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

Queen Margaret University

Status

Completed

Conditions

Insulin Resistance

Treatments

Other: Placebo Dark chocolate

Other: Polyphenol-rich Dark chocolate

Study type

Interventional

Funder types

Other

Identifiers

NCT01749020

DC-Ins01

Details and patient eligibility

About

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

Full 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.

Enrollment

61 patients

Sex

All

Ages

18 to 65 years old

Volunteers

Accepts Healthy Volunteers

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)