They’ve known, mostly for over 30 years, that:
- we need to eat some omega 3 (n3) and omega 6 (n6) fats
- ratio of n3 to n6 fats is a big deal
- n3 and n6 compete with each other in some ways
- n3 helps with antioxidants and reducing inflammation
- n6 leads to more free radicals and inflammation
- 1:1 is a good ratio
- humans historically ate roughly the 1:1 ratio
- some people eating a regular diet with a lot of vegetable oil get very skewed ratios like 1:20, sometimes worse
- n6 fats (high ratio) cause weight in rats and mice given equal calories eaten
- vegetable oils have a lot of n6 fats (both amount and ratio)
- algae has a lot of n3, and is eaten by fish, so fish are a good n3 source
- if you eat a ton of n6 from vegetable oil, then supplementing some fish oil pills for n3, or eating fish a couple times a week, will not get your ratio anywhere near 1:1 (it still helps some)
- the only realistic way to get a good n3:n6 ratio is to limit vegetable oil consumption
- reducing vegetable oil consumption requires reducing processed and restaurant food
- most vegetable oil people eat isn’t on purpose. a typical person who stops buying any bottles of vegetable oil, but makes no other changes, will still eat way too much vegetable oil
- you are what you eat. your body is literally made out of food you ate
- if you eat more n6, you end up with more n6 in your body, e.g. in your muscles
- n6 is less stable than n3 or n9 to light, heat and oxygen
- building your body out of less stable molecules is bad. that can lead to free radicals, inflammation and all sorts of illnesses including cancer. less stable molecules means damage is more common which means stuff breaks more … which means heart attacks, strokes, chronic illnesses, etc.
- evolution designs plants with the most stable molecules it can. (I mean, due to selection pressure, plants with more stable molecules evolutionarily outcompete plants with less stable molecules). one of the main limiting factors for plants is they don’t want their fat to freeze. so plants use different fats depending on where they grew. tropical coconuts have the most stable molecules. Mediterranean olives have medium molecule stability which will stay liquid at temperatures they face. and the seeds for vegetable oil grow in cold climates like Russia and Ukraine, and have to use more unstable n6 fats that will stay liquid at those temperatures.
- animal bodies being made of lower amounts of n6 correlates well with longer lifespan. source
- regions where humans eat more n6 correlate with more coronary heart disease. source
- there’s some kind of modern health crisis that they need to figure out
Scientists knew this in 1993. And they still knew it in 2017. It wasn’t ignored because it was wrong; it wasn’t refuted; some scientists are still doing new experiments about basically the same issue and trying to get the word out. But the amount of vegetable oil in our diet has continued to go up, reaching roughly 20% of American calories in 2022. They knew this was hurting people for decades and they kept doing it.
Industry knows it too, which is why they’ve been trying to create modified vegetable oils with more n9 instead of n6 (making it more like olive oil).
But the government and health authorities keep telling people that vegetable oil lowers cholesterol and is therefore good, and to avoid animal fats because they contain more saturated fats. The US government continues subsidizing growing plants that vegetable oils are made of, especially soy and corn.
(What happens to the remaining plant material from soy or corn after vegetable oil is squeezed out? It’s used for animal feed, especially for chickens and pigs, but also for farm-raised fish, cows and more. Chicken is not a food that human beings traditionally/historically ate much of, and pigs were problematic in ancient times due to disease risk which led to some major religions forbidding eating pig. Pushing our diet to more of those animals, instead of cows/goats/sheep/ruminants, is unnatural and has downsides. Wild caught fish is also a traditional/historical food.)
The American Heart Association and Harvard Don’t Care About Your Health
The mainstream health “authorities” are unwilling to tell people to reduce vegetable oil consumption. They advise eating too much n6 and won’t acknowledge that many people are eating even more than their recommendation. They keep trying to tell everyone not to reduce eating n6. A ton of what Americans eat is grain, sugar/sweeteners and vegetable oil, and the elites/“experts” want to maintain that status quo.
Harvard put out a 2019 articled called No need to avoid healthy omega-6 fats. Quotes:
The benefits of omega-3 fats from fatty fish and likely from plant sources like flaxseeds and walnuts are well known.
The n3 in flaxseeds is the wrong type. Our bodies can convert it to the right type. But people estimate the conversion is 3-10% effective. In other words, if you eat 100 grams of n3 in flax seeds, you get the same benefit as eating 3-10 grams of n3 from fish. Plus flaxseeds have n6 in them. Flax isn’t the solution here. I guess they know this and are being dishonest.
Omega-6 fats, which we get mainly from vegetable oils, are also beneficial. They lower harmful LDL cholesterol and boost protective HDL. They help keep blood sugar in check by improving the body's sensitivity to insulin. Yet these fats don't enjoy the same sunny reputation as omega-3 fats.
There are a few studies (not many, not enough) that look at health outcomes instead of just easy-to-measure markers/proxies like LDL. Some found that vegetable oil did indeed lower LDL (that’s uncontroversial) but that the people eating vegetable oil nevertheless had worse health outcomes (e.g. more heart attacks and deaths). Lower LDL is not necessarily a good thing.
The critics argue that we should cut back on our intake of omega-6 fats to improve the ratio of omega-3 to omega-6s. Hogwash, says the American Heart Association (AHA). In a science advisory that was two years in the making, nine independent researchers from around the country, including three from Harvard, say that data from dozens of studies support the cardiovascular benefits of eating omega-6 fats (Circulation, Feb. 17, 2009). "Omega-6 fats are not only safe but they are also beneficial for the heart and circulation," says advisory coauthor Dr. Dariush Mozaffarian, an assistant professor of medicine at Harvard-affiliated Brigham and Women's Hospital.
Do you see how hard they’re trying to get you to eat lots of vegetable oil?
The latest nutrition guidelines call for consuming unsaturated fats like omega-6 fats in place of saturated fat. The AHA, along with the Institute of Medicine, recommends getting 5% to 10% of your daily calories from omega-6 fats.
So the title says not to reduce n6 intake. And it’s “hogwash” that we should cut back on n6 intake.
But also 5-10% of our calories should be n6. If we get 20% of our calories from vegetable oil, that’s roughly 10% n6 right there without considering what else we eat.
And where did the 5-10% range come from? Historically humans ate under 5%, which is the recommendation you get from Paleo people, vegetable oil critics, etc. And that’s an amount you can easily get without trying even if you stop eating vegetable oils.
So first of all the average American is already over 10% of their calories being n6, and a lot of people are above average so they’re further over that recommendation. Yet they’re being told not to cut back on eating n6.
And second, the 5-10% recommendation seems like they maybe made it up just to legitimize current vegetable oil intake, not based on any medical reason. It’s maybe because it’s their way of trying to tell you to eat less animal fat, so they are setting a high n6 recommendation to balance out a low animal fat recommendation (for no good reason). They know our n3:n6 ratios are skewed to n6, and they know that’s bad, but for some reason they keep trying to tell us not to reduce n6.
Here’s a source with n6 intake recommendations. It says: In 1992, the European Scientific Committee on Food advised getting 2% of your calories from n6 (roughly 6 grams). In 2009, The European Food Safety Authority said to limit n6 to 10 grams per day (that’s 3.3% based on 2%=6g). In 2002, the Food and Nutrition Board of the U.S. Institute of Medicine recommended around 13.5 grams (that’s 4.5% based on 2%=6g). The Japan Society for Lipid Nutrition recommended 3-4% n6. The World Health Organization recommended 2.5-9%. Those are all under 5% except the WHO which gives a large range with a bigger top number. I think the WHO gave a larger maximum about based on the hypothesis that n6 lowers cholesterol and therefore reduces heart attacks, and based on hostility to saturated/animal fat. The website says other recommendations were based more on avoiding a deficiency rather than eating extra n6 on purpose to try to gain a special health benefit like reducing heart attacks.
Most Americans eat more omega-6 fats than omega-3 fats, on average about 10 times more. A low intake of omega-3 fats is not good for cardiovascular health, so bringing the two into better balance is a good idea. But don't do this by cutting back on healthy omega-6 fats. Instead, add some extra omega-3s.
Telling people with 1:10 ratios to just eat some more n3s is bad advice. That won’t work. Raising their n3 consumption by 10x (without overeating on total calories) is way too hard. And a lot of people have a worse ratio than average and are hearing this advice. And some other sources claim the average is more like 1:20 not 1:10.
To avoid any reduction in vegetable oil (since it says not to cut back on n6) while raising n3 that much, the’d probably have to cut out lots of fruits and veggies, and other stuff. Their diet would be focused on eating the vegetable oil then enough high n3 foods like fish to try to make up for it, with a limited amount of space left in their diet for other stuff.
Instead, it makes way more sense to just eat less vegetable oil. But most mainstream health “experts” don’t want to say that. Are they shills for industry? Genuinely convinced that eating so much vegetable oil is going to save us from heart attacks any day now? Or do they have some other massive bias unrelated to truth and reason? It’s hard to come up with a better explanation.
Read The Science
I’ll close with the beginning of that 2017 scientific paper which I linked earlier:
Soybean oil consumption is increasing worldwide and parallels a rise in obesity. Rich in unsaturated fats, especially linoleic acid [omega 6], soybean oil is assumed to be healthy, and yet it induces obesity, diabetes, insulin resistance, and fatty liver in mice. Here, we show that the genetically modified soybean oil Plenish, which came on the U.S. market in 2014 and is low in linoleic acid, induces less obesity than conventional soybean oil in C57BL/6 male mice. […] While Plenish induced less insulin resistance than conventional soybean oil, it resulted in hepatomegaly and liver dysfunction as did olive oil, which has a similar fatty acid composition. […]
While humans have been cultivating soybeans for ~5000 years1, soybean oil has become a substantial part of our diet only in the last few decades2. This increase in soybean oil consumption is due in part to a reaction to large-scale population studies in the 1950s and 60s, which showed that a typical American diet rich in saturated fats from animal products was linked to an increased risk of cardiovascular disease3,4. It was subsequently assumed that most if not all saturated fats are unhealthy and conversely that all unsaturated fats are healthy, this despite the ambiguity of evidence of cardio-protective effects of vegetable oils, which are rich in unsaturated fats5,6. Similarly, it was assumed that whatever is healthy for the heart is also healthy for the rest of the body although this assumption was never rigorously tested7,8. Nonetheless, vegetable oil, and, in particular, soybean oil, began to replace animal fat in the American diet starting in the 1970s, resulting in an exponential rise in soybean oil consumption that parallels the increase in obesity in the U.S. and worldwide2,9,10. Indeed, soybean oil is the component in the American diet that has increased the most in the last 100 years2. It constitutes >60% of all edible vegetable oil consumption in the U.S11. and is ubiquitous in the American diet, especially in cooking oil and processed foods.
Soybean oil is comprised of primarily polyunsaturated fatty acids (PUFAs), particularly linoleic acid (LA, C18:2), an omega-6 (ω6) fatty acid that makes up ~55% of soybean oil.
I think this topic is disturbing, says really negative things about mainstream elites/experts/authorities (including government and large companies), and should get people to be less trusting. (Lots of small companies are untrustworthy too, but there’s more variance; some are better.)
Some other health topics where more knowledge also reduced my trust in the status quo include: sunscreen, caffeine, decaf tea and coffee, MSG, milk homogenization, food dye, and olive and avocado oil fraud (which is poorly policed by government or industry).
We don’t live in an adequate, safe, competent, trustworthy world.
Disclaimer: I’m not a health expert or scientist. This is not diet or medical advice. On the other hand, I’m an expert critical thinker. Judging arguments and finding errors is something I’m good at. So when I say don’t trust the experts, I’m speaking as an expert ;)