A randomized, double-blind study published in Phytomedicine (February 15, 2011; 18(4):251–258) examined the effects of olive leaf extract in patients with stage-1 hypertension, comparing its outcomes with those of the prescription drug captopril.

Captopril belongs to a class of medications known as ACE inhibitors (angiotensin-converting enzyme inhibitors), which are commonly used to lower blood pressure by affecting the renin–angiotensin system.

Study Design

Participants were divided into two treatment groups:

  • One group received captopril

  • The second group received olive leaf extract

At the beginning of the study:

  • Mean systolic blood pressure was 148.4 mmHg in the captopril group

  • Mean systolic blood pressure was 149.3 mmHg in the olive leaf extract group

Treatment continued for eight weeks.

Results

After the intervention period:

  • Systolic blood pressure decreased by 11.5 mmHg in the olive leaf extract group

  • Systolic blood pressure decreased by 13.7 mmHg in the captopril group

  • Diastolic blood pressure decreased by 4.8 mmHg with olive leaf extract

  • Diastolic blood pressure decreased by 6.4 mmHg with captopril

In addition to blood pressure changes, the group receiving olive leaf extract experienced a significant reduction in triglyceride levels, an effect not reported in the captopril group.

Authors’ Conclusion

The study authors concluded:

“Olive (Olea europaea) leaf extract, at the dosage regimen of 500 mg twice daily, was similarly effective in lowering systolic and diastolic blood pressures in subjects with stage-1 hypertension as captopril, given at its effective dose of 12.5–25 mg twice daily.”

Context

This study suggests that olive leaf extract may influence blood pressure regulation in individuals with mild hypertension, producing reductions comparable to a commonly prescribed ACE inhibitor over a short time frame. The additional triglyceride-lowering effect observed with olive leaf extract highlights potential metabolic effects beyond blood pressure alone.

As with many comparative trials, the findings are limited to the study population, dosage, and duration examined, and do not establish long-term outcomes or equivalence across broader clinical settings.