19/10/2026
Your feed is full of warnings about seed oils. But are they really that bad?
When you see how they’re made, it’s easy to understand the concern. Seeds are pressed, and the oil may be extracted with hexane, treated with sodium hydroxide, bleached and heated to around 207°C to remove its smell. The processing aids are then removed, leaving a highly refined oil.
That doesn’t sound very natural. It has also fueled some strange claims. You may have heard that canola oil was once used as machine lubricant. That’s true of an older variety, which contained much more erucic acid. The canola oil we eat today comes from varieties bred to contain far less. And some seed oils may lower the risk of cardiovascular disease when they replace saturated fat. Research link
Sunflower oil is often criticized for its omega-6 content. The claim is that omega-6 disrupts the balance with omega-3 and causes inflammation. But research has largely challenged that idea. Many people simply don’t get enough omega-3, while eating plenty of highly processed food. Source Source
So why are people replacing seed oils with butter? Often, they want foods that feel more natural and less processed. That can be a useful rule of thumb, but it doesn’t tell us whether one particular fat is healthier.
A large 2025 observational study followed more than 221,000 people for up to 33 years. Higher plant-oil intake, including soybean and canola oil, was associated with a 16% lower risk of death. Higher butter intake was associated with a 15% higher risk. Replacing 10 grams of butter a day with plant oil was associated with a 17% lower risk. Study
That doesn’t prove cause and effect. Lifestyle differences can still affect the results, even when researchers account for factors such as smoking, exercise, weight and overall diet. The ideal experiment—making thousands of people eat a specific oil or butter for years would be extremely difficult to run.
Still, the evidence doesn’t support the idea that seed oils are inherently harmful. A meta-analysis of 40 studies found that omega-6 lowered LDL cholesterol when it replaced saturated fat. Another review found little evidence that it raises inflammation markers. Meta-analysis Review
I understand why people make the connection. Seed oils are everywhere, from chips and cookies to sauces and ready meals. If you cut those foods out, you may feel better. But that doesn’t mean the oil itself was the problem. Those foods contain many other ingredients, and seed oil is often lumped together with ultra-processed food.
The case against seed oils can sound convincing: the manufacturing process, old stories about machine lubricant and personal accounts from people who feel better after avoiding them. But those stories don’t tell us what the research shows.
There’s no perfect evidence, and debate will continue. But the current research suggests that fears about seed oils are overstated. Using some seed oil at home is reasonable, especially when it replaces butter or other saturated fats. It makes sense to limit ultra-processed foods, but you don’t need to avoid a product just because it contains seed oil.
Disclaimer: This video is for general information only and isn’t personal nutrition or medical advice. Talk to a doctor or dietitian about questions concerning your health or diet.