Consumption of Stearidonic Acid−Rich Oil in Foods Increases Red Blood Cell Eicosapentaenoic Acid

Background Consumption of soybean oil enriched with stearidonic acid was previously shown to increase eicosapentaenoic acid (EPA) in red blood cells (RBC). Objective This study was designed to evaluate the effect of stearidonic acid oil used as a food ingredient in baked products and beverages on the RBC fatty acid profile. Design This was a randomized, double-blind, controlled, parallel-arm study. Participants Healthy men and women 21 to 65 years of age were included. Intervention Participants consumed either negative control (1.5 g/day high-oleic sunflower ethyl ester oil softgel capsules+foods containing 7 g/day high-oleic sunflower oil), positive control (1.5 g/day EPA oil ethyl ester softgel capsules+foods containing 7 g/day high-oleic sunflower oil), or active (1.5 g/day high-oleic sunflower ethyl ester oil softgel capsules+foods containing 7 g/day stearidonic acid soybean oil) for 12 weeks. Main outcome measures RBC membrane fatty acid profile (at weeks 0, 2, 4, 6, 8, 10, and 12); fasting serum lipids (weeks −2, 0, 6, 10, and 12); and fasting plasma glucose and insulin (weeks −2, 0, 10, and 12) were assessed. Statistical analyses performed A repeated measures analysis of covariance was used for continuous variables, and pair-wise comparisons between treatments were adjusted using a step-down Bonferroni method. Fisher's exact or χ 2 tests were used for categorical data. Results RBC %EPA throughout the 12-week study were significantly different between all groups. Means at 12 weeks were 0.50%±0.03%, 2.17%±0.21%, and 0.85%±0.05% for control, EPA, and stearidonic acid, respectively. Other efficacy outcome measures were not significantly different among treatment groups. Conclusions Consumption of stearidonic acid-enriched soybean oil incorporated into common foods increased RBC %EPA in healthy men and women. Stearidonic acid soybean oil, a sustainable and accessible source of long-chain n-3, can effectively be used to increase EPA in RBC.