Efficacy of Polyphenols From Milk and Dark Chocolate

Study Overview
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Brief Summary
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Dark chocolate is one of the richest sources of polyphenols though it has been hypothesised that the bioavailability and therefore probably the bioefficacy of epicatechin from milk chocolate was reduced compared to dark. This study is designed to compare milk and dark chocolate as a source of polyphenols with a control chocolate for improving a risk biomarker for vascular disease.

Detailed Description
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Dark chocolate is one of the richest sources of polyphenols, for example, a standard 40g portion of dark chocolate contains 400-800 mg of polyphenols, compared to red wine (170 mg /100ml) or an apple (200 mg/piece). Cocoa polyphenols, most notably the catechins, can exist in both lipid and water-based environments (amphipathic), meaning they can spare both lipophilic and hydrophilic vitamins. There have been a number of human trials conducted using chocolate or cocoa and measuring various endpoints. Most have been conducted with dark chocolate. An article in Nature found that the bioavailability of epicatechin from milk chocolate was substantially reduced compared to dark, and even dark taken with a glass of milk (Serafini et al 2003). The hypothesis was that the milk proteins bind to polyphenols, making them unavailable. Subsequent studies have not been able to reproduce this, but none have been conducted using solid chocolate as the first study, all have been done using a drink matrix, which may completely alter the binding interactions of the polyphenols and protein. To this end, this study is designed to compare solid chocolates as a source of polyphenols for improving a risk biomarker for vascular disease. This study is designed as a blinded, three arm crossover trial. The primary outcome measure is to compare endothelial function after consumption of 3 chocolates (1 milk, 1 dark, 1 polyphenol-free control) with a secondary outcome of arterial stiffness. All volunteers will take all chocolate types in a crossover design. Subjects will undergo medical screening, anthropometry, physical activity and dietary assessments before randomization for the order of consumption.

Official Title
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Efficacy of Polyphenols From Milk and Dark Chocolate

Conditions
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No Disease

Intervention / Treatment
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* Dietary Supplement: Dark Chocolate
* Dietary Supplement: Milk Chocolate
* Dietary Supplement: Control (polyphenol-free) Chocolate


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 25- 45 years, male and female Healthy as determined by the medical questionnaire Normal weight: BMI 19 - 25 Having given informed consent Exclusion Criteria: Intestinal or metabolic diseases/disorders such as diabetic, renal, hepatic, hypertension, pancreatic or ulcer, including lacto-intolerance. Have had a major gastrointestinal surgery. Have a regular consumption of medication. Have an exceptionally high intake of chocolate or similarly high polyphenol foods. Have a high and regular intake of vitamin supplements Have an alcohol intake: > 2 units a day Patient who cannot be expected to comply with treatment. Smoker Having a nut allergy Unwilling to consume chocolate Currently participating or having participated in another clinical trial during the last 3 weeks. Having given blood in the past three weeks More than 3 x 45 min of exercise per week

Ages Eligible for Study
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Minimum Age: 25 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: dark chocolate containing polyphenols<br>dark chocolate | Dietary Supplement: Dark Chocolate<br>* 1 portion<br>|
| Experimental: Milk chocolate containing polyphenols<br>Bespoke milk chocolate | Dietary Supplement: Milk Chocolate<br>* 1 portion<br>|
| Active Comparator: Control chocolate with no polyphenols<br>cocoa-free chocolate | Dietary Supplement: Control (polyphenol-free) Chocolate<br>* one portion<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Reactive Hyperemia Index (RHI) From Baseline (20 Min Before Product Intake) to 2 Hours Following Product Intake | Value of RHI at 2 hours minus value at baseline. RHI reflects the endothelial function of a vessel at the distal phalanx of a finger, i.e. the capacity of the vessel to dilate after an ischemia. RHI is the increase of blood flow following the occlusion of the brachial artery during 5 minutes by the inflation of an armcuff. RHI was measured by peripheral arterial tonometry using a fingerprobe connected to an EndoPat analyser. | Baseline and 2 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Arterial Stiffness From Baseline (20 Min Before Product Intake) to Two Hours Following Product Intake | Value of arterial stiffness at 2 hours minus value at baseline. Arterial stiffness is also automatically calculated by peripheral arterial tonometry which consists in measuring the peripheral vessel endothelial response to an ischemia provoked by a 5-min occlusion of the humeral artery using an armcuff. An increase in arterial stiffness means an increase in the resistance of the vessel wall which reflects an impaired endothelial response to ischemia. | baseline and 2 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Endothelial function, Arterial stiffness, Dark chocolate, Milk chocolate, Polyphenols