(P06-005-24) Delivering Soybean Oil Through Foods to Alter Linoleic Acid Blood Biomarkers

Objectives: Biomarkers of linoleic acid (LA), an essential omega-6 polyunsaturated fat, are inversely associated with risk of cardiovascular disease (CVD) and type 2 diabetes (T2DM), makers of inflammation, and liver and visceral fat. LA is the predominant fatty acid in cardiolipin (CL), a phospholipid important for mitochondria function. We have shown that consuming one cookie per day delivering 10g of LA-rich oil, for 2 weeks increases plasma and erythrocyte LA and peripheral blood mononuclear cells (PBMC) tetralinoleoyl cardiolipin (LA₄ CL) in adults. To further understand how using food to deliver LA-rich oils will increase blood LA while maintaining body weight, we conducted a pilot study providing adults with 30g of LA-rich soybean oil (SO) using various study foods. The aim of the study was to determine changes in blood LA and body weight after 4 weeks of consuming 3 foods per day made with LA-rich SO or palm oil (PO).

Methods: In this randomized placebo-controlled crossover study, 12 adults were randomly assigned to consume 3 study foods per day each made with 10g of LA-rich SO or PO for 4 weeks (30g oil/day) with a 2-week washout period in between. Study foods averaged about 200 kcal each and included cookies, muffins, brownies and bread. Participants were instructed to replace foods in their habitual diets with the study foods to maintain body weight. Fasting blood samples were collected to analyze dried blood spot (DBS), plasma, PBMC and erythrocyte fatty acids and PBMC cardiolipin species. Body weight was measured every 2 weeks.

Results: Nine adults completed the entire study. Preliminary analysis shows that the percent of DBS LA increased by 1 with the LA-rich SO foods and decreased by 1.5 with the PO foods (p=0.04). The percent of plasma LA increased by 2.3 with the LA-rich SO foods and decreased by 1.8 with the PO foods (p=0.01). The change in weight, PBMC and erythrocyte LA, and PBMC LA₄ CL was not different between the 2 diet periods.

Conclusions: Our findings suggest that delivering LA-rich oils through food should be explored in studies designed to assess if LA can impact CVD and T2DM risk, body composition, liver fat, and markers of inflammation. Future analysis of this study will assess adherence to consuming 3 foods per day and cumulative daily LA and energy intake.

Funding Sources: This work was supported by the United Soybean Board (funding reference number, 2411-108-0101).