The Acute Ingestion of Yerba Mate (Ilex paraguariensis) Infusion Does Not Modify Endothelial Function, Hemodynamics, or Heart Rate Variability: A Randomized Crossover Clinical Trial.

Background and aims: Herbal plants may contribute to reducing the incidence of cardiovascular disease. Yerba mate (YM) emerges as a candidate to improve endothelial function, hemodynamics, and heart rate variability (HRV) due to its antioxidant and anti-inflammatory properties, potentially decreasing cardiovascular risk. Therefore, studies are needed to assess the effect of YM ingestion on these parameters. This study aimed to evaluate the impact of acute ingestion of YM infusion (hot or cold) on endothelial function, hemodynamics, and HRV.

Methods and results: In this crossover randomized clinical trial, 13 participants (18-40 years old) of both genders were evaluated under three conditions: control (water), cold YM infusion, and hot YM infusion. The primary outcome was endothelial function assessed through flow-mediated dilation (FMD), with the secondary outcomes including blood pressure (BP), heart rate (HR) and HRV. Parameters were evaluated before and after intervention (40' and 80'). Analysis of variance (ANOVA) showed an intervention effect on FMD (%) (p < 0.05), with both cold and hot YM associated to higher FMD% compared to control, although no time or time*intervention effects were found. ANOVA also showed a time effect on BP, HR, and HRV time and frequency domains variables (p < 0.05), though no time*intervention or intervention effect was observed.

Conclusion: We did not find acute effects of YM infusion on endothelial function, central hemodynamic, or autonomic parameters in healthy adults. These results were not impacted by the temperature of YM. Further studies should assess the dose-response of acute and chronic YM ingestion on endothelial function.

Trial registration: U1111-1289-9324, retrospectively registered in May 2023.