Olive Leaf Extract:
Research Overview
This page provides a curated overview of selected peer-reviewed scientific studies examining olive leaf extract, a botanical extract derived from the leaves of Olea europaea. The goal of this page is to provide transparent access to commonly cited research in the scientific literature. The summaries below describe findings reported in published studies and include randomized controlled trials and systematic reviews commonly cited in the scientific literature. They are presented for educational purposes as part of a clinician-led review of the scientific literature.
Important Context for Readers
Scientific studies examine outcomes in defined populations under specific research conditions. Results reported in individual studies may not apply to all individuals, and findings should not be interpreted as guaranteed outcomes. This page summarizes selected research examining cardiovascular, metabolic, vascular, and oxidative stress-related biomarkers studied in relation to olive leaf extract. It is not intended to provide medical advice, diagnosis, or treatment recommendations. This page is provided for educational purposes and does not include product recommendations or affiliate links.
Summary of Evidence
Across human clinical studies and pooled analyses, olive leaf extract has been investigated in relation to blood pressure biomarkers, glucose metabolism markers, lipid biomarkers, inflammatory markers, and vascular physiology.
Across available human studies, blood pressure-related outcomes appear among the more consistently evaluated endpoints, particularly in populations with elevated baseline blood pressure markers. Evidence relating to glucose metabolism and insulin sensitivity is promising but more limited. Lipid findings are mixed and may vary according to population, formulation, dose, and duration.
Key Areas of Research
Cardiovascular Support
Evidence strength: Moderate
Human clinical studies have examined olive leaf extract in relation to:
• Blood pressure biomarkers
• Lipid biomarkers (LDL, triglycerides)
• Endothelial and vascular function markers
• Oxidative balance associated with cardiovascular wellness
Several clinical trials have reported changes in systolic and diastolic blood pressure markers over weeks of supplementation.
1) Perrinjaquet-Moccetti T, Busjahn A, Schmidlin C, et al. Food supplementation with an olive leaf extract reduces blood pressure in borderline hypertensive monozygotic twins. Phytother Res. 2008.
PMID: 18729245
DOI: https://doi.org/10.1002/ptr.2455
Population: Borderline hypertensive monozygotic twins.
Design: 8-week human study comparing olive leaf extract 500 mg/day or 1,000 mg/day.
Key findings:
• Mean systolic blood pressure differences within twin-pair comparisons of up to approximately 6 mmHg were reported in one dosing comparison.
• Additional differences of up to approximately 13 mmHg were reported in another comparison under study conditions.
• Mean diastolic blood pressure differences of up to approximately 5 mmHg were also reported under study conditions.
• LDL biomarker differences were also described.
2) Susalit E, Agus N, Effendi I, et al. Olive leaf extract effective in patients with stage-1 hypertension: comparison with captopril. Phytomedicine. 2011.
PMID: 21036582
DOI: https://doi.org/10.1016/j.phymed.2010.08.016
Population: Adults with stage-1 hypertension.
Design: Double-blind randomized 8-week study evaluating olive leaf extract 500 mg twice daily.
Key findings:
• Mean systolic blood pressure reductions of approximately 11.5 mmHg were reported in the olive leaf group during the intervention period.
• Mean diastolic blood pressure reductions of approximately 4.8 mmHg were reported in the olive leaf group during the intervention period.
• Triglyceride biomarker reductions were also reported in the studied population.
3) Lockyer S, Rowland I, Spencer JPE, et al. Impact of phenolic-rich olive leaf extract on blood pressure, plasma lipids and inflammatory markers: a randomised controlled trial. Eur J Nutr. 2017.
PMID: 26951205
DOI: https://doi.org/10.1007/s00394-016-1188-y
Population: Adults evaluated for cardiovascular risk-related biomarkers.
Design: Randomized controlled human trial.
Key findings:
• Modest changes in selected blood pressure and inflammatory biomarkers were reported under study conditions, though results were not uniform across all endpoints.
• Findings contributed to the human evidence base for olive leaf polyphenols and cardiovascular biomarkers.
4) Stevens Y, Winkens B, Jonkers D, et al. The effect of olive leaf extract on cardiovascular health markers: a randomized placebo-controlled clinical trial. Eur J Nutr. 2021.
PMID: 33034707
DOI: https://doi.org/10.1007/s00394-020-02397-9
Population: Overweight/obese adults with mildly elevated cholesterol markers
Design: Randomized placebo-controlled 8-week trial (500 mg/day)
Key findings:
• No statistically significant differences were reported versus placebo for lipids, blood pressure, glucose, insulin, or oxidized LDL biomarkers
• This neutral finding provides important context for interpreting the broader literature
Glucose and Insulin Metabolism
Evidence strength: Low to Moderate
Human studies have examined olive leaf extract in relation to:
• Fasting glucose biomarkers
• Insulin sensitivity markers
5) de Bock M, Derraik JGB, Brennan CM, et al. Olive leaf polyphenols and insulin sensitivity in middle-aged overweight men. PLOS ONE. 2013.
PMID: 23516412
DOI: https://doi.org/10.1371/journal.pone.0057622
Population: Middle-aged overweight men.
Design: Randomized placebo-controlled crossover study.
Key findings:
• Insulin sensitivity increased by approximately 15% under study conditions.
• Pancreatic beta-cell responsiveness increased by approximately 28%.
• Findings support further study of olive leaf polyphenols in glucose metabolism research.
6) Wainstein J, Ganz T, Boaz M, et al. Olive leaf extract as a hypoglycemic agent in human diabetic subjects and in rats. J Med Food. 2012.
PMID: 22512698
DOI: https://doi.org/10.1089/jmf.2011.0243
Population: Adults with diabetes, with accompanying experimental data.
Design: Human clinical study plus mechanistic animal research.
Key findings:
• Reductions in HbA1c and fasting insulin biomarkers were reported in the human study cohort.
• Findings support additional research into olive leaf extract and glucose metabolism markers.
Additional support
Evidence strength: Low
Olive leaf polyphenols are also being studied in relation to:
• Healthy aging pathways
• Cellular oxidative resilience
• Gut microbiome-related pathways
• Inflammatory signaling pathways and related biomarkers
7) Ismail MA, Norhayati MN, Mohamad N. Olive leaf extract effect on cardiometabolic profile among adults with prehypertension and hypertension: a systematic review and meta-analysis. PeerJ. 2021.
DOI: https://doi.org/10.7717/peerj.11173
Population: 5 trials involving 325 adults.
Design: Systematic review and meta-analysis.
Key findings:
• In pooled analyses under study conditions, a mean systolic blood pressure difference of approximately 5.8 mmHg was reported with 500 mg/day olive leaf extract over at least 8 weeks compared with control conditions.
• LDL biomarker differences of approximately 6 mg/dL were reported in one pooled comparison, though findings were not consistent across all analyses.
• Reductions in selected inflammatory biomarkers including IL-6, IL-8, and TNF-alpha were also described.
• Authors noted limited participant numbers and study heterogeneity.
8) Razmpoosh E, Abdollahi S, Mousavirad M, et al. The effects of olive leaf extract on cardiovascular risk factors in the general adult population: a systematic review and meta-analysis of randomized controlled trials. Diabetol Metab Syndr. 2022.
PMID: 36271405
DOI: https://doi.org/10.1186/s13098-022-00920-y
Population: Adults across randomized controlled trials evaluating cardiovascular and metabolic biomarkers
Design: Systematic review and meta-analysis of randomized controlled trials
Key findings:
• Pooled analyses reported a mean reduction in systolic blood pressure of approximately 3.9 mmHg under study conditions
• Mean reduction in triglycerides of approximately 10–15 mg/dL was reported across pooled data
• No statistically significant pooled effects were reported for LDL cholesterol, fasting glucose, or body weight in the overall analysis
• Subgroup analyses suggested variability based on study duration, baseline risk, and extract formulation
• Authors noted heterogeneity across included trials and limited total sample size
Educational Notice
These summaries are provided for educational purposes to review published scientific literature and should not be interpreted as medical advice, diagnosis, or treatment recommendations. Readers should consult qualified healthcare professionals for personal medical decisions.
FDA Disclaimer
These statements have not been evaluated by the U.S. Food and Drug Administration. Dietary supplements are not intended to diagnose, treat, cure, or prevent any disease.
FTC Affiliate Disclosure
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