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Absorption and Metabolism of Dietary Cocoa Procyanidins in Humans

Not Applicable
Completed
Conditions
Healthy
Interventions
Other: Flavanol- and procyanidins-containing drink
Other: Flavanol-containing drink
Other: Procyanidins-containing drink
Registration Number
NCT01483508
Lead Sponsor
University of California, Davis
Brief Summary

The purpose of this study is to determine whether or not the intake of dietary procyanidins (oligomers of flavanols) contribute to the systemic presence of flavanols in healthy humans.

Detailed Description

Flavanols and their oligomeric derivatives, the procyanidins, are plant-derived compounds normally present in the human diet. Accumulating data demonstrate a causal role for flavanols in mediating the cardiovascular benefits associated with the consumption of flavanol-/procyanidin-containing foods. Evidence for a direct, causal role for procyanidins in this context is far less profound. As this is often based on the poor absorption of procyanidins, it has been proposed that procyanidins may indirectly contribute to the systemic presence of bioactive compounds via derivatives generated from the breakdown or catabolism of procyanidins in the gastrointestinal tract. These postulated 'breakdown products' include: i) flavanols, putatively generated by acid hydrolysis in the stomach, and ii) series of phenolic compounds, including 5-(3,4-dihydroxyphenyl)-gamma-valerolactone, that are produced from procyanidin catabolism by the gut microbiome. Verification or rejection of these suppositions could significantly impact the interpretation of epidemiological-/dietary intervention data, and the design of food-content data bases. To address this question, healthy volunteers will consume specially designed cocoa-based dairy drinks containing flavanols and procyanidins (dimers to decamers) either together or individually.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
12
Inclusion Criteria
  • A normal blood chemistry and liver function
  • Fasting blood cholesterol and triglycerides < 300 mg/dl and < 3.0 mmol/l, respectively
  • BMI < 30 kg/m2 will be considered.
  • Volunteers must be able to read and speak English fluently, and thus, fully understand the researchers, research protocols, and their rights as a research volunteer.
Exclusion Criteria
  • A history of cardiovascular disease, stroke, uncontrolled hypertension (> 160/90 mm), renal, hepatic, or thyroid disease, GI tract disorders, previous GI surgery, metabolic syndrome, diabetes, taking cholesterol-lowering medication, hormone replacement therapy, antioxidant supplements, on aspirin therapy or taking anticoagulants, or on a medically prescribed diet.
  • A history of psychiatric illness or an allergy to peanuts.

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
Flavanol and procyanidinsFlavanol- and procyanidins-containing drink-
Flavanols onlyFlavanol-containing drink-
Procyanidins onlyProcyanidins-containing drink-
Primary Outcome Measures
NameTimeMethod
Peak plasma concentration of flavanol metabolitesAfter consumption at time points 0, 1, 2 and 4 h

The concentration of flavanol metabolites in plasma is expressed in nmol/L. Flavanol metabolites encompass a series of O-sulfonated, O-glucuronidated and O-methylated flavanol derivatives generated in the gastrointestinal tract and liver after flavanol absorption.

Area under the curve described by the concentration of flavanol metabolites in plasma versus timeAfter consumption at time points 0, 1, 2 and 4 h

The concentration of flavanol metabolites in plasma is expressed in nmol/L. Flavanol metabolites encompass a series of O-sulfonated, O-glucuronidated and O-methylated flavanol derivatives generated in the gastrointestinal tract and liver after flavanol absorption.

Secondary Outcome Measures
NameTimeMethod
Amount of flavanol metabolites excreted in urineurine collected up to 24h post-consumption

The amount of flavanol metabolites excreted in urine is expressed in µmol. Flavanol metabolites encompass a series of O-sulfonated, O-glucuronidated and O-methylated flavanol derivatives generated in the gastrointestinal tract and liver after flavanol absorption.

Amount of 5-(3,4-dihydroxyphenyl)-gamma-valerolactone metabolites in urineurine collected up to 24 h post-consumption

The amount of 5-(3,4-dihydroxyphenyl)-gamma-valerolactone metabolites excreted in urine is expressed in µmol. 5-(3,4-dihydroxyphenyl)-gamma-valerolactone metabolites encompass a series of O-sulfonated and O-glucuronidated derivatives generated in the gastrointestinal tract and liver after 5-(3,4-dihydroxyphenyl)-gamma-valerolactone absorption.

Trial Locations

Locations (1)

Ragle Facility-UC Davis

🇺🇸

Davis, California, United States

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