Why are people against seed oils?
“Some concerns stem from the fact that some seed oils are high in omega-6 polyunsaturated fats, which, when consumed in large amounts without enough omega-3s, may contribute to inflammation,” explains BDA spokesperson Ludlam-Raine.
The idea is that the inflammation could be damaging to cardiovascular health, with some influencers saying that a diet high in seed oils can increase the risk of heart disease and strokes. But Dr Louise Flanagan, head of research at the Stroke Association, says there isn’t evidence to back this up.
“While there is a lot of talk about seed oils being bad for health, scientific evidence does not support this. In fact, there’s generally not a lot of research looking at the benefits or drawbacks of specific plant oils.
“The most recent research, published in March 2025, studied the diet and health of over 200,000 people in the USA over around 30 years.
“The researchers looked at the relationship between how much butter and plant oil (which included various seed oils as well as olive oil) a person consumed and their likelihood of dying of cardiovascular disease (CVD), including stroke or cancer.
“The results showed that higher plant oil consumption is associated with a lower risk of death caused by CVD.
“Higher intakes of plant-based oils (whether made from seeds or flesh) were associated with lower risk of total mortality, or mortality due to cancer and cardiovascular disease.
“The researchers didn’t directly test what happens if someone switches from butter to plant oils, but they were able to calculate the likely effects. They found that switching to plant oils is likely to reduce your risk of death from any cause and reduce your risk of death from cancer, but the evidence was less clear on reducing your risk of death from CVD.”
Ludlam-Raine adds: “Population studies haven’t shown harm from seed oils – ultimately when you replace saturated fat (butter, for example) with unsaturated fat (such as seed oils), you get better health outcomes.”