The safety of the use of ethyl oleate in food is supported by metabolism data in rats and clinical safety data in humans

The absorption, distribution, and excretion of radiolabeled ethyl oleate (EO) was studied in Sprague–Dawley rats after a single, peroral dose of 1.7 or 3.4 g/kg body weight and was compared with a radiolabeled triacylglycerol (TG) containing only oleic acid as the fatty acid (triolein). Both test materials were well absorbed with approximately 70–90% of the EO dose absorbed and approximately 90–100% of the TG dose absorbed. At sacrifice (72 h post-dose), tissue distribution of EO-derived radioactivity and TG-derived radioactivity was similar. The tissue with the highest concentration of radioactivity in both groups was mesenteric fat. The other organs and tissues had very low concentrations of test material-derived radioactivity. Both test materials were rapidly and extensively excreted as CO 2 with no remarkable differences between their excretion profiles. Approximately 40–70% of the administered dose for both groups was excreted as CO 2 within the first 12 h (consistent with β-oxidation of fatty acids). Fecal elimination of EO appeared to be dose-dependent. At the dose of 1.7 g/kg, 7–8% of the administered dose was eliminated in the feces. At the dose of 3.4 g/kg, approximately 20% of the administered dose was excreted in the feces. Excretion of TG-derived radiolabel in the feces was approximately 2–4% for both doses. Overall, the results demonstrate that the absorption, distribution, and excretion of radiolabeled EO is similar to that of TG providing evidence that the oleic acid moiety of EO is utilized in the body as a normal dietary TG-derived fatty acid. To confirm the expected safety of EO in humans, a total of 235 subjects participated in a 12-week trial where two levels of ethyl oleate in a milk-based beverage were investigated: 8 g/day in a single serving (approximately 0.1 g/kg) and 16 g/day taken in two divided servings (approximately 0.2 g/kg). Adverse events (AEs) were recorded throughout the 12-week trial. In addition, a brief physical exam (including vital signs and body weight), ECGs, fasting serum chemistry profile, serum lipid profile, and urinalysis were performed at baseline and after study completion. Results showed the incidence of reported AEs was similar between the EO groups and the control groups. Analysis of comprehensive laboratory data revealed no EO exposure-related, clinically significant adverse changes in laboratory parameters. These studies demonstrated that EO has a highly favorable safety profile and is well tolerated