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

Insulin Resistance Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01749020
• Other study ID #: DC-Ins01
• Status: Completed
• Phase: N/A
• First received: December 10, 2012
• Last updated: November 19, 2013
• Start date: March 2012
• Est. completion date: July 2013

Study information

• Verified date: November 2013
• Source: Queen Margaret University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United Kingdom: Research Ethics Committee
• Study type: Interventional

Clinical Trial Summary

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

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 61
• Est. completion date: July 2013
• Est. primary completion date: July 2013
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years to 65 Years

Eligibility

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)

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Subject), Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Insulin Resistance

Intervention

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 Dark chocolate
Participants will be asked to consume 20g of dark chocolate containing little or no polyphenols for a period of 4 weeks

Locations

Country	Name	City	State
United Kingdom	Queen Margaret University Lab	Musselburgh	East Lothian

Sponsors (2)

Lead Sponsor	Collaborator
Queen Margaret University	Barry Callebaut

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Determine if the consumption of DC rich in polyphenols can induce a change in insulin sensitivity	Insulin sensitivity will be determined by determined by HOMA-IR (Homeostasis Model of Assessment - Insulin Resistance)	Baseline and week 4	No
Secondary	Determine if the consumption of DC rich in polyphenols can induce a change in glucose levels		Baseline and week 4	No
Secondary	Determine if the consumption of DC rich in polyphenols can induce a change in Lipid profile (TC, HDL, LDL & TG)		Baseline and week 4	No
Secondary	Determine if the consumption of DC rich in polyphenols can induce a change in oxidized LDL levels		Baseline and week 4	No
Secondary	Determine if the consumption of DC rich in polyphenols can induce a change in BMI and Waist circumference		Baseline and week 4	No
Secondary	Determine if the consumption of DC rich in polyphenols can induce a change in blood pressure		Baseline and week 4	No
Secondary	Determine if the consumption of DC rich in polyphenols can induce a change in salivary cortisol-to-cortisone ratio		Baseline and week 4	No
Secondary	Determine if the consumption of DC rich in polyphenols can induce a change in high sensitivity CRP		Baseline and Week 4	No