Diet, Food, and NutritionPOBASNCT03248115
Bioavailability of Green Tea and Coffee Polyphenols
A study testing Green tea and green coffee extract tablets in people with Diet, Food, and Nutrition and Dietary Supplements, run by MRC Human Nutrition Research at 1 site in United Kingdom.
Trial summary
There is little information on the dietary intake, absorption, metabolism and bioavailability (degree to which a substance becomes available to the target tissues upon administration) of polyphenols (natural substances present in a variety of foods) in human participants. Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Diet, Food, and Nutrition, Dietary Supplements
- What is being tested?
- Green tea and green coffee extract tablets
- Type of treatment
- Pill or oral medicine
- How many people
- 11 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 10 Apr 2013to 18 Oct 2013
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy men and women.
- 18-45 years of age.
- BMI between 18.5 and 24.9 kg/m2.
Who cannot join
- Smoking.
- Allergy or intolerance to intervention supplements.
- Chronic, acute or active inflammatory conditions, haematological disorders, or any other systemic illness of renal, hepatic or gastrointestinal origin.
- Major surgical operations in the gastrointestinal tract or medical treatment for gastrointestinal problems.
- Active cancer or diagnosis of malignancy within the last five years.
- Pregnant, lactating, contemplating pregnancy.
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
MRC HNR Elsie Widdowson Laboratory
Cambridge, CB1 9NL
About this study
Official title: Bioavailability of Green Tea and Coffee Polyphenols in Healthy Participants
There is little information on the dietary intake, absorption, metabolism and bioavailability (degree to which a substance becomes available to the target tissues upon administration) of polyphenols (natural substances present in a variety of foods) in human participants.
This study assessed the bioavailability in healthy participants of polyphenols from 2 supplements containing green tea and green coffee extracts.
Read more
Eleven participants were recruited and their habitual diet was assessed to estimate polyphenol intake. After completing a 24-hour urine collection, participants were given six green tea extract and three green coffee extract tablets, which they took daily for a period of 8 weeks. No tablets were taken during the last 4 weeks of the study. Further 24-hour urines were collected at 2, 4, 8 and 12 weeks.
Participants were required to attend HNR (medical laboratory) the day after each 24hour urine collection. At these visits, they were asked to bring along their urine collections, completed documents (urine collection sheet, checklist for tablet intake/side effects) and any remaining supplements, which were used to assess tablet compliance.
The investigators identified and quantified the amount of polyphenols in the supplement tablets as well as the amount of polyphenols and their metabolites in urine. The investigators then evaluated polyphenol bioavailability from the relationship between their dietary intake and urinary output.
Evidence from this research could inform future intervention studies by providing data on the bioavailability of green tea and coffee polyphenols, and on the individual differences related to phenolic intake.
- Conditions
- Diet, Food, and Nutrition, Dietary Supplements
- Being tested
- Green tea and green coffee extract tablets
- Keywords
- polyphenols, green tea catechins, coffee caffeoylquinic acids, metabolism, inter-individual variability, colonic microbiota
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Green tea and green coffee extract tabletsDietary supplement
- Tablets: participants were required to take 6 green tea and 3 green coffee extract tablets daily for a period of 8 weeks. No tablets were taken during the last 4 weeks of the study. Randomly chosen tablets were analysed to quantify their polyphenol content.
- Urine collections: Several urine collections were required during the supplementation period in order have sufficient time points to estimate the plateau of the concentration of green tea and coffee polyphenols excreted in the urine to then be able to determine their bioavailability. There was a total of five 24-hour urine collections (at week 0 -before supplementation-, 2, 4, 8, and 12 -4 weeks after finishing the supplementation period).
- Completion of study documents: Participants were provided with urine collection sheets, polyphenol questionnaires, checklists to record polyphenol tablet intake, and detailed instructions.
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from baseline phenolic metabolites in urine at 2 weeks
Assessment of the profile of metabolites coming from green tea and green coffee phytochemicals in urine
Measured: Week 0 -before supplementation- and week 2
Change from baseline phenolic metabolites in urine at 4 weeks
Assessment of the profile of metabolites coming from green tea and green coffee
Measured: Week 0 -before supplementation- and week 4
Change from baseline phenolic metabolites in urine at 8 weeks
Assessment of the profile of metabolites coming from green tea and green coffee
Measured: Week 0 -before supplementation- and week 8
Change from baseline phenolic metabolites in urine at 12 weeks
Assessment of the profile of metabolites coming from green tea and green coffee
Measured: Week 0 -before supplementation- and week 12 -4 weeks after finishing the supplementation period-
Secondary outcomes (1)
Phenolic compounds in tablets
Quantification of the tablet polyphenol content
Measured: Through study completion, an average of 3 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Aug 2017
- Study start10 Apr 2013
- Primary completion18 Oct 2013
- Study completion18 Oct 2013
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Diet, Food, and NutritionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 11 participants (actual)
Sponsor and investigators
- Lead sponsor
- MRC Human Nutrition Research
- Sponsor type
- Other government
- Responsible party
- Principal investigator, Virginia Tomatis, MRC Human Nutrition Research
- Investigators
- Virginia Tomatis, PhD, Principal investigator, MRC HNR
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03248115
- Sponsor's protocol ID
- HNR6480
- Acronym
- POBAS
- Status last verified
- Aug 2017
- First submitted
- 7 Aug 2017
- Last updated
- 21 Aug 2017
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 Aug 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Bioavailability of Green Tea and Coffee Polyphenols in Healthy Participants
- ClinicalTrials.gov ID
- NCT03248115
- Acronym / sponsor ID
- POBAS / HNR6480
- Conditions
- Diet, Food, and Nutrition, Dietary Supplements
- Keywords
- polyphenols, green tea catechins, coffee caffeoylquinic acids, metabolism, inter-individual variability, colonic microbiota
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 11 participants (actual)
- Lead sponsor
- MRC Human Nutrition ResearchOther government
- Study start
- 10 Apr 2013 (actual)
- Primary completion
- 18 Oct 2013 (actual)
- Study completion
- 18 Oct 2013 (actual)
- First posted
- 14 Aug 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
There is little information on the dietary intake, absorption, metabolism and bioavailability (degree to which a substance becomes available to the target tissues upon administration) of polyphenols (natural substances present in a variety of foods) in human participants.
This study assessed the bioavailability in healthy participants of polyphenols from 2 supplements containing green tea and green coffee extracts.
Eleven participants were recruited and their habitual diet was assessed to estimate polyphenol intake. After completing a 24-hour urine collection, participants were given six green tea extract and three green coffee extract tablets, which they took daily for a period of 8 weeks. No tablets were taken during the last 4 weeks of the study. Further 24-hour urines were collected at 2, 4, 8 and 12 weeks.
Participants were required to attend HNR (medical laboratory) the day after each 24hour urine collection. At these visits, they were asked to bring along their urine collections, completed documents (urine collection sheet, checklist for tablet intake/side effects) and any remaining supplements, which were used to assess tablet compliance.
The investigators identified and quantified the amount of polyphenols in the supplement tablets as well as the amount of polyphenols and their metabolites in urine. The investigators then evaluated polyphenol bioavailability from the relationship between their dietary intake and urinary output.
Evidence from this research could inform future intervention studies by providing data on the bioavailability of green tea and coffee polyphenols, and on the individual differences related to phenolic intake.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Healthy men and women.
- 18-45 years of age.
- BMI between 18.5 and 24.9 kg/m2.
Key exclusion criteria (6 listed)
- Smoking.
- Allergy or intolerance to intervention supplements.
- Chronic, acute or active inflammatory conditions, haematological disorders, or any other systemic illness of renal, hepatic or gastrointestinal origin.
- Major surgical operations in the gastrointestinal tract or medical treatment for gastrointestinal problems.
- Active cancer or diagnosis of malignancy within the last five years.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Green tea and green coffee extract tablets1. Tablets: participants were required to take 6 green tea and 3 green coffee extract tablets daily for a period of 8 weeks. No tablets were taken during the last 4 weeks of the study. Randomly chosen tablets were analysed to quantify their polyphenol content. 2. Urine collections: Several urine collections were required during the supplementation period in order have sufficient time points to estimate the plateau of the concentration of green tea and coffee polyphenols excreted in the urine to then be able to determine their bioavailability. There was a total of five 24-hour urine collections (at week 0 -before supplementation-, 2, 4, 8, and 12 -4 weeks after finishing the supplementation period). 3. Completion of study documents: Participants were provided with urine collection sheets, polyphenol questionnaires, checklists to record polyphenol tablet intake, and detailed instructions. | Dietary supplement | – |
Primary outcome
Change from baseline phenolic metabolites in urine at 2 weeks
Time frame: Week 0 -before supplementation- and week 2
Assessment of the profile of metabolites coming from green tea and green coffee phytochemicals in urine
Change from baseline phenolic metabolites in urine at 4 weeks
Time frame: Week 0 -before supplementation- and week 4
Assessment of the profile of metabolites coming from green tea and green coffee
Change from baseline phenolic metabolites in urine at 8 weeks
Time frame: Week 0 -before supplementation- and week 8
Assessment of the profile of metabolites coming from green tea and green coffee
Change from baseline phenolic metabolites in urine at 12 weeks
Time frame: Week 0 -before supplementation- and week 12 -4 weeks after finishing the supplementation period-
Assessment of the profile of metabolites coming from green tea and green coffee
1 secondary outcome
Phenolic compounds in tablets
Time frame: Through study completion, an average of 3 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Aug 2017.
- Individual participant dataSharing planned: No
Related trials for Diet, Food, and Nutrition
Not yet recruiting
Bite Sized Biomarkers
Dietary Assessment, Diet, Food, and Nutrition
Recruiting
Ripe for Revival: Outcomes Evaluation of a Mobile Produce Market With Vouchers
Diet Interventions, Food Security
Not yet recruiting
Metabolomics-Driven Insights Into Ultra-Processed Foods
Diet, Food and Nutrition
Recruiting
Randomized Evaluation of Voucher Interventions for Value and Effectiveness (REVIVE) in Philippines
Food Insecurity, Undernutrition
Enrolling by invitation
Improving Dietary Quality Through Animal Source Protein Accessibility in a Low-Resource Setting
Nutrition Intervention, Healthy Eating
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Virginia Tomatis, PhD principal investigator
MRC HNR
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Green tea and green coffee extract tablets in people with Diet, Food, and Nutrition and Dietary Supplements, run by MRC Human Nutrition Research at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 21 Aug 2017. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change from baseline phenolic metabolites in urine at 2 weeks (time frame: Week 0 -before supplementation- and week 2). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Aug 2017; AzTrials last refreshed its copy on 2 Nov 2026.