Dietary Polyphenols and Lipid Oxidation

Study Overview
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Brief Summary
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There are strong indications that (combinations of) polyphenols may be attractive candidates in the prevention of the metabolic syndrome and diabetes through modulation of pathways of fatty acid metabolism and mitochondrial function. We hypothesize that the combination of specific polyphenols, with partly distinct mechanisms of action, may have physiologically significant effects on fat oxidation through additive or synergistic effects, thereby improving body composition, insulin sensitivity and preventing type 2 diabetes. The following objective will be addressed in the current study: (1) to test short term (3 day) effects of combinations of polyphenols (supplements of EGCG either in combination with resveratrol or with resveratrol and genistein) to affect systemic lipolysis and fat oxidation during overnight fasted conditions and after ingestion of a high fat meal in overweight subjects

Official Title
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Dietary Polyphenols as Modulators of Lipid Oxidation and Mitochondrial Function in Overweight Volunteers

Conditions
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Obesity, Insulin Sensitivity, Type 2 Diabetes Mellitus

Intervention / Treatment
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* Dietary Supplement: Comparison of different combinations of polyphenols with respect to effects on fat oxidation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: overweight men and women (BMI≥25kg/m2- 29.9 kg/m2), aged 30-70 years, Caucasian, normal fasting glucose (< 6.1 mmol/L) and blood pressure (systolic blood pressure 100-140 mmHg, diastolic blood pressure 60-90 mmHg), weight stable in last 3 months (± 2kg). Exclusion criteria: Exclusion Criteria: women lactating, pregnant or (post)menopausal, regular smokers, people with intensive fitness training, eg. athletes (≥ 3 per week ≥ 1 hour training), habitual consumption of green tea (more than 1 cup per day) or products containing green tea extract, total caffeine consumption > 300 mg/day, alcohol intake >20 g/day, any dietary vitamins or dietary supplements, diabetes mellitus (defined as FPG ≥ 7.0 mmol/l and/or 2hPG ≥ 11.1 mmol/l); serious pulmonary, cardiovascular, hepatic or renal disease : history of cardiovascular disease, all other relevant medical disorders that potentially interfere with this trial, current use of medication interfering with study intervention or interfering with study endpoints/hypotheses.

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: EGCG and resveratrol<br> | Dietary Supplement: Comparison of different combinations of polyphenols with respect to effects on fat oxidation<br>* EGCG, resveratol and genistein<br>|
| Experimental: EGCG, resveratrol and genistein<br> | Dietary Supplement: Comparison of different combinations of polyphenols with respect to effects on fat oxidation<br>* EGCG, resveratol and genistein<br>|
| Placebo Comparator: placebo<br> | Dietary Supplement: Comparison of different combinations of polyphenols with respect to effects on fat oxidation<br>* EGCG, resveratol and genistein<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| postprandial fat oxidation | 3 day supplementation of different combinations of polyphenols in a randomised crossover design in healthy overweight volunteers. At the end of each supplementation period, postprandial fat oxidation is measured | 3 days |