Bioavailability of Hydroxytyrosol in Healthy Adult Humans

The Dose Response of a Commercially Available Olive Fruit Water (OliPhenolia®) on the Bioavailability of Hydroxytyrosol, and Its Metabolites, Over a Four-hour Time Period in Healthy Adult Humans.

Brief summary: There is current scientific interest in hydroxytyrosol due to its anti-inflammatory and antioxidant properties, efficient protection of vascular tissue and ability to neutralise free radicals via hydrogen donation. Recognised as the potent polyphenol within a commercially available olive-fruit water (OliPhenolia®), data from this research will determine the dose of OliPhenolia® required for the optimum absorption and metabolism of hydroxytyrosol. The primary aim of this research is to identify the dose of hydroxytyrosol (0.5, 1.0 or 1.5 mg∙kg-1) within OliPhenolia® that demonstrates the greatest area under the plasma concentration curve for hydroxytyrosol over a four-hour period. A secondary aim is to assess maximum concentration (CMAX) and time to maximum concentration (TMAX) of total hydroxytyrosol and secondary metabolites (Tyrosol, HT-3-glucoronide, HT-3-sulphate, 3,4-Dihydroxyphenylacetic Acid, Homovanillic Acid and Oleuropein) following consumption of 3 randomised doses of OliPhenolia® on separate occasions with healthy adult volunteers.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Dietary supplement: OliPhenolia®)

Detailed Description

There is current and significant scientific interest in the use of plant-based polyphenol supplementation to support health, protection against disease and recovery from exercise. Recent literature dictates that daily supplementation (~3d of >1,000mg of polyphenols) may enhance recovery from exercise and can therefore be associated with both an increased frequency of exercise and quality of movement. The large proportion of research to date has focussed on certain fruit extracts (blackcurrant, tart Montmorency cherry or pomegranate juice), however a recent study from our group utilising milled waste olive-water demonstrated that 16 days of supplementation may support recovery from exercise via the blunting of certain oxidative stress markers and enhance low-intensity exercise performance through a reduction in oxygen economy.

To date there has been significant clinical research interest in the properties of waste-water produced when cold pressing olives, which has been shown to contain high concentrations of natural polyphenols, particularly hydroxytyrosol, a potent scavenger of free radicals. Fattoria La Vialla is an Italian-based organic farm producing various products including cold-pressed olive oil. In doing so, they also produce an olive waste-water extract which is commercially available as 'OliPhenolia®' and currently advertised as a 'health promoting supplement'. Whilst several clinical studies have been undertaken using this product, to date there have been no studies investigating the dose response of OliPhenolia® on the bioavailability of hydroxytyrosol, and the secondary metabolites. As such this study proposes to investigate the bioavailability of hydroxytyrosol across three doses of OliPhenolia® (0.5, 1.0 or 1.5mg∙kg-1) in a randomised manner to understand and therefore inform pertinent supplementation strategies to support health and components of exercise.

Following a study briefing and provision of written informed consent, participants will be required to attend the Human Physiology Laboratory at Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University on three occasions. Each visit will follow an identical protocol, providing an randomly assigned dose (0.5, 1.0 or 1.5mg∙kg-1) of olive derived hydroxytyrosol from OliPhenolia® (based on body weight). Participants will be required to complete a weighed food diary and adhere to a 'low-polyphenol' diet for the three days prior to each visit, as well as consume a standardised pre-visit evening meal the night before each visit. Participants will arrive at each visit in a fasted (~10h) and hydrated state (500mL 1h prior to arrival). Following a resting blood sample, participants will consume one of the three doses of OliPhenolia® and then remain in a comfortable supine position for the remainder of the visit. Water will be provided at 90 and 180 minutes post OliPhenolia® consumption.

Blood samples - two 4mL wholeblood samples will be collected via cannulation at rest and then 20,40, 60, 120 and 240 minutes following each dose. Following collection, blood samples will be immediately centrifuged with plasma allocated into separate cryovials pre treated with 150µL citric acid for the analysis of: i) the main polyphenol compound- hydroxytyrosol; ii) the secondary metabolites of hydroxytyrosol (Tyrosol, HT-3-glucoronide, HT-3-sulphate, 3,4-Dihydroxyphenylacetic Acid, Homovanillic Acid and Oleuropein).

Nutritional supplementation - all products will be supplied/certified independently via Fattoria La Vialla, Italy (https://www.oliphenolia.it/uk/).

• Study Type: Interventional
• Enrollment (Actual): 8
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Cambridge, United Kingdom, CB5 8DZ
    • Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• UK based men and women aged ≥ 21 - 65
• Written, witnessed and cosigned informed consent
• Willingness and ability to conform to the full protocol

Exclusion Criteria:

• Current or recent (within the last 4 weeks) engagement with a strict dietary regime i.e., vegetarian / vegan / ketogenic / paleolithic / high protein / weight loss.
• Any known issues with blood taking.
• Any known bleeding disorders.
• Any known allergy to olives, grapes or prunes.
• Average alcohol use of >21 glasses per week for men and >14 glasses per week for women (on average for the last six months).
• Any drug or medicine abuse in the last six months
• Known cardiovascular disease, disease related to the immune system (including HIVand hepatitis) and / or the respiratory system.
• Known Diabetes Mellitus type I or type II.
• Known renal or liver issues or known thyroid dysfunction.
• Currently undertaking regular heavy and / or extreme exercise (please discuss with the lead researcher if you are unsure).
• Current smoker or stopped smoking for <one month prior to the first visit.
• Major medical or surgical event requiring hospitalisation in the previous three months and / or any scheduled during the scheduled study period.
• Current participation in any other clinical study within the month previous to the study start date (discuss with the lead researcher if unsure).
• Known pregnancy and / or lactation (women only)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 0.5mg∙kg-1 olive derived hydroxytyrosol from OliPhenolia®.; Olive derived hydroxytyrosol will be ingested via a commercially available olive fruit wastewater (OliPhenolia®) in a dose relative to participant body mass. In this arm participants will consume and oral bolus of 0.5mg∙kg-1 olive derived hydroxytyrosol.	Dietary supplement: OliPhenolia®); Olive derived hydroxytyrosol will be ingested via a commercially available olive fruit wastewater (OliPhenolia®) in a dose relative to participant body mass. Participants will consume three doses within the entire study, one dose per visit, separated by a ≥3 day wash out period.
Experimental: 1.0mg∙kg-1 olive derived hydroxytyrosol from OliPhenolia®.; Olive derived hydroxytyrosol will be ingested via a commercially available olive fruit wastewater (OliPhenolia®) in a dose relative to participant body mass. In this arm participants will consume and oral bolus of 1.0mg∙kg-1 olive derived hydroxytyrosol.	Dietary supplement: OliPhenolia®); Olive derived hydroxytyrosol will be ingested via a commercially available olive fruit wastewater (OliPhenolia®) in a dose relative to participant body mass. Participants will consume three doses within the entire study, one dose per visit, separated by a ≥3 day wash out period.
Experimental: 1.5mg∙kg-1 olive derived hydroxytyrosol from OliPhenolia®.; Olive derived hydroxytyrosol will be ingested via a commercially available olive fruit wastewater (OliPhenolia®) in a dose relative to participant body mass. In this arm participants will consume and oral bolus of 1.5mg∙kg-1 olive derived hydroxytyrosol.	Dietary supplement: OliPhenolia®); Olive derived hydroxytyrosol will be ingested via a commercially available olive fruit wastewater (OliPhenolia®) in a dose relative to participant body mass. Participants will consume three doses within the entire study, one dose per visit, separated by a ≥3 day wash out period.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Hydroxytyrosol bioavailability	Area under the plasma concentration curve of hydroxytyrosol (mg/L)	Four hours
Bioavailability of hydroxytyrosol metabolites.	Area under the plasma concentration curve of Tyrosol, HT-3-glucoronide, HT-3-sulphate, 3,4-Dihydroxyphenylacetic Acid, Homovanillic Acid and Oleuropein (mg/L)	Four hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Hydroxytyrosol CMax	Hydroxytyrosol peak plasma concentration (CMAX) in mg/L	Four hours
Hydroxytyrosol TMAX	Time to peak hydroxytyrosol (TMAX in minutes) - hydroxytyrosol measured in mg/L	Four hours
CMAX of hydroxytyrosol secondary metabolites	Peak plasma concentration (CMAX) of Tyrosol, HT-3-glucoronide, HT-3-sulphate, 3,4-Dihydroxyphenylacetic Acid, Homovanillic Acid and Oleuropein - all measured in mg/L	Four hours
TMAX of hydroxytyrosol secondary metabolites	Time to peak concentration (TMAX in minutes) of Tyrosol, HT-3-glucoronide, HT-3-sulphate, 3,4-Dihydroxyphenylacetic Acid, Homovanillic Acid and Oleuropein - all metabolites measured in mg/L	Four hours

Collaborators and Investigators

• Sponsor: Anglia Ruskin University
• Collaborators: Fattoria La Vialla; Instituto Kurz
• Investigators: Principal Investigator: Justin D Roberts, PhD, Anglia Ruskin University

Study record dates

Study Major Dates

• Study Start (Actual): February 3, 2024
• Primary Completion (Actual): March 30, 2024
• Study Completion (Actual): July 30, 2024

Study Registration Dates

• First Submitted: February 23, 2024
• First Submitted That Met QC Criteria: February 23, 2024
• First Posted (Actual): February 29, 2024

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: February 2, 2025
• Last Verified: February 1, 2025

More Information

Terms related to this study

• Keywords: Bioavailability; Hydroxytyrosol
• Other Study ID Numbers: ETH2324-2826

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No