Effect of Polyphenol-rich Dark Chocolate on Obesity
|ClinicalTrials.gov Identifier: NCT00815451|
Recruitment Status : Unknown
Verified September 2009 by Queen Margaret University.
Recruitment status was: Active, not recruiting
First Posted : December 30, 2008
Last Update Posted : September 18, 2009
This study aims to investigate the effect of polyphenol-rich dark chocolate (DC) on insulin resistance, adiponectin , blood pressure (BP), lipid profile in obese subjects and determine possible associations between all assessed parameters.
It hypothesizes that consumption of polyphenol-rich Dc could lower fasting glucose levels, insulin resistance and improve BP, total cholesterol, low-density lipoprotein (LDL) and triglycerides while increasing adiponectin and high-density lipoprotein (HDL) in overweight or obese individuals.
|Condition or disease||Intervention/treatment||Phase|
|Obesity||Dietary Supplement: placebo Dietary Supplement: Acticoa polyphenol-rich dark chocolate||Phase 2|
It is well acknowledged that the main mechanism by which cocoa and DC polyphenols improve fasting glucose levels, insulin sensitivity, BP and lipid profile in healthy individuals and those with hypertension and/or impaired glucose-tolerance, involves increased nitric oxide (NO) bioavailability. NO is essential for the regulation of blood pressure, glucose and lipid balance. This is evident in that e-NOsynthase knockout mice exhibit insulin resistance, hypertension and hyperlipidemia, a cluster of diseases that is also observed in the metabolic syndrome. Recently, it was shown that adiponectin regulates eNOsynthase activity through the phosphatidylinositol 3-kinase-dependent pathway wherein eNOsynthase is phosphorylated by 5'-AMP-activated protein kinase at Ser1179 and that plasma adiponectin levels are inversely correlated with BMI, waist-to-hip ratio, fasting plasma glucose, insulin, triglyceride, hyperinsulinemia, and glucose intolerance and positively with HDL-cholesterol, but not BP. This suggests a strong link between impaired NO bioavailability, adiponectin levels and obesity. Indeed, apart from exhibiting impaired NO bioavailability, obese individuals also have decreased plasma adiponectin levels. Since cocoa and DC are known to modulate NO activity, investigating the impact of cocoa or DC polyphenols on adiponectin levels and observing a correlation between its levels and improved fasting glucose levels, insulin resistance, BP and lipid profile is essential in improving our understanding of the relationship between diet and health, particularly that polyphenols in apples, oolong and green tea polyphenols have been previously shown to influence adiponectin levels.
This study uses a randomised single-blind, placebo-controlled design. Following a 1-week run-in phase, each group will be randomised to one of the two groups: placebo-polyphenol-rich DC, polyphenol-rich DC-placebo. Subjects will follow each diet for 4weeks, after which they will cross-over to the next diet separated by a 2-week washout period and until each subject completes both interventions.
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||50 participants|
|Intervention Model:||Crossover Assignment|
|Official Title:||Effect of Polyphenols on Glucoregulatory Biomarkers, Blood Pressure and Lipid Profile in Overweight and Obese Subjects|
|Study Start Date :||November 2008|
|Estimated Primary Completion Date :||October 2009|
|Estimated Study Completion Date :||December 2009|
Placebo Comparator: placebo dark chocolate
polyphenol-poor dark chocolate
Dietary Supplement: placebo
polyphenol-free dark chocolate 20g to be distributed throughout the day for 4 weeks
Other Name: barry callebaut
|Experimental: polyphenol-rich dark chocolate||
Dietary Supplement: Acticoa polyphenol-rich dark chocolate
20g to be distributed throughout the day for 4 weeks
Other Name: barry callebaut, acticoa
- adiponectin [ Time Frame: week 0, 4, 6, 10 ]
- insulin sensitivity [ Time Frame: week 0, 4, 6, 10 ]
- blood pressure [ Time Frame: week 0, 4, 6, 10 ]
- lipid profile [ Time Frame: week 0, 4, 6, 10 ]
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00815451
|Queen margaret university|
|Musselburgh, East Lothian, United Kingdom, eh21 6uu|
|Principal Investigator:||suzana h almoosawi, BScHons HN||QMU|