Insulin Resistance
Conditions
Keywords
Diabetes type II, Insulin sensitivity
Brief 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.
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.
Interventions
Participants will be asked to consume 20g of dark chocolate containing 500mg of polyphenols daily for a period of 4 weeks
Participants will be asked to consume 20g of dark chocolate containing little or no polyphenols for a period of 4 weeks
Sponsors
Barry Callebaut
Queen Margaret University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
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)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Determine if the consumption of DC rich in polyphenols can induce a change in insulin sensitivity | Baseline and week 4 | Insulin sensitivity will be determined by determined by HOMA-IR (Homeostasis Model of Assessment - Insulin Resistance) |
Secondary
| Measure | Time frame |
|---|---|
| Determine if the consumption of DC rich in polyphenols can induce a change in Lipid profile (TC, HDL, LDL & TG) | Baseline and week 4 |
| Determine if the consumption of DC rich in polyphenols can induce a change in oxidized LDL levels | Baseline and week 4 |
| Determine if the consumption of DC rich in polyphenols can induce a change in BMI and Waist circumference | Baseline and week 4 |
| Determine if the consumption of DC rich in polyphenols can induce a change in glucose levels | Baseline and week 4 |
| Determine if the consumption of DC rich in polyphenols can induce a change in salivary cortisol-to-cortisone ratio | Baseline and week 4 |
| Determine if the consumption of DC rich in polyphenols can induce a change in high sensitivity CRP | Baseline and Week 4 |
| Determine if the consumption of DC rich in polyphenols can induce a change in blood pressure | Baseline and week 4 |
Countries
United Kingdom
Outcome results
None listed