The goal of this postprandial clinical trial is to learn whether erythrodiol, a triterpene naturally present in pomace olive oil, can modulate the cell foam formation, ine of the first steps in atherosclerosis. The main questions it aims to answer are:

Is erythrodiol bioavailable in humans when administered as pomace olive oil? Does acute erythrodiol intake reduce postprandial triglyceride excursions after a high-fat meal? Does erythrodiol reduce the intake of postprandial triglyceride-rich lipoproteins by macrophages?

Researchers will compare participants receiving test meals enriched with different concentrations of erythrodiol (low, medium, high) to see if the intervention leads to improved postprandial metabolic and vascular responses.

Participants will:

Attend the research facility after an overnight fast. Consume a high-fat test meal enriched with a different doses of erythrodiol

Undergo serial postprandial assessments over several hours, including:

Blood sampling for lipids, glucose, inflammatory markers, and oxidative stress biomarkers Monitoring of subjective tolerability and adverse events

The present project builds on previous studies in which we suggested that erythrodiol, a bioactive component of pomace olive oil, is capable of helping prevent cardiovascular diseases when administered as part of pomace oil, through the inhibition of atherosclerosis development.

A total of 22 adult volunteers, both women and men (18-40 years old), healthy and of normal weight, will be selected. Participants will be recruited in two phases.

In the first phase, recruitment will take place at Pablo de Olavide University. Inclusion criteria for this phase include: age between 18 and 40 years; body mass index (BMI) between 18.5 and 24.9 kg/m²; ability to provide informed voluntary consent; and willingness to comply with all study procedures. Candidates will be excluded if, at the time of recruitment, they exhibit any of the following: presence of any type of pathology (digestive, metabolic, endocrine, infectious, neoplastic, etc.) or food-related allergies or intolerances. Individuals taking any type of medication-except contraceptives-will also be excluded, as well as pregnant or breastfeeding women, and anyone who has participated in a clinical trial involving an investigational product within the past 60 days or is currently enrolled in a clinical trial. Furthermore, any person with a physical or intellectual limitation that, in the investigator's opinion, could prevent adherence to and completion of the protocol will be excluded. In this phase, only clinical history, age, weight, and height data will be collected.

In the second phase, only those subjects whose complete biochemical and hematological analyses produce results within normal ranges will be included in the study.

At the Virgen del Rocío Hospital (Seville), and after a 12-hour fast, three experiments will be conducted. In each of them, participants will be administered pomace olive oil containing different concentrations (low, medium, or high) of erythrodiol, the protective agent, in an amount of 50 g on each occasion. On the study day, blood samples will be taken (between 6 and 24 mL per draw and 90 mL total), 15 minutes before (baseline) and every hour for 6 hours after ingestion of a meal rich in the corresponding pomace oil. The meal will be accompanied by coffee (black, without sugar) or skimmed milk and whole-grain toast (3 slices). The consumption of these foods carries no health risk.

Venous access will be obtained by puncture with an Abbocath® catheter fitted with a Smartsite™ valve (Ivac®, Spec-Sets®) and a Vacutainer® system for sterile Hemogard® tubes with a silicone separator. This procedure involves only the risks inherent to simple blood sampling.

Part of the collected samples will be processed at the Clinical Analysis Laboratory Service of the Virgen del Rocío University Hospital for biochemical analysis, while another portion will be sent to the Instituto de la Grasa-CSIC.

In addition to these analyses, participants will undergo simple anthropometric measurements (weight, height, hip and waist circumference) as well as blood pressure assessment.

This procedure will be repeated after four weeks with a second oil, and four weeks later with the third one, so that all participants will have consumed all three oils.

Inclusion Criteria:

• Adults aged 18 to 40 years.
• Male or female volunteers.
• Healthy individuals with no diagnosed diseases.
• Normal-weight participants with a Body Mass Index (BMI) between 18.5 and 24.9 kg/m².
• Ability to provide voluntary informed consent.
• Willingness to comply with all study procedures.
• Availability to participate in the two-phase selection process, including initial screening and subsequent laboratory tests.

Exclusion Criteria:

• Presence of any type of disease, including digestive, metabolic, endocrine, infectious, neoplastic conditions, or associated allergies and food intolerances.
• Current use of any medication, except hormonal contraceptives.
• Pregnant or breastfeeding women.
• Participation in a clinical trial with an investigational product within the last 60 days, or current enrolment in a clinical trial.
• Any physical or intellectual limitation that, in the opinion of the investigator, could impede following or completing the study protocol.