Feasibility Study of Soybean Oil-Fortified Foods to Alter Blood Content of Linoleic Acid and Body Weight: A...

Linoleic acid biomarkers are associated with positive health outcomes including lower risk of diabetes and cardiovascular disease. The effect of consuming linoleate-fortified foods (compared with palm oil-fortified foods) in a randomized controlled, double-masked crossover study to change linoleic acid biomarkers without changing bodyweight is unknown.

The aim of this study was to determine the effect of delivering soybean and palm oils through foods on the linoleic acid content of blood fractions and body weight in adults.

In this crossover pilot study, 4 male and 6 female adults, ages 25-76 y and body mass index from 26 to 41 kg/m², were randomly assigned to consume: 30 g of soybean and palm oil delivered in 3 study foods/d for 4 wk separated by a 2-wk washout period. Bodyweight, fatty acid profile of plasma, erythrocytes, peripheral blood mononuclear cells (PBMC), and dried blood spots, and PBMC cardiolipin were measured before and after each intervention period. Dietary intake was assessed using 24-h recalls. The outcomes were analyzed using the Wilcoxon Signed Rank Test.

After 4 wk of consuming 3 foods/d, plasma linoleic acid decreased during the palm oil intervention (-1.60, P = 0.04), whereas it tended to increase in plasma (2.35, P = 0.07) and erythrocytes (1.09, P = 0.05) during the soybean oil intervention. The percentage of PBMC tetralinoleoyl cardiolipin marginally increased during the soybean oil intervention (2.31, P = 0.05) but did not change during the palm oil intervention. There was no difference in energy intake between the 2 interventions (P = 0.65) and no change in bodyweight during either intervention (P > 0.40).

Foods can be used to deliver 30 g/d of dietary oil for 4 wk to impact linoleic acid biomarkers without incurring body weight changes. These foods are useful for future randomized controlled double-masked clinical trials assessing the impact of dietary oils on energy metabolism. The study was registered at clinicaltrials.gov as NCT04975763 (https://clinicaltrials.gov/study/NCT04975763).