Effects of Berry Peel Intake on Glucose Metabolism in Healthy Subjects

Study Overview
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Brief Summary
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The main objective of this study is to investigate the effect of a 4-weeks intake of berry peel powder on fasting and postprandial glucose metabolism and inflammatory markers. The berry peel product will be compared with a placebo in a single-blind, cross-over design. Furthermore, inflammation-related peripheral blood mononuclear cells (PBMCs) genes expression, appetite and cognitive performance will be included as a pilot study. Investigators hypothesize that long-term consumption of polyphenols and fibres of berry peel will exhibit both direct and indirect actions in healthy overweight subjects by improvement of glucose-associated markers as well as ameliorating inflammation. Moreover, above metabolic markers will correlated with improvements in inflammation-related PBMCs genes expression, subjective appetite and cognitive performance after long-term consumption of berry peel as a source of polyphenols.

Official Title
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Effects of Berry Peel Intake on Glucose Metabolism in Healthy Subjects

Conditions
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Healthy

Intervention / Treatment
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* Dietary Supplement: Berry peel drink
* Dietary Supplement: Control drink


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy males and females Signed informed consent BMI 25-30 kg/m2 Must be able to accept plant-based foods/drinks Exclusion Criteria: Below 18 years or above 40 years Smoking or using snuff vegetarian or vegan Stressed by venous blood sampling or previous experience of being difficult canulation

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Control drink<br>Dietary supplement: Control drink As control, subjects are asked to consume 150 ml control drink containing equal amount of insoluble fiber (cellulose) and sugar for 28 days. In addition, on days-1 and 28, subjects will receive an acute challenge of placebo drink at our clinical facility. After 30 min. control drink intake, subjects will be given standardized breakfast corresponding to 50 g available carbohydrates. | Dietary Supplement: Control drink<br> <br> |
| Experimental: Berry peel drink<br>Dietary supplement: Berry peel drink Subjects are asked to consume 150 ml experimental drink containing a berry peel fruit powder. In addition, on days-1 and 28, subjects will receive an acute challenge of test drink at our clinical facility. After 30 min. berry drink intake, subjects will be given standardized breakfast corresponding to 50 g available carbohydrates. | Dietary Supplement: Berry peel drink<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postprandial blood glucose response after acute intervention | The capillary blood will be collected for glucose analysis using a glucometer. | -30, 0, 15, 30, 45, 60, 120, and 180 min after challenge meal. | 
| Incremental area under curve (iAUC) blood glucose response after long-term intervention | The capillary blood will be collected for glucose analysis using a glucometer. | 4 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postprandial serum insulin response after acute intervention | The capillary blood will be collected for insulin analysis using commercial ELISA kits | -30, 0, 15, 30, 45, 60, 120, and 180 min. | 
| Incremental area under curve (iAUC) serum insulin response after long-term intervention | The capillary blood will be collected for insulin analysis using commercial ELISA kits | 4 weeks | 
| Postprandial subjective appetite rating after acute intervention | Appetite will be assessed using standard subjective 100mm visual analogue scaled (VAS). | -30, 0, 15, 30, 45, 60, 120, and 180 min. | 
| Incremental area under curve (iAUC) subjective appetite rating after long-term intervention | Appetite will be assessed using standard subjective 100mm visual analogue scaled (VAS). | 4 weeks | 
| Postprandial C-reactive protein (CRP) after acute intervention | The venous blood will be collected for CRP analysis using ELISA commercial kits | -30, 60, 120, and 180 min. | 
| Incremental area under curve (iAUC) of C-reactive protein (CRP) after long-term intervention | The venous blood will be collected for inflammatory analysis using ELISA commercial kits | 4 weeks | 
| Postprandial adiponectin after acute intervention | The venous blood will be collected for adiponectin analysis using ELISA commercial kits | -30, 0, 60, 120, and 180 min. | 
| Postprandial adiponectin after long-term intervention with berry peel | The venous blood will be collected for adiponectin analysis using ELISA commercial kits | 4 weeks | 
| Peripheral blood mononuclear cells (PBMCs) inflammatory genes expression after acute intervention | The venous blood samples will be taken for isolation of peripheral blood mononuclear cells (PBMCs). Extracted total RNA will then be used for running quantitative-PCR. | 180 min after challenge meal. | 
| Peripheral blood mononuclear cells (PBMCs) inflammatory genes expression after long-term intervention | The venous blood samples will be taken for isolation of peripheral blood mononuclear cells (PBMCs). Extracted total RNA will then be used for running quantitative-PCR. | -30 min. (Day-28 control); 180 min. (Day-28 control); -30 min. (Day-28 berry); 180 min. (Day-28 berry) | 
| Postprandial selective attention after long-term intervention | The selective attention will be assessed using a standardized software (Röd and Grön software) that measures wrong/right decisions and time of reaction when the subjects is faced with a challenging stimulus. | 45, 90, and 180 min after challenge meal. | 
| Postprandial interleukin-6 (IL-6) after acute intervention | The venous blood will be collected for IL-6 analysis using ELISA commercial kits | -30, 60, 120, and 180 min. | 
| Incremental area under curve (iAUC) of interleukin-6 (IL-6) after long-term intervention | The venous blood will be collected for IL-6 analysis using ELISA commercial kits | 4 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Berry, Inflammation, Cognition, Polyphenols, Appetite, Glucose metabolism