Effects of a combination of olive leaf extract and potassium on blood pressure in participants with mild to moderate hypertension: A double blind, randomized, placebo-controlled trial

BACKGROUND: Hypertension is a key modifiable driver of cardiovascular risk and often clusters with dyslipidemia and insulin resistance within the metabolic syndrome. Olive leaf extract (OLE) and potassium have traditionally been used to support blood pressure (BP) management and cardiometabolic health. PURPOSE: To investigate the effect of this OLE - potassium combination on BP and key cardiometabolic markers. STUDY DESIGN: In this randomized, double-blind, placebo-controlled study, 70 adults with untreated mildly to moderately elevated BP received an OLE - potassium supplement (1000 mg OLE, ≥160 mg oleuropein, 300 mg potassium/day) or placebo for 12 weeks. RESULTS: While office BP fell significantly over time in both groups, 7-day home-based BP monitoring showed a significant greater response, with morning systolic BP decreasing by 5.4 mmHg, in the verum group. Supplementation also reduced total cholesterol by 11.1 mg/dL, LDL-cholesterol by 6.9 mg/dL, and triglycerides by approximately 22 mg/dL at Week 6, while HDL-cholesterol remained stable. Fasting glucose and HbA1c were unchanged, but fasting insulin and HOMA-Index declined in the verum group, indicating a modest improvement in insulin sensitivity. Additionally, oxidized LDL decreased by ∼23 %, without changes in hs-CRP. Quality-of-life scores remained stable, although global self-ratings favoured the combination. The intervention was well tolerated, with no product-related serious adverse events. CONCLUSION: The combination of OLE and potassium is a safe adjunctive strategy for individuals with mildly to moderately elevated BP, with favourable effects on lipid profile, oxidative status, and insulin sensitivity that may help reduce cardiometabolic risk in the context of metabolic syndrome.