Evaluation of the effect of olive extracts on blood pressure and cardiovascular health markers in adults: Findings from a double-blind, placebo-controlled, randomised trial
Stef Lauwers, Annelies Breynaert, Annelies Verlaet, Erik Fransen, Tijs Bringmans, Lynn Roth, Emmy Tuenter, Johan Bosmans, Nina Hermans
Abstract
Despite advances in reducing cardiovascular disease (CVD) incidence, CVD mortality has increased, emphasising the need for new preventive strategies. Polyphenol-rich olive extracts have been proposed to lower blood pressure by reducing oxidative stress and enhancing nitric oxide production.
Introduction
Over the past few decades, remarkable progress has been made in developing strategies to lower the incidence of cardiovascular diseases (CVD). Despite these efforts, CVD remains the main cause of death and disability worldwide [1]. The declining CVD mortality rate that was observed remained stable in the last years or even increased in some populations [2,3].
Methods
A parallel randomised double-blind placebo-controlled clinical trial was conducted to investigate the short-term effect of a commercially available standardised olive extract in individuals with elevated blood pressure in relation to primary CVD prevention.
Results
From June 2021 to March 2024, 56 participants who met the inclusion criteria were randomly allocated to the intervention group (n = 28) or the control group (n = 28). Even though all participants completed the trial, one participant in each group had a compliance percentage of less than 80% and was thus excluded from the statistical analysis of the outcomes.
Discussion
In this double-blind, placebo-controlled, randomised clinical trial, the effect of eight weeks of supplementation with a commercially available olive extract was investigated on BP, lipid profile, and biomarkers of oxidative stress and CVD in participants with an SBP ≥ 130 mmHg in the context of primary CVD prevention.
Conclusion
In this double-blind, placebo-controlled, randomised clinical trial, the effect of an eight-week supplementation with a commercially available olive extract on BP, lipid profile, and biomarkers of oxidative stress and CVD was investigated in participants with a SBP ≥ 130 mmHg.
Citation: Lauwers S, Breynaert A, Verlaet A, Fransen E, Bringmans T, Roth L, et al. (2026) Evaluation of the effect of olive extracts on blood pressure and cardiovascular health markers in adults: Findings from a double-blind, placebo-controlled, randomised trial. PLoS One 21(3): e0344278. https://doi.org/10.1371/journal.pone.0344278
Editor: Vahideh Behrouz, Kerman University of Medical Sciences, IRAN, ISLAMIC REPUBLIC OF
Received: November 4, 2025; Accepted: February 11, 2026; Published: March 10, 2026
Copyright: © 2026 Lauwers et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: The minimal dataset required to replicate the findings of this study has been deposited in Zenodo and is available at https://doi.org/10.5281/zenodo.18268823.
Funding: This research was made possible by the University Research Fund (BOF) of the University of Antwerp (doctoral scholarship of Stef Lauwers, BOF UAntwerp ID: 42325) and the Tilman chair ‘Olive Polyphenols and Cardiovascular Health’. This study was partly funded by a grant from Tilman sa, Baillonville, Belgium: chair ‘Olive Polyphenols and Cardiovascular Health’. There was no contractual commitment regarding the study and the results. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Tilman had no access to the detailed study protocol or raw study data.
Competing interests: The authors have declared that no competing interest exist. This study was partly funded by a grant of Tilman sa, Baillonville, Belgium: chair ‘Olive Polyphenols and Cardiovascular Health’. There was no contractual commitment regarding the study and the results. Tilman had no methodological or any other input in the design, execution or reporting of this trial. Tilman had no access to the detailed study protocol or raw study data. Before starting the study, it was agreed that the results would be published, regardless of the outcome.
Abbreviations: Apo A1, Apolipoprotein A1; Apo B, Apolipoprotein B; BP, Blood pressure; CKD-EPI, Chronic Kidney Disease – Epidemiology Collaboration; CRP-US, C-reactive protein – ultra sensitive; CVD, Cardiovascular diseases; DASH, Dietary Approaches to Stop Hypertension; ECLIA, Electrochemiluminescence assay; EFSA, European Food Safety Authority; eGFR, Estimated glomerular filtration rate; ELISA, Enzyme-linked immunosorbent assay; eNOS, Endothelial nitric oxide synthase; FFQ, Food frequency questionnaire; GSH, Glutathione; HbA1c, Haemoglobin A1c; HDL, High-density lipoprotein; HPLC-ECD, High-performance liquid chromatography – electrochemical detection; HPLC-VIS, High-performance liquid chromatography – visible light detection; HT, Hydroxytyrosol; IL-1β, Interleukin 1β; iNOS, Inducible nitric oxide synthase; LDL, Low-density lipoprotein; Lp(a), Lipoprotein(a); MDA, Malondialdehyde; NADPH, Nicotinamide adenine dinucleotide phosphate; OLE, Oleuropein; OxLDL, Oxidised low-density lipoprotein; RAAS, Renin-angiotensin-aldosterone system; RBC, Red blood cells; SBP, Systolic blood pressure
