Consumption of stearidonic acid-rich oil in foods increases red blood cell eicosapentaenoic acid

Abstract

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.

Keywords: Eicosapentaenoic acid; Omega-3 Index; Red blood cells; Stearidonic acid.