Seed oils may lower heart attack risk and inflammation biomarkers

New research challenges the claim that seed oils promote inflammation, finding that linoleic acid may instead improve cardiometabolic health. The omega-6 fatty acid is found in plant foods and vegetable oils, especially in seed oils such as soybean and corn.

According to a study involving nearly 1,900 participants, higher levels of linoleic acid in blood plasma were associated with lower levels of heart risk biomarkers, including those related to inflammation.

The researchers note that the finding is consistent with previous observational studies showing that higher linoleic acid is linked to a lower risk of heart attacks, strokes, and type 2 diabetes.

Beliefs and research on seed oil

Public figures like US Health and Human Services Secretary Robert F. Kennedy Jr. have called for eliminating seed oils due to their alleged links to inflammation and disease. He has claimed that restaurants “unknowingly poison” consumers with seed oils, suggesting that the obesity epidemic is linked to when fast food restaurants switched from beef tallow to seed oils.

“There has been increasing attention on seed oils, with some claiming these oils promote inflammation and raise cardiometabolic risk,” affirms Kevin Maki, Ph.D., adjunct professor at the Indiana University School of Public Health-Bloomington and chief scientist at Midwest Biomedical Research, US.

However, a recent study of dietary habits suggests that eating more plant oils and less butter could lead to better health. More than 200,000 people were tracked for over 30 years, and those consuming more seed oils like soybean and canola next to olive oil had lower mortality than those consuming high butter.

Although another study found that linoleic acid drives the growth of a hard-to-treat “triple negative” breast cancer subtype, researchers caution against blanket statements and draw attention to individual biology — especially in cancer patients — highlighting the need for precision nutrition rather than dietary dogma.

Identifying biomarkers

Maki says his team measured various markers of inflammation and indicators of glucose metabolism.

For the new study, participants with higher linoleic acid had lower glucose, insulin, and the insulin resistance biomarker HOMA-IR. They also had low inflammation biomarkers C-reactive protein, glycoprotein acetyls, and serum amyloid A.

“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,” says Maki. 

“We saw consistent results across the different biomarkers measured. 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 that their findings need more interventional studies examining whether higher linoleic acid intake improves cardiometabolic risk factors and lowers the incidence of heart attacks, strokes, and type 2 diabetes.

In the future, they will study oils with varying fatty acid content and their impacts on cardiometabolic risk factors.

Pre-publishing, Maki’s study was presented at Nutrition 2025, US (May 31–June 3), the annual meeting of the American Society for Nutrition.