Seed oils have faced heavy criticism for years now.
The growing controversy, which dates back to Dr Paul Saladino’s infamous appearance on the Joe Rogan podcast, has seen the previously unremarkable oils, demonised.
During his 2020 appearance, Dr Saladino made several claims about the negative health impacts of vegetable and seed oils, sparking a huge public backlash against them. But rather than calming with time, the strength of public feeling against seed oils has only grown. In fact, it’s escalated to such an extreme, that United States Secretary of Health and Human Services, Robert F Kennedy Junior, has claimed consumers are being “unknowingly poisoned” by them.
Since then, scientists and health professionals have been working to get to the truth – are seed oils dangerous or not?
Are seed oils dangerous?New research, presented at Nutrition 2025, has found that higher blood levels of linoleic acid – a fat found in seed oils like soybean and corn – are linked to lower inflammation and better markers for heart and metabolic health. This directly contradicts claims that they cause inflammation in the body.
Linoleic acid is an essential omega-6 fatty acid, which the body cannot produce on its own, making dietary intake crucial. It’s found in a wide range of plant-based foods, and is found to be especially abundant in seed oils.
“There has been increasing attention on seed oils, with some claiming these oils promote inflammation and raise cardiometabolic risk,” says Dr Kevin C Maki, adjunct professor at the Indiana University School of Public Health-Bloomington and chief scientist at Midwest Biomedical Research. “Our study, based on almost 1,900 people, found that higher linoleic acid in blood plasma was associated with lower levels of biomarkers of cardiometabolic risk, including those related to inflammation.”
The new results are consistent with those from previous, observational studies, that have shown higher intake of linoleic acid to be associated with lower risks for type 2 diabetes and cardiovascular events, such as heart attacks and strokes.
“Although other studies have assessed relationships between linoleic acid and cardiometabolic risk factors, our study used objective biomarkers rather than diet records or food frequency questionnaires to assess linoleic acid intake,” explains Dr Maki.
The team also measured a range of markers of inflammation and indicators of glucose metabolism.
The researchers conducted a cross-sectional analysis on data from 1,894 people in an observational cohort focused on COVID-19. They found that higher levels of linoleic acid in plasma – indicative of dietary intake – were consistently associated with lower levels of risk factors for cardiovascular disease and type 2 diabetes.
Consumer concern over the potential health impacts of seed oils continues to grow. (Image: Getty/Noel Hendrickson)Biomarkers highlight benefits of seed oilsSpecifically, study participants with higher linoleic acid showed lower levels of glucose and insulin as well as HOMA-IR, a biomarker of insulin resistance. They were also found to have lower levels of inflammation biomarkers, including C-reactive protein, glycoprotein acetyls, and serum amyloid A.
“We saw consistent results across the different biomarkers measured,” explains Dr Maki. “People with higher levels of linoleic acid in their blood tended to have a healthier overall risk profile for heart disease and diabetes.”
The researchers say their findings support the need for additional intervention studies to test whether increasing linoleic acid intake improves cardiometabolic risk factors and lowers the incidence of heart attacks, strokes, and type 2 diabetes.
Seed oils are used in a wide range of food and beverage products, including cakes. (Image: Getty/Paul Bradbury)What does this mean for food and beverage?It’s safe to say the food and beverage industry relies heavily on seed oils. From crisps and crackers to ready meals and cakes, seed oils can be found in a huge range of products. So, increasing calls for them to be banned have been cause for widespread concern.
These new findings could help to reassure members of the public, who have safety concerns over seed oils. They could also help to inform future regulatory decisions by governments across the globe.