High‑phenolic versus low‑phenolic extra virgin olive oil for metabolic health in adults with central obesity
High Phenolic Olive Oil for Enhancing Metabolic Health: a Randomized-controlled Trial in Patients With Central Obesity
This trial will see if daily high‑phenolic extra virgin olive oil for eight weeks improves metabolic markers in adults with overweight or central obesity who have at least one metabolic abnormality.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 80 (estimated) |
| Ages | 18 Years to 80 Years |
| Sex | All |
| Sponsor | University of Peloponnese Academic / other |
| Locations | 1 site (Kalamata) |
| Trial ID | NCT07445503 on ClinicalTrials.gov |
What this trial studies
The study is a double‑blind, randomized, controlled trial enrolling 70–80 adults with overweight or obesity and at least one metabolic abnormality. Participants are randomized 1:1 to consume either high‑phenolic olive oil (>1000 mg/kg total polyphenols) or low‑phenolic olive oil (≤100 mg/kg) daily for eight weeks, with oil amounts tailored to individual fat‑energy targets alongside standardized mild weight‑loss dietary guidance. Key exclusions include untreated or insulin‑treated diabetes, major acute or chronic diseases, use of antioxidant‑rich supplements, pregnancy or lactation, and substance abuse. Outcomes include changes in blood lipids, glucose/insulin markers, and biomarkers of oxidative stress and inflammation collected at baseline and follow‑up.
Who should consider this trial
Good fit: Adults aged 18–80 with BMI >25 kg/m² or elevated waist circumference (men >94 cm, women >80 cm) and at least one metabolic abnormality (e.g., high triglycerides, low HDL, elevated fasting glucose, or treated hypertension) who can consent and comply with study procedures are ideal candidates.
Not a fit: People with untreated or insulin‑treated diabetes, major chronic illnesses, current use of antioxidant‑rich supplements, pregnancy or lactation, or inability to attend study visits are unlikely to benefit or are excluded.
Why it matters
Potential benefit: If successful, the intervention could improve blood lipid profiles, reduce oxidative stress and inflammation, and modestly improve insulin and other metabolic markers in people with central obesity.
How similar studies have performed: Prior observational studies and smaller interventions have suggested phenolic‑rich olive oil can improve lipids and oxidative markers, but large randomized trials specifically comparing very high versus low phenolic content remain limited.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Adult men and women 18-80 years of age, * Overweight/obesity (body mass index \> 25 or waist circumference \>94 cm for males and \>80 cm for females), and * The presence of at least one of the following metabolic abnormality: (1) triglyceride level ≥150 mg/dL or HDL cholesterol ≤40 mg/dL in men and ≤50 mg/dL in women; (2) increased blood pressure ≥ 130/85 mm Hg; (3) elevated fasting blood sugar ≥100 mg/dL; (4) standardized drug treatment regimen, and * Provided signed informed consent for participation. Exclusion Criteria: * Concomitant acute or chronic disease (e.g., infection, cancer, chronic heart failure, kidney disease, autoimmune diseases like rheumatoid arthritis, inflammatory bowel diseases, Hashimoto), * Untreated diabetes, * Women at pregnancy or lactation, * Individuals with psychiatric or mental disorder, * Any use of antioxidant-phytochemical rich supplement, anti-, pre- or probiotics pre-intervention, * Drug and/or alcohol abuse, * Those who did not consent or were unable to provide consent.
Where this trial is running
Kalamata
- Antikalamos Facilities of University of Peloponnese — Kalamata, Greece (Recruiting)
Study contacts
- Principal investigator: Aristea Gioxari — Department of Nutritional Science and Dietetics, School of Health Sciences, University of Peloponnese
- Study coordinator: Aristea Gioxari, Assistant Professor
- Email: a.gioxari@go.uop.gr
- Phone: +302721045326
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.