Corbella Extra Virgin Olive Oil, Urinary Phenolic Metabolites, and Exploratory Cardiometabolic Outcomes in Healthy Young Adults: The HEVOOC Trial

Extra virgin olive oil (EVOO) is a hallmark of the Mediterranean diet and an important dietary source of bioactive phenolic compounds, including hydroxytyrosol and tyrosol derivatives, which have been investigated in relation to cardiometabolic health. However, the potential metabolic effects of phenolic-rich EVOO in young healthy adults remain poorly characterized. In this randomized crossover trial, 28 healthy adults (29.0 ± 3.4 years) consumed either phenolic-rich EVOO or regular olive oil (OO) (0.7 g/kg/day) for 4 weeks. The cardiometabolic outcomes reported here were secondary endpoints of the trial. Anthropometric measurements, cardiometabolic biomarkers, and urinary phenolic metabolites were assessed at baseline and after each intervention period; selected phenolic metabolites were quantified in 24-h urine using targeted LC–HRMS. Treatment effects were evaluated using mixed-effects models. Compared with OO, EVOO markedly increased urinary hydroxytyrosol-glucuronide (GMR = 9.9; 95% CI: 2.0, 49.0; p = 0.005), together with other hydroxytyrosol- and tyrosol-derived metabolites, providing objective evidence of greater phenolic exposure during the EVOO intervention. Exploratory between-intervention differences favored EVOO for waist circumference (β = −2.21 cm; 95% CI: −3.37, −1.05), waist-related indices, and HbA1c (β = −0.13%; 95% CI: −0.25, −0.01). In exploratory analyses, increases in urinary hydroxytyrosol-glucuronide during EVOO intake were inversely correlated with changes in HbA1c (Spearman’s rho = −0.49, p = 0.011) and WHR (rho = −0.38, p = 0.048). Post hoc sensitivity analyses showed greater stability for the waist-circumference estimate than for HbA1c. Overall, phenolic-rich ‘Corbella’ EVOO substantially increased urinary phenolic metabolite exposure, whereas the observed cardiometabolic differences should be considered exploratory and hypothesis-generating and require confirmation in larger trials specifically powered for these outcomes.