Turn over a few packets in the supermarket. Mayo, dressings, crackers, frozen crumbed things. Seed oils are in an astonishing amount of food, and the internet has strong opinions about seed oils, omega-6 and inflammation. Particularly in the keto and low carb groups.
The usual argument: seed oils are full of omega-6, omega-6 turns into inflammation, so seed oils inflame you. I went looking for how much of that holds up. The honest answer is less dramatic than either side makes it sound.
Here’s what I found, and what I actually do in my own kitchen. The second part is a cautious choice, not a rule for anyone else.
The short version
- Seed oils (sunflower, canola, soybean, corn and friends) are mostly omega-6 fat, mainly one called linoleic acid.
- In the human trials I could read, more or less of it didn’t shift blood tests for inflammation much. The trials were short, in mostly healthy adults, and none measured pain.
- The body can turn omega-6 into inflammation messengers. That’s real. But very little converts, and some of those messengers help switch inflammation off.
- The scarier findings mostly come from mice and lab work.
- I couldn’t find a single trial in people with CRPS.
- The research is inconclusive. I cook without seed oils anyway, because caution costs me very little.
What the research shows about omega-6 and inflammation
Each point starts with a tag. Limited evidence means small, short or mixed studies, or ones that only show a link. Early or lab evidence means animals, test tubes or biochemistry.
Limited evidence, trials (30 trials, 1,377 adults, mostly healthy): Eating more linoleic acid made no clear difference to blood markers of inflammation like CRP, IL-6 and TNF-alpha (Su and colleagues, 2017). Supplements of arachidonic acid, the omega-6 the body makes from it, mostly didn’t move them either (Calder and colleagues, 2019). A marker isn’t a symptom, though. These trials measured blood tests, not pain or how anyone felt.
Early or lab evidence, the body science: The pathway is real. Omega-6 can become arachidonic acid, which cells turn into messengers linked to swelling, fever and pain signalling (Innes and Calder, 2018). But small tracer studies suggest well under 1% converts, and a review found changing how much omega-6 adults ate didn’t change blood arachidonic acid (Rett and Whelan, 2011). Some of the same messengers also help wind inflammation down (Levy and colleagues, 2001). So calling omega-6 simply “inflammatory” leaves out half the picture.
Limited evidence, long-term and gene studies: In 1,287 healthy Finnish men, those with the most omega-6 in their blood had lower CRP, not higher (Virtanen and colleagues, 2018). Gene studies, which try to get around the “which came first” problem, are mixed. The most relevant found “no convincing evidence of a simple pro- and anti-inflammatory dichotomy” (Crick and colleagues, 2025). The omega-6 to omega-3 ratio is still argued about.
Early or lab evidence, mice and heated oil: The worrying results mostly come from animals fed very high-fat diets (Deol and colleagues, 2017). Mice aren’t people and nobody eats like that. Repeatedly heated oil also makes breakdown products, and rats fed it showed more inflammation markers. I couldn’t find a human trial of heated oil and inflammation.
One thing I couldn’t find: a trial that cut omega-6 while keeping omega-3 the same, then measured inflammation or pain. That’s the experiment that would settle it.
What about CRPS and pain?
Plainly: I couldn’t find a trial of omega-6, or of cutting it, in people with CRPS.
Early evidence (20 people with CRPS, 15 without): A small 2010 study found higher levels of some omega-6 fats in the blood of people with CRPS. It measured blood, not diet, so it can’t say whether food has anything to do with it (Ramsden and colleagues, 2010).
Limited evidence (182 adults with migraine): In a 2021 trial, diets that raised omega-3 cut headache days, and the one that also cut omega-6 did better on that measure. But both diets changed omega-3, so it can’t show that cutting omega-6 alone helps. The main quality-of-life score wasn’t statistically significant either (Ramsden and colleagues, BMJ). It was migraine, not CRPS.
What the official bodies say
Official position: In May 2026 the Heart Foundation said seed oils don’t cause inflammation in people, and it recommends canola, sunflower and soybean oils over butter, coconut oil and ghee (Heart Foundation). That’s heart-health advice. It doesn’t name an inflammation trial or address pain.
Official position: The NHMRC sets an adequate intake of linoleic acid at 13 g a day for men and 8 g for women, with no upper limit because no harmful level is known (NHMRC). A 2009 American Heart Association advisory said higher omega-6 intake went with neutral or lower inflammation markers in observational studies (AHA). None of these say omega-6 raises inflammation, and none speak to pain.
My butter-and-ghee kitchen sits on the other side of the Heart Foundation’s advice. If you have heart risk or take cholesterol medication, run any change in the fats you eat past your GP or an Accredited Practising Dietitian.
Who paid for the research?
With any nutrition study, I ask who paid and who’s selling something. A lot of what I read was American, though I didn’t find a comparison showing the US is worse than anywhere else.
- Documented history: Documents show the sugar industry funded 1960s research that pointed the finger at fat instead of sugar (NBC News on the 2016 analysis).
- Limited evidence: In 1,461 articles from 10 leading nutrition journals, about 13% involved the food industry, and more than half of those had industry-friendly findings. Without industry involvement it was under 10% (Sacks and colleagues, 2020). That’s a pattern. It doesn’t prove the money changed the results.
- Documented ties: One analysis found 19 of 20 members of the 2020 US dietary guidelines committee had ties to food or pharmaceutical companies (Carriedo Lutzenkirchen, 2024). I didn’t find a study showing pharmaceutical funding changes nutrition research results, so I won’t claim it.
- Documented ties, omega-6 research: One big study linking blood omega-6 to heart outcomes was partly funded by a restricted Unilever grant, though the authors say Unilever had no role (Marklund and colleagues, 2019). In another report, a scientist said six of his seven industry-funded studies found no benefit for the products tested (Undark, 2026). Industry money doesn’t automatically rig a result, and some seed oil critics sell books, supplements or programs too.
Funding is a reason to read more carefully. It isn’t a reason to bin a study. My four questions: who paid, who sells something, what was measured, and does the claim go further than the data?
Where I land, and what I do
The omega-6 pathway is real. The human evidence that it does much to inflammation at normal intakes is thin, and on pain it’s missing. Inconclusive doesn’t mean harmful. It doesn’t mean safe either. It means nobody knows yet.
When nobody knows and the swap is cheap, I lean cautious. In my kitchen that looks like this:
- Avocado oil is my main cooking oil.
- Ghee for some cooking.
- Full cream butter. I rarely use the blends because most of them use seed oils.
- Whipped butter. I whip butter blocks with avocado oil so it spreads straight from the fridge.
- From scratch: I don’t add seed oils to anything I make.
- Shop-bought food: Seed oils are in so many things that avoiding them completely is close to impossible. I limit what I can and leave it there.
If you’re wondering what to do
If seed oils worry you, the easiest lever is the oil you add yourself. Reading every label in the supermarket costs spoons you may not have. Frozen, jarred and packaged food are still fine tools on a low-spoon day.
If seed oils don’t worry you, nothing I found says you need to panic.
Mine’s a cautious kitchen. Yours can be whatever works for your body, your budget and the energy you’ve got today.
