Postprandial Effect of Olive Leaf Biscuits and Tea Consumption on Blood Biomarkers in Healthy Individuals

NCT06983145 | Active Not Recruiting

• 1 other identifier: OliherbCT
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

This randomized controlled nutritional intervention study aims to investigate the bioactivity of dried olive leaves in biscuit and tea preparations, focusing on their postprandial effects on selected biomarkers and plasma antioxidant status. Healthy volunteers aged 18 to 65 from Limnos, Greece, will participate in the study, held at the Human Nutrition Unit of the University of the Aegean. The study will last 15 days and features a cross-over design involving three groups: Control Group: Consumes biscuits made with butter, flour, sugar, and caramel coloring, along with natural mineral water. Intervention Group A: Receives the same biscuits with added dried olive leaf powder, accompanied by the same water. Intervention Group B: Eats the standard biscuits with olive leaf tea instead of water. On each study day, participants will consume their meal over 15 minutes, followed by the liquid within 10 minutes. After a 7-day washout period, the groups will switch treatments for the second phase. The procedure will be repeated on the 15th day, ensuring that all participants experience each condition. Blood samples will be collected before and at 60, 120, and 240 minutes post-meal for analysis. Statistical processing will then be conducted to evaluate the effects on biomarkers and antioxidant status.

Conditions

Oxidative Stress; Inflammation Biomarkers

Keywords

olive leaf tea; olive leaf biscuits; inflammation; oxidative stress; acute clinical study

Outcome Measures

Primary Outcomes (2)

• Total Antioxidant Capacity Concentration (mmol/L)

  Changes of Total Antioxidant Capacity Concentration from baseline

  1 hour, 2 hours, 4 hours

• C- Reactive Protein Concentration (mg/dL)

  Changes of C-Reactive Protein Concentration from baseline

  1 hour, 2 hours, 4 hours

Secondary Outcomes (8)

• Total Cholesterol Concentration (mg/dL)

  1 hour, 2 hours, 4 hours

• High Density Cholesterol

  1 hour, 2 hours, 4 hours

• Low Density Cholesterol Concentration (mg/dL)

  1 hour, 2 hours, 4 hours

• Glucose Concentration (mg/dL)

  1 hour, 2 hours, 4 hours

• Triglycerides

  1 hour, 2 hours, 4 hours

Study Arms (3)

Control

PLACEBO COMPARATOR

The individuals will consume 2-3 pieces of biscuits with caramel coloring (total 120 g) and a glass (250 mL) of tea (natural mineral water with caramel coloring) for the control group

Other: Olive Leaf tea

Olive Leaf biscuit

ACTIVE COMPARATOR

The individuals will consume 2-3 pieces of biscuits with 1.25 g. dried olive leaf powder (total 121.25 g) and a glass (250 mL) of tea (natural mineral water with caramel coloring)

Other: Olive Leaf tea

Olive Leaf tea

EXPERIMENTAL

Individuals will consume 2-3 pieces of biscuits with caramel coloring (total 120 g) and a glass (250 mL) of tea (natural mineral water with 1.25 g. dried olive leaves)

Other: Olive Leaf tea

Interventions

Olive Leaf tea OTHER

Individuals will consume 2-3 pieces of biscuits with caramel coloring (total 120 g) and a glass (250 mL) of tea (natural mineral water with 1.25 g. dried olive leaves)

Control; Olive Leaf biscuit; Olive Leaf tea

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Healthy, without underlying diseases (e.g. diabetes, cardiovascular, hypertension, hypercholesterolemia, hypertriglyceridemia, morbid obesity with BMI\>40kg/m2)
• Aged 18-65 years at the start of the study
• Signed written consent to participate in the study and access by doctors to their medical history (diseases, medication)

You may not qualify if:

• People with a BMI \>40
• Professional athletes
• People taking contraceptive treatment in the last 3 months
• People with a history of food allergy with hypersensitivity to any of the components of the administered product (e.g. milk protein or allergy-hypersensitivity to plants of the Oleaceae family) People taking supplements (e.g. antioxidants) or drugs that affect intestinal function (e.g. antibiotics) in the last 3 months or medication (hypoglycemic drugs or antihypertensive drugs or diuretics) that may interact with the administered product
• People taking any medication or supplement that may affect metabolism (e.g. GLP-1 analogues and receptor agonists, caffeine supplement, supplements weight loss/gain)
• Pregnant, lactating or menopausal women
• Individuals with substance abuse (drugs) or chronic alcoholism or total daily alcohol intake \> 50 g/d
• Individuals with a chronic condition (history of cardiovascular disease, cancer, diabetes, hypertension, hyperlipidemia, neurological and neuropsychological disorders, active liver disease, severe renal dysfunction, severe stroke and conditions associated with increased risk of bleeding)
• Individuals with any other serious medical condition that may affect the individual's ability to participate in a nutritional intervention study.
• Individuals whose dietary preferences do not allow them to do so (e.g., vegetarians, vegans)
• Individuals who are not willing to comply with the study protocol and the periods of fasting and eating
• Individuals who are considered unreliable by the researcher or have a shorter life expectancy than the expected duration of the study, due to some disease or if they are in any condition that, in the opinion of the researcher, does not allow their safe participation in the study (drug addiction, alcohol abuse)

Sponsors & Collaborators

• University of the Aegean: lead

Study Sites (1)

Lab of Human Nutrition and Public Health

Myrina, Limnos, 81400, Greece

Location

MeSH Terms

Conditions

Inflammation

Condition Hierarchy (Ancestors)

Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: SCREENING
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Proffessor

Model Details: Control: 2-3 pieces of biscuits with caramel coloring (total 120 g) and a glass (250 mL) of tea (natural mineral water with caramel coloring) for the control group Olive Leaf biscuit: 2-3 pieces of biscuits with 1.25 g. dried olive leaf powder (total 121.25 g) and a glass (250 mL) of tea (natural mineral water with caramel coloring) for the intervention group A and Olive leaf tea: 2-3 pieces of biscuits with caramel coloring (total 120 g) and a glass (250 mL) of tea (natural mineral water with 1.25 g. dried olive leaves) for the intervention group B.

Study Record Dates

• First Submitted: March 29, 2025
• First Posted: May 21, 2025
• Study Start: November 20, 2024
• Primary Completion: March 11, 2025
• Study Completion: September 30, 2025
• Last Updated: May 21, 2025

Record last verified: 2025-05

Data Sharing

• IPD Sharing: Will not share

Locations

GR (1)