Olive Leaf Extract Research
46 peer-reviewed studies · Evidence score: 8.5/10
Herbal Medicine for Treating Herpes Labialis: A Systematic Review
Anheyer M et al. • Journal of integrative and complementary medicine (2025)
Future well-designed, large-scale RCTs employing standardized methodologies are necessary to confirm these findings and to establish optimal treatment protocols for diverse patient populations (Inplasy protocol number: 202350038).
- Lemon balm preparations consistently reduced pain intensity and swelling, with some studies also reporting a significant decrease in lesion size compared with placebo or acyclovir.
- Olive leaf extract demonstrated a statistically significant faster improvement in symptoms and a shorter healing time compared with acyclovir.
- Discussion: The findings indicate that topical herbal therapies may provide effective and well-tolerated alternatives or adjuncts to conventional antiviral treatments for herpes labialis.
The impact of oleuropein, hydroxytyrosol, and tyrosol on cardiometabolic risk factors: a meta-analysis of randomized controlled trials
Frumuzachi O et al. • Critical reviews in food science and nutrition (2025)
Overall, the meta-analysis suggests that supplementation with OLE, HT, and TYR may beneficially impact some cardiometabolic parameters, though further studies are needed to confirm these findings.
- Fourteen human intervention studies with 594 participants were included.
- Subgroup analysis showed that, in certain contexts, interventions may be more beneficial for BMI <30, non-Mediterranean, and cardiometabolic disease individuals, while intervention compound, type of intervention, and duration might have differential effects regarding considered outcomes.
- Overall, the meta-analysis suggests that supplementation with OLE, HT, and TYR may beneficially impact some cardiometabolic parameters, though further studies are needed to confirm these findings.
Olive leaf extract effect on cardiometabolic risk factors: a systematic review and meta-analysis of randomized clinical trials
Álvares AA et al. • Nutrition reviews (2024)
In the meta-analysis, fasting glycemia, as evaluated in studies using a low dose of OLE, showed a significant result favoring the control group.
- In the meta-analysis, fasting glycemia, as evaluated in studies using a low dose of OLE, showed a significant result favoring the control group.
- To obtain more consistent results, further clinical studies in humans, using similar methodologies, are required.
- Further research warranted to confirm findings
Exploring the Benefits of Extra Virgin Olive Oil on Cardiovascular Health Enhancement and Disease Prevention: A Systematic Review
Ussia S et al. • Nutrients (2025)
Despite these results, further multicenter clinical studies with a wider range of patients are required to confirm and better understand EVOO's effects on the prevention of cardiovascular risk.
- The beneficial effect was attributed to the polyphenols contained in EVOO.
- Indeed, EVOO supplementation as part of the Mediterranean diet could improve patients' quality of life in secondary prevention by demonstrating a positive correlation with the cardioprotective role of polyphenols.
- Discussion: A balanced diet with VOO represents a simple yet potent method to counteract metabolic dysfunctions associated with CVD.
Revealing VNN1: An Emerging and Promising Target for Inflammation and Redox Balance
Lv L et al. • Immunity, inflammation and disease (2025)
VNN1 represents a promising therapeutic target for modulating oxidative stress and immunometabolism in various diseases.
- VNN1 represents a promising therapeutic target for modulating oxidative stress and immunometabolism in various diseases.
- Future research should develop disease-specific inhibitors, clarify tissue-specific mechanisms, and conduct clinical trials for translation.
- Further research warranted to confirm findings
Ethnomedicinal Plants for the Management of Diabetes Worldwide: A Systematic Review
Aumeeruddy MZ et al. • Current medicinal chemistry (2021)
This review is the first to provide a compiled list of traditional medicinal plants used worldwide against diabetes.
- This review is the first to provide a compiled list of traditional medicinal plants used worldwide against diabetes.
- Published in Current medicinal chemistry (2021)
- Further research warranted to confirm findings
What is the efficacy of dietary, nutraceutical, and probiotic interventions for the management of gastroesophageal reflux disease symptoms? A systematic literature review and meta-analysis
Martin Z et al. • Clinical nutrition ESPEN (2022)
Evidence to guide the dietary management of GERD symptoms is limited in scope, quality, and feasibility.
- Ginger-containing supplements could be meta-analyzed, and improved incidence of GERD symptom alleviation (n = 2 studies, OR: 7.50 [95%CI: 3.62-15.54], GRADE: high).
- No clinically and/or statistically significant effects were found for the remaining n = 16 highly heterogenous interventions.
- Evidence to guide the dietary management of GERD symptoms is limited in scope, quality, and feasibility.
Nutri-Epigenetic Effects of Phenolic Compounds from Extra Virgin Olive Oil: A Systematic Review
Del Saz-Lara A et al. • Advances in nutrition (Bethesda, Md.) (2022)
Published by Oxford University Press on behalf of the American Society for Nutrition.
- We conclude that EVOO and its OOPCs can regulate gene expression by modifying epigenetic mechanisms that impact human pathophysiology.
- A full elucidation of the epigenetic effects of EVOO and its OOPCs may contribute to developing different pharma-nutritional strategies that exploit them as epigenetic agents.
- This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) as CRD42022320316.© The Author(s) 2022.
Anti-cancer properties of olive oil secoiridoid phenols: a systematic review of in vivo studies
Fabiani R • Food & function (2016)
Further investigations are necessary to clarify the real chemopreventive potential of olive oil secoiridoid phenols on humans performing intervention studies on populations at high cancer risk.
- All human intervention trials have investigated the effects of olive oil phenols on DNA damage.
- Among the five selected studies, three have shown a significant preventive effect on oxidative DNA damage in terms of reduction of 8-oxo-7,8-dihydro-2'-deoxyguanosine in urine, in mitochondria DNA of mononuclear cells and in lymphocyte DNA.
- The other two studies failed to see an effect on the urinary excretion of either etheno-DNA adducts or oxidation products of guanine.
Neuroprotective effects of olive oil and its phenolic compounds on neuroinflammation: a systematic review
Medoro A et al. • Nutritional neuroscience (2026)
Hydroxytyrosol emerged as the most frequently studied and effective compound.
- Systematic review examining Olive Leaf Extract efficacy
- Published in Nutritional neuroscience (2026)
- Further research warranted to confirm findings
Efficacy of olive leaf extracts in controlling blood pressure in hypertensive patients: a double-blind randomized clinical trial
Lamti F et al. • Journal of hypertension (2025)
OLE can decrease 24-h BP, BPL, and diastolic BPV with improvement of lipid profile, systemic inflammation, and body weight in hypertensive patients.
- OLE significantly reduced 24-h SBP compared to baseline and placebo group [respectively -6.4 mmHg (95% confidence interval, 95% CI -10 to -2.1) and -1.5 mmHg (95% CI -3.9 to 0.51); P < 0.01].
- In OLE group, systolic BPL decreased from 53.9% at baseline to 42.2% at 12-week ( P = 0.03); in placebo group, it did not change significantly ( P = 0.55).
- Diastolic BPL decreased from 30.7 to 21.2% ( P = 0.03) in OLE group and did not change significantly in placebo group ( P = 0.12).
Low Dose Monacolin K Combined with Coenzyme Q10, Grape Seed, and Olive Leaf Extracts Lowers LDL Cholesterol in Patients with Mild Dyslipidemia: A Multicenter, Randomized Controlled Trial
Angelopoulos N et al. • Nutrients (2023)
Our results confirm the LDL-C-lowering properties of monacolin are clinically meaningful even in lower doses of 3 mg/day.
- LDL-C decreased by 26.46% on average (p < 0.001) during treatment with 10 mg of monacolin and by 16.77% on average during treatment with 3 mg of monacolin (p < 0.001).
- We observed a slight but significant reduction of the triglyceride levels only in the high-dose-treated group (mean -4.25%; 95% CI of mean -11.11 to 2.61).
- No severe adverse events occurred during the study.
Antihypertensive potential of combined extracts of olive leaf, green coffee bean and beetroot: a randomized, double-blind, placebo-controlled crossover trial
Wong RH et al. • Nutrients (2014)
Further dose-response evaluation of olive leaf, green coffee bean or beetroot extracts is required to confirm or refute the purported benefits.
- Baseline clinic BP in 37 overweight middle-aged men and women who completed the trial averaged 145/84 mmHg.
- There was no significant effect of treatment on ABP or any other outcome measure.
- The failure to confirm prior evidence of the antihypertensive benefits of these extracts emphasises the importance of placebo control and the value of ABP monitoring.
Olive Leaf Extract Supplementation Improves Postmenopausal Symptoms: A Randomized, Double-Blind, Placebo-Controlled Parallel Study on Postmenopausal Women
Imperatrice M et al. • Nutrients (2024)
Further studies are needed to elucidate the mechanisms underlying the observed effects.
- After six and twelve weeks of OLE supplementation, the overall MENQoL score significantly improved (estimated mean difference [95% CI]: -0.2 [-0.4-0.2], p = 0.027) compared to the placebo.
- A significant improvement (+0.017 [0.003, 0.030], p = 0.019) was recorded in the BMD in the right arm in the OLE group compared to the placebo.
- TG concentrations and the TG/HDL-C ratio were significantly decreased (-0.1 [-0.2, 0.0], p = 0.010; -0.1 [-0.2, -0.0], p = 0.029, respectively) in the OLE group compared to the placebo.
Oleuropein Supplementation Increases Resting Skeletal Muscle Fractional Pyruvate Dehydrogenase Activity but Does Not Influence Whole-Body Metabolism: A Randomized, Double-Blind, and Placebo-Controlled Trial in Healthy, Older Males
Pinckaers PJ et al. • The Journal of nutrition (2025)
Chronic OLE supplementation resulted in higher skeletal muscle fractional PDH activity in healthy, older males, which may impact resting energy metabolism.
- Ribonucleic acid sequencing revealed upregulation of oxidative phosphorylation gene pathways (false discovery rate < 0.05), whereas PDH-Serine293-phosphorylation was higher after acute OLE compared with PLA ingestion (P = 0.015).
- Following chronic supplementation, fractional PDH activity was ∼25% greater in OLE compared with PLA (49 ± 14 compared with 38 ± 10%; P = 0.016) with no differences in absolute PDH activity and PDH-Serine293-phosphorylation between groups.
- Plasma low-density lipoprotein cholesterol was lower after chronic OLE compared with PLA (P = 0.043), with no differences in other blood metabolic markers.
Phenolic-rich extract of olive leaf with a hypocaloric diet alleviates oxidative stress in obese females: a randomized double-blind placebo controlled trial
Haidari F et al. • Nutrition, metabolism, and cardiovascular diseases : NMCD (2025)
Adding OLE to a hypocaloric diet improves oxidative stress more effectively compared with a hypocaloric diet alone in obese women.
- Adding OLE to a hypocaloric diet improves oxidative stress more effectively compared with a hypocaloric diet alone in obese women.
- Published in Nutrition, metabolism, and cardiovascular diseases : NMCD (2025)
- Further research warranted to confirm findings
The efficacy of olive leaf extract on healing herpes simplex virus labialis: A randomized double-blind study
Toulabi T et al. • Explore (New York, N.Y.) (2022)
The evidence from these trials suggests the OLE cream is superior in the healing of episodes of HSV-1 over the acyclovir cream.
- The evidence from these trials suggests the OLE cream is superior in the healing of episodes of HSV-1 over the acyclovir cream.
- Future studies are recommended to investigate if OLE could be an adjunct to acyclovir treatment.
- Further research warranted to confirm findings
Beneficial Effect of Olive Leaf Extract as an Adjunct to Standard Antifungal Therapy in Treating Candida-Related Oral Diseases
Kinkela Devčić M et al. • International journal of molecular sciences (2025)
Further research is needed to explore its potential therapeutic benefits on oral health.
- In the OLE + NYS group, a significant increase in salivation rate was observed, while a significant decrease in tongue burning was reported in the OLE + MIC group.
- A significant reduction in burning of the oral mucosa and tongue was observed in the MIC group.
- OLE, as an adjunct to standard antifungal therapy, did not significantly reduce Candida spp. colony number or salivary IL-17A levels.
Impact of olive leaf extract on pain management and functional improvement in elderly patients with knee osteoarthritis: A randomized controlled trial
Roshani M et al. • Explore (New York, N.Y.) (2025)
Hydroalcoholic olive leaf extract effectively reduces pain and improves physical functioning in elderly patients with knee osteoarthritis, offering a promising complementary treatment option for managing osteoarthritis symptoms.
- The intervention groups showed significantly more significant reductions in mean pain scores than the control group (p < 0.05).
- The mean score for daily functioning improved significantly over time in all groups (p = 0.007).
- A decrease of 1.19 units per time increment was observed in the group using the ointment, while the oral capsule group showed a decrease of 0.89 units, both statistically significant (p = 0.006).
Efficacy and safety of olive leaf extract (Olea europaea L.) for glycaemic control in adults with type 2 diabetes mellitus (ESOLED): A pilot randomised controlled trial
Leach MJ et al. • Complementary therapies in clinical practice (2025)
The ESOLED trial has provided preliminary evidence on the tolerability of OLE in adults with type 2 diabetes, but was inconclusive in determining whether OLE is effective at improving glycaemic control, insulin sensitivity, diabetes-related distress and quality of life.
- Analyses found no statistically significant time-group interactions for HbA1c, diabetes-related distress or health-related quality of life.
- The ESOLED trial has provided preliminary evidence on the tolerability of OLE in adults with type 2 diabetes, but was inconclusive in determining whether OLE is effective at improving glycaemic control, insulin sensitivity, diabetes-related distress and quality of life.
- Larger trials and further exploration of the bioavailability of OLE are needed to fully assess the therapeutic potential of OLE in diabetes.