Efficacy of Polyphenols From Milk and Dark Chocolate

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.

Study Overview

• Status: Completed
• Conditions: No Disease
• Intervention / Treatment: Dietary supplement: Dark Chocolate; Dietary supplement: Milk Chocolate; Dietary supplement: Control (polyphenol-free) "Chocolate"

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 6
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Vaud
    • Lausanne, Vaud, Switzerland, 1000
      • Nestlé Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 25 years to 45 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: BASIC_SCIENCE
• Allocation: RANDOMIZED
• Interventional Model: CROSSOVER
• Masking: SINGLE

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: dark chocolate containing polyphenols; dark chocolate	Dietary supplement: Dark Chocolate; 1 portion
EXPERIMENTAL: Milk chocolate containing polyphenols; Bespoke milk chocolate	Dietary supplement: Milk Chocolate; 1 portion
ACTIVE_COMPARATOR: Control chocolate with no polyphenols; cocoa-free chocolate	Dietary supplement: Control (polyphenol-free) "Chocolate"; one portion

What is the study measuring?

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

Collaborators and Investigators

• Sponsor: Nestlé
• Investigators: Principal Investigator: Karen A Cooper, PhD, Nestle; Study Director: Gary Williamson, PhD, Nestle

Publications and helpful links

General Publications

• Heiss C, Finis D, Kleinbongard P, Hoffmann A, Rassaf T, Kelm M, Sies H. Sustained increase in flow-mediated dilation after daily intake of high-flavanol cocoa drink over 1 week. J Cardiovasc Pharmacol. 2007 Feb;49(2):74-80. doi: 10.1097/FJC.0b013e31802d0001.
• Fisher ND, Hollenberg NK. Aging and vascular responses to flavanol-rich cocoa. J Hypertens. 2006 Aug;24(8):1575-80. doi: 10.1097/01.hjh.0000239293.40507.2a.

Study record dates

Study Major Dates

• Study Start: June 1, 2008
• Primary Completion (ACTUAL): June 1, 2009
• Study Completion (ACTUAL): April 1, 2012

Study Registration Dates

• First Submitted: August 6, 2007
• First Submitted That Met QC Criteria: August 6, 2007
• First Posted (ESTIMATE): August 8, 2007

Study Record Updates

• Last Update Posted (ESTIMATE): August 14, 2013
• Last Update Submitted That Met QC Criteria: July 12, 2013
• Last Verified: July 1, 2013

More Information

Terms related to this study

• Keywords: Endothelial function; Arterial stiffness; Polyphenols; Dark chocolate; Milk chocolate
• Other Study ID Numbers: 06.38.MET