The most recent published literature has been reviewed (from the year 2000 onwards) with the purpose of providing healthcare professionals with up-to-date research on the health benefits of Olive Leaf Extract. Only human studies have been reviewed.

• Search terms included: Olive Leaf Extract OR Olea europaea OR Oleuropein OR hydroxytyrosol OR Article AND Review OR literature review.

Series One – Heart Health

Part 1 – Olive (Olea europaea) leaf extract effective in patients with stage-1 hypertension: Comparison with Captopril

A double-blind, randomized, parallel and active-controlled clinical study with 148 patients found Olive (Olea europaea) leaf extract caplets, at the dosage regimen of 500 mg twice daily, was similarly effective in lowering systolic and diastolic blood pressures and improving the lipid profile in subjects with stage-1 hypertension as Captopril (anti-hypertensive medication), given at its effective dose of 12.5-25 mg twice daily.

Key results: Evaluation of BP was performed every week for 8 weeks of treatment. Mean systolic blood pressure (SBP) at baseline were 149.3±5.58 mmHg in Olive group and 148.4±5.56 mmHg in Captopril group; and mean diastolic blood pressure (DBP) were 93.9±4.51 and 93.8±4.88 mmHg, respectively. After 8 weeks of treatment, both groups experienced a significant reduction of SBP and DBP from baseline; SBPs were -11.5±8.5 and -13.7±7.6 mmHg in Olive and Captopril groups, respectively; and those of DBP were -4.8±5.5 and -6.4±5.2 mmHg, respectively.

Haematology parameters were evaluated at baseline, weeks 4 and 8 to assess the lipid profile of patients. A significant reduction of triglyceride levels in the Olive leaf extract group of −11.90±46.17 mg/dl, compared to almost no changes found with Captopril treatment group (−1.26±43.31 mg/dl). In the subgroup of subjects with high baseline triglyceride level (>200 mg/dl), the effect of the Olive leaf extract was even more remarkable (Fig. 1): the triglyceride level diminished up to 23.2% (−53.13±58.71 mg/dl) from baseline, compared to 13.9% reduction (−38.44±53.53 mg/dl) in the Captopril group. However, subset analysis was not statistically significant. Administration of Olive leaf extract also resulted in a slight reduction of LDL-cholesterol from baseline with no effect on HDL-cholesterol level observed. Such beneficial effects on cholesterol levels were not found in the Captopril group.

Table 1. Baseline and end of study values of blood pressure, total-cholesterol and triglyceride levels.

Figure 1.  Plasma Triglyceride levels throughout the study in the subgroup with baseline triglyceride level of > 200mg/dl.

Take home Message: Systolic and diastolic blood pressure were effectively lowered in patients with stage-1 hypertension from Olive (Olea europaea L.) leaf extract at the dosage regimen of 500 mg twice daily (1000 mg daily) comparable to Captopril. The lipid profile improved in the Olive leaf extract group shown by a significant reduction in total-cholesterol and triglyceride levels. This study also demonstrated the safety and tolerability of Olive leaf extract. Further studies are needed on Olive leaf extract effect’s on lipid profile to further add to the evidence base.

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