Efficacy of Polyphenols From Milk and Dark Chocolate
|No Disease||Dietary Supplement: Dark Chocolate Dietary Supplement: Milk Chocolate Dietary Supplement: Control (polyphenol-free) "Chocolate"|
|Study Design:||Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single Blind (Investigator)
Primary Purpose: Basic Science
|Official Title:||Efficacy of Polyphenols From Milk and Dark Chocolate|
- Change in Reactive Hyperemia Index (RHI) From Baseline (20 Min Before Product Intake) to 2 Hours Following Product Intake [ Time Frame: Baseline and 2 hours ]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.
- Change in Arterial Stiffness From Baseline (20 Min Before Product Intake) to Two Hours Following Product Intake [ Time Frame: baseline and 2 hours ]
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.
|Study Start Date:||June 2008|
|Study Completion Date:||April 2012|
|Primary Completion Date:||June 2009 (Final data collection date for primary outcome measure)|
Experimental: dark chocolate containing polyphenols
Dietary Supplement: Dark Chocolate
Experimental: Milk chocolate containing polyphenols
Bespoke milk chocolate
Dietary Supplement: Milk Chocolate
Active Comparator: Control chocolate with no polyphenols
Dietary Supplement: Control (polyphenol-free) "Chocolate"
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.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00513344
|Nestle Research Center|
|Lausanne, Vaud, Switzerland, 1000|
|Principal Investigator:||Karen A Cooper, PhD||Nestlé|
|Study Director:||Gary Williamson, PhD||Nestlé|