Foods Fortified with Soybean or Palm Oil Show No Effect on Inflammation or Oxidized Low-Density Lipoprotein in Adults with Overweight or Obesity: a Secondary Analysis of a Randomized Placebo-Controlled Crossover Trial

Cheng-Tse Yang; Rachel M Cole; Eric Colombo; Austin Angelotti; Andy Ni; Martha A Belury

doi:10.1016/j.cdnut.2025.107635

Foods Fortified with Soybean or Palm Oil Show No Effect on Inflammation or Oxidized Low-Density Lipoprotein in Adults with Overweight or Obesity: a Secondary Analysis of a Randomized Placebo-Controlled Crossover Trial

Curr Dev Nutr. 2026 Jan 7;10(2):107635. doi: 10.1016/j.cdnut.2025.107635. eCollection 2026 Feb.

Authors

Cheng-Tse Yang¹, Rachel M Cole¹, Eric Colombo², Austin Angelotti³, Andy Ni⁴, Martha A Belury¹

Affiliations

¹ Department of Food Science and Technology, The Ohio State University, Columbus, OH, United States.
² Department of Nutrition Services, The Ohio State University Wexner Medical Center, The Ohio State University, Columbus, OH, United States.
³ Heart and Vascular Institute, Department of Medicine, College of Medicine, Penn State University, Hershey, PA, United States.
⁴ Division of Biostatistics, College of Public Health, The Ohio State University, Columbus, OH, United States.

Abstract

Background: Popular and social media outlets have recent posts claiming that vegetable and seed oils high in linoleic acid (LA) cause inflammation and oxidative stress. However, substantial evidence in the scientific literature shows LA biomarkers are associated with lower risks for type 2 diabetes, cardiovascular disease, and systemic inflammation.

Objectives: The primary aim of this study is to evaluate the impact of dietary fortification with soybean oil (high in LA) compared with palm oil on markers of systemic inflammation and oxidized low-density lipoprotein (oxLDL) in healthy overweight adult participants.

Methods: This double-masked crossover clinical trial consisted of 2 diet periods where adults with overweight or obesity were randomly assigned to receive 3 study foods delivering 30 g oil/d of either soybean or palm oil for 4-wk periods. During a 2-wk wash-out period, participants refrained from consuming study foods. Erythrocyte and plasma fatty acid composition, blood biomarkers of systemic inflammation and oxLDL, desaturase indices, and body weights were measured at each study visit.

Results: After 4 wk of consuming 30 g/d of soybean or palm oil snacks, most inflammatory markers and oxLDL remained unchanged. However, interleukin-6 showed a trend toward reduction in the soybean oil group (P = 0.09). Fatty acid analysis revealed that C20:4n-6 (arachidonic acid) significantly decreased in erythrocytes after soybean oil intake (P = 0.0234), suggesting altered n-6 fatty acid metabolism through δ-6 and δ-5 desaturases. There were no lingering treatment effects during the 2-week washout period between diet periods 1 and 2.

Conclusions: Incorporating study foods containing 30 g oil/d of soybean or palm oil had no significant impact on inflammatory markers, suggesting that higher LA intake is not proinflammatory as is stated in popular media outlets. In addition, a two week washout period may be sufficient for dietary oil interventions in crossover study designs.This trial was registered at clinicaltrials.gov as NCT04975763.

Keywords: IL-6; arachidonic acid; inflammation; linoleic acid; omega-6 fatty acids; oxidized LDL; seed oils; soybean oil.

Associated data

ClinicalTrials.gov/NCT04975763