Seed oils: nuance, not a new food villain
Seed oils – sunflower, soybean, rapeseed, corn – have become the internet’s latest bad guys. Scroll long enough and you’ll see them blamed for everything from obesity and diabetes to acne, brain fog and chronic inflammation.
The story usually goes like this: seed oils are high in omega‑6 fats, omega‑6 equals inflammation, inflammation equals every modern disease. Therefore, the bottle of oil is the problem.
It sounds neat. But it's not what the totality of the research shows.
Omega‑6, inflammation and what the evidence actually says
Omega‑6 fats, especially linoleic acid, are found in many seed oils but also in nuts, seeds and some other plant foods. They are essential fats – your body needs them and can’t make them itself. The concern online is that higher omega‑6 intake will automatically crank up inflammatory pathways.
Randomised trials and large observational studies don’t really back that up. Reviews of controlled trials show that increasing linoleic acid intake does not raise inflammatory markers in humans; in some cases, higher omega‑6 status is associated with a lower inflammatory profile. On the cardiovascular side, data following thousands of people over years suggest that:
higher linoleic acid levels are linked with lower risk of heart attacks, strokes and type 2 diabetes
swapping saturated fat (like butter) for polyunsaturated fats (including many seed oils) is associated with lower cardiovascular event risk
That doesn’t make seed oils magical. It does mean the blanket claim “seed oils are inherently inflammatory and causing heart disease” isn’t supported when you zoom out and look at all the data together.
So why do they get such a bad reputation?
Partly because seed oils often travel with ultra‑processed foods. Think crisps, biscuits, fried snacks, fast food. When people reduce those foods and cook more at home, they almost always feel better. It’s easy to point at the oil on the label and ignore the refined carbs, lack of fibre, low micronutrient density, sleep deprivation and stress alongside it.
There are also a few older trials where specific high‑omega‑6 interventions in unwell populations had mixed results, and these get circulated without context. But again, you have to look at the full picture: overall diet, what those fats replaced, and the quality of the evidence.
Where it makes sense to be thoughtful
You don’t need to panic about seed oils. But it is reasonable to think about:
The overall pattern of your fats. Using mostly extra‑virgin olive oil for everyday cooking, with some rapeseed or sunflower oil and small amounts of butter, is very different to having almost all your fats from deep‑fried fast food. A Mediterranean‑style pattern – olive oil, nuts, seeds, oily fish, a bit of dairy – still has the best evidence base for heart and metabolic health.
Getting enough omega‑3s – from omega‑3‑rich fish, flax, chia or walnuts – alongside omega‑6s, rather than seeing omega‑6 as the enemy. Both are essential; balance and overall context matter more than eliminating one.
The way oils are used. Industrial deep‑frying at very high temperatures is a different thing from roasting some veg at home.
If your week is full of colourful, plant‑focused meals, some oily fish, nuts, seeds, decent fibre, and relatively few ultra‑processed fillers, you don’t need to be terrified that a bit of sunflower oil in a hummus is silently ruining your health.
Seed oils, skin and hormones
For acne, skin flares and hormone‑linked issues, nuance is again your friend. What really tends to drive breakouts and skin texture for most people is:
blood‑sugar swings and frequent big hits of ultra‑processed carbs and fats together (think pastries, fried snacks, constant grazing)
low intake of key skin nutrients such as zinc, vitamin A, vitamin C and omega‑3s
gut imbalances and bloating or digestive discomfort, especially when there’s low plant diversity and poor digestion
chronic stress, poor sleep and hormonal changes (PMS, perimenopause, PCOS)
Shifting towards more whole foods, regular meal timings, better blood‑sugar balance, simple gut‑supportive habits, and specific nutrients makes far more difference to skin and hormones than obsessing over whether one salad dressing contains sunflower oil.
When worry about seed oils becomes a problem
If reading about seed oils has left you:
scared to eat anything you haven’t cooked yourself
staring at labels in a mild panic
avoiding social situations because of what oil might be used
adding yet another layer of food rules on top of dieting history or disordered eating
then the conversation has stopped being helpful. At that point, your nervous system is under more threat from food anxiety than from the occasional seed oil, especially if the rest of your diet is broadly supportive.
Where your energy is better spent
If you care about inflammation, heart health, skin, hormones and long‑term health, the big levers are boringly consistent:
More plants: vegetables, fruit, beans, lentils, whole grains, nuts and seeds.
Enough protein spread through the day.
A mix of fats from olive oil, nuts, seeds, oily fish, and some dairy if you enjoy it.
Fewer ultra‑processed foods and deep‑fried odds and ends – not none, but less central.
Support for blood sugar with regular meals, not all‑day grazing or giant sugar‑fat bombs.
Attention to sleep, movement and basic stress‑supportive habits.
Checking in on cholesterol, blood pressure, blood sugar and other markers with your GP.
Seed oils can absolutely sit within a healthy pattern. They don’t have to be your main fat, but they don’t need to be your main fear either.
If you’re feeling tangled up in conflicting nutrition messages and want to focus on what will actually help your gut, skin and hormones – without a side of food guilt – you’re welcome to book a free introductory call. We can look at your current pattern, your symptoms and your priorities, and build something that serves you, not the algorithm.