet (or from another POV, a Michael Pollan diet). Funny to see the political factions shifting around and the horseshoe connecting left and right on nutrition.
fkyoureadthedoc
Seed oils are part of RFK's agenda, he doesn't like them. I'm not sure that position is informed by facts though. He recently did a publicity stunt with a restaurant that replaced their fry oil with beef tallow.
JohnTHaller
Most of what RFK (and MAGA as a whole) does is without any sort of peer reviewed science behind it. They're against masks, mRNA vaccines, vaccines in general, seed oils, wind, solar, etc.
JohnTHaller
MAGA is against mRNA, seed oils, and all sorts of random stuff because a random higher up in their movement said so. This is generally without evidence.
CSMastermind
It's been building for decades in alternative health circles.
There's legitimate science about them dating back to the late 80s/early 90s.
In 1999 Sally Fallon published a book called Nourishing Traditions which argued for rejecting modern industrial foods. A lot of the arguments you see today about seed oils originate from this book.
These got amplified in 2014 by Nina Teicholz who published a book called The Big Fat Surprise which made it the topic de jure of alternative health influencers.
Then it's been a steady build across social media for about a decade.
davidmurdoch
I think the source is that years and years ago someone plotted seed oil consumption and heart disease on a graph, probably attempting to show a correlation. And now we've got claims of causation.
ceejayoz
That'd be a good one to add to https://www.tylervigen.com/spurious-correlations.
mmsimanga
Much like you I too have just woken up from under my rock to find this out. On the bright side it seems we didn't miss anything so as you were.
giardini
I thought the "Cholesterol Hypothesis" was dead! What is all this whoop-ti-do?
thumbsup-_-
The real test is to just test the quantity of trans fats in all oils under various conditions. Like when they are cold and at various temperatures. Why don't just do that and share data.
amelius
> Social media is currently awash with influencers promoting butter as a health food and claiming that seed oils are deadly
Ok, I guess soon there will be no buying options then.
I wish we could get studies without any conflicts of interest to confirm or deny this. This study has a few that we know of:
Conflict of Interest Disclosures: Dr Guasch-Ferré reported grants from the Novo Nordisk Foundation and the International Nut and Dried Fruit Council outside the submitted work. Dr Willett reported grants from the National Institutes of Health during the conduct of the study. Dr Stampfer reported grants from the National Institutes of Health during the conduct of the study. No other disclosures were reported.