Seed oils like soybean and corn oil have taken a beating online, where influencers blame them for everything from inflammation to chronic disease. But a new study offers a very different view — one based on blood samples, not social media opinions.
Researchers found that people with higher levels of linoleic acid, the most common omega-6 fatty acid consumed through seed oils and plant-based foods, had lower levels of inflammation and insulin resistance, two major risk factors for heart disease and type 2 diabetes.
“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,” said lead researcher Kevin C. Maki, Ph.D., of Indiana University and Midwest Biomedical Research.
Linoleic acid is found in many plant foods but is especially concentrated in seed oils such as soybean, corn and sunflower oil. These oils have been widely used in cooking and food production for decades, but recent online trends have vilified them for allegedly promoting inflammation.
To put those claims to the test, Maki’s team analyzed blood samples from nearly 1,900 adults. Those with the highest linoleic acid levels had:
Lower fasting glucose and insulin
Lower HOMA-IR, a marker of insulin resistance
Lower inflammation markers, including C-reactive protein (CRP) and serum amyloid A
Unlike previous studies that relied on self-reported diets, this one used objective biomarkers in blood plasma, providing stronger evidence that linoleic acid intake is linked to better cardiometabolic health.
“People with higher levels of linoleic acid in their blood tended to have a healthier overall risk profile for heart disease and diabetes,” Maki said.
The study was presented at the American Society for Nutrition’s NUTRITION 2025 meeting and has not yet been peer-reviewed. Still, it adds to a growing body of research suggesting that seed oils may be more helpful than harmful when it comes to chronic disease prevention.
The researchers say more controlled trials are needed to determine whether increasing linoleic acid in the diet can reduce actual disease incidence. But for now, this study is a reminder that not all internet health claims hold up under scientific scrutiny.
This research was funded by the Indiana University Foundation.