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Effect of Polyphenol-rich Dark Chocolate on Insulin Sensitivity in Normal Weight and Overweight Adults

This study has been completed.
Sponsor:
Collaborator:
Barry Callebaut
Information provided by (Responsible Party):
Grace Farhat, Queen Margaret University
ClinicalTrials.gov Identifier:
NCT01749020
First received: December 10, 2012
Last updated: November 19, 2013
Last verified: November 2013
  Purpose

The purpose of the study is to determine the effect of polyphenol-rich dark chocolate on insulin sensitivity in normal weight and overweight adults.


Condition Intervention
Insulin Resistance
Other: Polyphenol-rich Dark chocolate
Other: Placebo Dark chocolate

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Single Blind (Subject)
Primary Purpose: Basic Science
Official Title: Effect of Polyphenol-rich Dark Chocolate on Insulin Sensitivity in Normal Weight and Overweight Adults

Resource links provided by NLM:


Further study details as provided by Queen Margaret University:

Primary Outcome Measures:
  • Determine if the consumption of DC rich in polyphenols can induce a change in insulin sensitivity [ Time Frame: Baseline and week 4 ] [ Designated as safety issue: No ]
    Insulin sensitivity will be determined by determined by HOMA-IR (Homeostasis Model of Assessment - Insulin Resistance)


Secondary Outcome Measures:
  • Determine if the consumption of DC rich in polyphenols can induce a change in glucose levels [ Time Frame: Baseline and week 4 ] [ Designated as safety issue: No ]
  • Determine if the consumption of DC rich in polyphenols can induce a change in Lipid profile (TC, HDL, LDL & TG) [ Time Frame: Baseline and week 4 ] [ Designated as safety issue: No ]
  • Determine if the consumption of DC rich in polyphenols can induce a change in oxidized LDL levels [ Time Frame: Baseline and week 4 ] [ Designated as safety issue: No ]
  • Determine if the consumption of DC rich in polyphenols can induce a change in BMI and Waist circumference [ Time Frame: Baseline and week 4 ] [ Designated as safety issue: No ]
  • Determine if the consumption of DC rich in polyphenols can induce a change in blood pressure [ Time Frame: Baseline and week 4 ] [ Designated as safety issue: No ]
  • Determine if the consumption of DC rich in polyphenols can induce a change in salivary cortisol-to-cortisone ratio [ Time Frame: Baseline and week 4 ] [ Designated as safety issue: No ]
  • Determine if the consumption of DC rich in polyphenols can induce a change in high sensitivity CRP [ Time Frame: Baseline and Week 4 ] [ Designated as safety issue: No ]

Enrollment: 61
Study Start Date: March 2012
Study Completion Date: July 2013
Primary Completion Date: July 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Polyphenol-rich Dark chocolate
Dark chocolate with 500 mg of polyphenols
Other: Polyphenol-rich Dark chocolate
Participants will be asked to consume 20g of dark chocolate containing 500mg of polyphenols daily for a period of 4 weeks
Placebo Comparator: Placebo Dark chocolate
This chocolate contains little or no polyphenols
Other: Placebo Dark chocolate
Participants will be asked to consume 20g of dark chocolate containing little or no polyphenols for a period of 4 weeks

Detailed Description:

Polyphenols may have several favourable effects on health. Dark chocolate (DC) is one of the highest sources of polyphenols in foods. The aim of the study is to determine the effect of polyphenol-rich dark chocolate on insulin sensitivity in normal weight and overweight adults. Seventy four volunteers with no history of hypertension, cardiovascular diseases or diabetes will be recruited. Participants will randomly receive 20g daily of one of the two different types of DC: Placebo DC (low in polyphenols) or DC rich in polyphenols (500mg) for a period of four weeks. Participants will be asked to make two appointments to the university clinical lab. Anthropometric measurements (height, weight, waist circumference), blood and saliva samples will be taken during each of the 2 visits. Compliance will be tested by the measure of total polyphenols in a 24-hour urine sample in some random samples before and at the end of the intervention. To monitor any fluctuations in the participants' diet or physical activity during the study period, a three-day diet diary and a physical activity questionnaire will be collected before the start of the study and after four weeks. Data will be analysed with an ANCOVA with time (pre- and post-) and treatment (DC and placebo) as between-subject factor.

  Eligibility

Ages Eligible for Study:   18 Years to 65 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Adults with no history of hypertension, diabetes and cardiovascular diseases
  • BMI from 18-24.9 and BMI >25
  • Males and Females
  • Age: 18-65 years

Exclusion Criteria:

  • Participants with cardiovascular diseases, hypertension or diabetes
  • Smokers and heavy alcohol drinkers
  • Participants taking any medications that affect insulin, cholesterol, triglycerides or blood pressure
  • Participants taking dietary supplements containing high doses of antioxidants
  • Postmenopausal women taking HRT (Hormone Replacement Therapy)
  • Participants who recently participated or are currently on a weight management program
  • Participants with regular consumption of cocoa or DC (> 1 serving/week)
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01749020

Locations
United Kingdom
Queen Margaret University Lab
Musselburgh, East Lothian, United Kingdom, EH21 6UU
Sponsors and Collaborators
Queen Margaret University
Barry Callebaut
Investigators
Study Director: Emad Al-Dujaili, PhD Queen Margaret University
  More Information

No publications provided

Responsible Party: Grace Farhat, PhD research student, Queen Margaret University
ClinicalTrials.gov Identifier: NCT01749020     History of Changes
Other Study ID Numbers: DC-Ins01
Study First Received: December 10, 2012
Last Updated: November 19, 2013
Health Authority: United Kingdom: Research Ethics Committee

Keywords provided by Queen Margaret University:
Diabetes type II, Insulin sensitivity

Additional relevant MeSH terms:
Insulin Resistance
Overweight
Body Weight
Glucose Metabolism Disorders
Hyperinsulinism
Metabolic Diseases
Signs and Symptoms
Insulin
Hypoglycemic Agents
Pharmacologic Actions
Physiological Effects of Drugs

ClinicalTrials.gov processed this record on November 25, 2014