Cardiovascular DiseasesNCT05545865
Chardonnay Marc and Vascular Response
A study testing Low Flavanol Cocoa Powder, High Flavanol Cocoa Powder and Vine to Bar Chocolate - 2 servings in people with Cardiovascular Diseases and Vascular Dilation, run by University of California, Davis at 1 site in United States.
Trial summary
This study aims to obtain data on the potential influence of Vine to Bar product(s) containing Chardonnay marc on cardiometabolic health. These initial studies will inform the design and timing of data collection for future dietary intervention trials that will examine the influence of Chardonnay marc intake on… Read more about this study
- Who is it for?
- Ages 30 to 50 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Cardiovascular Diseases, Vascular Dilation, Oxidative Stress
- What is being tested?
- Low Flavanol Cocoa Powder, High Flavanol Cocoa Powder and Vine to Bar Chocolate - 2 servings
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 5 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Sep 2022to 24 Aug 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 30 to 50 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Screening or Visit 1 Reactive Hyperemia Index (RHI; EndoPAT 2000) < 2.0
- Subject is willing and able to comply with the study protocols.
- Subject is willing to participate in all study procedures
- BMI 25.0 - 35 kg/m2
Who cannot join
- BMI ≥ 35 kg/m2
- Indivduals that weight less than a 110 lbs
- Donation of blood within the previous 30 days
- Visit 1 Reactive Hyperemia Index (RHI; EndoPAT 2000) ≥ 2.0
- 1 ug/ml and 3 ug/ml collagen screening maximal platelet aggregatory response of < 65%.
- Platelet counts < 150,000 / ul
Show all 30Show fewer
- Anemia, which includes self report, or a screening hemoglobin and hematocrit that is less than the normal reference range or as diagnosed by study physician upon review of complete blood cell count reports.
- Dislike or allergy for nuts, cocoa or grape products
- Self-reported use of daily anticoagulation agents including aspirin, NSAIDs
- Vegan, Vegetarians, food faddists or those consuming a non-traditional diet
- Fruit consumption ≥ 3 cups/day
- Vegetable consumption ≥ 4 cups/day
- Nut intake ≥ 2 servings/ week
- Coffee/tea ≥ 3 cups/day
- Dark chocolate ≥ 3 oz/day
- Self-reported restriction of physical activity due to a chronic health condition
- Self-reported chronic/routine high intensity exercise
- Self-reported diabetes
- Blood pressure ≥ 140/90 mm Hg
- Self-reported renal or liver disease
- Self-reported heart disease, which includes cardiovascular events and stroke
- Peripheral artery disease, Raynaud's syndrome
- Inability to properly place or wear the PAT probes or abnormal measurements on pre- screening PAT
- Self-reported cancer within past 5 years
- Self-reported malabsorption
- Currently taking prescription drugs or supplements.
- Supplement use or unwillingness to stop any supplement use, including herbal, plant or botanical, fish oil, oil supplements a month prior to study enrollment.
- Indications of substance or alcohol abuse within the last 3 years
- smoking, vaping, cannabis use
- Current enrollee in a clinical research study.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Academic Surge, University of California, Davis
Davis, California, 95616
Roberta R Holt, PhD, 530-400-5952, rrholt@ucdavis.edu
About this study
Official title: Preclinical Trials to Determine the Range of Chardonnay Mark Intake for Improved Metabolic and Vascular Response.
This study aims to obtain data on the potential influence of Vine to Bar product(s) containing Chardonnay marc on cardiometabolic health. These initial studies will inform the design and timing of data collection for future dietary intervention trials that will examine the influence of Chardonnay marc intake on outcomes/biomarkers of both cardiometabolic health and the gut microbiome. This includes collecting data on the potential differences in response to the products based on the unique food matrix for each of the products that will be tested. Moreover, as there is a paucity of data on the influence of cocoa flavanol intake on vascular function beyond 4 hours post intake, the response of the selected outcomes will be assessed after 6 hours of flavanol intake. This is a time point that captures the increased circulating presence of microbial derived flavanol metabolites.
Read the detailed description
The current set of trials will be of an acute (single intake, followed over 6 hours) that examines the postprandial response of individuals to the products. These preclinical trials will be conducted in the same individuals in an crossover design in order to limit individual variability, and keep the numbers small (5 individuals maximum), but still be able to assess the response to the different products.
- Conditions
- Cardiovascular Diseases, Vascular Dilation, Oxidative Stress
- Being tested
- Low Flavanol Cocoa Powder, High Flavanol Cocoa Powder, Vine to Bar Chocolate - 2 servings, Vine to Bar Chocolate - 1 serving, Vine to Bar Chocolate covered almonds
- Medical subject headings
- Cardiovascular Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Low Flavanol Cocoa PowderOther
Measure the response 2 and 6 hours post low flavanol cocoa intake
High Flavanol Cocoa PowderOther
Measure the response 2 and 6 hours post high flavanol cocoa intake
Vine to Bar Chocolate - 2 servingsOther
Measure the response 2 and 6 hours post chocolate intake
Vine to Bar Chocolate - 1 servingOther
Measure the response 2 and 6 hours post chocolate intake
Vine to Bar Chocolate covered almondsOther
Measure the response 2 and 6 hours post chocolate covered almond intake
| Study group | Role | What they receive |
|---|---|---|
| Low Flavanol Cocoa Powder | Placebo comparator | 12 g of Low Flavanol Cocoa Powder (30 mg of cocoa flavanols) provided as a beverage mixed in water Receives: Other: High Flavanol Cocoa Powder; Other: Vine to Bar Chocolate - 2 servings; Other: Vine to Bar Chocolate - 1 serving |
| High Flavanol Cocoa Powder | Experimental | High Flavanol Cocoa Powder (435 mg of flavanols) will be provided as a beverage mixed in water. Receives: Other: Low Flavanol Cocoa Powder; Other: Vine to Bar Chocolate - 2 servings; Other: Vine to Bar Chocolate - 1 serving; Other: Vine to Bar Chocolate covered almonds |
| Two Servings of Vine to Bar Chocolate | Experimental | Two servings (60g, 6 pieces) of Vine to Bar Chocolate providing both cocoa flavanols and Chardonnay marc. Receives: Other: Vine to Bar Chocolate - 1 serving; Other: Vine to Bar Chocolate covered almonds |
| One Serving of Vine to Bar Chocolate | Experimental | A single serving (30g, 3 pieces) of Vine to Bar Chocolate providing both cocoa flavanols and Chardonnay marc. Receives: Other: Low Flavanol Cocoa Powder; Other: High Flavanol Cocoa Powder; Other: Vine to Bar Chocolate - 2 servings; Other: Vine to Bar Chocolate covered almonds |
| Vine to Bar Chocolate covered Almonds | Experimental | 11 pieces (45g) of Vine to Bar Chocolate providing both cocoa flavanols and Chardonnay marc, with almonds Receives: Other: Vine to Bar Chocolate - 2 servings; Other: Vine to Bar Chocolate - 1 serving |
What is being measured
The primary outcome is the main question the study is designed to answer.
Framingham Reactive Hyperemia Index (fRHI)
measurement of microvascular function using peripheral arterial tonometry (EndoPAT2000)
Measured: 6 hours
Secondary outcomes (5)
Platelet aggregation
Platelet aggregation after collagen activation will be assessed using platelet aggregometry
Measured: 6 hours
soluble NADPH oxidase
measure of oxidative stress
Measured: 6 hours
Glucose
Plasma glucose will be measured
Measured: 6 hours
Insulin
Serum insulin levels will be measured
Measured: 6 hours
Total nitrate
circulating levels of nitrate
Measured: 6 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Sep 2022
- Study start1 Sep 2022
- Primary completion24 Aug 2026 (estimated)
- Study completion24 Aug 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cardiovascular DiseasesStudies 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
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Acute crossover design
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 5 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of California, Davis
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Carl L Keen, Principal investigator, Distinguished Professor Emeritus of Nutrition
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05545865
- Sponsor's protocol ID
- 1810396
- Status last verified
- Feb 2026
- First submitted
- 9 Sep 2022
- Last updated
- 18 Feb 2026
- Results posted
- No
- Data monitoring committee
- 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 18 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Preclinical Trials to Determine the Range of Chardonnay Mark Intake for Improved Metabolic and Vascular Response.
- ClinicalTrials.gov ID
- NCT05545865
- Acronym / sponsor ID
- 1810396
- Conditions
- Cardiovascular Diseases, Vascular Dilation, Oxidative Stress
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 5 participants (estimated)
- Lead sponsor
- University of California, DavisUniversity, hospital or other
- Study start
- 1 Sep 2022 (actual)
- Primary completion
- 24 Aug 2026 (estimated)
- Study completion
- 24 Aug 2026 (estimated)
- First posted
- 19 Sep 2022 (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.
This study aims to obtain data on the potential influence of Vine to Bar product(s) containing Chardonnay marc on cardiometabolic health. These initial studies will inform the design and timing of data collection for future dietary intervention trials that will examine the influence of Chardonnay marc intake on outcomes/biomarkers of both cardiometabolic health and the gut microbiome. This includes collecting data on the potential differences in response to the products based on the unique food matrix for each of the products that will be tested. Moreover, as there is a paucity of data on the influence of cocoa flavanol intake on vascular function beyond 4 hours post intake, the response of the selected outcomes will be assessed after 6 hours of flavanol intake. This is a time point that captures the increased circulating presence of microbial derived flavanol metabolites.
Detailed description
The current set of trials will be of an acute (single intake, followed over 6 hours) that examines the postprandial response of individuals to the products. These preclinical trials will be conducted in the same individuals in an crossover design in order to limit individual variability, and keep the numbers small (5 individuals maximum), but still be able to assess the response to the different products.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 5
- Model description
- Acute crossover design
| Arm | Type | Receives |
|---|---|---|
| Low Flavanol Cocoa Powder | Placebo comparator | Other: High Flavanol Cocoa Powder, Other: Vine to Bar Chocolate - 2 servings, Other: Vine to Bar Chocolate - 1 serving12 g of Low Flavanol Cocoa Powder (30 mg of cocoa flavanols) provided as a beverage mixed in water |
| High Flavanol Cocoa Powder | Experimental | Other: Low Flavanol Cocoa Powder, Other: Vine to Bar Chocolate - 2 servings, Other: Vine to Bar Chocolate - 1 serving, Other: Vine to Bar Chocolate covered almondsHigh Flavanol Cocoa Powder (435 mg of flavanols) will be provided as a beverage mixed in water. |
| Two Servings of Vine to Bar Chocolate | Experimental | Other: Vine to Bar Chocolate - 1 serving, Other: Vine to Bar Chocolate covered almondsTwo servings (60g, 6 pieces) of Vine to Bar Chocolate providing both cocoa flavanols and Chardonnay marc. |
| One Serving of Vine to Bar Chocolate | Experimental | Other: Low Flavanol Cocoa Powder, Other: High Flavanol Cocoa Powder, Other: Vine to Bar Chocolate - 2 servings, Other: Vine to Bar Chocolate covered almondsA single serving (30g, 3 pieces) of Vine to Bar Chocolate providing both cocoa flavanols and Chardonnay marc. |
| Vine to Bar Chocolate covered Almonds | Experimental | Other: Vine to Bar Chocolate - 2 servings, Other: Vine to Bar Chocolate - 1 serving11 pieces (45g) of Vine to Bar Chocolate providing both cocoa flavanols and Chardonnay marc, with almonds |
Who may qualify
- Ages
- 30 to 50 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Screening or Visit 1 Reactive Hyperemia Index (RHI; EndoPAT 2000) < 2.0
- Subject is willing and able to comply with the study protocols.
- Subject is willing to participate in all study procedures
- BMI 25.0 - 35 kg/m2
Key exclusion criteria (30 listed)
- BMI ≥ 35 kg/m2
- Indivduals that weight less than a 110 lbs
- Donation of blood within the previous 30 days
- Visit 1 Reactive Hyperemia Index (RHI; EndoPAT 2000) ≥ 2.0
- 1 ug/ml and 3 ug/ml collagen screening maximal platelet aggregatory response of < 65%.
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 |
|---|---|---|
| Low Flavanol Cocoa PowderMeasure the response 2 and 6 hours post low flavanol cocoa intake | Other | High Flavanol Cocoa Powder, One Serving of Vine to Bar Chocolate |
| High Flavanol Cocoa PowderMeasure the response 2 and 6 hours post high flavanol cocoa intake | Other | Low Flavanol Cocoa Powder, One Serving of Vine to Bar Chocolate |
| Vine to Bar Chocolate - 2 servingsMeasure the response 2 and 6 hours post chocolate intake | Other | High Flavanol Cocoa Powder, Low Flavanol Cocoa Powder, One Serving of Vine to Bar Chocolate, Vine to Bar Chocolate covered Almonds |
| Vine to Bar Chocolate - 1 servingMeasure the response 2 and 6 hours post chocolate intake | Other | High Flavanol Cocoa Powder, Low Flavanol Cocoa Powder, Two Servings of Vine to Bar Chocolate, Vine to Bar Chocolate covered Almonds |
| Vine to Bar Chocolate covered almondsMeasure the response 2 and 6 hours post chocolate covered almond intake | Other | High Flavanol Cocoa Powder, One Serving of Vine to Bar Chocolate, Two Servings of Vine to Bar Chocolate |
Primary outcome
Framingham Reactive Hyperemia Index (fRHI)
Time frame: 6 hours
measurement of microvascular function using peripheral arterial tonometry (EndoPAT2000)
5 secondary outcomes
Platelet aggregation
Time frame: 6 hours
soluble NADPH oxidase
Time frame: 6 hours
Glucose
Time frame: 6 hours
Insulin
Time frame: 6 hours
Total nitrate
Time frame: 6 hours
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Feb 2026.
- Individual participant dataSharing planned: No
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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.
Carl L Keen principal investigator
Distinguished Professor Emeritus of Nutrition
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Low Flavanol Cocoa Powder, High Flavanol Cocoa Powder and Vine to Bar Chocolate - 2 servings in people with Cardiovascular Diseases and Vascular Dilation, run by University of California, Davis at 1 site in United States.
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 4 inclusion and 30 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: looking for participants now, as of the sponsor's last update on 18 Feb 2026. 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 States. 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. Some participants in this study may receive a placebo. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Roberta R Holt (5304005952, rrholt@ucdavis.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Framingham Reactive Hyperemia Index (fRHI) (time frame: 6 hours). 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 18 Feb 2026.