Quick Summary

Olive leaf, derived from Olea europaea, contains polyphenols such as oleuropein, hydroxytyrosol, and related compounds. Preclinical and some clinical evidence suggest potential benefits in cardiometabolic health, glycemic control, wound healing, and anti-inflammatory effects. Olive leaf extracts are being studied alone and in combination nutraceuticals for metabolic syndrome, hyperglycemia, and wound healing. Preparations including olive leaf extract hydrogels show promise in accelerating wound healing in difficult-to-heal ulcers. Evidence is preliminary or limited in some contexts, and further well-powered clinical trials are needed.

What Is It?

Olive leaf comes from the leaves of the olive tree (Olea europaea), which is native to the Mediterranean region. The leaves contain bioactive polyphenols such as oleuropein and hydroxytyrosol, which have been the focus of research for their antioxidant and anti-inflammatory properties.

Traditional Uses

Traditionally, olive leaf has been used in folk medicine for its purported health benefits, including supporting cardiovascular health, balancing blood sugar levels, and treating infections. It has also been applied topically for wound healing and skin conditions.

Active Compounds

  • Oleuropein
  • Hydroxytyrosol
  • Tyrosol
  • Other polyphenols

Potential Benefits with Evidence Levels

Improvement in Glycemic Control and Blood Pressure in Metabolic Syndrome and Diabetes

Evidence level: Moderate Human Clinical Evidence

  • A meta-analysis of 20 clinical studies showed olive leaf supplementation modestly reduces fasting blood glucose, glycated hemoglobin, and blood pressure in patients with metabolic disorders, although study heterogeneity limits definitive conclusions. [PMID: 41816507]
  • An observational study of a nutraceutical combining olive leaf extract with other plant extracts showed improvements in lipid and glycemic parameters in metabolic syndrome patients. [PMID: 39421612]

Cardioprotective Effects Including Improved Lipid Profiles and Antioxidant Status

Evidence level: Limited Human Clinical and Preclinical Evidence

  • Reviews suggest olive leaf polyphenols may modulate oxidative stress, inflammation, and endothelial function related to cardiovascular protection, but clinical evidence is mostly short-term and heterogeneous. [PMID: 41598329]
  • Systematic reviews of randomized controlled trials (RCTs) indicate oleuropein and hydroxytyrosol supplementation may improve some cardiometabolic outcomes and cognitive health, although results are mixed and further research is needed. [PMID: 39334699]
  • Meta-analyses have found that olive oil phenolics including oleuropein and hydroxytyrosol reduce cholesterol, triglycerides, and insulin levels in humans. [PMID: 39828996]

Acceleration of Wound Healing, Including in Diabetic and Chronic Wounds

Evidence level: Preliminary Human Clinical and Preclinical Evidence

  • Randomized controlled trials found hydrogels containing olive leaf extract significantly improved wound healing rates in hard-to-heal pressure, venous, and diabetic foot ulcers compared to standard care. [PMID: 38131948], [PMID: 37514112]
  • Preclinical studies suggest olive leaf polyphenols modulate inflammation, oxidative stress, angiogenesis, and extracellular matrix remodeling important for diabetic ulcer healing. [PMID: 41614737]

Potential Antimicrobial Activity Against Multidrug-Resistant Pathogens

Evidence level: Preclinical In Vitro and Animal Evidence

  • Methanolic olive leaf extracts demonstrated potent antimicrobial activity against multidrug-resistant bacteria in vitro, but animal studies indicated potential toxicity at higher doses, highlighting the need for cautious dose evaluation. [PMID: 40458712]

Potential Benefit for Oral Health in Adjunctive Therapy

Evidence level: Limited Clinical Evidence

  • A systematic review of clinical trials found that olive oil and ozonated olive oil improved bleeding on probing and gingival health indices in periodontal disease and gingivitis, suggesting anti-inflammatory benefits. [PMID: 41487705]
  • A randomized controlled trial reported topical olive leaf extract led to faster healing and symptom improvement in herpes labialis with minimal adverse effects. [PMID: 40526027]

Side Effects

  • Minimal adverse events reported in human clinical trials.
  • Preclinical animal studies have noted histopathological changes at high doses.
  • No serious adverse effects reported in wound healing or metabolic syndrome clinical trials.

Drug Interactions

No specific clinically documented herb-drug interactions for olive leaf were identified. However, due to olive leaf’s effects on blood pressure and glucose metabolism, potential interactions with antihypertensive and antidiabetic medications cannot be excluded and warrant further investigation.

Who Should Avoid It

No specific contraindications have been identified, but caution is advised for individuals with hypotension or hypoglycemia risk due to potential additive effects. Safety during pregnancy and breastfeeding is unclear; use is recommended only under medical supervision during these periods.

Evidence Limitations

  • Clinical studies often have small sample sizes, short durations, and heterogeneous populations.
  • Variability in olive leaf extract preparations and dosages limit comparability.
  • Preclinical findings require translation and confirmation in rigorously designed human trials.
  • Limited data on long-term safety, pharmacokinetics, and herb-drug interactions.
  • Lack of data in special populations, including pregnant and breastfeeding women.
  • Some benefits are based on preliminary evidence or surrogate biomarkers rather than definitive clinical outcomes.

References

Last Reviewed

June 2024

Disclaimer: This page is for informational purposes only and does not constitute medical advice. Olive leaf supplements may have potential benefits but also risks. You should consult a qualified healthcare professional before starting any new supplement or therapy, especially if you have existing health conditions or are taking medications.